Compressible ductile segmental lining structure with vibration reduction function and construction method of compressible ductile segmental lining structure

Abstract

The invention relates to a compressible ductile segmental lining structure with a vibration reduction function and a construction method of the compressible ductile segmental lining structure. The structure comprises a plurality of lining units, and each lining unit comprises a segmental lining on the inner side and a compressible layer on the outer side; the compressible layer comprises a plurality of porous rigid cushion layers which are annularly arranged at intervals, the porous rigid cushion layers are longitudinally arranged, the longitudinal length of the porous rigid cushion layers is consistent with the annular width of the segment, a porous flexible cushion layer is longitudinally arranged at the bottom of the inner side between every two annularly adjacent porous rigid cushion layers, and lining blocks are arranged on the outer sides of the porous flexible cushion layers; and the outer side surfaces of the lining blocks and the outer side surface of the porous rigid cushion layer are smoothly spliced to form the outer side surface of the lining. The compressible layer is added to the outer side of the conventional segmental lining to form a combined lining structure, on one hand, the rigidity requirement of a conventional tunnel lining is met, on the other hand, the active compression deformation requirement under the action of an external additional load can be met, outward transmission of train operation vibration can be obviously weakened, and the quality of the environment along the line can be greatly improved.

Description

Technical Field

[0001] This invention relates to the field of underground engineering construction technology, specifically to a compressible tough segment lining structure with vibration reduction function and its construction method. Background Technology

[0002] Currently, as urban underground engineering develops towards greater depths and larger cross-sections, the surrounding environment faced by underground projects will become increasingly complex due to urban development and existing structures, and the uncertainty of geological conditions will also increase. Conventional shield tunnel segment lining is mainly composed of reinforced concrete structures, which, while having sufficient rigidity, lack sufficient toughness and cannot effectively cope with the demands of special geological conditions or changes in the external environment, such as changes in geological conditions, external overload, stratum fractures or ground fissures, and excessive ground stress in deeply buried tunnels. Such conditions can lead to joint opening and leakage, segment cracking and fragmentation in conventional shield tunnel segment lining, posing serious hidden dangers to the normal use and structural safety of shield tunnels. At the same time, in recent years, complaints from residents along urban rail transit lines have frequently occurred. The main reason is the increasing trend of vibration and noise caused by train operation, which has had an unpredictable impact on the normal life and work of residents in the surrounding areas. As the operation time of urban rail transit extends, the impact on the surrounding environment is showing an increasingly serious trend.

[0003] Conventional shield tunnel segment lining structure designs cannot meet the requirements of increasingly complex surrounding environments. They suffer from insufficient toughness, limited vibration reduction capacity, and poor environmental adaptability, falling far short of the construction goals of environmentally friendly urban rail transit projects. Therefore, it is urgent to break with traditional thinking and develop a segment lining construction method that can effectively improve the toughness and vibration reduction effect of shield tunnel lining structures. Summary of the Invention

[0004] The purpose of this invention is to provide a compressible tough segment lining structure with vibration reduction function and its construction method, so as to solve the problems of poor environmental adaptability, insufficient toughness and limited vibration reduction capacity of existing shield tunnel segment linings.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] A compressible and resilient segment lining structure with vibration damping function is provided, the structure comprising multiple lining units, each lining unit comprising an inner segment lining and an outer compressible layer;

[0007] The compressible layer includes a plurality of porous rigid pads arranged circumferentially. The porous rigid pads are arranged longitudinally and their longitudinal length is consistent with the circumferential width of the segment. A longitudinally arranged porous flexible pad is provided on the inner bottom between two circumferentially adjacent porous rigid pads. A lining block is provided on the outer side of the porous flexible pad. The outer surface of the lining block and the outer surface of the porous rigid pad are smoothly spliced ​​together to form the outer surface of the lining.

[0008] Furthermore, the vertical cross-section of the porous rigid pad is a trapezoid with a smaller outer diameter and a larger inner diameter, and both the outer and inner surfaces are arc surfaces.

[0009] The vertical cross-section of the porous flexible pad is a trapezoid with a smaller inner diameter and a larger outer diameter, and both the outer and inner surfaces are arc surfaces.

[0010] The vertical cross-section of the lining block is a trapezoid with a smaller inner section and a larger outer section, and both the outer and inner surfaces are arc surfaces.

