Prestress bolt type shield segment and segment joint thereof

Abstract

The utility model relates to a prestressing bolt type shield segment and a segment joint thereof, the segment joint comprises a prestressing tenon type joint and a prestressing mortise type joint, the end part of the prestressing tenon type joint is provided with a tenon, and a first prestressing duct penetrating through the prestressing tenon type joint and the tenon is arranged in the prestressing tenon type joint; a concave mortise is arranged at the end of the prestress mortise type connector, a second prestress hole channel penetrating through the prestress mortise type connector and the concave mortise is formed in the prestress mortise type connector, and under the condition that the tenon and the concave mortise are positioned in a matched mode, the first prestress hole channel and the second prestress hole channel are communicated and form a complete prestress hole channel. The complete prestressed ducts are used for injecting grouting materials, so that the first prestressed ducts are connected with the second prestressed ducts. Extra axial force is provided for the segment joint by applying prestress, so that on one hand, the positioning precision, the splicing efficiency and the shearing resistance of the segment joint are effectively improved; on the other hand, prestress is applied to enable the connector to be in a pressed state, and integrity and deformation resistance of the connector are improved.

Description

Technical Field

[0001] The utility model relates to the technical field of shield tunnels, in particular to a prestressed pin-type shield segment and a segment joint thereof. Background Art

[0002] The current shield tunnel structure is a non-continuous structure composed of multiple shield segments connected by bolts and other connectors. It needs to rely on the surrounding rock load around the tunnel to form a stable structural system. However, the strength of the shield segment connection bolts is limited, and they are prone to rust in the humid tunnel environment, resulting in defects such as low overall stiffness and weak deformation resistance of the shield segment structure. The segment joints are often equipped with a waterproof structure on the water-facing side, which is prone to leakage after structural deformation. In addition, construction adjacent to the tunnel will also change the original load distribution of the tunnel structure, aggravating structural deformation and cracking. These problems will cause diseases in the tunnel structure and affect the safe and stable operation of the tunnel.

[0003] The patent document with the announcement number CN215170041U discloses a pin-type shield pipe connector and a shield pipe. The shield pipe includes a first shield pipe, a second shield pipe and the connector described above. Both ends of the first shield pipe and the second shield pipe are respectively pre-embedded with pre-embedded sleeves and pre-embedded fasteners, and bolts are inserted into the pre-embedded sleeves; the first shield pipe is inserted into the pre-embedded fastener of the second shield pipe through the bolts to achieve a detachable connection between the first shield pipe and the second shield pipe. Although the connector can achieve an effective connection between the shield pipes and make the connection between the shield pipes firm, the waterproof effect of the connector is poor.

[0004] The existing prestressed shield tunnel structure may have many defects during operation. On the one hand, the waterproof structure of the shield segment has not been changed, and there is still the problem of water leakage at the joints after the shield segment structure is deformed; on the other hand, it is impossible to prevent the leakage of water from the segment joints into the prestressed duct, and it is also impossible to prevent the slurry from seeping out from the end of the prestressed duct during grouting of the duct. In the long-term operation of the tunnel structure, it is easy to cause corrosion of the prestressed steel bundles, accelerate the loss of prestress, and affect the bearing capacity and safety of the tunnel structure.

[0005] In addition, the loads borne by the shield tunnel structure include water and soil loads, train vibration loads, external disturbance loads, etc. When the external load changes, it is easy to cause uneven stress on the shield segments and deformation, which will lead to problems such as rupture and water leakage. On the one hand, the deformation of the shield segments will cause the prestress value of the prestressed steel bundles in the prestressed channel to change, and even cause the prestressed steel bundles to break, causing accidents; on the other hand, the leakage water will gradually corrode the concrete and enter the prestressed channel, causing the prestressed steel bundles to rust, reducing the strength and prestress value of the prestressed steel bundles, and affecting the durability and safety of the tunnel structure.

[0006] The shield tunnel structure is assembled from multiple shield segments, and there are many shield segment joints. Prestressed steel strands cannot be constructed using the pre-tensioning method like cast-in-place structures. Prestressed steel strands must be prestressed by laying prestressed channels in the shield segments and threading and tensioning them after assembly. However, the amount of prestress applied to the prestressed steel strands is determined by the construction personnel based on their work experience, which makes the construction effect related to the construction experience, resulting in unstable construction results.

[0007] As shown above, how to make the contact parts between the shield segments waterproof, prevent water leakage from entering the prestressed duct, and at the same time determine the prestress value of the prestressed steel strands is a problem that needs to be solved.

[0008] In addition, on the one hand, there are differences in understanding among technical personnel in this field; on the other hand, the applicant studied a large number of documents and patents when making the present utility model, but due to space limitations, not all details and contents are listed in detail. However, this does not mean that the present utility model does not have the characteristics of these prior arts. On the contrary, the present utility model already has all the characteristics of the prior art, and the applicant reserves the right to add relevant prior art to the background technology. Utility Model Content

[0009] The existing prestressed shield tunnel structure may have many defects during operation. On the one hand, the waterproof structure of the shield segment has not been changed, and there is still the problem of water leakage at the joints after the shield segment structure is deformed; on the other hand, it is impossible to prevent the leakage of water from the joints of the shield segment from entering the prestressed channel, and it is also impossible to prevent the slurry from seeping out from the end of the prestressed channel during grouting of the channel. The long-term operation of the tunnel structure is prone to corrosion of the prestressed steel bundles, accelerating the loss of prestress, and affecting the bearing capacity and safety of the tunnel structure.

