Integral vibration reduction prestressed shield tunnel structure and construction method

Abstract

The invention relates to an integral vibration reduction prestressed shield tunnel structure and a construction method. The structure comprises a pre-stressed pipe ring and a pre-stressed system, the pre-stressed pipe ring comprises a pre-stressed vibration reduction block, a pre-stressed anchoring block, a pre-stressed adjacent block and a pre-stressed top sealing block, the pre-stressed system comprises an annular pre-stressed system and a longitudinal pre-stressed system, and the pre-stressed pipe ring is formed by splicing a plurality of pipe piece blocks. Annular and longitudinal pre-stress is applied through a pre-stress system, duct grouting and anchoring groove filling are carried out after a tunnel hole or a shield is excavated for a certain distance, so that an integral vibration reduction pre-stress shield tunnel structure is formed, and the tunnel structure achieves the ultra-long service life through a method that tensioning is carried out after a duct is reserved and a cable is replaced at the same hole position of a reserved reusable service hole. The construction method comprises the following steps: prefabricating segment blocks; pre-stressed pipe rings are assembled, and circumferential and longitudinal pre-stress is applied; and after a tunnel hole or a shield is excavated for a certain distance, duct grouting and anchoring groove filling are conducted, and finally the overall vibration reduction prestressed shield tunnel structure is formed.

Description

Technical Field

[0001] The invention relates to the technical field of shield tunnels, and in particular to an integral vibration-damping prestressed shield tunnel structure and a construction method. Background Art

[0002] The shield construction technology is widely used in tunnel construction due to its high efficiency and safety. This technology uses a shield machine to advance underground or underwater, while installing segments to form a tunnel lining. Its high safety is reflected in the shield body's ability to support the surrounding soil, prevent collapse, and effectively protect the safety of construction workers. The impact on the environment during construction is minimal, and it will neither interfere with ground traffic and facilities nor affect river navigation, and is not restricted by seasonal and climatic conditions. Since the processes of advancement, excavation, and assembly of linings are automated, construction efficiency is significantly improved and labor intensity is reduced. In addition, the shield method is also highly adaptable and can cope with a variety of geological conditions such as soft soil, hard rock, and aquifers. The key links of construction include the construction of the working well, the installation and commissioning of the shield machine, the excavation and advancement of the soil layer, the synchronous assembly of the lining, and the back injection of the lining to prevent surface subsidence. These links ensure the smooth implementation of the shield construction technology and the high-quality completion of the tunnel project.

[0003] The existing tunnel structure has many defects during operation. On the one hand, the segment structure is a discontinuous structure composed of multiple segments connected by longitudinal and circumferential connectors. It has low structural stiffness and weak deformation resistance, and is prone to problems such as excessive deformation, cracking, water leakage, and bolt corrosion. On the other hand, the ballast structure and the segment structure are two independent casting systems, which are prone to peeling defects under the vibration load of the train, causing mud bubbling on the connection surface and ballast bed de-airing. The above-mentioned defects directly affect the bearing capacity and durability of the tunnel structure, further affecting the stability of driving and the safety of subway operations, and are major safety hazards.

[0004] In addition, on the one hand, there are differences in understanding among those skilled in the art; on the other hand, the applicant studied a large number of documents and patents when making the present invention, but due to space limitations, not all details and contents are listed in detail. However, this does not mean that the present invention does not have the characteristics of these prior arts. On the contrary, the present invention already has all the characteristics of the prior art, and the applicant reserves the right to add relevant prior art to the background technology. Summary of the invention

[0005] The prior art has already presented a technical method for improving the bearing capacity and durability of the tunnel structure by connecting multiple segments into an integrated closed loop. For example, the patent document with publication number CN112239969A discloses a prefabricated assembled vibration-damping track system, comprising multiple segments connected in sequence, the multiple segments forming a closed loop, and multiple prefabricated track plates connected in sequence, the multiple prefabricated track plates being arranged circumferentially along the inner surface of the closed loop, a self-compacting concrete layer being arranged between the segments and the prefabricated track plates, a limiting groove matching the lower surface of the self-compacting concrete layer being provided on the segments, an isolation layer being provided between the segments and the self-compacting concrete layer, a through hole matching the upper surface of the self-compacting concrete layer being provided on the prefabricated track plates, and a vibration-damping cushion layer being provided between the prefabricated track plates and the self-compacting concrete layer. In this technical method, both ends of the segments are provided with hand holes for splicing two adjacent segments in the transverse direction, and the sides of the segments are provided with bolt holes for connecting adjacent segments in the longitudinal direction or in the track direction. However, in this technical method, adjacent segments are combined only by separate and independent connecting structures. The more connecting parts there are in this arrangement, the worse the integrity of the integrated vibration-damping track system formed after the combination, and the worse the vibration-damping effect it can achieve. At the same time, once a connecting part between adjacent segments is damaged or fails, the vibration of the segment structure connected to it will be aggravated, and then the stability of the overall assembled vibration-damping system will fail, thereby significantly reducing the service life of the assembled vibration-damping track system.

[0006] In view of the shortcomings of the prior art, the present invention provides an integral vibration-damping prestressed shield tunnel structure and construction method. The present invention can effectively improve the overall stiffness and deformation resistance of the tunnel structure, avoid the leakage, settlement, deformation and other defects of the traditional tunnel structure, and significantly reduce the amount of steel bars used. At the same time, the present invention can reduce the vibration of trains in tunnel operation, solve the problem of separation between the roadbed and the segment structure, and achieve ultra-long service performance of the shield tunnel structure.

[0007] The present invention discloses an integral vibration-damping prestressed shield tunnel structure, comprising a prestressed pipe ring and a prestressed system, wherein the prestressed pipe ring comprises a prestressed vibration-damping block located at the bottom of the tunnel structure, prestressed anchoring blocks located on both sides of the prestressed vibration-damping block, a prestressed adjacent block connected to the prestressed anchoring block, and a prestressed capping block located at the top of the tunnel structure, wherein the prestressed system comprises an annular prestressed system and a longitudinal prestressed system, wherein the prestressed pipe ring is assembled from a plurality of pipe segments in blocks, and an annular prestress is applied through the annular prestressed system, and longitudinal prestress is applied through the longitudinal prestressed system after the plurality of prestressed pipe rings are assembled, and after the tunnel is opened or the shield is excavated for a certain distance, duct grouting and anchoring groove filling are performed to form an integral vibration-damping prestressed shield tunnel structure. Different from the prior art, the integral vibration-damping prestressed shield tunnel structure of the present invention can form an annular main body of the shield tunnel structure through a combined prestressed pipe ring structure, and can apply annular prestress to the prestressed pipe ring through the annular prestressed system, and longitudinal prestress is applied through the longitudinal prestressed system after the plurality of prestressed pipe rings are assembled. Based on the above-mentioned distinguishing technical features, the problems to be solved by the present invention may include: how to simultaneously improve the circumferential connection strength and longitudinal connection strength of the shield tunnel structure through an integral connection structure. Specifically, the existing shield prefabricated segments mainly focus on the connection strength between adjacent plates. Large shield tunnels usually have a large diameter span, so it is necessary to set up multiple sets of segments for combined connection. The more segments connected in the annular direction, the more connection structures need to be set up, and the probability of overall annular connection instability due to failure of the connection structure is also higher, and the existence of multiple sets of connection structures also leads to poor integrity of the annular main body of the shield tunnel. On the contrary, the present invention connects the prestressed pipe ring composed of multiple segments through a unified annular prestressing system and applies corresponding annular prestress, thereby improving the integrity of the shield tunnel structure, and thereby improving the connection strength and stability of the prestressed pipe ring; at the same time, the prestressed pipe ring connected by the annular prestressing system can be connected and applied with longitudinal prestress through the longitudinal prestressing system, thereby improving the integrity of the connected prestressed pipe ring, and finally achieving a stable connection of the entire shield tunnel.

[0008] According to a preferred embodiment, for a large-diameter shield tunnel with more than 6 segments of prestressed pipe ring, prestressed standard blocks for connecting other segment blocks can be added according to design requirements, and the size of each segment block can be adjusted according to the layout of the prestressed anchor block, wherein the prestressed anchor block is an arc-shaped structure, a plurality of annular prestressed channels are arranged in the middle of the longitudinal section, and an annular anchor platform for tensioning is arranged in the middle of the inner arc surface.

[0009] According to a preferred embodiment, a straight channel and a variable curvature channel connected to the annular prestressed channel are provided inside the annular anchoring platform, and a tensioning groove is provided at the channel port, wherein the channel inside the annular anchoring platform is respectively led out from the tensioning grooves at both ends in a cross manner. Different from the prior art, the prestressed anchor block of the present invention is provided with an annular prestressed channel for accommodating annular prestressed steel bundles inside, and the annular prestressed channel is led out from the tensioning grooves at both ends of the annular anchoring platform through the straight channel and the variable curvature channel connected thereto. Based on the above-mentioned distinguishing technical features, the problems to be solved by the present invention may include: how to perform tensioning operation on the annular prestressed steel bundles arranged inside the annular segments to improve the stability and integrity between the annular connected segments. Specifically, in order to improve the stability of the annular prestressed steel bundles inside the segments, it is necessary to arrange the annular prestressed steel bundles inside the annular prestressed channels of the same depth in the segments. This arrangement method of burying them inside the segments will make it difficult to install the annular prestressed steel bundles and perform tensioning operations. To this end, the present invention leads the two ends of the annular prestressed channel out from the tensioning groove of the annular anchoring platform through a straight channel and a variable curvature channel at the annular anchoring platform, thereby making it convenient for construction personnel to install and tension the annular prestressed steel bundle on the inner side of the shield tunnel structure.

[0010] According to a preferred embodiment, when 4 annular prestressed channels are provided, 2 annular prestressed channels on one side are through holes, and the middle of the 2 annular prestressed channels on the other side is an annular anchoring platform; when 3 annular prestressed channels are provided, 1 annular prestressed channel on one side is a through hole or has an annular anchoring platform in the middle, and the middle of the 2 annular prestressed channels on the other side is an annular anchoring platform or a through hole. When 4 annular prestressed channels are provided, a bonding tensioning method can be used. After the segments are assembled into a ring, only the annular prestressed steel strands of the two outer channels are tensioned. When the segments reach the design life or the prestress loss exceeds the design requirements, the two middle channels are tensioned. When three annular prestressed channels are set up, the non-bonded tensioning method can be adopted. After the segments are assembled into a ring, only the annular prestressed steel strands of the two outer channels are tensioned. When the segments reach the design life or the prestress loss exceeds the design requirements, the middle channel is tensioned first, and then the prestressed steel strands of the two outer channels are replaced in turn, and finally the prestressed steel strands of the middle channel are removed.

