Tunnel station integrated construction method and special-shaped segment load servo supporting system thereof

Abstract

The invention relates to a tunnel station integrated construction method and a special-shaped segment load servo supporting system thereof. The tunnel station integrated construction method comprises the following steps: performing segment lining assembly operation in a shield tunneling stage; temporary supports are erected, and jack servo devices are installed between the L-shaped plug pipe pieces and the adjacent pipe pieces; excavating a middle soil body between the two shield tunnels by steps, and constructing a support and a lining to form a station structure; and the temporary transverse support, the adjacent block duct piece close to the station structure, the temporary vertical support and the jack load servo device on the lower portion are sequentially dismantled, the arch bottom area is backfilled, the station internal structure is constructed, and the L-shaped plug duct piece plug serves as a suspension fulcrum of a contact network system. According to the method, a novel tunnel station integrated construction method is formed on the basis of the concepts of connector reserving, active conversion, first erecting, then breaking and first supporting and then disassembling, the actual requirement for continuous shield tunneling of stations and intervals is met, and a more flexible selection space is provided for urban rail transit engineering construction.

Description

Technical Field

[0001] The present invention relates to the technical field of underground engineering construction, and in particular to a tunnel station integrated construction method and a special-shaped segment load servo support system thereof. Background Art

[0002] At present, as urban rail transit develops towards greater burial depth, larger cross-sections and spaces, the environment surrounding station projects is becoming increasingly complex due to the influence of urban development and existing structures. According to the overall construction planning arrangement, the station project is generally implemented first (the two ends of the station provide access conditions for the interval tunnel construction or shield excavation), and then the interval tunnel project is constructed. However, due to the constraints of the surrounding environment, the station project in the core area of ​​the city faces a very severe situation of traffic diversion, pipeline relocation and structure protection, resulting in delayed start of station project and inability to meet the needs of shield starting or receiving. At this time, it is necessary to consider the construction of the tunnel first, and then expand the excavation to form a station based on the completed tunnel project.

[0003] In the past, the expansion technology based on the existing shield tunnel required first breaking the segment lining and then connecting the old and new lining structures to form an effective stress conversion or load transfer path. As a result, there were problems such as unclear load conversion path and ineffective control of stratum settlement. In addition, complex stratum pre-reinforcement measures and internal support systems had to be set up, which were costly and risky. Therefore, it was urgent to break away from traditional thinking and develop a segment lining construction method that could effectively improve the efficiency of shield tunnel expansion and risk management. Summary of the Invention

[0004] The purpose of the present invention is to provide a tunnel station integrated construction method and its special-shaped segment load servo support system to solve the problems existing in the existing shield tunnel excavation process, such as unclear load conversion path, uncontrollable stratum settlement, and the need to set up complex internal supports.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is:

[0006] Provided is a load servo support system for special-shaped segments in a tunnel-station integrated construction method, the system comprising L-shaped plug segments, L-shaped joint segments, and adjacent block segments;

[0007] The L-shaped plug segment includes a top L-shaped plug segment and a bottom L-shaped plug segment, which is composed of a segment with a curvature radius consistent with that of the shield tunnel and a large plug protruding inward at the end of the segment, and has an L-shaped cross section;

[0008] The L-shaped joint segments include a top L-shaped joint segment and a bottom L-shaped joint segment, each of which is composed of a segment with a curvature radius consistent with that of the shield tunnel and a small joint protruding inward at the end of the segment, and has an L-shaped cross section;

[0009] The top L-shaped plug segment and the top L-shaped joint segment are arranged on both sides of the tunnel vault, the small joint of the top L-shaped joint segment is connected to the back of the large plug of the top L-shaped plug segment, and the joint position is located at the tunnel vault; the bottom L-shaped plug segment and the bottom L-shaped joint segment are arranged on both sides of the tunnel vault, the small joint of the bottom L-shaped joint segment is connected to the back of the large plug of the bottom L-shaped plug segment, and the joint position is located at the tunnel vault;

[0010] The adjacent block segments are arc-shaped structures, and a plurality of adjacent block segments are respectively connected between the top L-shaped plug segment and the bottom L-shaped plug segment, and between the top L-shaped joint segment and the bottom L-shaped joint segment, and are circumferentially closed into a ring.