[0010] Prestressed steel strands cannot be constructed using the pre-tensioning method like cast-in-place structures. Prestress must be applied by laying prestressed channels in the shield segments and threading and tensioning them after assembly. However, the amount of prestress applied to the prestressed steel strands is determined by the construction personnel based on their work experience, which makes the construction effect related to the construction experience, resulting in unstable construction results.

[0011] In view of the deficiencies in the prior art, the utility model provides, from a first aspect, a prestressed pin-type shield segment joint, including a prestressed tenon-type joint and a prestressed mortise-type joint, wherein a convex tenon is arranged at the end of the prestressed tenon-type joint, and a first prestressed channel penetrating the prestressed tenon-type joint and the convex tenon is arranged inside the prestressed tenon-type joint, and a concave mortise is arranged at the end of the prestressed mortise-type joint, and a second prestressed channel penetrating the prestressed mortise-type joint and the concave mortise is arranged inside the prestressed mortise-type joint, when the convex tenon and the concave mortise are positioned in a matching manner, the first prestressed channel and the second prestressed channel are connected to form a complete prestressed channel, and the complete prestressed channel is used for injecting grouting material, thereby connecting the first prestressed channel and the second prestressed channel.

[0012] The prestressed holes in the segment joints make the connection between the tenon and the mortise more stable after the slurry is injected, and the prestressed holes can withstand stronger prestress.

[0013] According to a preferred embodiment, a prestressed steel bundle is further included. When the prestressed mortise joint and the prestressed mortise joint are assembled, before the grouting material is injected, the prestressed steel bundle runs through the first prestressed channel and the second prestressed channel and is arranged in a tensioning manner. The prestressed steel bundle is arranged in each prestressed channel so that each shield segment is connected together, and each prestressed channel can improve the stress bearing capacity.

[0014] According to a preferred embodiment, the end of the prestressed tenon joint provided with the convex tenon includes a steel fiber casting, and the end of the prestressed mortise joint provided with the concave tenon includes a steel fiber casting, and when the convex tenon and the concave tenon are inserted and connected, the two steel fiber castings are arranged oppositely and in contact. Steel fiber concrete is superior to ordinary concrete in many aspects such as compressive strength, tensile strength, crack resistance, and durability. By casting steel fiber concrete at the joint of the convex tenon and the concave tenon and forming a steel fiber casting, the mechanical properties of the connector of the shield segment can be effectively improved, and at the same time, the use of ordinary concrete in other parts of the shield segment can reduce the preparation cost.

[0015] According to a preferred embodiment, when the prestressed tenon joint and the prestressed mortise joint are assembled, the axes of the first prestressed hole and the second prestressed hole are on the same line, or the axes of the first prestressed hole and the second prestressed hole are approximately on the same line. This arrangement can improve the shear resistance of the connector.

[0016] According to a preferred embodiment, at least one first sealing groove is provided at the end of the prestressed tenon joint near the water-facing surface and the back-facing surface, and at least one first sealing groove is provided at the end of the prestressed mortise joint near the water-facing surface and the back-facing surface, respectively, and a first sealing gasket is provided in the first sealing groove. Providing sealing grooves and sealing gaskets at the end of the shield segment near the water-facing surface and the back-facing surface, respectively, can bring about a better waterproof effect.

[0017] According to a preferred embodiment, at least one second sealing groove is provided around the convex tenon in a circumferential manner, and at least one second sealing groove is provided around the concave tenon in a circumferential manner, and a second sealing gasket is provided in the second sealing groove. The second sealing gaskets on both sides are tightly fitted under the prestress of the prestressed steel bundle, which can effectively prevent leakage water from entering each prestressed channel through the plug and prevent slurry from leaking from the plug during grouting in each prestressed channel, thereby slowing down the corrosion of the prestressed steel bundle, reducing the loss of prestress in the operation stage, and enhancing the durability and safety of the pipe segment joint.

[0018] According to a preferred embodiment, a plurality of through holes are provided on the second sealing gasket to increase the elasticity of the gasket body, and a friction-reducing coating is provided on the extrusion surface of the second sealing gasket that does not contact the second sealing groove. The friction-reducing coating can effectively reduce the displacement of the two sealing gaskets caused by friction when the shield segments are assembled, increase their contact area, and improve the anti-seepage ability of the latch.

[0019] According to a preferred embodiment, at least one magnetic flux sensor is respectively arranged on the periphery of the first prestressed channel and the second prestressed channel to collect the prestress values ​​of the first prestressed channel and the second prestressed channel, and the data line of the magnetic flux sensor extends from the wiring slot on the back surface of the prestressed pin-type shield segment to facilitate connection with the receiver during construction and transmission of the prestress value. The magnetic flux sensor installed on the outer ring of the prestressed channel can be used to monitor the prestress of the prestressed steel strands during operation, so as to understand the health status of the segment joints.

[0020] The utility model provides a prestressed pin-type shield segment from a second aspect, comprising a segment body and a segment joint, the segment joint comprising a prestressed tenon-type joint and a prestressed mortise-type joint, a convex tenon being arranged at the end of the prestressed tenon-type joint, a first prestressed channel penetrating the prestressed tenon-type joint and the convex tenon being arranged inside the prestressed tenon-type joint, a concave mortise being arranged at the end of the prestressed mortise-type joint, a second prestressed channel penetrating the prestressed tenon-type joint and the concave mortise being arranged inside the prestressed mortise-type joint, when the convex tenon and the concave mortise are positioned in a manner matching each other, the first prestressed channel and the second prestressed channel are connected to form a complete prestressed channel, when the prestressed tenon-type joint and the prestressed mortise-type joint are assembled, before the grouting material is injected, the prestressed steel bundle penetrates the first prestressed channel and the second prestressed channel and is arranged in a tensioning manner.