[0011] According to a preferred embodiment, the prestressed vibration damping block is an integral prefabricated component of the arc-shaped segment structure and the ballast bed structure, two rows of sleeper grooves are arranged on the inner arc surface, a longitudinal cavity for pipeline laying is arranged below the sleeper grooves, and a plurality of circumferential prestressed channels and a plurality of longitudinal prestressed channels are arranged inside the prestressed vibration damping block. The circumferential prestressed anchoring ends of the present invention are arranged on both sides of the tunnel structure, which can make the circumferential prestress distribution of the tunnel structure more uniform. The prestressed vibration damping block is arranged at the bottom of the tunnel structure, and the sleeper grooves above it are convenient for track laying during shield construction and before operation, and the flat bottom surface is convenient for setting up pedestrian walkways. In addition, the anchoring end of the prestressed system can be embedded in the segment, and a longitudinal cavity for pipeline laying is arranged inside the prestressed vibration damping block, which not only avoids the problem of tunnel structure intrusion, but also avoids a large number of embedded bars or anchor bolts for the construction of pipeline bridges, so that the tunnel structure is not weakened, and the wiring is convenient, and the tunnel is neat and beautiful.

[0012] According to a preferred embodiment, the prestressed vibration damping block is divided into a longitudinal common block and a longitudinal anchor block. The longitudinal prestressed channel of the longitudinal common block is a through hole arranged in the middle of the annular section, and the middle of the longitudinal prestressed channel of the longitudinal anchor block is a longitudinal anchor groove. The longitudinal prestressed anchor end is arranged at the bottom of the larger tunnel structure, which is convenient for construction and application of greater longitudinal prestress, and the longitudinal connection is formed by the bolt and the prestressed tendons to form a longitudinal beam structure system, which can greatly improve the overall longitudinal performance.

[0013] According to a preferred embodiment, a grouting hole is provided on one side of the outer arc surface in the middle of each prestressed channel of the prestressed capping block, and the grouting hole is connected to the exhaust pipe. The other end of the exhaust pipe is led out from the inner arc surface of the pipe segment and connected to the valve to remove the air in the channel. The grouting hole is used to remove the air in the pipeline to ensure the grouting density. The grouting density affects the overall bonding performance of the structure and protects the prestressed steel bundle. If the non-bonded prestressing tensioning method is adopted, the grouting hole and other supporting equipment may not be provided.

[0014] According to a preferred embodiment, the annular prestressed steel bundle configured therein includes a steel bundle body, a traction steel bundle and a conical steel cap. The steel bundle body is composed of multiple steel strands. The traction steel bundle is a relatively long steel strand extending from the middle of the steel bundle body. The conical steel cap is sleeved at the transition between the steel bundle body and the traction steel bundle. The annular prestressed steel bundle is threaded by a cable threading machine using a single traction and overall push method, that is, the cable threading machine first inserts the traction steel bundle from one side of the annular anchoring platform, goes around the prestressed pipe ring once and then passes out from the other side of the annular anchoring platform, and then pulls the traction steel bundle while pushing the steel bundle body to complete the threading. After the threading of the annular prestressed steel bundles of multiple channels is completed, the tensioning equipment is immediately used for bidirectional synchronous graded tensioning, and the pipe segments are connected into an integral prestressed pipe ring by the annular prestressing.

[0015] According to a preferred embodiment, the annular prestressed system is formed in the following manner: the traction steel bundle is inserted from one side of the annular anchoring platform, passes through the prestressed pipe ring once and then passes out from the other side of the annular anchoring platform, and then the traction steel bundle is pulled while the steel bundle body is pushed to complete the cable threading, and finally a two-way synchronous graded tensioning method is adopted.

[0016] According to a preferred embodiment, the prestressed anchor block is provided with annular anchoring concrete for fixing the end of the prestressed steel bundle, wherein the annular prestressed channel provided in the segment block forms a branch channel near the inner surface or outer surface of the segment block where it is located, the branch channel is connected to the annular prestressed channel, and the annular anchoring concrete is filled at the end of the branch channel. The end of the prestressed steel bundle is firmly fixed by the annular anchoring concrete to prevent it from loosening or displacement due to factors such as vibration and load changes during long-term operation, thereby enhancing the overall stability and durability of the tunnel structure. As a transition medium between the prestressed steel bundle and the segment block, the annular anchoring concrete can effectively transfer the prestress from the steel bundle to the segment concrete, ensuring the uniform distribution and effective transfer of the prestress in the tunnel structure, and improving the bearing capacity of the structure.

[0017] According to a preferred embodiment, the upper surface of the prestressed vibration damping block constitutes a sleeper, and the lower surface thereof is bent downward. At least one annular prestressed channel is provided inside the prestressed vibration damping block, and the annular prestressed channel is consistent with the arc-shaped bending direction of the lower surface of the prestressed vibration damping block. The interior of the prestressed vibration damping block is provided with axial sealing and anchoring concrete. The axial sealing and anchoring concrete is located in the annular prestressed channel near the middle of the upper surface of the prestressed vibration damping block, and protrudes toward the lower surface, and is used to stretch the axial steel cable of the prestressed pipe ring. The existence of the annular prestressed channel allows the prestressed steel bundles to be more evenly distributed throughout the structure, thereby improving the overall bearing capacity and durability. Through the fixing and supporting effects of the axial sealing and anchoring concrete, the axial steel cable can withstand tension more stably, thereby improving the longitudinal stability and integrity of the entire tunnel structure.

[0018] In the second aspect, the present invention discloses a construction method of an integral vibration-damping prestressed shield tunnel structure, which includes: prefabricating a prestressed vibration-damping block, a prestressed anchoring block, a prestressed adjacent block and a prestressed capping block; the prestressed vibration-damping block is set at the bottom of the tunnel structure, the prestressed anchoring block is set on both sides of the prestressed vibration-damping block, the prestressed adjacent block is connected to the prestressed anchoring block, and the prestressed capping block is set at the top of the tunnel structure to assemble into a prestressed pipe ring, and then the circumferential prestress is applied through the circumferential prestressing system, and after the assembly of multiple prestressed pipe rings is completed, the longitudinal prestress is applied through the longitudinal prestressing system; after the tunnel is opened or the shield is excavated for a certain distance, the hole grouting and anchoring groove filling are performed to finally form an integral vibration-damping prestressed shield tunnel structure. The present invention connects the pipe segments into an integral structure by the circumferential and longitudinal prestressing systems, effectively improving the overall stiffness and deformation resistance of the tunnel structure, avoiding various diseases such as leakage, cracking, and settlement existing in the traditional pipe segment structure, and reducing the amount of steel bars. The pipe segment and the ballast structure of the present invention are integrally prefabricated. Compared with the multiple pouring processes of the existing structure, the present invention is simple to construct and has high construction quality. At the same time, it reduces the vibration of the train during tunnel operation, solves the separation problem of the ballast and the tunnel structure, and greatly reduces the cost of later operation and maintenance. Based on the bonding tensioning method or the non-bonding tensioning method, during operation, the tunnel structure can achieve an ultra-long service life by reserving the hole for post-tensioning and reserving the same hole position for reusing the service hole, which is a new green and low-carbon technology.

[0019] In the third aspect, the present invention discloses a method for extending the service life of an integral vibration-damping prestressed shield tunnel structure, which is achieved by post-tensioning of a reserved channel and replacing the cable at the same hole position of a reserved and reused service hole, and includes the following steps: determining the method to be executed according to the type of tensioning method adopted by the prestressed system. When the annular prestressed channels are set to 4, the prestressed system adopts a bonded tensioning method and executes the post-tensioning method of the reserved channel; when the annular prestressed channels are set to 3, the prestressed system adopts a non-bonded tensioning method and executes the cable replacement method of the reserved and reused service hole at the same hole position. The present invention achieves an effective extension of the service life of the tunnel structure by post-tensioning of the reserved channel and replacing the cable at the same hole position of the reserved and reused service hole. This method determines the execution method according to the type of tensioning method adopted by the prestressed system, providing flexibility and adaptability. When the annular prestressed channels are set to 4, a bonded tensioning method is adopted, which allows the prestressed tendons to form an integral body with the surrounding concrete, thereby improving the bearing capacity and durability of the structure. When the number of annular prestressed channels is set to three, the non-bonded tensioning method is adopted, which facilitates the replacement of prestressed tendons, so that the prestressed tendons can be effectively replaced when the prestress is lost or reaches the design life, thereby extending the service life of the structure.

[0020] In a fourth aspect, the present invention discloses a method for post-tensioning a reserved channel for an integral vibration-damping prestressed shield tunnel structure, which is achieved by the following steps: first, the annular anchoring concrete is chiseled out, and then the two reserved channels in the middle are tensioned with bonded steel bundles, and after the tensioning is completed, the channels are grouted and the anchor grooves are refilled. The method for post-tensioning a reserved channel of the present invention achieves the reinforcement and maintenance of the tunnel structure by first chiseling out the annular anchoring concrete, and then the two reserved channels in the middle are tensioned with bonded steel bundles. This method restores or increases the prestress level of the structure by re-tensioning and grouting, thereby improving the stability and durability of the structure. After the tensioning is completed, the channels are grouted and the anchor grooves are refilled, which not only ensures the effective anchoring of the prestressed tendons, but also enhances the integrity and sealing of the structure, and prevents potential problems caused by poor anchoring.

[0021] In the fifth aspect, the present invention discloses a method for replacing cables in the same hole position of a reserved and reused service hole for an integral vibration-damping prestressed shield tunnel structure, which is achieved by the following steps: first, the annular sealing and anchoring concrete is chiseled out, and then the prestressed steel bundles of a middle service hole channel are tensioned, and then the prestressed steel bundles on both sides are replaced in sequence by a non-bonding method, and finally the prestressed steel bundles in the middle channel are removed for later reuse. The method for replacing cables in the same hole position of a reserved and reused service hole of the present invention provides an economical and efficient strategy for replacing prestressed tendons by first chiseling out the annular sealing and anchoring concrete, and then tensioning the prestressed steel bundles of the middle service hole channel, and then replacing the prestressed steel bundles on both sides in sequence by a non-bonding method, and finally removing the prestressed steel bundles in the middle channel for later reuse. This method allows the prestressing level of the structure to be restored by replacing the prestressed tendons only without replacing the entire pipe segment, which greatly reduces the maintenance cost. At the same time, the operation is performed through the reserved service hole, which simplifies the construction process, reduces interference with the tunnel structure, and ensures the safety and efficiency of the construction. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a front view of the integral vibration-damping prestressed shield tunnel structure provided by the present invention;

[0023] Figure 2 It is a top view of the integral vibration reduction prestressed shield tunnel structure provided by the present invention;

[0024] Figure 3 This is a front view of the protruding structure of the prestressed anchor block provided by the present invention;

[0025] Figure 4 This is a front view of the embedded structure of the prestressed anchor block provided by the present invention;

[0026] Figure 5 It is a top view of a first hole arrangement of a prestressed anchor block provided by the present invention;

[0027] Figure 6 is a top view of a second hole arrangement of a prestressed anchor block provided by the present invention;

[0028] Figure 7 It is a top view of the third hole arrangement of the prestressed anchor block provided by the present invention;

[0029] Figure 8 It is a top view of a longitudinal common block of the prestressed vibration damping block provided by the present invention;

[0030] Fig. 9 It is a top view of the longitudinal anchor block of the prestressed vibration damping block provided by the present invention;

[0031] Fig.10 is a top view of the prestressed standard block provided by the present invention;

[0032] Fig.11 is a top view of the prestressed adjacent block provided by the present invention;

[0033] Fig.12 is a top view of the prestressed capping block provided by the present invention;

[0034] Fig.13 yes Fig.12 A schematic structural diagram of the A-A section of the prestressed capping block;