[0011] The porous rigid pad, the porous flexible pad, and the lining block are tightly joined together to form the compressible layer with a uniform radial thickness.

[0012] Furthermore, the porous flexible pad is an EPDM rubber pad, and the porous rigid pad is a concrete pad or a ceramic pad.

[0013] Furthermore, the lining unit includes a top capping block, adjacent blocks on both sides of the top, and standard blocks at the bottom and on both sides of the bottom.

[0014] The capping block, the adjacent block, and the standard block are joined together in a ring, and then joined together in a longitudinal direction to form an integral tunnel.

[0015] Furthermore, the circumferential and longitudinal end faces of the segment lining are provided with sealing gasket grooves located in the middle and outer part. When the lining unit is spliced ​​in the circumferential and longitudinal directions, the sealing gasket grooves are filled with sealing gaskets.

[0016] Furthermore, a circumferential caulking groove is provided on the circumferential end face of the segment lining, located on the inner side. When the lining unit is longitudinally spliced, the caulking groove is filled with waterproof sealant.

[0017] Furthermore, bolt holes are provided on the circumferential and longitudinal end faces of the lining segments, and the lining units are connected by bolts when they are spliced ​​circumferentially.

[0018] Furthermore, the total radial thickness of the segment lining and the compressible layer is the same as the thickness of a conventional segment, and the radial thickness of the segment lining is greater than the radial thickness of the compressible layer.

[0019] On the other hand, a construction method is provided for a compressible and resilient segment lining structure with vibration damping function as described above, the method comprising:

[0020] Precast lining blocks, porous flexible cushion layers and porous rigid cushion layers;

[0021] The porous flexible pad and the porous rigid pad are cut, then bonded and assembled. Lining blocks are inserted into the groove space formed after assembly and bonded to form a compressible layer.

[0022] Place the reinforcing cage into the steel mold, tie the bolt hole mold to the reinforcing cage, reserve the positions of the caulking groove and sealing gasket groove on the steel mold, and then pour the segment lining.

[0023] After the steam curing of the tunnel lining is completed and before demolding, adhesive material is applied to the outer surface of the tunnel lining. Then, the pre-made compressible layer is placed into the steel mold and bonded to the outer surface of the tunnel lining. Ballasting, static curing, demolding, and curing are then performed to complete the fabrication.

[0024] Furthermore, under the action of external additional loads, the porous rigid cushion layer is slightly compressed, and the porous flexible cushion layer is significantly compressed and squeezed in a specific area. Then, the compressible layer undergoes coordinated radial deformation, and the deformed porous rigid cushion layer and the outer surface of the lining block are located in the same radius of curvature range.

[0025] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0026] This invention provides a compressible and resilient tunnel lining structure with vibration reduction function and its construction method. Based on the concept of "active compression and coordinated deformation," a compressible layer is added to the outside of conventional tunnel lining to form a composite lining structure. This satisfies both the stiffness requirements of conventional tunnel lining and the active compression deformation requirements under external additional loads. Furthermore, this invention proposes the concept of "combining rigidity and flexibility, and active isolation." The material stiffness and toughness of the compressible layer are significantly different from those of reinforced concrete lining. During the propagation of vibration waves from train operation inside the tunnel, multiple reflections and refractions are required within the porous cushion layer inside the compressible layer. Combined with the significant difference in stiffness between the two materials, this significantly weakens the outward transmission of train vibrations, greatly improving the environmental quality along the tunnel route. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other embodiments can be obtained from these drawings without creative effort.

[0028] Figure 1This is a cross-sectional view of a compressible tough segment lining structure with vibration reduction function provided in an embodiment of the present invention.

[0029] Figure 2 This is a front view of the capping block provided in an embodiment of the present invention (before compression).

[0030] Figure 3 This is a front view (compressed) of the capping block provided in an embodiment of the present invention.

[0031] Figure 4 This is a longitudinal cross-sectional view (before compression) of the capping block along the tunnel provided in an embodiment of the present invention.

[0032] Figure 5 This is a diagram of the segment lining compression deformation caused by geological dislocation in the ground fissure area (along the tunnel longitudinal direction) provided in an embodiment of the present invention.