[0021] The pipe segment of the utility model adopts a pin as a positioning and connecting member, and provides additional axial force to the pipe segment joint by applying prestress. In this way, on the one hand, the pin can effectively improve the positioning accuracy, assembly efficiency and shear resistance of the pipe segment joint; on the other hand, applying prestress can put the pipe segment joint in a compressed state, thereby improving the durability of concrete, the integrity of the joint and the deformation resistance.

[0022] According to a preferred embodiment, at least one magnetic flux sensor is respectively arranged on the periphery of the first prestressed channel and the second prestressed channel to collect the prestress values ​​of the first prestressed channel and the second prestressed channel, and the data line of the magnetic flux sensor extends from the wiring groove on the back water surface of the prestressed pin-type shield segment to facilitate connection with the receiver during construction and transmission of the prestress value.

[0023] The magnetic flux sensors can be used to monitor the prestress of the prestressed steel strands during operation, so as to understand the health status of the segment joints.

[0024] The utility model provides a prestressed pin-type shield segment joint from a third aspect, including a prestressed tenon-type joint and a prestressed mortise-type joint, wherein the prestressed tenon-type joint is provided with a first prestressed hole running through the prestressed tenon-type joint, and the prestressed mortise-type joint is provided with a second prestressed hole running through the prestressed tenon-type joint, and at least one magnetic flux sensor is respectively provided on the periphery of the first prestressed hole and the second prestressed hole to collect the prestress values ​​of the first prestressed hole and the second prestressed hole, and the data line of the magnetic flux sensor extends from the wiring slot on the back surface of the prestressed pin-type shield segment to facilitate connection with a receiver during construction and transmission of the prestress value. Prefabricating the magnetic flux sensor in the shield segment helps to realize the monitoring of the prestress value of the prestressed steel bundle.

[0025] According to a preferred embodiment, the segment joint further includes a prestressed steel bundle. When the prestressed tenon joint and the prestressed mortise joint are assembled, before the grouting material is injected, the prestressed steel bundle runs through the first prestressed channel and the second prestressed channel and is arranged in a tensioning manner; during the operation of the shield tunnel, the magnetic flux sensor sends the measured prestress value and its change of the prestressed steel bundle to an external receiver. Such an arrangement facilitates monitoring the prestress value and its change of the prestressed steel bundle after construction, and also facilitates monitoring the prestress value and its change of the prestressed steel bundle during construction.

[0026] According to a preferred embodiment, a convex tenon is provided at the end of the prestressed tenon-type joint, a first prestressed channel runs through the convex tenon, a concave tenon is provided at the end of the prestressed mortise-type joint, a second prestressed channel runs through the concave tenon, and when the convex tenon and the concave tenon are positioned in a matching manner, the first prestressed channel and the second prestressed channel are connected to form a complete prestressed channel, and the complete prestressed channel is used to inject grouting material, so that the first prestressed channel and the second prestressed channel are connected. With such a configuration, the prestressed channel in the shield segment makes the connection between the convex tenon and the concave tenon more stable after the grouting is injected, and the prestressed channel can withstand stronger prestress. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a front view of the prestressed pin-type shield segment joint structure provided by the utility model;

[0028] Figure 2 This is the AA section of the prestressed pin-type shield segment joint provided by the utility model;

[0029] Figure 3 It is the first tenon type of the BB section of the prestressed pin-type shield segment joint provided by the utility model;

[0030] Figure 4 It is the second tenon type of the BB section of the prestressed pin-type shield segment joint provided by the utility model;

[0031] Figure 5 It is a partial enlarged view of the AA section of the prestressed bolt-type shield segment joint provided by the utility model;

[0032] Figure 6 This is a structural schematic diagram of a second sealing pad provided by the utility model;

[0033] Figure 7 It is a structural schematic diagram of another second sealing gasket provided by the utility model;

[0034] Figure 8 It is a CC section of a structural schematic diagram of a second sealing gasket provided by the utility model;

[0035] Fig. 9 It is a schematic diagram of the axial force of the shield segment provided by the utility model;

[0036] Fig.10 It is a schematic diagram of the bending moment force of the shield segment provided by the utility model.

[0037] Reference numerals list

[0038] 101: prestressed mortise joint; 102: prestressed mortise joint; 103: steel fiber casting; 104: ordinary casting; 121: first sealing groove; 122: first sealing gasket; 123: second sealing groove; 124: second sealing gasket; 125: convex tenon; 126: concave mortise; 127: chamfer; 131: first prestressed channel; 132: prestressed steel strand; 133: grouting material; 134: second prestressed channel; 141: through hole; 142: anti-friction coating; 143: main reinforcement of the pin; 144: stirrup reinforcement of the pin; 150: magnetic flux sensor; 151: wiring slot; 152: sensor lead; 153: receiver. DETAILED DESCRIPTION

[0039] The following is a detailed description with reference to the accompanying drawings.

[0040] In tunnel shield construction, the shield segment is the basic unit of the tunnel lining, usually composed of prefabricated concrete components. When discussing the water-facing and water-receiving sides of the shield segment, we are describing the installation direction and position of the shield segment in the tunnel.