[0035] Fig.14 It is a schematic diagram of the structure of the annular prestressed steel bundle provided by the present invention;

[0036] Fig.15 It is a schematic diagram of a longitudinal prestressing connection method provided by the present invention;

[0037] Fig.16 It is a schematic diagram of another longitudinal prestressing connection method provided by the present invention;

[0038] Fig.17 This is a schematic diagram of the reinforcement structure of the prestressed anchor block of the first method;

[0039] Fig.18 yes Fig.17 Schematic diagram of the reinforcement structure of the B-B section of the prestressed anchor block;

[0040] Fig.19 It is a schematic diagram of the reinforcement structure of the prestressed vibration damping block provided by the present invention;

[0041] Fig. 20 It is an assembly schematic diagram of the first step of the construction method of the integral vibration-damping prestressed shield tunnel structure provided by the present invention;

[0042] Fig.21It is an assembly schematic diagram of the second step of the construction method of the integral vibration-damping prestressed shield tunnel structure provided by the present invention;

[0043] Fig. 22 It is an assembly schematic diagram of the third step of the construction method of the integral vibration-damping prestressed shield tunnel structure provided by the present invention;

[0044] Fig.23 It is a schematic diagram of the force distribution state of the triangle at the end position of the prestressed steel bundle in the prestressed pipe ring provided by the present invention;

[0045] Fig.24 It is a comparison diagram of the axial forces between the prestressed pipe segment provided by the present invention and the ordinary pipe segment;

[0046] Fig.25 It is a comparison diagram of the bending moments of the prestressed pipe segment provided by the present invention and the ordinary pipe segment;

[0047] Fig.26 : is a horizontal displacement deformation diagram of a common segment in an embodiment of the present invention;

[0048] Fig. 27 is a horizontal displacement deformation diagram of a prestressed pipe segment in an embodiment of the present invention;

[0049] Fig.28 is a schematic diagram of a group of prestressed pipe rings that bear the same longitudinal preload in an embodiment of the present invention;

[0050] Fig.29 It is a schematic diagram of a scene of placing a tensioning device in a prestressed pipe ring and performing a tensioning operation in an embodiment of the present invention;

[0051] Fig.30 is a schematic diagram of the axial force of the simulation results when the anchoring ends of the two prestressed ducts are arranged on the left side in the embodiment of the present invention;

[0052] Fig.31 is a schematic diagram of the axial force of the simulation results when the anchoring ends of the two prestressed ducts are arranged on the right side in the embodiment of the present invention;

[0053] Fig.32 is a schematic diagram of the axial force of the simulation results when the anchoring ends of two prestressed ducts are symmetrically arranged in an embodiment of the present invention;

[0054] Reference numerals list

[0055] 100: middle prestressed ring; 101: prestressed pipe ring; 102: annular prestressed system; 103: longitudinal prestressed system; 110: prestressed vibration damping block; 111: prestressed anchor block; 112: prestressed adjacent block; 113: prestressed capping block; 114: prestressed standard block; 115: sleeper groove; 116: longitudinal common block; 117: longitudinal anchor block; 118: annular anchor platform; 119: tensioning groove; 119a: circumferential wall; 11 9b: tensioning lead-in portion; 120: annular prestressing channel; 120a: another annular prestressing channel; 121: annular prestressing steel strand; 121a: steel strand exit end; 121b: steel strand entry end; 123a, b, c, d: annular anchoring concrete; 123e: axial anchoring concrete; 124: anchor pad; 124a: anchor pad of circumferential wall 119a; 125: steel strand body; 126: traction steel strand; 127: conical steel cap; 128 : variable curvature channel; 129: straight channel; 130: longitudinal prestressed channel; 131: longitudinal prestressed steel strand; 132: longitudinal anchor groove; 133: longitudinal cavity; 140: longitudinal joint; 140a: longitudinal female joint; 140b: longitudinal male joint; 141: grouting air hole; 142: exhaust pipe; 143: valve; 150: integral anti-collapse steel bar; 151: hanging bar; 152: local anti-collapse steel bar; 153: contour bar; 154: Frame reinforcement; 155: spiral reinforcement; 156: anti-floating reinforcement; 157: post-anchor tension reinforcement; 158: local bending reinforcement; 160: connecting anchor plate; 161: clamp; 162: protective cover; 163: ordinary anchor plate; 164: single-hole connector; 165: wire dividing plate; 201: female connector; 202: male connector; 203, 204: longitudinal seam surface; 300a: full-circle prestressed steel strand; 300b: half-circle prestressed steel strand; 400: inner prestressed ring. DETAILED DESCRIPTION

[0056] The following is a detailed description with reference to the accompanying drawings.

[0057] Example 1

[0058] Combination Figure 1 and Figure 2 As shown, the present invention provides an integral vibration-damping prestressed shield tunnel structure, which includes a prestressed pipe ring 101 having a prestressed system or a prestressed pipe ring subjected to the action of the prestressed system. The prestressed system includes an annular prestressed system 102 and a longitudinal prestressed system 103, wherein the annular prestressed system 102 is a circumferential force system that uses steel bars to apply an action along the circumference of at least some of the prestressed pipe rings 101 connected to each other through an annular prestressed channel 120 (see Fig.28), and the longitudinal prestressing system 103 is a longitudinal force system that uses steel bars along the length direction of the tunnel through the longitudinal prestressing channel 130 to act on multiple prestressed pipe rings 101 that are connected to each other in the length direction and at least some of which are subjected to circumferential prestress (see also Fig.28 ).

[0059] Figure 1 This is a cross-sectional view. For the sake of overview, the section line of the tunnel segment structure itself is omitted. In the prestressed system of the present invention, the annular prestressed channel 120 forms at least one annular channel in the cross-sectional view inside the tunnel segment, preferably a group of annular channels with the same radius and colinear centers in the tunnel length direction. The annular channel and the outer contour of the tunnel segment are concentric circles with each other and are used to bear circumferential forces. The structure of the annular prestressed channel 120 will be explained in detail in conjunction with each segment below.

[0060] exist Figure 1 The lower middle area shows a prestressed vibration damping block 110 as an integral prefabricated structure with an annular prestressed channel 120 formed inside, which has a curvature outside the tunnel but is integrally formed with the ballast inside the tunnel (see also Figure 2 The prestressed vibration damping block 110 is connected to the left and right sides of the prestressed anchor block 111 with an annular prestressed channel 120, respectively. The three are connected to each other through the longitudinal seams 203 and 204 on both sides in a manner that the annular prestressed channel 120 is connected to each other, especially in a manner that the same curvature is connected. These longitudinal seams form planes with the same size as each segment block in the tunnel length direction. Figure 1 The two prestressed anchor blocks 111 shown are located near the pedestrian passage of the shield machine, which is convenient for passing the cable through the annular prestressed hole 120 and facilitating the placement and tensioning operation of the tensioning equipment. Fig.29 .

[0061] exist Figure 1 In the embodiment, other tunnel segments with annular prestressed channels 120 of the same curvature are also directly or indirectly fixed to the prestressed anchor blocks 111 along the circumferential direction, and thus a prestressed pipe ring 101 is obtained with annular prestressed channels 120 in the 360° circumferential direction. The annular structure formed by splicing multiple segments inside the tunnel in the above manner. By laying the annular structure with annular prestressed channels 120 in the length direction of the tunnel (see Fig.28 ), a tunnel lining with circumferential stress can be formed. In a prestressed pipe ring 101, in addition to the prestressed anchor block 111, other tunnel segments as segment blocks may include a prestressed vibration reduction block 110, a prestressed adjacent block 112 and a prestressed capping block 113, all of which have circumferential prestressed channels 120, especially with the same curvature.

[0062] exist Figure 1 In the embodiment, the annular prestressed steel strand 121 is inserted into the annular prestressed channel 120 of the prestressed pipe ring 101. Figure 1 As an example, the simplest way of installing the steel strands is explained: the annular prestressed steel strand 121 can be inserted into the annular prestressed channel 120 along the circumferential direction in the figure through the first prestressed anchor block 111 (for example, from Figure 1 The second prestressed anchor block 111 ( Figure 1 left side), a prestressed adjacent block 112, a prestressed capping block 113 at the top and another prestressed adjacent block 112 are then entered and anchored (for example, from Figure 1 On the middle right side 123c) at the first prestressed anchor block 111.

[0063] Combine the following Figure 3 , Figure 4 and Fig.21 as well as Fig. 22 The method of inserting the full-circle prestressed steel strand 300a is described in detail.

[0064] Figure 3 and Figure 4 The prestressed anchor block 111 of the embodiment differs from the embodiment in that the annular anchoring platform 118 is disposed in a manner, thereby obtaining the prestressed anchor blocks of the first embodiment and the second embodiment, respectively. Figure 3 The inner annular surface of the annular anchoring platform 118 of the given prestressed anchor block 111 is closer to the radial inner side than the inner annular surface defined by the prestressed pipe ring 101, thereby Figure 3 In the embodiment shown, the outlet of the straight channel 129 opened inside the annular anchoring platform 118 is roughly tangential to the inner annular surface defined by the prestressed pipe ring 101. Therefore, compared with the inner wall of the tunnel defining the inner annular surface of the prestressed pipe ring 101, the inner annular surface where the annular anchoring platform 118 is located has a step height h, and the step height h is formed by the distance between the outlet center tangent of the straight channel 129 on the circumferential wall 119a of the annular anchoring platform 118 and the tangent of the annular inner wall of the annular anchoring platform 118. Therefore, the prestressed anchor block 111 of the first embodiment has a tensioning groove 119 that is easier to access in the circumferential direction, and the tensioning groove 119 provides the operator with a larger tensioning space (see Fig.29 ) so that anchoring operations can be performed on the circumferential wall 119a of the annular anchoring platform 118. The radially thicker circumferential wall 119a also provides a stronger anchoring strength, which is conducive to applying a larger annular prestress at the corresponding position of the prestressed pipe ring 101. Figure 4A radially lower annular anchoring platform 118 is provided, which, by providing a uniform inner wall diameter, is helpful for the deployment of various engineering machinery during tunnel construction and is also beneficial for tunnel maintenance operations. Different operation sections of the same tunnel will be selectively adopted according to geological conditions, tunnel operation requirements, tunnel size, and curve conditions.

[0065] Figure 3 and Figure 4 The two types of prestressed anchor blocks 111 provided can be advantageously implemented at different locations along the tunnel length of the same prestressed pipe ring 101, so as to apply different stresses to different sections of the same prestressed pipe ring 101. For this reason, preferably according to the present invention (not shown in the figure), by using prestressed anchor blocks 111 with circumferential anchor platforms 118 of different heights, different circumferential preloads can be applied to different sections along the tunnel length, for example, a larger circumferential preload is applied at both ends of the tunnel length or in areas with more severe geological conditions, while a relatively smaller circumferential preload is applied in the middle area, which can save the cost caused by the high-strength prestressed steel strands themselves on the one hand, and provide more flexible construction options on the other hand.

[0066] Preferably, each prestressed pipe ring in the length direction of the tunnel can adopt a first prestressed anchor block 111 with a first annular anchor platform 118 in pairs or a second prestressed anchor block 111 with a second annular anchor platform 118 in pairs, wherein the first annular anchor platform 118 with a step height h has at least one straight channel 129 for passing or anchoring the prestressed steel bundle 300a, and its outlet roughly points to the tangent of the inner annular surface defined by the prestressed pipe ring 101; wherein the inner annular surface where the second annular anchor platform 118 is located is at the same radial height position as the inner annular surface defined by the prestressed pipe ring 101.