[0033] The diagram is labeled as follows:

[0034] 1-Segment lining, 2-Compressible layer, 3-Catalyst groove, 4-Sealing gasket groove, 5-Liner block, 6-Porous flexible cushion layer, 7-Porous rigid cushion layer, 8-Bolt hole, 9-Extrusion layer, 10-Ground fissure, 11-Upper plate, 12-Lower plate, 13-Grouting for filling voids at the bottom, 14-Original tunnel outline;

[0035] 1-1-Cap block, 1-2-Adjacent block, 1-3-Standard block;

[0036] 2-1- Compressible layer after extrusion deformation. Detailed Implementation

[0037] To facilitate understanding of the present invention, a more complete description will be given below with reference to the accompanying drawings. Preferred embodiments of the invention are shown in the drawings. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the invention.

[0038] In the description of this invention, it should be understood that the terms "center", "upper", "lower", "vertical", "horizontal", "top", "bottom", "inner", "outer", "longitudinal", "horizontal", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0039] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "splicing," "connection," and "setting" should be interpreted broadly. For example, they can refer to a fixed connection or setting, a detachable connection or setting, or an integral connection or setting. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0040] It should also be noted that although the order of steps is mentioned in the method description, in some cases, steps may be performed in a different order than that described here, and this should not be interpreted as a restriction on the order of steps.

[0041] In a specific implementation, the tunnel alignment direction is defined as "longitudinal," the direction perpendicular to it is defined as "lateral," the height direction of the segment lining (i.e., the direction perpendicular to the horizontal plane) is defined as "vertical," and the tunnel cross-section outline is defined as "circumferential." Furthermore, the area near the surrounding rock is defined as "outer side," and the area near the tunnel interior is defined as "inner side."

[0042] In the engineering practice of shield tunnel segment lining, the reinforced concrete segment lining is first precast, followed by shield tunnel excavation and segment lining assembly. After the assembled segment lining gradually exits the shield tail, grouting at the shield tail ensures close contact between the segment lining and the surrounding strata. However, segment lining constructed using this general method suffers from poor toughness, making it difficult to effectively cope with the complex and sensitive surrounding environment, the complex strata stress in deep tunnels, and the vibrations and adverse effects of train operation inside the tunnel. Therefore, this invention provides a compressible tough segment lining structure with vibration reduction function, improving the performance of shield tunnel segment lining in coping with changes in surrounding rock pressure.

[0043] Specifically, the structure includes multiple lining units, each lining unit comprising a top capping block 1-1, adjacent blocks 1-2 on both sides of the top, and standard blocks 1-3 at the bottom and on both sides of the bottom. The capping block 1-1, adjacent blocks 1-2, and standard blocks 1-3 are circumferentially spliced ​​into a ring, and then longitudinally spliced ​​to form an integral tunnel. Figure 1 In this embodiment, the vertical cross-section of the structure is circular, and it includes six lining units circumferentially. The capping block 1-1 is located at the top and center, with a relatively small circumferential width. Adjacent blocks 1-2 are symmetrically arranged on both sides of the capping block 1-1, totaling two, with a larger circumferential width. Standard blocks 1-3 are evenly distributed at the bottom and on both sides of the bottom, totaling three, with the largest circumferential width. The longitudinal seams connecting the lining units are located on the radius line of the circular cross-section.

[0044] like Figure 2The lining units have the same structural form, including an inner segment lining 1 and an outer compressible layer 2. The compressible layer 2 includes multiple circumferentially spaced porous rigid pads 7, arranged longitudinally with a length consistent with the circumferential width of the segment. A longitudinally arranged porous flexible pad 6 is placed at the bottom inner side between two adjacent circumferentially spaced porous rigid pads 7. Lining blocks 5 are placed on the outer side of the porous flexible pads 6, and their outer surfaces are smoothly joined to form the outer surface of the lining. Specifically, the vertical cross-section of the porous rigid pad 7 is a trapezoid with a smaller outer section and a larger inner section, and both the outer and inner surfaces are curved. The vertical cross-section of the porous flexible pad 6 is also a trapezoid with a smaller inner section and a larger outer section, and both the outer and inner surfaces are curved. The vertical cross-section of the lining block 5 is a trapezoid with a smaller inner section and a larger outer section, and both the outer and inner surfaces are curved. This trapezoidal structure facilitates deformation towards the center of the shield tunnel under external additional loads. The extended lines of the trapezoidal edges on both sides of the lining block 5 coincide exactly with the boundary lines of the porous flexible pad 6 and the porous rigid pad 7. The lines connecting the two sides of the outer compressible layer 2 of each lining unit to the center of the shield tunnel pass exactly through the two sides of the inner segment lining 1.

