Truss structure for supporting shield segment

Abstract

The utility model belongs to the technical field of urban rail transit and comprehensive pipe gallery construction, and provides a truss structure for supporting shield segments. The utility model relates to a truss structure for supporting a shield segment. The truss structure comprises an arched first chord member and a second chord member, wherein the arched first chord member is positioned in the shield segment and two ends of the outer side of the arched first chord member are assembled to a concrete base; the second chord member is located between the concrete base and the track, and the two ends of the second chord member are detachably connected with the two ends of the inner side of the first chord member to form a supporting body; the supporting rods are obliquely arranged, and the two ends of each supporting rod are detachably connected to the inner side portion of the shield segment and the outer side portion of the first chord member so as to disperse unbalanced force borne by the truss structure used for supporting the shield segment; unbalanced force borne by the shield segment is converted into pressure acting on the shield segment by the supporting rod and external thrust acting on the first chord member, and the external thrust acting on the first chord member can be counteracted through the second chord member with the two ends detachably connected to the two ends of the inner side of the first chord member correspondingly; therefore, the purpose of eliminating the unbalanced force borne by the shield segment is achieved.

Description

Technical Field

[0001] This utility model belongs to the field of urban rail transit and integrated utility tunnel construction technology, and more specifically, it relates to a truss structure for supporting tunnel segments. Background Technology

[0002] With the acceleration of my country's industrialization, underground space in cities is being developed and utilized. In the construction of urban rail transit, underground entrances and exits, and underground pedestrian crossings, the shield tunneling method is widely used in these projects due to its advantages such as fast construction speed, high degree of automation, and minimal environmental impact.

[0003] Shield tunneling projects using the shield method are typically carried out under complex geological conditions, facing numerous difficulties and challenges. These include tunnels traversing ground fissures, active fault zones, and karst formations (where shield segments must withstand significant shear forces); tunnels crossing rivers (where shield segments must withstand significant water pressure); tunnels passing through existing subway tunnels and pipelines; tunnels located in seismic zones (where shield segments must meet safety and durability requirements); and tunnels traversing soft soil layers and other special geological conditions (in which case the surrounding rock is soft, low in strength, has poor self-supporting capacity, and experiences large settlement, making it difficult to control the stability of the shield segments). Under these conditions, the shield segments experience unbalanced stress, specifically manifested in significant shear forces between adjacent segments and large bending moments on the bolts. This not only fails to meet the bolt stiffness requirements but also easily leads to cracks and uneven deformation in the shield segments. Therefore, those skilled in the art have conducted extensive research on shield segment reinforcement technologies in shield tunneling projects, including but not limited to steel ring reinforcement, grid-type supports, and full-span supports. Among these methods, steel ring reinforcement suffers from problems such as excessive self-weight, complex construction, large steel consumption, and high cost; grid-type supports are difficult to control to maintain stable deformation of shield tunnel segments, resulting in limited efficiency in reinforcing shield tunnel segments using this technique; and full-span supports not only require excessive support materials but also have high construction complexity and can only provide temporary protection in shield tunnels. In summary, existing reinforcement technologies cannot transfer or even eliminate the unbalanced forces acting on tunnel segments.

[0004] Therefore, there is an urgent need to invent a truss structure for supporting tunnel segments to solve the aforementioned technical problems. Utility Model Content

[0005] The technical problem to be solved by this utility model is how to disperse or even eliminate the unbalanced forces on the shield tunnel segments. In view of the above problem, a truss structure for supporting shield tunnel segments is provided.

[0006] The technical solution of this utility model to solve the above-mentioned technical problems is to provide a truss structure for supporting tunnel segments, wherein the bottom of the tunnel segments sequentially supports a concrete base and a track; including:

[0007] The arched first chord is located within the tunnel cavity enclosed by the shield segments;

[0008] The second chord is located between the concrete base and the track, and its two ends are detachably connected to the two ends of the first chord to form a support body.

[0009] Multiple support rods are arranged at an angle and their ends are detachably connected to the inner side of the shield segment and the outer side of the first chord to disperse and eliminate the unbalanced force on the shield segment.

[0010] In one embodiment, the shield tunnel segment is formed by sequentially joining multiple shield tunnel segments, and support rods are installed on both sides of each adjacent joint position of the shield tunnel segments.

[0011] Within the same vertical cross section, multiple support rods are arranged in an arch shape, with one end of each of the two end rods pressing against the outer side of the first chord, and the other end of each support rod and the corresponding end of the adjacent support rod pressing against the same position of the shield tunnel segment; one end of each of the middle support rods and the corresponding end of the adjacent support rod press against the same position of the shield tunnel segment or the first chord.

[0012] In one embodiment, it also includes a plurality of connectors integrally formed with the shield tunnel segment;

[0013] Each of the support rods is pressed against the shield tunnel segment via the connector.