[0067] Preferably, in the same prestressed pipe ring 101, two prestressed anchor blocks 111 of different embodiments may be used in combination, wherein one prestressed anchor block 111 has an annular anchor platform 118 that is consistent with the height of the inner wall of the tunnel defined by the prestressed pipe ring 101, while the annular anchor platform 118 of the other prestressed anchor block 111 has a higher step height h than the inner wall of the tunnel defined by the prestressed pipe ring 101. The two prestressed anchor blocks 111 of different embodiments may be located on both sides, respectively, and may be correctly arranged by the different heights of their annular anchor platforms 118. During the construction process, construction personnel can visually observe the heights of both sides (see Fig.29 ), therefore, simply relying on the implementation method of the prestressed anchor block 111, it is possible to provide intuitive preload setting instructions to construction personnel, thereby avoiding the application of excessive or insufficient preload.

[0068] exist Figure 5 In the embodiment of the four annular prestressed ducts 120 shown, the prestressed anchor blocks 111 located on both sides have two annular anchoring platforms 118 that are consistent with each other at the corresponding tunnel height positions in order to evenly anchor the annular prestressed steel strands, that is, both use a lower annular anchoring platform 118 or both use annular anchoring platforms 118 with a step height h compared to the tunnel inner wall defined by the prestressed pipe ring 101. It is particularly preferred for the present invention that in the prestressed pipe ring group that applies longitudinal prestressing force along the length direction of the tunnel by the same longitudinal prestressing system 103 (see Figure 2 ), the two ends of the prestressed pipe ring group subjected to the same longitudinal prestressing system 103 adopt the prestressed anchor blocks 111 (of the first embodiment) which are more conducive to bearing higher radial preload Figure 3 ), and the middle prestressed pipe ring of the prestressed pipe ring group subjected to the same longitudinal prestressed system 103 force adopts the prestressed anchor block 111 ( Figure 4 ), which has an annular anchoring platform 118 that is consistent with the height of the tunnel inner wall defined by the prestressed pipe ring 101.

[0069] In addition, only one prestressed anchor block 111 is shown separately. Figure 3 and Figure 4 Two non-circular channels interlaced in space are shown in solid lines. In order to pass the prestressed steel strand 121 to generate prestress, the two channels include a variable curvature channel 128 and a straight channel 129 connected in sequence, thereby forming two spatially interlaced introduction channels in the annular anchoring platform 118. The solid lines are to show that the two introduction channels are both located in an annular anchoring platform 118 of a prestressed anchoring block 111 and are interlaced in space. In fact, their positions in the tunnel length direction are very close to each other but do not cross (see Figure 2 ). Observing along the insertion direction of the annular prestressed steel strand 121, the introduction channel starts from the straight channel 129 and smoothly transitions to the annular prestressed channel 120 of the prestressed anchor block 111 via the variable curvature channel 128; observing along the exit direction of the annular prestressed steel strand 121, the introduction channel smoothly transitions from the annular prestressed channel 120 via the variable curvature channel 128 to the straight channel 129 of the prestressed anchor block 111.

[0070] Figure 3 and Figure 4 Another annular prestressed channel 120a shown in dotted lines indicates at least one other channel in the tunnel length direction away from the drawing direction, i.e., another annular prestressed channel 120a, which has the same radius as the annular prestressed channel 120, but is located at a distance from each other in the tunnel length direction of the same prestressed pipe ring 101. Figure 2It can be known that the annular prestressed steel strand passing through another annular prestressed channel 120a can be fixed on the annular anchoring platform 118 of the prestressed anchoring block 111 on the opposite side.

[0071] Fig.21 and Fig. 22 Two layout methods of prestressed steel tendons are given respectively. Fig.21 In the figure, the whole-circle prestressed steel strand 300a shown by the dotted line is inserted into the annular anchoring platform 118 of the inner wall of the second prestressed anchoring block 111 from a tensioning groove 119 at the second prestressed anchoring block 111 (on the left side of the figure), and the annular prestressed steel strand 121 smoothly transitions into the annular prestressed channel 120 of the second prestressed anchoring block 111 in the clockwise direction through the straight channel 129 and the variable curvature channel 128 in the annular anchoring platform 118 ( Figure 3 , Figure 4 ); then, along the annular prestressed channel 120 of the second prestressed anchor block 111 through the male connector 202 at its circumferential end ( Figure 4 The left side of the prestressed adjacent block 112 enters the corresponding female joint 201 (not shown) of the prestressed adjacent block 112 in the clockwise direction, and then passes through the annular prestressed channel 120 prefabricated in the prestressed adjacent block 112, and then passes through the subsequent prestressed capping block 113, another prestressed adjacent block 112 ( Fig.21 The first prestressed anchor block 111, the prestressed vibration damping block 110 and finally return to and anchor to the annular anchoring platform 118 of the second prestressed anchor block 111. Thus, the full-circle prestressed steel strand 300a passes through and out of the same prestressed anchor block 111 of a prestressed pipe ring 101 and is fixed to the same annular anchoring platform 118 of the same prestressed anchor block 111, so it itself constitutes a 360° annular prestressed steel strand 121 (see FIG. 121 ) acting on the pipe ring in the tunnel length direction. Fig.28 ).

[0072] After threading the steel bundle, you can Fig. 22 As shown, anchoring concrete is injected into the corresponding tensioning groove 119 to firmly anchor the steel strand to the corresponding prestressed anchor block 111. In addition to the anchoring concrete, Fig. 22Another arrangement method of prestressed steel strands is also provided, that is, a semi-circular prestressed steel strand 300b, which is fixed to the prestressed anchor block 111 on the other side through the prestressed anchor block 111 on one side and only passes approximately 180° of the prestressed pipe ring 101. For example, one of the semi-circular prestressed steel strands 300b is fixed at one end in a tensioning groove occupied by the annular anchor concrete 123a, and at the other end in another tensioning groove occupied by the annular anchor concrete 123d; another semi-circular prestressed steel strand 300b is fixed at one end in a tensioning groove occupied by the annular anchor concrete 123b, and at the other end in another tensioning groove occupied by the annular anchor concrete 123c, see Fig. 22 . It is conceivable that different prestressed steel bundles are arranged in different areas of the same prestressed pipe ring 101 in the tunnel length direction, for example, semi-circular prestressed steel bundles 300b and full-circle prestressed steel bundles 300a are arranged at intervals. According to a particularly preferred embodiment of the present invention, in the prestressed pipe ring 101 close to the outer side in the tunnel length direction in the prestressed pipe ring group that bears the same longitudinal prestressing force, a semi-circular prestressed steel bundle 300b is additionally provided for the lower section where the prestressed vibration damping block 110 is located, so as to apply additional prestressing effect to the axial anchor concrete 123e in the longitudinal anchor groove 132 opened in the prestressed vibration damping block 110. Compared with the full-circle prestressed steel strands 300a that act on all the segments in the circumferential direction, the half-circle prestressed steel strands 300b with an even number of relatively threaded ones can effectively reduce costs, not only because the cost of shorter prestressed steel bars is significantly lower than that of longer prestressed steel bars, but also because the transportation, storage and tensioning in the tunnel can save a lot of manpower and time. In addition, the first prestressing force can be applied to the segment blocks in the upper semicircular area, such as the prestressed adjacent block 112, the prestressed standard block 114 or the prestressed capping block 113, while the second prestressing force can be applied to the segment blocks in the lower semicircular area, such as the prestressed vibration reduction block 110 and the two prestressed anchor blocks 111 connected to the left and right sides thereof. The first prestressing force can be different from the second prestressing force, so that a flexible and variable annular prestress can be adaptively set for different geological conditions and / or the longitudinal prestressing system 103.

[0073] Fig.28A group of prestressed pipe rings that bear the same longitudinal preload is shown. For the sake of simplicity, the prestressed pipe rings all use full-circumferential prestressed steel bundles 300a. As shown in the figure, the second annular steel bundle from the right to the left applies prestress in a 360° circumferential direction. The steel bundle starts from the prestressed steel bundle entry end 121b and ends at the stress steel bundle exit end 121a. The penultimate annular steel bundle acts on the outer end prestressed pipe ring 101 in the tunnel length direction, while the rightmost annular prestressed steel bundle 121 acts on the outer end of the same prestressed pipe ring 101 (the right end in the figure). The two full-circumferential prestressed steel bundles 300a are respectively fixed on the two prestressed anchor blocks 111 on both sides of the prestressed vibration damping block 110 of the same prestressed pipe ring 101. According to the present invention, it is particularly preferred that the prestressed pipe ring 101 located at the outer end in the length direction of the tunnel is arranged with at least two annular prestressed steel bundles 121, and the two annular prestressed steel bundles 121 are respectively formed by independent full-circle prestressed steel bundles 300a, and the at least two annular prestressed steel bundles 121 are respectively fixed on two different prestressed anchor blocks 111, wherein the two prestressed anchor blocks 111 of the prestressed pipe ring 101 are connected to the annular prestressed channel in the prestressed vibration damping block 110 of the prestressed pipe ring 101 via their own annular prestressed channels in the circumferential direction. The reason why this arrangement is advantageous is that the existence of the friction resistance of the prestressed channel will produce prestress loss, and the prestress value decreases as the distance from the prestressed tensioning end increases, that is, the prestress value at the diagonal of the tensioning end is the lowest; the place where the prestress of the left channel is the smallest is exactly the place where the prestress of the right channel is larger, and the prestress values ​​of the two channels can complement each other, so that the tunnel structure is more evenly stressed. In addition, the full-circle prestressed steel strand 300a can be tensioned by different operators during the operation (see Fig.29 ), the problem of inconsistent preload force implied by manual operation (such as caused by the calibration of tensioning equipment, force sensors and displacement sensors) cannot be absolutely avoided, but the potential risk of excessive bias caused by the same group of workers always using equipment with the same error for tensioning can be avoided to a certain extent through simultaneous construction on both sides, which is conducive to speeding up the construction progress and improving the construction quality.

[0074] like Fig.28 As shown in the example, in a group of prestressed pipe ring groups that jointly bear the same longitudinal prestressing force, the prestressed pipe ring group bears the same longitudinal prestressing force applied by the pipe rings at both ends of the group in the length direction of the tunnel, but in the annular direction, the prestressed steel strands of each prestressed pipe ring exert their own circumferential force.

[0075] Figure 24 to Figure 27 Numerical simulations clearly demonstrate that Fig.28Here, the numerical model includes prestressed segments and ordinary segments. The outer diameter of the segments is 6.0m, the ring width is 1200mm, and the thickness is 300mm. The prestressed segments are arranged with two prestressed channels along the center of the section. The prestressed beams are inserted into the channels. The tensioning ends are located on both sides of the tunnel structure. The structural form of the prestressed segments is shown in Figure 1 Compared with the ordinary segment, there is no prestressing setting. The modified conventional model is used for calculation. The stiffness reduction coefficient of the ordinary segment is 0.8, and the stiffness reduction coefficient of the prestressed segment is 0.9 due to the prestressing reinforcement. The prestressed steel strands use 4 bundles of φ15.6mm-1860MPa, and the controlled tension is 1320MPa. Table 1 shows the water and soil loads of the two segment structures.