[0041] Water-facing surface: The part below the groundwater level or underwater where water pressure acts on the concrete structure surface. In layman's terms, if water has a tendency to penetrate from one side to another, then the first side, that is, the side that the water flow first contacts, is the water-facing surface. For example, in shield tunnel construction, when groundwater penetrates from the outside to the inside, the outside wall surface is the water-facing surface.

[0042] Back surface: refers to the other side relative to the front surface, that is, the side in the opposite direction of water penetration under the action of water pressure. In a concrete structure, if one side is the front surface, directly bearing the pressure and penetration of water, then the other side opposite to it is the back surface.

[0043] For a shield pipe, the outer side of the connection of the shield pipe is the water-facing side, and the inner side of the connection inside the pipe is the water-repelling side.

[0044] Steel fiber concrete: is a composite material that enhances the mechanical properties of ordinary concrete by evenly dispersing short and thin steel fibers. The length of these steel fibers is usually between 20 and 60 mm, the diameter is between 0.3 and 1.0 mm, and their volume content in concrete is generally between 0.5% and 2.0%. The addition of steel fibers can significantly improve the tensile strength, crack resistance, toughness and durability of concrete, making it perform better when subjected to dynamic loads and impact loads.

[0045] Ordinary concrete: is a building material made by mixing cement, fine aggregate (sand), coarse aggregate (crushed stone or pebbles) and water in a certain proportion. This mixture undergoes a hydration reaction when water is added, and the cement gradually hardens and forms a hard solid structure. The strength and performance of ordinary concrete depend on the nature of its constituent materials, their proportions, and the mixing and curing process. Ordinary concrete is one of the most commonly used materials in the construction industry and is widely used in various structures, including buildings, bridges, roads, and infrastructure. Ordinary concrete has good compressive strength, but its tensile strength is relatively low, and it is usually combined with reinforcing materials such as steel bars to improve the overall structural performance.

[0046] Segment joint: refers to the contact surface or interface between segments, which is the part where shield segments directly contact each other. In shield tunnel construction, segment joints are the key parts for transferring loads between shield segments and ensuring structural integrity and sealing. The design of segment joints needs to consider factors such as joint stiffness, load-bearing capacity, and waterproof performance. Common segment joint forms include right-angle joints, mortise and tenon joints, bolted joints, etc.

[0047] Example 1

[0048] The existing prestressed shield tunnel structure may have many defects during operation. On the one hand, the waterproof structure of the shield segment has not been changed, and there is still the problem of water leakage at the joints after the shield segment structure is deformed; on the other hand, it is impossible to prevent the leakage of water from the joints of the shield segment from entering the prestressed channel, and it is also impossible to prevent the slurry from seeping out from the end of the prestressed channel during grouting of the channel. The long-term operation of the tunnel structure is prone to corrosion of the prestressed steel bundles, accelerating the loss of prestress, and affecting the bearing capacity and safety of the tunnel structure.

[0049] The utility model provides a prestressed pin-type shield segment and a segment joint thereof. The shield segment comprises a segment body and a segment joint.

[0050] The pipe segment joints include a prestressed tenon joint 101 and a prestressed mortise joint 102. Figure 1 and Figure 2 As shown, the end of the prestressed tenon joint 101 is provided with a tenon 125. The prestressed tenon joint 101 is provided with a first prestressed channel 131 that passes through the prestressed tenon joint 101 and the tenon 125. When a plurality of tenons 125 are provided at the end of the prestressed tenon joint 101, the number of the first prestressed channel 131 is more than one. Preferably, for a single tenon 125, the number of the first prestressed channel 131 that passes through it may also be more than one.

[0051] The end of the prestressed mortise joint 102 is provided with a recessed mortise 126. The prestressed mortise joint 102 is provided with a second prestressed channel 134 that penetrates the prestressed mortise joint 102 and the recessed mortise 126. When a plurality of recessed mortise 126 are provided at the end of the prestressed mortise joint 102, the number of the second prestressed channel 134 is more than one. Preferably, for a single recessed mortise 126, the number of the second prestressed channel 134 that penetrates the same may also be more than one.

[0052] The size and shape of the tenon 125 and the mortise 126 match. When the prestressed mortise joint 101 and the prestressed mortise joint 102 are assembled, the tenon 125 can be inserted into the mortise 126. The first prestressed duct 131 and the second prestressed duct 134 are connected to form a complete prestressed duct. The complete prestressed duct is used to inject grouting material 133, so that the first prestressed duct 131 and the second prestressed duct 134 are connected as a whole.

[0053] When the prestressed mortise joint 101 and the prestressed mortise joint 102 are assembled, before the grouting material 133 is injected, the prestressed steel strand 132 is inserted into the first prestressed channel 131 and the second prestressed channel 134, and passes through the prestressed mortise joint 101 and the prestressed mortise joint 102. The prestressed steel strand 132 passes through the first prestressed channel 131 and the second prestressed channel 134 and is arranged in a tensioned manner.

[0054] The utility model adopts the positioning and connecting parts of the pipe segment joint, and provides additional axial force to the pipe segment joint by applying prestress. On the one hand, the latch can effectively improve the positioning accuracy, assembly efficiency and shear resistance of the pipe segment joint; on the other hand, applying prestress can put the pipe segment joint in a compressed state, improving the durability of concrete, the integrity of the joint and the deformation resistance.