[0045] The porous rigid pad 7, the porous flexible pad 6, and the lining block 5 are tightly spliced ​​together to form a compressible layer 2 with a uniform radial thickness. The total radial thickness of the segment lining 1 and the compressible layer 2 is approximately equal to or the same as the thickness of a conventional segment, but the radial thickness of the segment lining 1 is greater than the radial thickness of the compressible layer 2, resulting in a relatively thin conventional segment structure. In some embodiments, such as Figure 2 The thickness of the segment lining 1 is approximately 2 / 3 of the thickness H of a conventional segment, and the compressible layer 2 is generally about 1 / 3 of the thickness of a conventional segment. Figure 3 The maximum compression amount h0 is about 1 / 3 to 1 / 2 of the thickness of the compressible layer 2, which is determined by the thickness and compressibility of the porous pad. The thickness of the compressible layer 2-1 after extrusion deformation is h1.

[0046] In the compressible layer 2, the porous flexible pad 6 can be made of EPDM rubber, which can undergo significant deformation and has good compressibility, but relatively low stiffness. The porous rigid pad 7 can be made of concrete or ceramic, which can undergo slight deformation, but has relatively poor compressibility and relatively high stiffness. The lining block 5 is a conventional reinforced concrete structure. Therefore, the compressibility of the compressible layer 2 is mainly determined by the porous flexible pad 6. Under external additional loads, the two types of porous pads below and on the sides of the lining block 5 will undergo corresponding compressive deformation to accommodate the release of surrounding rock pressure in deep tunnels or the need for stratum displacement in geological fault areas, while significantly reducing the propagation and diffusion of vibration or noise from train operation inside the tunnel. Specifically, for example... Figure 3The compressible layer 2 is compressed, mainly through the compression of the porous flexible pad 6 beneath the lining block 5. The porous rigid pads 7 on both sides of the lining block 5 also undergo compression, but the amount of compression is relatively small. This primarily involves effectively compressing the porous flexible pad 6 within a specific area while maintaining a certain degree of deformation coordination, ensuring coordinated deformation of the compressible layer 2 along its thickness direction. The deformed porous rigid pad 7 and the outer surface of the lining block 5 are located within the same radius of curvature. The compressible layer 2 undergoes some compression deformation along its radial thickness direction, with the surrounding rock (strata) squeezing into the original segment lining outline, forming a compression layer 9, effectively releasing the deformation tendency of the surrounding rock. Based on the concepts of "active compression and coordinated deformation" and "rigidity and flexibility combined, active isolation," this invention forms a novel compressible segment lining, meeting the actual needs of increased ground stress in deep underground spaces and geological fault or fissure areas, providing a more flexible selection space for the construction of shield tunnels in urban rail transit and underground engineering.

[0047] Under normal operating conditions, including the transportation of tunnel segments, the assembly of linings, and the formation of a complete tunnel segment lining ring by exiting the shield tail, the overall stiffness of the compressible layer 2 can ensure that the tunnel segment lining does not undergo compressive deformation in its thickness direction.

[0048] During the segment casting process, in the circumferential direction of the segment, the main components in direct contact with the steel mold are the segment lining 1 and the porous rigid pad 7, while the lining block 5 and the porous flexible pad 6 below it do not directly contact the steel mold. The construction of the compressible layer 2 is mainly achieved through the bonding between the porous pads and the bonding between the porous pads and the segment lining 1, and its inner and outer curvature must perfectly match that of the segment lining 1.

[0049] In addition, such as Figure 2 The circumferential sealing groove 4 is provided on the annular and longitudinal end faces of the segment lining 1, located in the outer part of the middle. When the lining units are spliced ​​circumferentially and longitudinally, a sealing gasket is filled around the sealing groove 4. A circumferential caulking groove 3 is also provided on the annular end face of the segment lining 1, located on the inner side. When the lining units are spliced ​​longitudinally, the caulking groove 3 is filled with waterproof sealant. For example... Figure 4 Bolt holes 8 are provided on the circumferential and longitudinal end faces of the lining segment 1. The lining units are connected by bolts when they are spliced ​​in the circumferential direction. In some embodiments, two bolt holes 8 are provided on each segment along the longitudinal seam of the lining segment 1. The bolt holes 8 are evenly arranged in the circumferential direction along the circumferential seam of the lining segment 1, and generally 10 can be considered.