[0076] Table 1 Calculation results of basic combined loads

[0077]

[0078] Figure 24 to Figure 27 The axial force, bending moment and horizontal displacement deformation of ordinary segments and prestressed segments are shown respectively. The top of the tunnel is 0°, and the angle increases clockwise. The axial force and bending moment of the most unfavorable section of the ordinary segment are 870kN and 193kN·m, respectively, and the axial force and bending moment of the most unfavorable section of the prestressed segment are 1770kN and 204kN·m, respectively. The maximum horizontal deformation of the ordinary segment and prestressed segment are 9.663mm and 8.980mm, respectively. Compared with ordinary segments, the axial force of the prestressed segment can be increased by 103.4%, the bending moment increased by 5.7%, and the deformation reduced by 7.1%. That is, the prestressed segment can give full play to the compressive performance of concrete and reduce structural deformation. The structural force is more reasonable, and it has the advantages of higher overall stiffness and better anti-deformation ability.

[0079] Figure 30 to Figure 32 The simulation results of the two prestressed duct anchorage ends arranged on the left, right and symmetrically on both sides, among which, the axial force of the prestressed beam when arranged on the left and right sides is 705kN~1096kN, the maximum and minimum axial force differ by 391kN, and it is asymmetric along the two sides of the tunnel. There is an eccentric load in the tunnel structure, and the structure is biased to one side; when the two sides are symmetrically arranged, the axial force of the prestressed beam is 800kN~1078kN, the maximum and minimum axial force differ by 278kN, and it is symmetrical along the two sides of the tunnel (corresponding to Fig.28 According to the above simulation results, the layout of the annular prestressed duct can be selectively adopted according to the geological conditions and the annular prestressed steel strands can be anchored accordingly.

[0080] Example 2

[0081] This embodiment is a further improvement and / or replacement of the above-mentioned embodiment, and the repeated contents are not repeated here. The features described here can be used in each of the above-mentioned embodiments as long as these features do not contradict each other.

[0082] According to this embodiment, a plurality of tensioning grooves 119 are provided in the circumferentially centered region of the prestressed anchor block 111. These tensioning grooves 119 are formed by providing tensioning introduction portions 119b on the radial inner wall of the prestressed anchor block 111. The tensioning introduction portions 119b are gradually deepened from both circumferential sides to the circumferential center (see, for example, Figure 3 and Figure 4 ), and the tensioning introduction portion 119b presents a shape in which the width gradually increases from the circumferential sides to the circumferential middle (see Figure 5 and Figure 6 ), thereby forming a wider plane in the circumferential middle area, which bears the force of the annular prestressed steel strand 121 with a larger contact area and thus a smaller pressure. In the circumferential middle area of ​​the prestressed anchor block 111, an annular anchoring platform 118 is defined between "two tensioning grooves 119 approximately located near the same annular prestressed channel area in the circumferential direction", and in particular, the circumferential walls 119a of the two tensioning grooves 119 that extend approximately radially to the bottom of the tensioning grooves respectively define the two end walls of the annular anchoring platform 118, and the annular anchoring platform fixes the annular prestressed steel strand 121 of the annular prestressed system 102 by means of the end walls. Preferably, the circumferential wall 119a having a depth in the radial direction indirectly bears the force of the annular prestressed steel strand 121 via the anchor pad 124a of the circumferential wall 119a fixed in a surface contact manner.

[0083] In such Fig.21 After the annular prestressed steel strand 121 is passed through as shown, when the segment structure is subjected to the water and soil load during the shield construction after the prestressing construction is completed, the corresponding hole grouting and anchor groove filling are performed through the tensioning groove 119. This can be arranged to be carried out uniformly after the tunnel is opened or the shield is excavated for a certain distance, which is conducive to making full use of the limited space of the shield tail of the shield machine. The hole grouting is mainly for the bonded tensioning method, and the non-bonded tensioning method does not need to perform this operation. When the anchor groove is filled in the tensioning groove 119, annular anchor sealing concrete 123a, 123b, 123c, 123d, 123e ( Fig. 22 ), these anchoring concretes can be made of low-grade plain concrete, self-compacting concrete and other cementitious materials that are easy to chisel. In the present invention, the annular anchoring concrete 123a, 123b, 123c, 123d of the prestressed anchor block 111 can be pre-buried during construction for the construction and laying of auxiliary pipelines in the later stage, which is convenient for construction and does not weaken the structure. The service life of the tunnel structure can be effectively extended by pre-tensioning the reserved channel and replacing the cable at the same hole position.

[0084] Preferably, the prestressed anchor block 111 may have an odd number of annular anchoring platforms 118 (see Figure 6 ) or an even number of annular anchoring platforms 118. An even number of annular anchoring platforms 118 is advantageous, especially when two annular anchoring platforms 118 of one prestressed anchoring block 111 are located adjacent to each other on one side in the length direction of the tunnel, and the other two annular anchoring platforms 118 of another prestressed anchoring block 111 fixed to the prestressed vibration damping block 110 together with the two annular anchoring platforms 118 are located adjacent to each other on the other side in the length direction of the tunnel, so that the two groups of four annular anchoring platforms 118 apply prestress to the same prestressed pipe ring 101 including the one prestressed anchoring block 111 and the other prestressed anchoring block 111 in a manner of applying prestress on the opposite sides respectively, so as to compensate for the prestress of the two groups of ducts, so that the tunnel structure where the prestressed pipe ring 101 is located is evenly stressed.

[0085] According to a particularly advantageous embodiment (such as Figure 3 and Figure 4 As shown in the figure, each annular anchoring platform 118 has a circumferential wall 119a with a straight channel 129 opening on both sides of the circumference. The circumferential wall 119a applies a pre-tightening force to the annular anchoring platform 118 from both sides of the circumference. The pre-tightening force is transmitted to the prestressed anchor block 111 along the straight channel 129 and the variable curvature channel 128. The two intersecting prestressing forces are transmitted along the normal direction of the opening section of the straight channel 129 but in opposite directions. Their radial components act on the entire prestressed pipe ring 101 from the annular anchoring platform 118 along the radial direction of the tunnel, thereby generating a strong bending moment at the annular anchoring platform 118, and the tensioning grooves 119 reserved on the left and right sides of the annular anchoring platform 118 for passing the steel strands play the role of predetermined bending points. Therefore, the maximum groove depth of the tensioning groove 119 accounts for less than 50%, especially less than 30%, and especially less than 20% of the entire prestressed anchor block 111. Figure 3 and Figure 4 In particular, in order to increase the strength of the annular anchoring platform 118, Figure 3 It is also provided that the annular anchoring platform 118 has a larger thickness h than the annular inner wall of the prestressed anchoring block 111, which is more suitable as the prestressed anchoring block 111 close to the outer side in the length direction of the tunnel in the prestressed pipe ring group that jointly bears the same longitudinal preload.

[0086] According to a preferred embodiment of the present invention, the following arrangement is also provided for strength. Figures 17 to 19The schematic diagram of the reinforcement structure of the prestressed vibration damping block 110 and the prestressed anchor block 111 is shown. By applying the annular prestress, the axial force of the pipe segment structure can be effectively increased and the deformation can be reduced, but the bending moment remains basically unchanged. The stress form of the pipe segment structure is better, and the corresponding stress steel bars can be reduced. For example, if steel fiber concrete is used, stress steel bars can be omitted. After the annular prestress is tensioned, a large radial force toward the center of the pipe ring will be generated on the inner wall of the annular prestressed channel 120, causing tensile damage to the concrete. All loads of the annular anchor platform 118 act on the anchor pad 124a fixed to the circumferential wall 119a (see Figure 5 , Figure 6 and Figure 7 ) on the concrete in contact with it, it is easy to cause stress concentration in the concrete in this area and cause damage. It is necessary to design prestressed protective steel bars in a targeted manner.

[0087] like Fig.17 As shown, a plurality of U-shaped integral anti-collapse steel bars 150 can be arranged at intervals on the annular prestressed channel 120 of each segment block, and the spacing is controlled at about 150 to 300 mm. Preferably, the tension that the integral anti-collapse steel bar 150 can provide is greater than the maximum radial force generated when the annular prestressing is tensioned, so as to ensure the safety of the segment structure. In addition, two suspension bars 151 are arranged above each annular prestressed channel 120, that is, in the direction of the outer arc surface of the segment block, for hanging and fixing the annular prestressed channel 120. For prestressed steel fiber concrete segments, since there are only lightweight prestressed protective steel bars in the segment structure and the prestressed channel is a hollow structure, when the segment is cast, additional anti-floating bars 156 extending along the length of the tunnel are arranged. The anti-floating reinforcement 156 preferably extends through the entire segment block along the length direction of the tunnel, for example, acts on the prestressed protective steel bars and / or prestressed channels for each annular prestressed channel 120 through multiple fixed points. On the one hand, it can uniformly deal with the buoyancy during pouring to avoid uneven burial depths of various prestressed channels, thereby avoiding excessive deviations in annular prestress from different channels. At the same time, several anti-floating reinforcements 156 parallel to each other in space also constitute annular prestressed distribution reinforcements within the segment block along the length direction of the tunnel.

[0088] like Fig.18As shown, compared with other segment blocks, the variable curvature channel 128 of the prestressed anchor block 111 is the weakest part of the annular prestressed channel 120, and multiple U-shaped local anti-collapse steel bars 152 can be additionally configured, with the spacing controlled at about 50 mm. Preferably, the straight channel 129 is provided with a gate-shaped contour rib 153 and a frame rib 154 for fixing. Preferably, an anchor pad 124 and a spiral rib 155 can also be provided at the end of the straight channel 129, and a post-anchor tensioning rib 157 and a local bending rib 158 can also be provided inside the annular anchor platform 118. The above-mentioned prestressed protective steel bars can improve the bearing capacity of the concrete in the anchoring area and disperse the concentrated force during prestressing to ensure the safety of the structure. The longitudinal prestressed channels 130 of the prestressed vibration damping block 110 are all straight channels, and there is no need to set anti-collapse steel bars. However, multiple rows of criss-cross steel meshes, anchor plates 124 and spiral bars 155 can be set along the longitudinal direction on both sides of the longitudinal anchoring groove 132 of the longitudinal anchoring block 117 to ensure the structural safety of the longitudinal anchoring area.

[0089] Example 3

[0090] This embodiment is a further improvement and / or replacement of the above-mentioned embodiment, and the repeated contents are not repeated here. The features described here can be used in each of the above-mentioned embodiments as long as these features do not contradict each other.

[0091] Figure 2 The partially cut-away segment is shown in a top-down viewing direction, omitting the top prestressed capping block 113 and the prestressed adjacent blocks 112 on the left and right sides, to show the combined longitudinal and circumferential effects of the prestressed system of the present invention. Only the annular prestressed duct 120 located at the prestressed vibration damping block 110 and the prestressed anchor blocks 111 on the left and right sides and the annular prestressed steel strands 121 arranged therein are shown.