[0055] like Figure 1 and Figure 2 As shown, the end of the prestressed mortise joint 101 provided with the convex tenon 125 includes a steel fiber casting 103. The portion of the prestressed mortise joint 101 that is not a steel fiber casting is a common casting 104. The end of the prestressed mortise joint 102 provided with the concave tenon 126 includes a steel fiber casting 103. The portion of the prestressed mortise joint 102 that is not a steel fiber casting is a common casting 104. The steel fiber casting 103 is formed by casting steel fiber concrete. The common casting 104 is formed by casting concrete of a general formula.

[0056] When the convex tenon 125 and the concave mortise 126 are inserted and connected, the two steel fiber casting bodies 103 are arranged oppositely and in contact. The segment joint is the weakest part of the shield tunnel structure. The damage of the segment joint is basically due to the crushing of the concrete in the joint area. Therefore, improving the performance of the concrete material in the joint area is an important measure to enhance the performance of the segment joint. The steel fiber concrete of the same grade is superior to ordinary concrete in many aspects such as compressive strength, tensile strength, crack resistance, and durability. By pouring steel fiber concrete at the joint of the convex tenon 125 and the concave mortise 126 and forming a steel fiber casting body 103, the various mechanical properties of the shield segment joint can be effectively improved. At the same time, the use of ordinary concrete in other parts of the shield segment can reduce the preparation cost.

[0057] The pipe ring is an annular structure formed by splicing prestressed pin-type shield segments. Multiple pipe rings are connected along the axis of the pipe ring to form a shield tunnel. According to a preferred embodiment, Figure 3 and Figure 4 As shown, the tenon 125 is located in the middle of the end of the prestressed tenon joint 101. At least two tenons 125 are arranged along the axial direction of the pipe ring. The cross section of the tenon 125 is rectangular (such as Figure 3 as shown) or round (as Figure 4 As shown in Figure 3 As shown, when the cross section of the tenon 125 is a rectangle, its long side is along the width direction of the shield segment. The use of a rectangular cross section can effectively increase the cross-sectional area and improve the shear resistance of the segment joint. The second sealing gasket 124 is arranged around the tenon 125. The shape of the second sealing gasket 124 is similar to the shape of the tenon 125. When the cross section of the tenon 125 is a rectangle, the shape of the second sealing gasket 124 is also a rectangle. The corners of the rectangle can be set to have arc-shaped rounded corners.

[0058] like Figure 4 As shown, the cross section of the tenon 125 is circular, which is convenient for the alignment and assembly of the latch. As the protrusion height of the tenon 125 increases, the radius of its cross section gradually decreases. When the cross section of the tenon 125 is circular, the shape of the second sealing gasket 124 is also circular.

[0059] like Figure 5 As shown, the top of the tenon 125 is a plane, and chamfers 127 are arranged around the top and bottom. Figure 1 , Figure 2 and Figure 5 As shown, the concave mortise 126 is a groove that matches or even completely matches the position, shape and size of the convex tenon 125, and the two can form a latch structure. The use of a variable cross-sectional size setting for the latch structure can ensure that the top of the convex tenon 125 can easily enter the concave mortise 126 during the shield segment assembly process, thereby improving the assembly positioning efficiency. The convex tenon 125 and the concave mortise 126 are set to the same or similar shape and size to reduce the amount of misalignment caused by assembly. Figure 5In the figure, the bottom of the concave mortise 126 is also provided with a chamfer 127 corresponding to the convex tenon 125. The top of the convex tenon 125 and the bottom of the concave mortise 126 are provided with chamfers 127, which can ensure smooth demoulding of the shield segment preparation on the one hand, and prevent the corners from falling off due to stress concentration after assembly on the other hand. Two or more convex tenons 125 and concave mortise 126 can be arranged according to the characteristics of the tunnel load.

[0060] Figure 5 The figure shows a partial enlarged view of the shield segment joint. Figure 5 As shown, each prestressed channel is a pre-buried circular steel pipe or corrugated pipe that passes through the tenon 125 and the mortise 126, and a criss-cross steel mesh is welded in the end thereof. The criss-cross steel mesh includes a latch main reinforcement 143 along the extension direction of the first prestressed channel 131 and the second prestressed channel 134 and a latch stirrup 144 perpendicular thereto. When the prestressed tenon joint 101 and the prestressed mortise joint 102 are assembled, the axes of the first prestressed channel 131 and the second prestressed channel 134 are on the same line, or the axes of the first prestressed channel 131 and the second prestressed channel 134 are approximately on the same line. With this arrangement, the criss-cross steel mesh at the respective ends of the prestressed tenon joint 101 and the prestressed mortise joint 102 can respectively increase the bearing capacity of the tenon 125 and the mortise 126, and further improve the shear resistance of the pipe segment joint.

[0061] like Figures 2 to 4 As shown, at least one first sealing groove 121 is respectively provided at the end of the prestressed tenon joint 101 near the water-facing surface and the back-water surface. Similarly, at least one first sealing groove 121 is respectively provided at the end of the prestressed mortise joint 102 near the water-facing surface and the back-water surface. Figure 2 For the convenience of display, only the first sealing groove 121 on one side of the prestressed mortise joint 102 is marked. A first sealing gasket 122 is provided in each of the first sealing grooves 121. The first sealing groove 121 extends along the axial direction of the prestressed shield segment. The axial direction here refers to the extension direction of the central axis of the pipe ring. The first sealing groove 121 on the prestressed mortise joint 101 is opposite to the first sealing groove 121 of the prestressed mortise joint 102. When the prestressed mortise joint 101 and the prestressed mortise joint 102 are assembled, the two first sealing gaskets 122 in the two opposite first sealing grooves 121 are in contact and form a waterproof sealing condition under compression. In this way, the waterproof function is achieved on both the water-facing and water-retaining surfaces of the prestressed mortise joint 101 and the prestressed mortise joint 102.