[0014] In one embodiment, the plurality of the support rods are arranged symmetrically about the vertical plane of the truss structure used to support tunnel segments.

[0015] In one embodiment, a web member is also included, and the two ends of the web member are respectively fixed to the inner side of the first chord member near the top wall of the shield segment.

[0016] In one embodiment, the connector has at least two mounting holes, and each of the support rods is fastened to the mounting hole and pressed against the corresponding shield tunnel segment.

[0017] In one embodiment, the first chord and multiple pressure points on each of the shield tunnel segments are equipped with reinforcing plates.

[0018] In one embodiment, the vertical cross-section of the connector is arc-shaped.

[0019] In one embodiment, the second chord and the web member are both transverse I-beams, and the first chord is an arched I-beam.

[0020] In one embodiment, the truss structure for supporting tunnel segments is symmetrical about the vertical plane of the tunnel segments.

[0021] The beneficial effects of this utility model are as follows: by arranging multiple inclined support rods between the arched first chord surrounded by the shield tunnel segments and the shield tunnel segments, the unbalanced force on the shield tunnel segments is transformed into the pressure exerted by the support rods on the shield tunnel segments (as a supporting force for the shield tunnel segments, which does not need to be eliminated) and the outward thrust of the first chord. The arched first chord not only has good compressive characteristics, but also can offset the outward thrust acting on the first chord through the second chords that are detachably connected to the inner ends of the first chord at both ends, thereby achieving the purpose of eliminating the unbalanced force on the shield tunnel segments. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of a truss structure for supporting tunnel segments in one direction according to an embodiment of the present invention.

[0023] Figure label:

[0024] 1. A truss structure for supporting tunnel segments; 10. First chord; 11. Second chord; 12. Web member; 13. Supporting rod; 14. Connecting member;

[0025] 2. Shield tunnel segment; 20. Capping block; 21. Adjacent block; 22. Standard block; 23. Arch bottom block. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.

[0027] refer to Figure 1This utility model provides a truss structure 1 for supporting shield tunnel segments 2, wherein the bottom of the shield tunnel segment 2 is sequentially supported by a concrete base and a track. It includes a first chord 10, a second chord 11 connected to the first chord 10, and multiple support rods 13 placed between the first chord 10 and the shield tunnel segment 2, so as to maintain the camber of the first chord 10 through the second chord 11 (see below for details), and at the same time, the force exerted on the first chord 10 by the shield tunnel segment 2 by the multiple support rods 13, thereby achieving the purpose of effectively supporting the shield tunnel segment 2.

[0028] The first chord 10 can be arched and is located within the tunnel cavity enclosed by the shield segments 2.

[0029] The second chord 11 is located between the concrete base and the track, and its two ends are detachably connected to the inner ends of the first chord 10 to form a supporting body. It can be understood that the second chord 11 also plays a role in maintaining the camber of the first chord 10 to prevent the first chord 10 from deforming during the support of the shield tunnel segment 2.

[0030] Multiple support rods 13 are arranged at an angle and their ends are detachably connected to the inner side of the shield segment 2 and the outer side of the first chord 10 to disperse and eliminate the unbalanced force on the shield segment 2.

[0031] In one embodiment, the shield tunnel segment 2 is formed by sequentially joining multiple shield tunnel segments. Specifically, each shield tunnel segment includes a top capping block 20, two adjacent blocks 21 with one end respectively joined to both ends of the top capping block 20, standard blocks 22 each joined to the other end of the two adjacent blocks 21, and an arch bottom block 23 at the bottom. To ensure the joint strength between adjacent shield tunnel segments 2, support rods 13 are installed on both sides of the joint position of each adjacent shield tunnel segment. More specifically, within the same vertical section, multiple support rods 13 are arranged in an arch shape, and one end of each of the two end support rods 13 presses against the outer side of the first chord 10, while the other end and the corresponding end of the adjacent support rod 13 press against the same position of the shield tunnel segment; one end of each middle support rod 13 and the corresponding end of the adjacent support rod 13 press against the same position of the shield tunnel segment or the first chord 10.

[0032] In one embodiment, it also includes a plurality of connectors 14 integrally formed with the shield tunnel segment; each support rod 13 is pressed against the shield tunnel segment through the connector 14.

[0033] It should be noted that, as mentioned above, the capping block 20 has at least one connector 14, the arch bottom block 23 does not have a connector 14, while the adjacent block 21 and the standard block each have at least two connectors 14, and the number of support rods 13 matches the number of connectors 14. In this specific embodiment, the number of support rods 13 can be 16. Of course, in other specific embodiments, the number of support rods 13 can also be other. Furthermore, when any segment of the shield tunnel is subjected to significant pressure, the number of support rods 13 used to support the aforementioned shield tunnel segment can be increased as needed.

[0034] In one embodiment, in order to evenly distribute the force exerted on the first chord 10 by the shield segment 2 by the support rods 13, the multiple support rods 13 are arranged symmetrically about the vertical plane of a truss structure 1 for supporting the shield segment.