[0092] exist Figure 2 Observing along the length direction of the tunnel, two types of prestressed vibration damping blocks 110 are provided in a section of the tunnel, namely, a longitudinal common block 116 with a longitudinal prestressed channel 130 and a longitudinal anchor block 117 with a longitudinal anchor groove 132, wherein the two longitudinal anchor blocks 117 are respectively located at the two ends of the length direction of the tunnel section, and a number of longitudinal common blocks 116 are arranged between the two longitudinal anchor blocks 117.

[0093] Figure 8The longitudinal common block 116 of the prestressed vibration damping block 110 is shown. By opening at least one channel for installing the longitudinal prestressed steel strand 131 in the longitudinal common block 116 along the tunnel length in the bottom center area, a longitudinal prestressed channel 130 in the longitudinal common block 116 is formed. Preferably, at least two longitudinal prestressed channels 130 extending parallel to each other, preferably in parallel, are formed in the area between the two sleeper grooves 115 of the prestressed vibration damping block 110. The longitudinal prestressed channel 130 is formed with a longitudinal female joint 140a and a longitudinal male joint 140b in the area entering and leaving the longitudinal common block 116. The longitudinal joint 140 formed by the longitudinal female joint 140a and the longitudinal male joint 140b enables the longitudinal prestressed channels 130 in the longitudinal common block 116 to be connected to each other, so as to pass the longitudinal prestressed steel strand 131, thereby forming a longitudinal prestressed system 103.

[0094] Fig. 9 The longitudinal anchor block 117 of the prestressed vibration damping block 110 is shown, and the axial anchor concrete 123e is omitted for the convenience of description. The longitudinal anchor block 117 and the longitudinal prestressed channel 130 in the longitudinal common block 116 can allow the steel bars to act on a plurality of prestressed pipe rings 101 connected to each other along the length direction of the tunnel through the longitudinal prestressed channel 130, wherein two longitudinal anchor blocks 117 are located at the longitudinal ends of the prestressed pipe rings 101 connected to each other along the length direction of the tunnel, and a plurality of longitudinal common blocks 116 are respectively located between the longitudinal anchor blocks 117 at the two ends, thereby forming a longitudinal prestressed system 103 that exerts a pretightening effect in the longitudinal direction.

[0095] according to Figure 1 , Fig. 9 , Fig.15 and Fig.16 The prestressed vibration damping block 110 is provided with a longitudinal anchoring groove 132 opened radially inwardly in its central region, and the longitudinal anchoring groove 132 as a whole constitutes a rectangular cavity extending along the length direction of the tunnel, wherein the longitudinal prestressed steel strand 131 of the longitudinal prestressed channel 130 from the longitudinal common block 116 is used to be fixed. In particular, after the end of the longitudinal prestressed steel strand 131 is mechanically anchored, concrete is filled in the longitudinal anchoring groove 132 constituting the rectangular cavity to form an axial anchoring concrete 123e, thereby completing the load-bearing end of the longitudinal prestressed system 103 in the tunnel length direction that exerts a pretightening effect in the longitudinal direction.

[0096] according to Fig. 9The longitudinal anchoring groove 132 is provided with at least one channel which also serves as the longitudinal prestressing channel 130 in the tunnel length direction, and the channel is also formed with a longitudinal female joint 140a and a longitudinal male joint 140b at the end of the tunnel length. The longitudinal joint 140 formed by the longitudinal female joint 140a and the longitudinal male joint 140b enables the longitudinal prestressing channel 130 of the prestressed vibration damping block 110 to receive the longitudinal prestressing steel strand 131 passed through the longitudinal prestressing channel 130 of the longitudinal common block 116 and fix it in the longitudinal anchoring groove 132 of the prestressed vibration damping block 110, thereby forming a longitudinal prestressing system 103 with the two prestressed vibration damping blocks 110 located at the end as the longitudinal anchoring blocks 117 in the tunnel length direction and the plurality of prestressed vibration damping blocks 110 between them as the longitudinal common blocks 116.

[0097] like Figure 2 As shown, the prestressed vibration damping blocks 110, which are the longitudinal common blocks 116 and the longitudinal anchoring blocks 117, are provided with two sets of sleeper grooves 115 on the radial inner surface facing the inner side of the tunnel for laying and positioning sleepers. Figure 2 In the top view of , each sleeper groove 115 is a rectangle having a greater length in the circumferential direction; Figure 1 In the side cross-sectional view, each sleeper groove 115 has a flat bottom and a depth less than the longitudinal anchor groove 132. These sleeper grooves 115 are arranged on the radial inner surface of each prestressed vibration damping block 110 in a manner of pairing two by two in the circumferential direction and aligning with each other in the length direction; and the longitudinal anchor groove 132, which is also rectangular, is positioned between the sleeper grooves 115 that are paired two by two in the circumferential direction and has a significantly greater depth. The aforementioned "at least one channel as the longitudinal prestressed channel 130" is opened in the area of ​​the longitudinal anchor groove 132 that is deeper than the sleeper groove 115, so that the longitudinal prestressed channel 130 in the prestressed vibration damping block 110 as the longitudinal anchor block 117 is closer to the annular prestressed channel 120 of the prestressed vibration damping block 110, especially compared to the inner surface of the tunnel. However, the longitudinal prestressed channel 130 of the prestressed vibration damping block 110 is still spaced apart from the annular prestressed channel 120.

[0098] In addition, if Figure 2 As shown, a longitudinal cavity 133 is also provided below the sleeper groove 115 and passes through a plurality of prestressed vibration damping blocks 110, which is used for laying equipment pipelines in the tunnel, protecting the pipelines and making the tunnel beautiful. Preferably, an inspection port can be provided at a certain interval in the longitudinal cavity 133 for later pipeline maintenance.

[0099] In such Figure 8 and Fig. 9In the illustrated prestressed vibration damping block 110, two longitudinal cavities 133 are symmetrically arranged on both sides of the longitudinal prestressed channel 130 about the longitudinal center line of the prestressed vibration damping block 110. The longitudinal cavity 133 is substantially at the same buried depth as the longitudinal prestressed channel 130, but is spaced apart from the annular prestressed channel 120.

[0100] Preferably, Fig.15 and Fig.16 The schematic diagram of the connection method of the longitudinal prestressed steel bundle 131 is shown. The longitudinal prestressed channel 130 is a straight channel. The longitudinal prestressed steel bundle 131 is composed of multiple steel strands and does not require special design. Preferably, after one longitudinal anchor group is assembled, the whole bundle is threaded through the longitudinal anchor groove 132 on one side and then through the longitudinal anchor groove 132 on the other side. After the shuttle is completed, tensioning is immediately performed on one side to connect the longitudinal anchor group as a whole. Preferably, in order to achieve prestressing of the entire longitudinal section, the longitudinal prestressed steel bundle 131 can be connected in the longitudinal anchor groove 132, and a connecting anchor plate 160 or a common anchor plate 163 plus a single-hole connector 164 can be selected to connect the longitudinal prestressed steel bundle 131 of the subsequent longitudinal anchor group.

[0101] Preferably, the connection of the connecting anchor plate refers to the use of the connecting anchor plate 160 as the common anchor plate of the preceding longitudinal anchor group and the succeeding longitudinal anchor group, the preceding longitudinal prestressed steel bundle 131 is fixed to the middle anchor hole of the connecting anchor plate 160 by the clamp 161, and the succeeding longitudinal prestressed steel bundle 131 is fixed to the outer ring anchor hole of the connecting anchor plate 160 by the clamp 161. Preferably, the connection of the common anchor plate plus the single-hole connector refers to the use of the common anchor plate 163 as the anchor plate of the preceding longitudinal anchor group, and the preceding longitudinal prestressed steel bundle 131 is fixed by the clamp 161, and the succeeding longitudinal prestressed steel bundle 131 is connected to the preceding longitudinal prestressed steel bundle 131 by the wire dividing plate 165 and the single-hole connector 164. Preferably, the exposed prestressed parts in the longitudinal anchor groove 132 of the two connection methods are protected by the protective cover 162.

[0102] Example 4

[0103] This embodiment is a further improvement and / or replacement of the above-mentioned embodiment, and the repeated contents are not repeated here. The features described here can be used in each of the above-mentioned embodiments as long as these features do not contradict each other.

[0104] Since the configuration of the annular prestressed steel bundle 121 inside the prestressed pipe ring 101 can be in the form of an approximate circular ring or a partial circular ring, this configuration makes the tensile force line generated by the steel bundle roughly coincide with the position of the circular annular prestressed channel 120 connecting all the pipe segments in the prestressed pipe ring 101. For the convenience of description, the force line that coincides with the annular prestressed steel bundle 121 and the annular prestressed channel 120 can be defined as the middle prestressed ring 100. The middle prestressed ring 100 is located between the inner surface and the outer surface of each pipe segment block, close to the center area. According to the movement mode of the annular prestressed steel bundle 121, the middle prestressed ring 100 can present different forms: when the annular prestressed steel bundle 121 is arranged using the full-circle prestressed steel bundle 300a, the middle prestressed ring 100 is consistent in form with the arc direction of the prestressed pipe ring 101, forming a complete circular ring. When the annular prestressed steel strand 121 is arranged using a semi-circular prestressed steel strand 300b, the middle prestressed ring 100 will be presented as two arc segments, located at the upper and lower parts of the prestressed pipe ring 101, respectively, wherein the two ends of the upper arc segment are respectively connected to the branch channel connected to the annular anchor concrete 123b and the annular anchor concrete 123c and the connecting end of the annular prestressed duct 120; the two ends of the lower arc segment are respectively connected to the branch channel connected to the annular anchor concrete 123a and the annular anchor concrete 123d and the connecting end of the annular prestressed duct 120. The shape of the middle prestressed ring 100 reflects the distribution position of the main prestress of the annular prestressed steel strand 121 when the prestressed pipe ring 101 is tensioned, so it can be used to describe the stress situation of the prestressed pipe ring 101 under normal conditions.

[0105] Preferably, the tension lines of the annular prestressed steel strand 121 at its two ends do not overlap with the middle prestressed ring 100. The annular anchoring concrete 123d is taken as an example to illustrate the force direction of the annular prestressed steel strand 121 at its two ends. Figure 1 As shown, the force direction of the annular prestressed steel strand 121 is consistent with the normal direction of the end surface of the annular anchor concrete 123d connected thereto. Figure 1It is manifested as a downward inclined tension. The point of action of the tension is located near the center point of the end face of the annular anchor concrete 123d, and the point of action is closer to the center position of the prestressed pipe ring 101 than the middle prestressed ring 100. With the center point of the prestressed pipe ring 101 as the center of the circle and the distance between the point of action and the center point as the radius, a circle can be defined, which connects the annular anchor concrete 123a, the annular anchor concrete 123b, the annular anchor concrete 123c and the annular anchor concrete 123d. For the convenience of description, this virtual circle is defined as the inner prestressed ring 400. The inner prestressed ring 400 is an area defined by the tension lines of the annular prestressed steel bundle 121. When the annular prestressed steel bundle 121 applies tension, its lines of force act on the end positions such as the annular anchor concrete 123d, and the directions of these lines of force and the corresponding force points are interrelated. From the perspective of the force direction, the tension lines of the annular prestressed steel strand 121 at its two ends do not coincide with the middle prestressed ring 100, but are biased inward, forming a state tangent to the inner prestressed ring 400. In particular, the force direction of the annular anchoring concrete 123d is consistent with its normal direction, and the point of action of the tension is close to the center of the prestressed pipe ring 101. This means that, through the distribution of the force lines, a virtual circle defined by the stress state can be formed between the middle prestressed ring 100 and the inner surface of the prestressed pipe ring 101, namely the inner prestressed ring 400. Therefore, the inner prestressed ring 400 can be regarded as an area defined by the tension lines of the annular prestressed steel strand 121, and the stress state in this area is directly related to the prestress generated at the end of the annular prestressed steel strand 121. This design causes the tension distribution position of the annular prestressed steel strand 121 to shift inward, thereby affecting the geometric characteristics and stress conditions of the inner prestressed ring 400. The tension direction of the annular prestressed steel strand 121 is tangent to the inner prestressed ring 400, where Figure 1 As shown, the tension direction of the annular prestressed steel strand 121 at the annular anchor concrete 123a and the annular anchor concrete 123d is obliquely downward, while the tension direction of the annular prestressed steel strand 121 at the annular anchor concrete 123b and the annular anchor concrete 123c is obliquely upward.