[0050] like Figure 5For areas with significant external loads, ground fissures 10, or geological faults, the potential energy of dislocations in the strata will be released when it accumulates to a certain extent. For example, the strata 11 on the hanging wall of the normal fault ground fissure 10 will show a downward displacement trend, while the strata 12 on the footwall will remain relatively fixed. This will lead to compression deformation at the top of the shield tunnel at the location of the ground fissure on the hanging wall 11, and local voids at the bottom. Since the dislocation trend of the normal fault ground fissure 10 takes a long time and the change process is slow, when dislocation deformation occurs, as the hanging wall strata subside and deform, the compressible layer 2 at the corresponding arch position of the segment lining 1 will undergo compression deformation. The surrounding strata (compression layer 9) will be squeezed into the original tunnel outline range 14. At the same time, local voids will appear in the tunnel arch bottom area after strata settlement. Based on the monitoring situation, the voided area at the bottom will be backfilled and grouted in a timely manner to ensure close contact between the tunnel and the surrounding rock. Regarding the compression deformation of the compressible layer 2 at the arch crown of the tunnel lining 1, the compression deformation in the upper plate 11 area is larger and is the active deformation zone, while the compression deformation in the lower plate 12 area is smaller and is the passive deformation zone. The active and passive deformation zones are effectively connected and uniformly transitioned at the ground fissure 10. At the tunnel arch bottom, only the upper plate 11 area shows tunnel arch bottom detachment, while the lower plate 12 area is relatively fixed and no bottom detachment phenomenon is observed.

[0051] In addition, thanks to the porous structure of the compressible layer 2, the vibration of the train running inside the tunnel is repeatedly refracted and reflected within the porous medium between the segment lining 1 and the cushion layer, and its vibration energy is effectively dissipated or weakened.

[0052] The lining units in the aforementioned compressible and resilient segment lining structure with vibration damping function are prefabricated, specifically including the following steps:

[0053] S1: Precast lining block 5, porous flexible pad 6 and porous rigid pad 7.

[0054] S2: The shield tunnel's first ring segment includes one capping block 1-1, two adjacent blocks, and three standard blocks 1-3. Based on the thickness, inner and outer curvature, and arc length of the compressible layer 2 designed concentrically with the segment lining, and according to the corresponding contour shape and size, as well as the number and size requirements of the segment lining 1, the porous flexible pad 6 and porous rigid pad 7 are cut and then bonded together. This assembly must perfectly correspond to the number and size of the segments in the segment lining 1. Simultaneously, it should be ensured that each segment end in the tunnel circumferential direction corresponds to a porous rigid pad 7. Generally, the thickness of the porous flexible pad 6 below the compressible layer 2 can be considered as 1 / 2 the thickness of the compressible layer 2, i.e., 50mm. Lining blocks 5 are inserted into the grooved space formed after assembly and bonded (epoxy resin is applied to the contact area between the lining block 5 and the pad lining before insertion) to form the compressible layer 2. Generally, the thickness of the compressible layer 2 can be considered as 1 / 3 the thickness of the segment, i.e., ≥100mm.

[0055] S3: According to the conventional shield tunnel segment casting process requirements, the tied steel cage is placed into the steel mold, the bolt hole mold is tied and fixed to the steel cage, the positions of the caulking groove 3 and the sealing gasket groove 4 are reserved on the steel mold, and then the segment lining 1 is poured.

[0056] S4: After the steam curing of the segment lining 1 is completed and before demolding, apply adhesive material (two coats of epoxy resin) to the outer surface of the segment lining 1. Then, place the pre-made compressible layer 2 into the steel mold and bond it to the outer surface of the segment lining 1. After the upper ballast is applied and the mold is left to stand for a period of time, demold the segment. Then, perform curing to complete the fabrication of the compressible segment lining.