[0062] The traditional shield segment joint only has a waterproof sealing groove with a depth of about 10mm near the water-facing surface, and a waterproof sealing pad with a thickness of about 20mm is installed. When the shield segments are assembled and the structure is subjected to water and soil loads, the 20mm thick waterproof sealing pad needs to be compressed to about 10mm, which will produce a large concentrated load on the waterproof sealing groove, which can easily cause damage to this part and affect the waterproof effect. The utility model sets at least one first sealing groove 121 at each position close to the water-facing surface and the back water surface, and sets a first sealing pad 122 corresponding thereto. The two sealing structures on both sides can bring better waterproof effect.

[0063] According to a preferred embodiment, the depth of the first sealing groove 121 is about 5 mm. The thickness of the first sealing gasket 122 is about 6-7 mm. The depth of the first sealing groove 121 in the utility model is shallow and the thickness of the first sealing gasket 122 is thinner than that of the conventional sealing specifications. The thinner first sealing gasket 122 can reduce stress concentration.

[0064] At least one second sealing groove 123 is provided around the tenon 125. The second sealing groove 123 is an annular groove. The second sealing groove 123 is provided in a manner surrounding the tenon 125. Similarly, at least one second sealing groove 123 is provided around the mortise 126. The second sealing groove 123 is provided in a manner surrounding the mortise 126. A second sealing gasket 124 is installed in the second sealing groove 123. Since the second sealing gasket 124 covers the second sealing groove 123, Figure 3 and Figure 4 The second sealing groove 123 is not directly shown in the figure, and the shape and position of the second sealing groove 123 can be directly determined by visually observing the shape and position of the second sealing pad 124.

[0065] The second sealing groove 123 on the prestressed tenon joint 101 is opposite to the second sealing groove 123 of the prestressed mortise joint 102. When the prestressed tenon joint 101 and the prestressed mortise joint 102 are assembled, the two second sealing pads 124 in the two opposite second sealing grooves 123 are in contact and form a waterproof sealing condition under the condition of being squeezed. With this arrangement, the second sealing pads 124 on both sides fit tightly under the prestress of the prestressed steel bundle 132, which can effectively prevent leakage water from entering each prestressed channel through the plug and prevent slurry from leaking from the plug during grouting in each prestressed channel, thereby slowing down the corrosion of the prestressed steel bundle 132, reducing the prestress loss during the operation stage, and enhancing the durability and safety of the segment joint.

[0066] The number of sealing grooves and sealing pads of the utility model is not limited to the number shown in the drawings, and can be adjusted according to construction requirements.

[0067] like Figure 6 and Figure 7As shown, the second sealing gasket 124 is provided with a plurality of through holes 141. The through holes 141 can increase the elasticity and buffering effect of the second sealing gasket 124, thereby increasing the service life. Figure 3 and Figure 6 As shown in FIG. 1 , when the cross section of the tenon 125 is rectangular, the outline of the mortise 126 is also rectangular. The second sealing gasket 124 is arranged around the four sides of the tenon 125 and forms a rectangular sealing gasket. Figure 4 and Figure 7 As shown, when the cross section of the tenon 125 is circular, the profile of the recessed mortise 126 is also circular. The second sealing gasket 124 is arranged around the periphery of the tenon 125 and forms a circular sealing gasket.

[0068] According to a preferred embodiment, the cross section of the second gasket 124 is trapezoidal and is made of a water-swellable material. The expansion coefficient and the raised height after installation of the second gasket 124 should be greater than the first gasket 122. A larger raised height can ensure that the compression amount of the second gasket 124 is greater than the first gasket 122 after the shield segments are assembled, thereby avoiding the situation where the second gasket 124 does not fit.

[0069] like Figure 8 As shown, the second sealing gasket 124 has an extrusion surface that does not contact the second sealing groove 123 and a mounting surface that contacts the second sealing groove 123 .

[0070] The extrusion surface of the second sealing gasket 124 that does not contact the second sealing groove 123 is provided with a friction-reducing coating 142. The friction-reducing coating 142 can be made of polytetrafluoroethylene, molybdenum disulfide, or a material that reduces friction, is wear-resistant, and is corrosion-resistant, and can be fixed to the extrusion surface in a variety of ways. The fixing methods of the friction-reducing coating 142 include:

[0071] (1) The anti-friction coating 142 and the latch seal 124 are simultaneously vulcanized and formed in one step;

[0072] (2) The friction-reducing coating 142 is sprayed or adhered to the extrusion surface of the second sealing gasket 124 .

[0073] The friction-reducing coating 142 can effectively reduce the displacement of the two sealing pads due to friction when assembling the shield segments, increase their contact area, and improve the anti-seepage ability of the pin.

[0074] Example 2

[0075] This embodiment is a further improvement on Embodiment 1, and the repeated contents will not be repeated here.

[0076] The loads borne by the shield tunnel structure include water and soil loads, train vibration loads, external disturbance loads, etc. When the external loads change, the shield segments are unevenly stressed and deformed, which leads to problems such as rupture and water leakage. On the one hand, the deformation of the segments will cause the prestress value of the prestressed steel strands 132 in the prestressed channel to change, and even cause the prestressed steel strands 132 to break, causing accidents; on the other hand, the leaking water will gradually corrode the concrete and enter the prestressed channel, causing the prestressed steel strands 132 to rust, reducing the strength and prestress value of the prestressed steel strands, and affecting the durability and safety of the tunnel structure.