[0011] Furthermore, a temporary vertical support is provided between the large plug of the top L-shaped plug segment and the large plug of the bottom L-shaped plug segment;

[0012] A temporary transverse support is also provided in the middle of the system, with both ends of the temporary transverse support tightly against the adjacent segments on both sides;

[0013] The temporary vertical supports and the temporary horizontal supports are arranged at intervals along the longitudinal direction according to the ring width of the shield tunnel.

[0014] Furthermore, a wedge-shaped space is provided between the large plug of the L-shaped plug segment and the small joint of the L-shaped joint segment and is filled with foam.

[0015] Furthermore, an oblique jack servo device is provided between the inner side of the large plug of the L-shaped plug segment and the adjacent block segment on that side.

[0016] Furthermore, longitudinal bolt connection holes are provided on the L-shaped plug segment, the L-shaped joint segment and the adjacent block segment for connecting the circumferential joints and longitudinal joints of the segments.

[0017] On the other hand, a method for constructing an integrated tunnel station based on the special-shaped segment load servo support system is provided, the method comprising:

[0018] Prefabricated shield segments, including L-shaped plug segments, L-shaped joint segments and adjacent block segments;

[0019] During the shield tunneling phase, segment lining assembly work is carried out, with two lines constructed separately;

[0020] Erect temporary vertical supports and temporary horizontal supports inside the shield tunnel;

[0021] Install a jack servo device between the inner side of the large plug of the L-shaped plug segment and the adjacent block segment on that side;

[0022] Excavate the soil between the two shield tunnels in steps, and promptly apply support and lining to form the station structure.

[0023] Remove the temporary horizontal supports, adjacent segments close to the station structure, and temporary vertical supports in sequence;

[0024] The lower jack load servo device was removed, low-grade concrete was used to backfill the bottom of the station structure, and the internal structure of the station was constructed. The large plug of the L-shaped plug segment was used as the suspension support point of the contact network system.

[0025] Furthermore, when prefabricating shield segments, longitudinal bolt connection holes are prefabricated on the L-shaped plug segments, L-shaped joint segments and adjacent block segments, and triangular foam boards are pasted at positions corresponding to the wedge-shaped spaces on the L-shaped plug segments and L-shaped joint segments.

[0026] Furthermore, the segment lining assembly operation includes:

[0027] First, assemble the bottom L-shaped plug segments, and then position the full ring segment lining through the assembly of the bottom L-shaped plug segments;

[0028] Then assemble the bottom L-shaped joint segments, and then assemble the adjacent block segments, top L-shaped plug segments and top L-shaped joint segments in an alternating manner from left to right;

[0029] All shield segments within the station area are assembled with through-seam technology;

[0030] The top L-shaped joint segment is wedge-shaped along the longitudinal direction of the tunnel.

[0031] Furthermore, temporary vertical supports and temporary horizontal supports are set up inside the shield tunnel, including:

[0032] Weld a steel top block below the L-shaped plug segment at the top of the shield tunnel, and weld a steel bottom block inside the L-shaped plug segment at the bottom;

[0033] Erect temporary vertical supports between the steel top block and the steel bottom block;

[0034] Set up temporary transverse supports, and use wedges at both ends to lock the adjacent segments on both sides;

[0035] Temporary vertical supports and temporary horizontal supports are arranged at intervals along the longitudinal direction of the tunnel according to the requirement of arranging one ring of segments.

[0036] Furthermore, a jack servo device is installed, including:

[0037] On the outer upper section of the shield tunnel, a jack load servo device is used to press one end against the inner side of the top L-shaped plug segment and the other end against the adjacent segment to apply prestress, ensuring that the shield tunnel vault has an upward displacement trend.