[0035] In one embodiment, in order to further maintain the arch of the first chord 10, the truss structure 1 for supporting the shield tunnel segment further includes a web member 12, and the two ends of the web member 12 are respectively fixed to the inner side of the first chord 10 near the top wall of the shield tunnel segment 2.

[0036] In one embodiment, the connector 14 has at least two mounting holes, and each support rod 13 is fastened to the mounting hole and pressed against the corresponding tunnel segment. Clearly, the two mounting holes are symmetrically arranged or positioned at corresponding locations on the connector 14.

[0037] In one embodiment, in order to prevent the first chord 10 from being damaged by the shear force generated by the two support rods 13 acting at the same position on the first chord 10, the first chord 10 and multiple pressure points on each shield tunnel segment are equipped with reinforcing plates (not shown).

[0038] In one embodiment, since I-beams have advantages such as good bending and torsional resistance, high strength, convenient processing, strong combinability and low cost, the second chord 11 and web member 12 can both be transverse I-beams, and the first chord 10 can also be an arched I-beam.

[0039] In one embodiment, in order to further distribute the force exerted on the first chord 10 by the shield segment 2 evenly by the support rod 13, a truss structure 1 for supporting the shield segment can be symmetrical about the vertical plane of the shield segment 2.

[0040] The installation steps of the truss structure 1 for supporting tunnel segments according to this utility model are as follows:

[0041] 1) Based on the requirements of the internal clearance, subway clearance, and track width after the shield tunnel segment 2 is assembled, determine the bending arc, length, and bolt hole arrangement of the first chord 10, the length of the second chord 11, the support rod 13, and the web member 12, and the arrangement of the aforementioned members (the arrangement of the support rod 13 is determined based on the joint position of adjacent shield tunnel segments). Then, design a specific shape of a truss structure 1 for supporting the shield tunnel segment (including stress analysis, stress and bending moment calculation of the entire truss structure 1 for supporting the shield tunnel segment to verify the truss structure for supporting the shield tunnel segment). 1) Check if the shape of structure 1 meets the requirements, and calculate the force on each member and check if the selected I-beam meets the strength requirements; 2) Based on the above steps, process a member (including first chord 10, second chord 11, web member 12 and support rod 13) for supporting shield tunnel segments; 3) After pouring concrete at the bottom of the shield tunnel, install the first chord 10 and the second chord 11 and lay the track; 4) Connect the web member 12 and support rod 13 in sequence with bolts, and install a reinforcing plate at the same pressing position of the two support rods 13 on the first chord 10 as needed.

[0042] The above are merely preferred embodiments of this utility model, but the scope of protection of this utility model is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this utility model should be included within the scope of protection of this utility model. Therefore, the scope of protection of this utility model should be determined by the scope of the claims.

Claims

1. A truss structure for supporting a shield segment, the shield segment bottom supporting a concrete base and a track in sequence, characterized in that, The utility model relates to a kind of truss structure for supporting shield segment, which comprises: Shield segment, a plurality of shield segments are sequentially connected to form a shield tunnel; First chord, which is an arched I-beam, is located in the tunnel chamber enclosed by the shield segment; Second chord, which is an arched I-beam, is located between the concrete base and the track, and is detachably connected to both ends of the first chord to form a support body; Web, which is an arched I-beam, is fixed to the inner side of the first chord near the top wall of the shield segment; A plurality of support rods are obliquely arranged and detachably connected to the inner side of the shield segment and the outer side of the first chord to disperse and eliminate the unbalanced force on the shield segment; and support rods are installed on both sides of the connection position of each adjacent shield segment segment. In the same vertical section, a plurality of support rods are arranged in an arch shape, and one end of each of the two support rods is pressed against the outer side of the first chord, and the other end is pressed against the corresponding end of the adjacent support rod at the same position of the shield segment segment; one end of each of the intermediate support rods is pressed against the corresponding end of the adjacent support rod at the same position of the shield segment segment or the first chord. The shield segment segment further comprises a plurality of connectors, each support rod is pressed against the shield segment segment through the connector, the connector has at least two mounting holes, and each support rod is pressed against the corresponding shield segment segment by connecting the mounting hole with a fastener.

2. The truss structure for supporting a shield segment according to claim 1, characterized by, A plurality of support rods are symmetrically arranged about the vertical plane of the truss structure for supporting shield segment.

3. A truss structure for supporting a shield segment according to claim 1, wherein The first chord and the plurality of pressed positions on each shield segment segment are provided with reinforcing plates.

4. The truss structure for supporting a shield segment according to claim 1, wherein The vertical section of the connector is arc-shaped.

5. The truss structure for supporting a shield segment according to claim 1, wherein The truss structure for supporting shield segment is symmetric about the vertical plane of the shield segment.

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