[0077] The shield tunnel structure is assembled from multiple shield segments, and there are multiple segment joints. The prestressed steel strand 132 cannot be constructed using the prestressing method like a cast-in-place structure. It is necessary to lay out prestressed channels in the segments and thread and tension them after assembly to apply prestress. Therefore, the prestress value of the prestressed steel strand 132 can only be monitored by installing a magnetic flux sensor 150 on the outer jacket of the prestressed channel.

[0078] like Figure 1 and Figure 2 As shown, at least one magnetic flux sensor 150 is respectively arranged on the periphery of the first prestressed duct 131 and the second prestressed duct 134 to collect the prestress value of the prestressed steel strand 132 in the first prestressed duct 131 and the second prestressed duct 134. The data line of the magnetic flux sensor 150 extends from the wiring slot 151 on the back surface of the prestressed shield segment to facilitate connection with the receiver 153 during construction and transmission of the prestress value. The receiver 153 can be a memory with a receiving port for receiving data.

[0079] The principle of the magnetic flux sensor 150 measuring the prestress value of the prestressed steel strand 132 is:

[0080] The magnetic flux sensor 150 is composed of a primary coil and a secondary coil. When a ferromagnetic material (such as the prestressed steel bundle 132) is subjected to an external force, its internal magnetic permeability changes, and this change affects the magnetic field generated by the pulse current passing through the primary coil, and further affects the induced voltage generated in the secondary coil. A pulse current is passed through the primary coil of the magnetic flux sensor 150, and an induced voltage is generated in the secondary coil due to the magnetoelastic effect of the ferromagnetic material. By measuring the change in this induced voltage, the change in the magnetic permeability of the material can be calculated. The measured voltage integral value is linearly related to the change in the magnetic permeability of the prestressed steel bundle 132. By calculating these data and combining them with the magnetization characteristic curve of the material, the stress state of the prestressed steel bundle 132 can be inferred.

[0081] During the operation of the shield tunnel, the magnetic flux sensor 150 sends the measured prestress value and its change of the prestressed steel strand 132 to the external receiver 153. This arrangement facilitates monitoring the prestress value and its change of the prestressed steel strand 132 after construction, and also facilitates monitoring the prestress value and its change of the prestressed steel strand 132 during construction.

[0082] Specifically, when prefabricating shield segments, the magnetic flux sensor 150 is pre-buried around each prestressed channel and cast together with the segment joint. In order not to affect the casting of the segment joint and the assembly of the shield segment, a wiring slot 151 for leading out and receiving the sensor lead 152 of the magnetic flux sensor 150 should be provided on the back surface of the segment joint. By connecting the receiver 153 with the sensor lead 152 of the magnetic flux sensor 150, the prestress value of the prestressed steel strand 132 can be obtained.

[0083] Under similar design conditions, the loads on the shield segment structure are basically the same. In order to reduce the monitoring cost and make the monitoring data representative, it is not necessary to arrange magnetic flux sensors 150 at all joints of all shield segments. For a single segment ring, Fig. 9 and Fig.10 As shown, the segment structure is in an unfavorable working condition when subjected to large bending moment and small axial force, and the top, bottom, left side and right side of the shield segment structure are unfavorable load points. For the entire tunnel section, changes in stratum conditions (rock layer, soil layer, fault, groundwater, etc.) will affect the stress of the segment joints, so a shield segment structure with a large difference in stratum conditions can be selected, and a magnetic flux sensor 150 is set at the segment joint that is subjected to unfavorable loads. Multiple magnetic flux sensors 150 of a single segment ring are connected to a receiver 153. Multiple receivers 153 of multiple segment rings are connected to a host computer outside the tunnel via wired or wireless means. The host computer can set the monitoring frequency and operate the receiver 153 to measure the prestress value of the magnetic flux sensor 150.

[0084] The monitoring of the prestress value of the prestressed steel tendon 132 can be divided into various situations:

[0085] 1) During the prestressing process, the prestress value of the prestressed steel strand 132 should be monitored in real time to ensure that the prestress value at the segment joint reaches the design level;

[0086] 2) After the shield segment is separated from the shield tail to the segment wall, grouting is carried out until the grouting is completed. At this time, the external load on the segment joint gradually increases, the segment joint deforms, and the prestress value changes. The prestress value can be monitored once after each excavation step of the shield tunnel is completed;

[0087] 3) During the operation of the tunnel, the load on the segment joints is basically stable, so the monitoring frequency can be reduced to once every 1 to 2 months;

[0088] 4) During the operation of the tunnel, nearby construction, such as new tunnels, stations, foundation pit excavation, etc., will destroy the stability of the segment joints. The monitoring frequency should be increased, such as monitoring at a frequency of 1 to 2 days per time.

[0089] like Fig. 9 and Fig.10 As shown, the loads borne by the prestressed pin-type shield segment joints include water and soil loads and prestress loads. Water and soil loads are divided into bending moment and axial force, and the prestress load is the prestress value that only provides axial force. During the construction and operation of the shield tunnel, external loads will change the prestress value, thereby changing the axial force of the segment joints. Using the magnetic flux sensor 150 to monitor the data, when the prestress value at the segment joint increases or decreases rapidly, measures need to be taken to protect the safety of the tunnel structure, such as stopping surrounding operations and strengthening the tunnel structure.