[0038] At the lower section outside the shield tunnel, a jack load servo device is used to press one side of the steel bottom block with one end and the adjacent block segment with the other end, applying prestress to ensure that the L-shaped plug segment at the bottom of the shield tunnel can withstand horizontal forces.

[0039] After the station structure is formed, the circular profile force-bearing system of the shield tunnel is converted into an integrated elliptical profile force-bearing system of the tunnel and station consisting of the arch cover lining, top L-shaped plug segments, adjacent block segments, jack servo devices, bottom L-shaped plug segments and arch bottom lining of the station structure.

[0040] Compared with the prior art, the present invention has the following beneficial effects:

[0041] The present invention provides a method for constructing an integrated tunnel station and a load servo support system for special-shaped segments thereof. L-shaped plug segments, L-shaped joint segments, and adjacent block segments are prefabricated in a factory according to design requirements. Based on the construction plan, the excavation of the left and right shield tunnels is completed in succession. Within the station area, the segment lining is assembled through seams to ensure that the wedge-shaped space outside the L-shaped segment is located at the top and bottom of the tunnel vault, thereby achieving the purpose of "reserving joints and active conversion." The wedge-shaped space and connecting plug segments reserved at the top and bottom of the shield tunnel vault provide working space for the effective connection between the top and bottom lining structures of the expanded excavation area and the shield tunnel segment lining, thus achieving active conversion of the load system before the segment lining is removed. At the same time, through the jack load servo device connected to the L-shaped segment, active loading can be performed according to the situation to control the settlement and deformation of the tunnel top, further realizing the "first erection, then destruction, first support, then dismantling" method, that is, after the load conversion system is completed, the shield segment lining is broken and the temporary support in the tunnel is removed, which effectively overcomes the previous disadvantage of having to dismantle the segment lining before establishing a complete load conversion system, effectively controls the ground settlement, and the internal support is simple and effective. At the same time, it also solves the water leakage risk faced by the junction of the new and old structures in the conventional excavation process, with significant economic and social benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, without paying any creative work, they can also obtain drawings of other embodiments based on these drawings.

[0043] Figure 1A diagram of single-line shield tunnel excavation and segment lining assembly provided in an embodiment of the present invention.

[0044] Figure 2 A diagram of double-track shield tunnel excavation and segment lining assembly provided in an embodiment of the present invention.

[0045] Figure 3 This is a diagram of the advance support of the soil body and the upper step excavation and lining operations provided in an embodiment of the present invention.

[0046] Figure 4 This is a diagram of the excavation and lining operations of the lower step of the soil body provided in an embodiment of the present invention.

[0047] Figure 5 This is a diagram of step excavation in a soil body provided by an embodiment of the present invention.

[0048] Figure 6 Diagram of segment lining and temporary support removal provided in an embodiment of the present invention.

[0049] Figure 7 This is a construction drawing of the station's internal structure, including bottom backfill and platform slabs, provided in an embodiment of the present invention.

[0050] The symbols in the figure are:

[0051] 1-Shield tunnel, 2-Top L-shaped plug segment, 3-Top L-shaped joint segment, 4-Bottom L-shaped plug segment, 5-Bottom L-shaped joint segment, 6-Adjacent block segment, 7-Top wedge space, 8-Bottom wedge space, 9-Jack servo device, 10-Temporary vertical support, 11-Temporary lateral support, 12-Steel top block, 13-Steel bottom block, 14-Advanced support, 15-Arch initial support, 16-Arch cover lining, 17-Arch bottom initial support, 18-Cast-in-situ arch bottom lining, 19-Backfill layer, 20-Platform slab, 21-Wedge-shaped I-beam, 22-Contact network system, 23-Ballad, 24-Vehicle, 25-Upper step, 26-Middle step, 27-Lower step. DETAILED DESCRIPTION

[0052] To facilitate understanding of the present invention, the present invention will be described more fully below with reference to the accompanying drawings. The accompanying drawings illustrate preferred embodiments of the present invention. However, the present invention may be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and comprehensive understanding of the present disclosure.