[0106] Preferably, the prestressed steel strands will generate four tensile forces that are tangential to the inner prestressed ring 400 and have different directions at the four circumferential anchoring concretes 123 of the prestressed pipe ring 101. By vector decomposing the tensile force on the circumferential cross-sectional view of the prestressed pipe ring 101, two components can be obtained: one is the vertical component perpendicular to the upper surface of the prestressed vibration damping block 110 (that is, perpendicular to the axial anchoring concrete 123e), and the other is the transverse component pointing to the outside of the prestressed pipe ring 101 (that is, away from its center). Based on the directions and points of action of the longitudinal and transverse components, two imaginary isosceles triangles can be constructed inside the prestressed pipe ring 101. As shown in FIG. Fig.23As shown, these two triangles are inscribed in the inner prestressed ring 400 to describe the force distribution state of the end of the annular prestressed steel strand 121 in the prestressed pipe ring 101. Among them, the vertices of the first isosceles triangle are set as follows: the first vertex is the axial anchoring concrete 123e located on the prestressed vibration damping block 110 at the bottom of the prestressed pipe ring 101; the second vertex and the third vertex correspond to the annular anchoring concrete 123a and the annular anchoring concrete 123d on the prestressed anchoring blocks 111 on both sides of the prestressed vibration damping block 110, respectively. The second isosceles triangle has the same first vertex as the first isosceles triangle, and its second vertex and the third vertex correspond to the annular anchoring concrete 123b and the annular anchoring concrete 123c on the prestressed anchoring blocks 111 on both sides of the prestressed vibration damping block 110, respectively. For the convenience of explanation, the line between the second vertex and the third vertex constitutes the first chord, the line between the first vertex and the second vertex (or the third vertex) is defined as the second chord (or the third chord), the angle between the first chord and the second chord (or the third chord) is defined as β, and the angle between the second chord and the third chord is defined as α.

[0107] Preferably, if Fig.23 As shown in FIG. 1 , in the geometric configuration of two isosceles triangles, the vertex angle α of the first isosceles triangle is set to 100°, and the base angle β is set to 40°; the vertex angle α of the second isosceles triangle is set to 90°, and the base angle β is set to 45°. The end force of the prestressed steel cable can be equivalent to a virtual third isosceles triangle located between the two isosceles triangles, as shown in FIG. Fig.23The middle triangle shown. The shape of this third isosceles triangle will change slightly with the change of the load on the prestressed pipe ring 101, and its change rule is: the first vertex is fixed, and the second vertex and the third vertex move clockwise or counterclockwise along the inner prestressed ring 400 respectively. For example, in a shield tunnel, when a train enters the section where the prestressed pipe ring 101 is located, the radial downward pressure generated by the train operation will cause the third isosceles triangle to undergo the following changes: the second vertex moves counterclockwise along the inner prestressed ring 400, and the third vertex moves clockwise. This change causes the α angle to decrease due to structural deformation, tending to the α angle value of the second isosceles triangle; at the same time, the β angle increases accordingly, tending to the β angle value of the second isosceles triangle. This change reflects the increase in the tension of the prestressed steel cable. On the contrary, when the train leaves, the α angle value of the third isosceles triangle increases, the β angle value decreases, and it can be restored to its original shape, which indicates that the tension of the prestressed steel cable is reduced. The third isosceles triangle is synthesized by the equivalent forces of the first and second isosceles triangles. At the same time, the first and second isosceles triangles also limit the variation range of the third isosceles triangle: the variation range of angle α is, for example, between 90° and 100°, and the variation range of angle β is, for example, between 40° and 45°. By controlling the variation of angles α and β of the third isosceles triangle within a specific angle range, the prestressed pipe ring 101 can give full play to the compressive properties of concrete and reduce structural deformation, thereby making the structural stress more reasonable. This design gives the structure higher overall stiffness and better anti-deformation ability, so that the overall vibration-damping prestressed shield tunnel structure provided by the present invention has higher stability.

[0108] Example 5

[0109] This embodiment is a further improvement and / or replacement of the above-mentioned embodiment, and the repeated contents are not repeated here. The features described here can be used in each of the above-mentioned embodiments as long as these features do not contradict each other.

[0110] like Figure 20 to Figure 22 As shown, the present invention also provides a construction method for an integral vibration-damping prestressed shield tunnel structure, the construction method comprising:

[0111] S1: prefabricated prestressed vibration damping blocks 110 , prestressed anchoring blocks 111 , prestressed adjacent blocks 112 , prestressed capping blocks 113 and prestressed standard blocks 114 .

[0112] Preferably, if Figure 10 to Figure 14As shown in 20, a special mold is prepared according to the design parameters of the prestressed vibration damping block 110, the prestressed anchor block 111, the prestressed adjacent block 112, the prestressed capping block 113 and the prestressed standard block 114, and the steel cage is tied, and the annular prestressed channel 120 is bent according to the design requirements. Preferably, before the segment is cast in blocks, the steel cage is first placed in the mold, and then the anchor plate 124 and the spiral rib 155 are placed at the straight channel 129 and the longitudinal anchor groove 132. The anchor plate 124 is connected to the mold with bolts, and then the annular prestressed channel 120 and the longitudinal prestressed channel 130 are inserted and fixed. Magnetic flux sensors can also be installed on the prestressed channels at specific positions according to monitoring requirements. Finally, ordinary concrete or steel fiber concrete is cast and cured.

[0113] Preferably, in the present invention, each segment block is prefabricated in the segment factory to ensure the quality and accuracy of the segment structure. The setting of prestressed protective steel bars can avoid damage to the structure caused by prestress. The installation of magnetic flux sensors can monitor the loss of circumferential and longitudinal prestress for a long time, understand the stress state of the shield tunnel structure, and the prestress monitoring data can also be used as a basis for subsequent prestress cable replacement. At the same time, the segments of the prestressed vibration damping block 110 are prefabricated as a whole with the ballast structure, which reduces the multiple pouring processes of the existing structure, is simple to construct, has high construction quality, and reduces the vibration of trains in tunnel operation, solves the problem of ballast and tunnel structure separation, and greatly reduces the cost of later operation and maintenance.

[0114] S2: Each segment is assembled into a prestressed pipe ring 101 according to design requirements, and annular prestress is applied through annular prestressing system 102. Multiple prestressed pipe rings 101 are combined into a longitudinal anchoring group by applying longitudinal prestress through longitudinal prestressing system 103.

[0115] Preferably, if Fig.21 As shown, the prestressed cable threading equipment and tensioning equipment are placed near the shield assembly machine and move with the shield. Preferably, the complete set of segment blocks, annular prestressed steel bundles 121, and longitudinal prestressed steel bundles 131 required for assembling the prestressed pipe ring 101 are transported to the vicinity of the shield assembly machine by the muck truck. After each ring of the shield is excavated, the segment is assembled at the shield tail using the through-seam assembly process. First, the shield assembly machine grabs the prestressed vibration damping block 110 and installs it at the bottom of the tunnel structure; then, grabs two prestressed anchor blocks 111 and places them on both sides of the prestressed vibration damping block 110, and positions and fixes them through the pins of the longitudinal seam. The anchoring ends of the two prestressed anchor blocks 111 are not in the same plane; then, grabs two prestressed adjacent blocks 112 and connects them to the two prestressed anchor blocks 111 respectively, and ensures that the inclined surfaces of the longitudinal seams are opposite; finally, the prestressed capping block 113 is installed at the top of the tunnel structure and matches the inclined surface of the prestressed adjacent block 112.

[0116] Preferably, the prestressed capping block 113 is located at the top of the tunnel structure, and a grouting hole 141 is provided on one side of the outer arc surface in the middle of each annular prestressed channel 120, that is, the grouting hole 141 faces upward after the prestressed pipe ring 101 is assembled. Preferably, the grouting hole 141 is connected to the exhaust pipe 142, and the other end of the exhaust pipe 142 is led out from the inner arc surface of the pipe segment and connected to the valve 143. Preferably, the grouting hole 141 can adopt G3 / 4 pipe thread, and the exhaust pipe 142 can adopt a steel wire hose with internal threads at both ends. Preferably, when grouting the channel, the valve 143 is opened, and the slurry is injected from the grouting hole of the (annular) anchor plate 124, and the slurry is discharged from the valve 143 after the channel is filled with the slurry. Preferably, if the non-bonded prestressed tensioning method is adopted, the grouting hole 141 and other supporting equipment may not be provided.

[0117] Preferably, for shield tunnels with more than 6 segments of the prestressed pipe ring 101, prestressed standard blocks 114 can be added according to design requirements to connect other segments, but the prestressed segments after assembly should be symmetrical, and the prestressed anchor blocks 111 should be located near the pedestrian passage of the shield machine to facilitate the placement and tensioning of the cable threading and tensioning equipment. Preferably, the annular prestressed steel bundle 121 includes a steel bundle body 125, a traction steel bundle 126 and a conical steel cap 127, wherein the steel bundle body 125 is composed of a plurality of steel strands, and the length is the length of the tunnel plus the reserved length required for tensioning; the traction steel bundle 126 is a longer steel strand extending from the middle of the steel bundle body 125; and the conical steel cap 127 is sleeved at the transition between the steel bundle body 125 and the traction steel bundle 126.

[0118] Preferably, after the segments are assembled into the prestressed pipe ring 101 according to the design requirements, the construction of the annular prestressed system 102 is immediately carried out. Preferably, the construction of the annular prestressed system 102 can be carried out before the segments are out of the shield tail, and it can be carried out by taking advantage of the time gap between the shield slag discharge and the excavation of the next ring. Preferably, the annular prestressed steel bundle 121 is threaded by a cable threading machine using a single traction and overall pushing method, that is, the cable threading machine first inserts the traction steel bundle 126 from one side of the annular anchor platform 118, and then passes out from the other side of the annular anchor platform 118 after a circle around the prestressed pipe ring 101, and then pulls the traction steel bundle 126 while pushing the steel bundle body 125 to complete the threading. Preferably, after the threading of the annular prestressed steel bundles 121 of multiple channels is completed, the tensioning equipment is immediately used for bidirectional synchronous graded tensioning, and the segments are connected into an integral prestressed pipe ring 101 by the annular prestressing.