[0057] During the shield tunnel excavation, a ring of segment lining 1 is assembled inside the shield tail in the order of standard block 1-3, adjacent block 1-2, and capping block 1-1. It then exits the shield tail and contacts the surrounding strata through the grouting layer. As the pressure of the surrounding strata increases or the strata dislocation in the fractured area is affected, the compressible layer 2 on the outer side of the compressed segment lining 1 gradually undergoes compressive deformation. When the compressive deformation is within 1 / 6 of the lining structure thickness (for a conventional 6m diameter subway tunnel, the corresponding 1 / 6 lining structure thickness is 50mm), it can be adjusted entirely by changing the thickness of the compressible layer 2, reaching the maximum compressible adjustment limit corresponding to the strata squeezed into the original shield tunnel outline. Through continuous compressive deformation of the segment lining 1 within a certain range, longitudinal deformation adjustment of 3.3% (corresponding to a segment ring width of 1.5m) or 4.2% (corresponding to a segment ring width of 1.2m) can be achieved.

[0058] like Figure 5 In the area of ​​ground fissure 10, dislocation deformation occurred in the strata, and the hanging wall 11 of the ground fissure subsided and deformed. The compressible layer 2 on the outer side of the tunnel arch at the corresponding location was squeezed, and the surrounding strata (surrounding rock) 9 was squeezed into the tunnel outline. Due to strata subsidence, a void appeared at the bottom of the tunnel arch at the location of the hanging wall 11. Grouting 13 was carried out in a timely manner to backfill the void based on the monitoring situation. At the tunnel arch location, at the junction of the hanging wall 11 and the footwall 12 on both sides of ground fissure 10, the compression deformation of the compressible layer transitioned continuously and evenly. The side of the hanging wall 11 was a relatively large active deformation zone, while the side of the footwall 12 was a relatively small passive deformation zone.

[0059] Under the vibration load of trains inside the tunnel, vibration waves propagate along the path of train wheels, rails, track bed, lining structure, stratum, and surrounding environment. Traditional reinforced concrete lining structures have sufficient overall stiffness but insufficient toughness, and train vibration waves cannot be effectively weakened. The compressible segment lining proposed in this invention patent has a porous medium. Before the vibration waves are transmitted through the inner segment lining 1 to the outer stratum, they need to pass through the porous medium. The stiffness of the porous medium is significantly different from that of the segment lining 1, and the propagation of vibration waves in the porous medium requires repeated refraction and reflection, which will effectively reduce the vibration frequency and amplitude, and reduce the vibration impact on the stratum and surrounding environment.

[0060] In the structure of this invention, the dimensions of the lining block 5 are relatively fixed, generally with a thickness of about 50mm, an outer long side of about 100mm, and an inner short side of about 80mm. The elastic modulus and compressive deformation resistance of the porous flexible pad 6 are significantly less than those of the porous rigid pad 7, but it can ensure that no compressive deformation occurs during the entire process of transporting, assembling, and removing the tunnel lining from the shield tail, while maintaining close contact with the stratum. Along the circumferential direction of the tunnel lining, the left and right ends of each tunnel segment are sealed by the porous rigid pad 7, which ensures that the external stiffness of the tunnel lining is relatively large, while the internal stiffness is relatively small, which is beneficial to its stability during transportation and assembly. The number of lining blocks 5 distributed on the compressible layer 2 on the outer side of each tunnel lining 1, their circumferential spacing, and the thickness of the porous flexible pad 6 below the trapezoidal lining block 5 can all be adjusted according to the estimated compression deformation requirements to adapt to different external environmental changes.

[0061] The structure of the present invention includes an outer compressible layer 2 and an inner segment lining 1. The compressible layer 2 is mainly composed of lining blocks 5, porous flexible pads 6 and porous rigid pads 7. Overall, the lining blocks 5 are wrapped by the lower porous flexible pads 6 and the two sides porous rigid pads 7. The radius of curvature and the inner and outer arc dimensions of the overall compressible layer 2 are concentric with the inner segment lining 1 and fully meet the requirements of the overall number and size of segments in the segment structure.

[0062] For the inner segment lining 1, its cross-sectional structure is basically the same as that of conventional segment lining. The main difference is that the thickness of the lining structure is about 2 / 3 of the conventional thickness. For the commonly used urban rail transit shield tunnels, the thickness of segment lining 1 is generally 200-220mm, and should not be less than 200mm. For the compressible layer 2, its thickness should not be less than 100mm, and the corresponding maximum compression is generally within 50mm.