[0053] In the description of the present invention, it should be understood that the terms "up", "down", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0054] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "installed" and "disposed" should be understood in a broad sense. For example, they may refer to fixed connection or arrangement, detachable connection or arrangement, or integral connection or arrangement. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0055] It should also be noted that although the steps are described in order, in some cases they may be performed in an order different from that shown, and this should not be construed as limiting the order of the steps.

[0056] In a specific implementation, the tunnel line direction is defined as "longitudinal", the direction perpendicular thereto is defined as "transverse", and the height direction of the segment lining, i.e., the direction perpendicular to the horizontal plane, is defined as "vertical", and the "vertical" is also referred to as "vertical".

[0057] In engineering practice, tunnel excavation is first carried out, and then the station is formed by excavation on the basis of the completed tunnel project. This is the construction process of tunnel excavation. In order to overcome the problems existing in the current tunnel excavation construction process, such as the lining structure is first broken and then erected, the load transfer system is built lagging, the ground settlement caused by the excavation construction is difficult to be effectively controlled, and the safety protection requirements of the excavation construction itself and the surrounding environment cannot be met, the present invention provides a tunnel station integrated construction method based on the special-shaped segment load servo support system. The method specifically includes the following steps:

[0058] S1: Factory prefabrication of lining structure including L-shaped joint segments and shield tunneling construction.

[0059] According to the design requirements, the top L-shaped plug segment 2, the top L-shaped joint segment 3, the bottom L-shaped plug segment 4, the bottom L-shaped joint segment 5 and the adjacent block segment 6 are prefabricated in advance at the segment factory. Figure 1 In the embodiment, the cross section of the shield tunnel can be divided into 9 segments, that is, two adjacent segments 6 are set on the left and three adjacent segments 6 are set on the right.

[0060] The shield method is used for continuous excavation construction of urban rail transit section tunnels and station areas. According to the design plan and engineering planning requirements, the shield excavation construction of the left and right lines of the section tunnels is completed successively. The two lines are constructed separately at a certain distance along the longitudinal direction. The net distance between the two tunnels should generally not be less than one tunnel diameter. Based on the contour circularity and force requirements, the dark excavation outline and range between the left and right tunnels are given.

[0061] During the shield excavation stage, the segment lining assembly operation is carried out according to the design requirements. The assembly of the lowest bottom L-shaped plug segment 4 should be carried out first. The full ring segment lining is positioned by assembling the bottom plug segment lining. Then the assembly of the bottom L-shaped joint segment 5 is carried out. Finally, the adjacent block segment 6, the top L-shaped plug segment 2 and the top L-shaped joint segment 3 are assembled in an alternating manner from left to right. All the shield segments in the station range are assembled with through-seam. Among them, the last assembled L-shaped joint segment 3 is wedge-shaped (transverse to the tunnel, the arc lengths of the front and rear sides are inconsistent), and its construction method is similar to that of the conventional shield tunnel segment capping block.

[0062] The maximum plug height of the L-shaped plug segment must be greater than the sum of the height of the top and bottom wedge spaces and the lining thickness of the L-shaped joint segment. The maximum plug thickness (≥700mm) can generally be considered as twice the segment lining thickness (≥350mm). The side dimension of the plug of the top wedge space 7 is generally not less than 600mm and must meet the construction conditions of the arch initial support 15 and the arch cover lining 16, while ensuring that the horizontal load of the arch cover lining 16 can be effectively transferred to the top L-shaped plug segment 2. The side dimension of the plug of the bottom wedge space 8 is generally not less than 800mm and must meet the construction conditions of the arch bottom initial support 17 and the arch bottom lining 18, while ensuring that the horizontal load of the arch cover lining 18 can be effectively transferred to the bottom L-shaped plug segment 4.

[0063] Before assembling the top L-shaped joint segment 3 and the bottom L-shaped joint segment 5, triangular foam boards are pasted on their back sides according to the external contour requirements of the shield tunnel to fill the top and bottom wedge-shaped spaces and meet the roundness requirements of the external contour of the shield tunnel.