[0119] Preferably, when assembling the shield longitudinal prestressed pipe ring 101, the bottom prestressed vibration damping block 110 can be assembled with the longitudinal anchor block 117, multiple longitudinal common blocks 116 and longitudinal anchor block 117 in sequence according to the design requirements to form a longitudinal anchor group. Preferably, after assembling one longitudinal anchor group, the whole bundle cable is passed through the longitudinal anchor groove 132 on one side and then passed out from the longitudinal anchor groove 132 on the other side. After the shuttle is completed, the bidirectional synchronous graded tensioning method is immediately used to connect the multiple prestressed pipe rings 101 as a whole through the longitudinal prestress.

[0120] Preferably, in the present invention, the segments are connected in blocks into an integral structure through the annular prestressing system 102 and the longitudinal prestressing system 103, which effectively improves the overall stiffness and deformation resistance of the tunnel structure, avoids various defects such as leakage, cracking, and settlement of the traditional segment structure, and greatly reduces the amount of steel bars. At the same time, the prestressed anchor ends are arranged on both sides of the tunnel structure, which can make the annular prestress distribution of the tunnel structure more uniform. Preferably, the prestressed vibration damping block 110 is arranged at the bottom of the tunnel structure, and the sleeper groove 115 above it is convenient for track laying during shield construction and before operation, and the flat bottom surface is convenient for setting up pedestrian walkways. The longitudinal prestressed anchor end is arranged at the bottom of the larger tunnel structure, which is convenient for construction and application of greater longitudinal prestress, and the longitudinal connection is composed of a pin and prestressed tendons, similar to a beam structure, which can greatly improve the overall longitudinal performance.

[0121] S3: After the tunnel is through or the shield is excavated for a certain distance, the hole grouting and anchor groove filling are carried out to finally form an overall vibration-damping prestressed shield tunnel structure. When the segment reaches the design life or the prestress loss exceeds the design requirements, the tunnel structure can be extended in service life by reserving the hole for post-tensioning and reserving the same hole position for reusing the service hole.

[0122] Preferably, if Fig. 22As shown, the segment structure can withstand the water and soil loads during the shield construction after the prestressing construction is completed. At the same time, considering the limited operating space of the shield tail of the shield machine, the hole grouting and anchor groove filling are arranged to be carried out uniformly after the tunnel is opened or the shield is excavated for a certain distance. Preferably, the hole grouting is mainly for the bonding tensioning method, and the non-bonding tensioning method does not need to perform this operation. The anchor groove is filled with anchoring concrete 123a, 123b, 123c, 123d, and 123e. These anchoring concretes can be selected from low-grade plain concrete, self-compacting concrete and other cementitious materials that are easy to chisel. When the segment reaches the design life or the prestress loss is monitored to exceed the design requirements, the reserved hole can be tensioned and the cable can be replaced at the same hole position according to the bonding or non-bonding tensioning method adopted by the prestressing system. When there are four annular prestressed channels 120, the method of post-tensioning after reserving channels can be adopted. First, the annular sealing and anchoring concrete 123a, 123b, 123c, and 123d are chiseled out, and then the two reserved channels in the middle are tensioned with bonded steel strands. After the tensioning is completed, the channels are grouted and the anchor grooves are refilled. When there are three annular prestressed channels 120, the method of replacing cables in the same hole position of the reserved reused service hole can be adopted. First, the annular sealing and anchoring concrete 123a, 123b, 123c, and 123d are chiseled out, and then the prestressed steel strands of the middle service hole are tensioned, and then the non-bonding method is used to replace the prestressed steel strands on both sides in turn, and finally the prestressed steel strands in the middle channel are removed for reuse later.

[0123] Preferably, the longitudinal prestressing system 103 has two longitudinal prestressing channels 130, and the method of pre-reserving the channels for post-tensioning and replacing the cables at the same hole position is similar to that of the annular prestressing system 102. In the present invention, the anchoring concrete 123a, 123b, 123c, and 123d of the prestressed anchor block 111 can be pre-buried during construction for the later auxiliary pipeline construction and laying of the required components, which is convenient for construction and does not weaken the structure. The service life of the tunnel structure can be effectively extended by pre-reserving the channels for post-tensioning and replacing the cables at the same hole position.

[0124] It should be noted that the above-mentioned specific embodiments are exemplary, and those skilled in the art can come up with various solutions inspired by the disclosure of the present invention, and these solutions also belong to the disclosure scope of the present invention and fall within the protection scope of the present invention. Those skilled in the art should understand that the present invention specification and its drawings are illustrative and do not constitute a limitation of the claims. The scope of protection of the present invention is defined by the claims and their equivalents. The present invention specification contains multiple inventive concepts, such as "preferably" or "according to a preferred embodiment", which means that the corresponding paragraph discloses an independent concept, and the applicant reserves the right to file a divisional application based on each inventive concept. Throughout the text, the features guided by "preferably" are only an optional method and should not be understood as a must-have setting. Therefore, the applicant reserves the right to abandon or delete the relevant preferred features at any time.

Claims

1. An integral vibration-damping prestressed shield tunnel structure, comprising a prestressed pipe ring (101) and a prestressed system, characterized in that: The prestressed pipe ring (101) comprises a prestressed vibration damping block (110) located at the bottom of the tunnel structure, and prestressed anchoring blocks (111) located at both sides of the prestressed vibration damping block (110). The prestressed pipe ring (101) is assembled from a plurality of pipe segments, and annular prestress is applied by the annular prestressing system (102). After the plurality of prestressed pipe rings (101) are assembled, longitudinal prestress is applied through a longitudinal prestressing system (103). After the tunnel is completed or the shield is excavated for a certain distance, grouting of the channel and filling of the anchor groove are carried out to form an overall vibration-damping prestressed shield tunnel structure.

2. The integral vibration-damping prestressed shield tunnel structure according to claim 1 is characterized in that: For a large-diameter shield tunnel in which the segment blocks of the prestressed pipe ring (101) exceed 6, a prestressed standard block (114) for connecting other segment blocks can be added according to design requirements, and the size of each segment block can be adjusted according to the arrangement of the prestressed anchor block (111), wherein the prestressed anchor block (111) is an arc-shaped structure, a plurality of annular prestressed channels (120) are arranged in the middle of the longitudinal section, and an annular anchor platform (118) for tensioning is arranged in the middle of the inner arc surface.

3. The integral vibration-damping prestressed shield tunnel structure according to claim 1 or 2, characterized in that: The annular anchoring platform (118) is provided with a straight channel (129) and a variable curvature channel (128) connected to the annular prestressed channel (120), and a tensioning groove (119) is provided at the channel port, wherein the internal channel of the annular anchoring platform (118) is led out from the tensioning grooves (119) at both ends in a cross manner.

4. The integral vibration-damping prestressed shield tunnel structure according to any one of claims 1 to 3, characterized in that: When four annular prestressed channels (120) are provided, two annular prestressed channels (120) on one side are through holes, and the middle of the two annular prestressed channels (120) on the other side is the annular anchoring platform (118); When three annular prestressed channels (120) are provided, one of the annular prestressed channels (120) on one side is a through hole or has the annular anchoring platform (118) in the middle, and the two annular prestressed channels (120) on the other side have the annular anchoring platform (118) or a through hole in the middle.

5. The integral vibration-damping prestressed shield tunnel structure according to any one of claims 1 to 4, characterized in that: The prestressed vibration damping block (110) is an integral prefabricated component of an arc-shaped segment structure and a ballast bed structure, two rows of sleeper grooves (115) are arranged on the inner arc surface, a longitudinal cavity (133) for pipeline laying is arranged below the sleeper groove (115), and a plurality of annular prestressed channels (120) and a plurality of longitudinal prestressed channels (130) are arranged inside the prestressed vibration damping block (110).

6. The integral vibration-damping prestressed shield tunnel structure according to any one of claims 1 to 5, characterized in that: The annular prestressed system (102) is formed in the following manner: a traction steel bundle (126) is inserted from one side of the annular anchoring platform (118), and after circling the prestressed pipe ring (101), it is inserted from the other side of the annular anchoring platform (118), and then the traction steel bundle (126) is pulled while the steel bundle body (125) is pushed to complete the cable threading, and finally a bidirectional synchronous graded tensioning method is adopted.

7. The integral vibration-damping prestressed shield tunnel structure according to any one of claims 1 to 6, characterized in that: The prestressed anchor block (111) is provided with annular anchoring concrete (123a, 123b, 123c, 123d) for fixing the end of the prestressed steel bundle, wherein the annular prestressed hole (120) provided in the segment block is formed with a branch channel near the inner surface or outer surface of the segment block where it is located, the branch channel is connected to the annular prestressed hole (120), and the annular anchoring concrete (123a, 123b, 123c, 123d) is filled at the end of the branch channel.

8. The integral vibration-damping prestressed shield tunnel structure according to any one of claims 1 to 7, characterized in that: The upper surface of the prestressed vibration damping block (110) forms a rail sleeper, and the lower surface thereof is bent downward. At least one annular prestressed hole (120) is provided inside the prestressed vibration damping block (110), and the annular prestressed hole (120) is consistent with the arc-shaped bending direction of the lower surface of the prestressed vibration damping block (110). Axial anchoring concrete (123e) is provided inside the prestressed vibration damping block (110). The axial anchoring concrete (123e) is located in the annular prestressed channel (120) near the middle of the upper surface of the prestressed vibration damping block (110) and protrudes toward the lower surface, and is used to stretch the axial steel cable of the prestressed pipe ring (101).

9. A construction method for an integral vibration-damping prestressed shield tunnel structure, characterized in that: It includes: Prefabricated prestressed vibration-damping blocks (110), prestressed anchoring blocks (111), prestressed adjacent blocks (112) and prestressed capping blocks (113); The prestressed vibration damping block (110) is arranged at the bottom of the tunnel structure, the prestressed anchoring block (111) is arranged on both sides of the prestressed vibration damping block (110), the prestressed adjacent block (112) is connected to the prestressed anchoring block (111), and the prestressed capping block (113) is arranged at the top of the tunnel structure to assemble a prestressed pipe ring (101), and then an annular prestress is applied through the annular prestressing system (102), and after the assembly of multiple prestressed pipe rings (101) is completed, longitudinal prestress is applied through the longitudinal prestressing system (103); After the tunnel is completed or the shield is excavated for a certain distance, grouting of the channel and filling of the anchor groove are carried out to finally form an overall vibration-damping prestressed shield tunnel structure. During operation, the service life of the tunnel structure can be extended by reserving channel post-tensioning and reserving cable replacement methods at the same hole position of the service hole for reuse.

10. A method for extending the service life of the integral vibration-damping prestressed shield tunnel structure according to any one of claims 1 to 8, characterized in that: The method is realized by post-tensioning the reserved channel and replacing the cable at the same hole position of the reserved reused service hole, including the following steps: The method of implementation is determined by the type of tensioning method used in the prestressing system, among which, When the number of the annular prestressed ducts (120) is 4, the prestressed system adopts a bonding tensioning method and performs a post-tensioning method of pre-reserving ducts; When the number of annular prestressed ducts (120) is set to 3, the prestressed system adopts a non-bonded tensioning method and implements a cable replacement method for the same hole position of a reserved and reused service hole.

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