[0063] The elastic modulus of the porous flexible pad 6 is significantly smaller than that of the porous rigid pad 7. The compression deformation of the compressible layer 2 mainly relies on the compression of the porous flexible pad 6. At the same time, the porous flexible pad 6 has good toughness and deformation recovery ability. In addition, the porous flexible pad 6 is coated with weather-resistant varnish (such as polyurethane or fluorocarbon coating) or fluorinated, so its durability fully meets the service life requirements of shield tunnel segment lining.

[0064] Along the tunnel cross section, lining blocks 5 and porous rigid cushion layer 7 are staggered; along the tunnel longitudinal section, lining blocks 5, porous flexible cushion layer 6, and porous rigid cushion layer 7 are continuously arranged along the tunnel circumference. When the tunnel is subjected to uneven external loads, such as surface overload or uneven foundation settlement, the tunnel cross section can adjust and adapt to the external loads in a timely manner through the deformation of compressible layer 2 according to the distribution of external additional loads (the compression deformation values ​​are basically the same); when ground dislocation occurs within a certain range along the tunnel longitudinal direction (such as ground fissures or geological fault areas), in the tunnel longitudinal section, adaptive adjustments can be made according to the longitudinal transition deformation of the compressible layer (the compression deformation value gradually transitions from zero to the maximum value).

[0065] The core technology of this invention is the compressible layer 2 on the outside of the segment lining 1, which consists of lining block 5, porous flexible pad 6, and porous rigid pad 7. On the one hand, it provides a certain compressible deformation space for the lining structure, which can better adapt to the action of external additional loads. On the other hand, it also increases the toughness and vibration reduction and noise reduction level of the shield tunnel, which meets the construction goals of environmentally friendly underground engineering.

[0066] In the structural system of this invention, both the segment lining 1 and the lining block 5 are conventional reinforced concrete structures, and the porous cushion layer is made of EPDM rubber and ceramic (or concrete). The size of the pores can be flexibly adjusted according to the overall compression deformation requirements, stiffness, stability, etc.

[0067] The construction method provided by this invention requires the following precautions during implementation:

[0068] 1. The compressible segment lining structure mainly consists of conventional segment lining 1 and an outer compressible layer 2. The manufacturing cost and construction process are relatively high, so it is mainly used in specific areas where external loads or environments may change significantly, or where there are ground fractures or ground fissures.

[0069] 2. The compressibility of the compressible layer 2 is mainly determined by the deformation capacity of the porous flexible pad 6 under the lining block 5. Therefore, it is necessary to make targeted designs in advance according to the dislocation or deformation requirements of the stratum. For general urban rail transit shield tunnels, the maximum deformation should be controlled within 50mm.

[0070] For additional loads or ground dislocation requirements along the tunnel longitudinal direction, the uniform deformation of the ring segment lining can be continuously adjusted and transitioned to meet the large deformation requirements in the tunnel longitudinal direction.

[0071] The structure of this invention has the following features and advantages:

[0072] 1) Based on the concept of "active compression and coordinated deformation", this invention uses a combined lining structure with a compressible layer 2 added to the outside of the conventional segment lining 1 to meet the stiffness requirements of conventional tunnel lining and the active compression deformation requirements under external additional loads.

[0073] 2) The concept of “rigidity and flexibility combined, active isolation” proposed in this invention is mainly due to the fact that the material stiffness and toughness of the compressible layer 2 are significantly different from those of the reinforced concrete lining. During the propagation of train vibration waves inside the tunnel, multiple reflections and refractions are required in the porous cushion layer inside the compressible layer 2. In addition, the significant difference in stiffness between the two materials can significantly weaken the outward transmission of train vibration and greatly improve the environmental quality along the line.

[0074] 3) The "active deformation and vibration isolation" method based on "compressible layer structure" described in this invention has a clear concept, simple process, and convenient construction. It has high economic and social benefits and has broad application prospects in tunnel engineering involving urban underground space development, rail transit, railway projects, etc.

[0075] The above examples illustrate the present invention only to aid in understanding it and are not intended to limit the scope of the invention. Those skilled in the art can make various simple deductions, modifications, or substitutions based on the principles of this invention.