[0064] In the cross-sectional direction of the shield tunnel, that is, on the annular surface of the segment lining, longitudinal bolt connection holes are evenly arranged based on a 360° angle. They can be evenly arranged at intervals of about 20°, and at the same time, a certain distance must be maintained from the longitudinal joint position of the cross-sectional segment.

[0065] S2: Erection of internal support system of shield tunnel.

[0066] like Figure 1, weld a steel top block 12 beneath the L-shaped plug segment 2 at the top of the shield tunnel, and weld a steel bottom block 13 inside the L-shaped plug segment 4 at the bottom. Then, install temporary vertical supports 10 between the top and bottom blocks 12 and 13. Then, install temporary transverse supports 11, each secured to the segment lining with wedges. Temporary vertical supports 10 and temporary transverse supports 11 are spaced one per segment ring, with the longitudinal spacing consistent with the segment ring width.

[0067] Load servo devices, primarily composed of inclined jacks, are installed at both the tunnel's vault and base. Specifically, in the upper left section of the tunnel, one end of the jack-load servo device 9 presses against the inner side of the L-shaped plug segment, while the other end presses against the adjacent segment 6. A certain amount of prestress is applied to ensure a certain upward displacement of the tunnel vault. In the lower left section of the tunnel, one end of the jack-load servo device 9 presses against one side of the steel block 13, while the other end presses against the adjacent segment 6. A certain amount of prestress is applied to ensure that the L-shaped plug segment 4 at the tunnel base withstands a certain amount of horizontal force.

[0068] S3: Excavate the soil between the two shield tunnels.

[0069] like Figure 2 After the excavation of the two-line shield tunnels, the assembly of the pipe segments and the erection of the internal support system are completed, the excavation of the middle sandwich body is carried out. First, the sandwich body range is divided into three parts: the upper step 25, the middle step 26 and the lower step 27. It can also be divided into four steps from top to bottom according to the stratum conditions.

[0070] like Figure 3 First, advance pre-reinforcement of the strata outside the excavation contour of the upper step 25 is performed. Depending on the situation, the advance support 14 can use a large pipe shed or pipe curtain. The diameter and spacing of the large pipe shed or pipe curtain are determined by the requirements for controlling the settlement and deformation of the upper strata. Generally, the diameter of the large pipe shed should not be less than 194mm, the circumferential spacing can generally be considered to be 300-500mm, the longitudinal length should not be less than 15m, and the longitudinal overlap length should not be less than 3m. An elevation angle of approximately 15° should be considered along the longitudinal direction of the tunnel. The connection between the end of the constructed arch lining 16 and the top L-shaped plug segment 2 is achieved by welding the pre-embedded steel plate pre-embedded on the back side of the top L-shaped plug segment 2 to the arch lining 16 steel bars.

[0071] Under the protection of advanced support measures, the soil of the upper step 25 is excavated according to design requirements. Depending on the situation, full-section excavation or reserved core soil excavation can be adopted. This method first excavates the arch ring step to meet the construction requirements of the arch initial support 15 and the pouring of the arch cap lining 16. After the arch lining reaches the design strength requirements, the remaining soil of the upper step 25 is excavated. The scope of the advanced support 14 must include the wedge-shaped space behind the L-shaped plug segment. At the same time, during the construction of the initial support and secondary lining, the foam board in the corresponding position must be removed.

[0072] After the arch cover lining 16 is completed and reaches the design strength, a certain load should be applied through the upper jack servo device 9 to form an effective load transfer path between the arch cover lining 16, the top L-shaped plug segment 2 and the jack servo device 9. At the same time, it is ensured that the arch cover lining 16 is subjected to a certain "pre-compression stress" and presents a certain "outward top" trend, effectively controlling the possible settlement and deformation risks of the tunnel arch.