[0090] 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 contents disclosed in the present utility model, and these solutions also belong to the disclosure scope of the present utility model and fall within the protection scope of the present utility model. Those skilled in the art should understand that the present utility model specification and its drawings are illustrative and do not constitute limitations on the claims. The scope of protection of the present utility model is defined by the claims and their equivalents. The present utility model specification contains multiple inventive concepts, such as "preferably" and "according to a preferred embodiment" both indicate that the corresponding paragraph discloses an independent concept, and the applicant reserves the right to file a divisional application based on each inventive concept.

Claims

1. A prestressed pin-type shield segment joint, characterized in that: It comprises a prestressed tenon joint (101) and a prestressed mortise joint (102), The end of the prestressed tenon joint (101) is provided with a tenon (125), and the prestressed tenon joint (101) is provided with a first prestressed hole (131) penetrating the prestressed tenon joint (101) and the tenon (125). The end of the prestressed mortise joint (102) is provided with a concave mortise (126), and the prestressed mortise joint (102) is provided with a second prestressed hole (134) penetrating the prestressed mortise joint (102) and the concave mortise (126). When the tenon (125) and the mortise (126) are positioned in a matching manner, the first prestressed channel (131) and the second prestressed channel (134) are connected to form a complete prestressed channel, and the complete prestressed channel is used to inject grouting material (133), so that the first prestressed channel (131) and the second prestressed channel (134) are connected.

2. The prestressed bolt-type shield segment joint according to claim 1 is characterized in that: Also included are prestressed steel tendons (132), When the prestressed tenon joint (101) and the prestressed mortise joint (102) are assembled, before the grouting material (133) is injected, the prestressed steel bundle (132) passes through the first prestressed channel (131) and the second prestressed channel (134) and is arranged in a tensioned manner.

3. The prestressed pin-type shield segment joint according to claim 2 is characterized in that: The end of the prestressed tenon joint (101) provided with the tenon (125) comprises a steel fiber casting (103), The end of the prestressed mortise joint (102) provided with the recessed mortise (126) comprises the steel fiber casting body (103), When the tenon (125) and the mortise (126) are inserted and connected, the two steel fiber casting bodies (103) are arranged opposite to each other and in contact.

4. The prestressed pin-type shield segment joint according to claim 3 is characterized in that: When the prestressed tenon joint (101) and the prestressed mortise joint (102) are assembled, the axes of the first prestressed hole (131) and the second prestressed hole (134) are on the same line, or The axes of the first prestressed hole (131) and the second prestressed hole (134) are approximately on the same line.

5. The prestressed pin-type shield segment joint according to claim 4 is characterized in that: At least one first sealing groove (121) is respectively provided at a position close to the water-facing surface and the water-receiving surface of the end of the prestressed tenon joint (101). At least one first sealing groove (121) is respectively provided at the end of the prestressed mortise joint (102) near the water-facing surface and the water-receiving surface. A first sealing gasket (122) is arranged in the first sealing groove (121).

6. The prestressed bolt-type shield segment joint according to any one of claims 1 to 5, characterized in that: At least one second sealing groove (123) is arranged around the tenon (125) in a surrounding manner. At least one second sealing groove (123) is arranged around the recess (126). A second sealing gasket (124) is arranged in the second sealing groove (123).

7. The prestressed pin-type shield segment joint according to claim 6 is characterized in that: The second sealing pad (124) is provided with a plurality of through holes (141) to increase the elasticity of the pad body. The extrusion surface of the second sealing gasket (124) that is not in contact with the second sealing groove (123) is provided with a friction-reducing coating (142).

8. The prestressed pin-type shield segment joint according to claim 6 is characterized in that: At least one magnetic flux sensor (150) is respectively arranged on the periphery of the first prestressed hole (131) and the second prestressed hole (134) to collect the prestress values ​​of the first prestressed hole (131) and the second prestressed hole (134). The data line of the magnetic flux sensor (150) extends out from the wiring slot (151) on the back water surface of the prestressed bolt-type shield segment, so as to connect with the receiver (153) during construction and transmit the prestress value.

9. A prestressed pin-type shield segment, comprising a segment body and a segment joint, characterized in that: The pipe segment joint comprises a prestressed tenon joint (101) and a prestressed mortise joint (102). The end of the prestressed tenon joint (101) is provided with a tenon (125), and the prestressed tenon joint (101) is provided with a first prestressed hole (131) penetrating the prestressed tenon joint (101) and the tenon (125). The end of the prestressed mortise joint (102) is provided with a concave mortise (126), and the prestressed mortise joint (102) is provided with a second prestressed hole (134) penetrating the prestressed mortise joint (102) and the concave mortise (126). When the tenon (125) and the mortise (126) are positioned in a matching manner, the first prestressed channel (131) and the second prestressed channel (134) are connected to form a complete prestressed channel. When the prestressed tenon joint (101) and the prestressed mortise joint (102) are assembled, before the grouting material (133) is injected, the prestressed steel strand (132) passes through the first prestressed channel (131) and the second prestressed channel (134) and is arranged in a tensioned manner.

10. The prestressed pin-type shield segment according to claim 9 is characterized in that: At least one magnetic flux sensor (150) is respectively arranged on the periphery of the first prestressed hole (131) and the second prestressed hole (134) to collect the prestress values ​​of the first prestressed hole (131) and the second prestressed hole (134). The data line of the magnetic flux sensor (150) extends out from the wiring slot (151) on the back water surface of the prestressed bolt-type shield segment, so as to be connected to the receiver (153) and transmit the prestress value during construction.

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