Claims

1. A compressible and resilient segment lining structure with vibration damping function, characterized in that: The structure includes multiple lining units, each lining unit including an inner segment lining (1) and an outer compressible layer (2); The compressible layer (2) includes a plurality of porous rigid pads (7) arranged circumferentially. The porous rigid pads (7) are arranged longitudinally and their longitudinal length is consistent with the circumferential width of the tube segment. A longitudinally arranged porous flexible pad (6) is provided on the inner bottom between two circumferentially adjacent porous rigid pads (7). A lining block (5) is provided on the outer side of the porous flexible pad (6). The outer surface of the lining block (5) is smoothly spliced ​​with the outer surface of the porous rigid pad (7) to form the outer surface of the lining.

2. The compressible and resilient segment lining structure with vibration damping function according to claim 1, characterized in that: The vertical cross-section of the porous rigid pad (7) is a trapezoid with a smaller outer side and a larger inner side, and both the outer and inner surfaces are arc surfaces; The vertical cross-section of the porous flexible pad (6) is a trapezoid with a smaller inner section and a larger outer section, and both the outer and inner surfaces are arc surfaces. The vertical cross section of the lining block (5) is a trapezoid with a smaller inner section and a larger outer section, and both the outer and inner surfaces are arc surfaces. The porous rigid pad (7), the porous flexible pad (6), and the lining block (5) are tightly spliced ​​together to form the compressible layer (2) with a uniform radial thickness.

3. The compressible and resilient segment lining structure with vibration damping function according to claim 2, characterized in that: The porous flexible pad (6) is an EPDM rubber pad, and the porous rigid pad (7) is a concrete pad or a ceramic pad.

4. The compressible and resilient segment lining structure with vibration damping function according to claim 3, characterized in that: The lining unit includes a top capping block (1-1), adjacent blocks on both sides of the top (1-2), and standard blocks (1-3) at the bottom and on both sides of the bottom; The capping block (1-1), the adjacent block (1-2), and the standard block (1-3) are spliced ​​together in a ring, and then spliced ​​together in a longitudinal direction to form an integral tunnel.

5. The compressible and resilient segment lining structure with vibration damping function according to claim 4, characterized in that: The circumferential and longitudinal end faces of the segment lining (1) are provided with sealing gasket grooves (4), which are located in the middle and on the outer side. When the lining unit is spliced ​​in the circumferential and longitudinal directions, the sealing gasket grooves (4) are filled with sealing gaskets.

6. The compressible and resilient segment lining structure with vibration damping function according to claim 5, characterized in that: The circumferential end face of the segment lining (1) is also provided with a circumferential caulking groove (3), located on the inner side. When the lining unit is spliced ​​longitudinally, the caulking groove (3) is filled with waterproof sealant.

7. The compressible and resilient segment lining structure with vibration damping function according to claim 6, characterized in that: Bolt holes (8) are provided on the circumferential and longitudinal end faces of the segment lining (1), and the lining units are connected by bolts when they are spliced ​​circumferentially.

8. The compressible and resilient segment lining structure with vibration damping function according to claim 7, characterized in that: The total radial thickness of the segment lining (1) and the compressible layer (2) is the same as that of a conventional segment, and the radial thickness of the segment lining (1) is greater than that of the compressible layer (2).

9. The construction method of the compressible toughness segment lining structure with vibration reduction function as described in claim 8, characterized in that: The method includes: Precast lining blocks (5), porous flexible cushion layer (6) and porous rigid cushion layer (7); The porous flexible pad (6) and the porous rigid pad (7) are cut and then bonded together. The lining block (5) is inserted into the groove space formed after assembly and bonded together to form a compressible layer (2). Place the steel cage into the steel mold, tie the bolt hole mold to the steel cage, reserve the positions of the caulking groove (3) and the sealing gasket groove (4) on the steel mold, and then pour the segment lining (1). After the steam curing of the segment lining (1) is completed and before demolding, adhesive material is applied to the outer surface of the segment lining (1). Then, the pre-made compressible layer (2) is placed into the steel mold and bonded to the outer surface of the segment lining (1). Ballasting, static curing, demolding, and curing are then performed to complete the production.

10. The construction method of the compressible toughness segment lining structure with vibration reduction function according to claim 9, characterized in that: Under the action of external additional load, the porous rigid pad (7) is slightly compressed, the porous flexible pad (6) is significantly compressed and squeezed in a specific area, and the compressible layer (2) undergoes radial coordinated deformation. The deformed porous rigid pad (7) and the outer surface of the lining block (5) are located in the same radius of curvature range.

Images