[0073] like Figure 4 , similar to the excavation of the upper step 25, the excavation of the lower step 27 is carried out. The top height of the lower step 27 should not exceed the height of the temporary horizontal support 11 in the tunnel. According to the needs of stratum stability, cross-section block excavation can be adopted, and the arch bottom initial support 17 and arch bottom lining 18 can be timely constructed. After the excavation of the lower step 27 is completed, the connection between the end of the arch bottom lining 18 and the bottom L-shaped plug segment 4 is achieved by welding the pre-embedded steel plate pre-embedded in the back side of the bottom L-shaped plug segment 4 to the arch bottom lining 18 steel bars. The design of the pre-embedded steel plate meets the joint waterproofing requirements of the cold joint of the structure, and more importantly, it effectively avoids the process of breaking the segment lining and breaking the existing force balance system in conventional excavation construction, and realizes effective load conversion first, and then breaking the segment lining and excavation construction.

[0074] like Figure 5 Finally, middle step 26 is excavated, connecting upper step 25 and lower step 27, forming the station structure outline between the two shield tunnels. The height range of middle step 26 should cover the height of temporary lateral support 11 inside shield tunnel 1.

[0075] During the excavation of the soil body, after the arch cover lining 16 is poured and reaches the design strength, the supporting force of the upper load servo device of the shield tunnel should be appropriately increased if necessary based on the monitoring of stratum displacement and settlement, so that the arch cover lining 16 has a certain upward arching trend and suppresses the settlement deformation of the upper stratum.

[0076] The jack load servo device 9 at the arch top has one end located inside the large plug of the top L-shaped plug segment 2, and the other end supported on the adjacent segment 6 above the tunnel haunch. An effective load transfer path is formed between the jack load servo device 9, the large plug of the top L-shaped plug segment 2, and the arch cover lining 16. The jack load servo device 9 at the arch bottom has one end located on one side of the steel bottom block 13 above the bottom L-shaped plug segment 4, and the other end supported on the adjacent segment 6 below the tunnel haunch. An effective load transfer path is formed between the jack load servo device 9, the steel bottom block 13, the large plug of the bottom L-shaped plug segment 4, and the arch bottom lining 18.

[0077] S4: Shield tunnel segment lining removal and station structure construction.

[0078] After the excavation of the soil between the left and right line shield tunnels is completed, the entire station outline structure has been completed. At this time, the circular outline force system of the shield tunnel has been converted into an integrated elliptical outline force system of the tunnel station consisting of the arch cover lining 16, the top L-shaped plug segment 2, the adjacent block segment 6, the jack servo device 9, the bottom L-shaped plug segment 4, and the arch bottom lining 18.

[0079] like Figure 6 , dismantle them in the order of temporary horizontal support 11, adjacent block segments 6, and temporary vertical support 10, dismantling them one ring at a time along the longitudinal direction of the tunnel. During the dismantling process, attention must be paid to the settlement trend of the tunnel arch.

[0080] like Figure 7 According to the design requirements, the jack load servo device 9 in the lower half of the shield tunnel section was removed. A certain height range above the arch bottom was then backfilled with low-grade concrete. The height of the backfill layer 19 was determined based on the bottom elevation of the track bed 23. The station's internal structure, including the platform slab 20 and lower support system, was then constructed. The track bed 23 and track structure were then poured as required, below the left and right lane vehicles 24 and above the backfill layer 20.

[0081] Afterwards, according to the requirements for setting up the contact network above the vehicle 24, the steel top block 12 on the top of the vertical temporary support 10 in the early shield tunnel 1 is used to fix the wedge-shaped I-beam 21 under the steel top block 12 by bolts, and the wedge-shaped I-beam 21 can provide a suspension fulcrum for the contact network system 22.

[0082] The method of the present invention is based on the concepts of "reserved joints, active conversion", "erecting first and then breaking, supporting first and then demolishing", forming a new "tunnel-station integrated" construction method, which meets the actual needs of using continuous shield tunneling in stations and sections, and provides more flexible options for urban rail transit project construction.

[0083] The load-servo support system for special-shaped segments involved in the above-mentioned construction method has a unique structure, including three types of segments: L-shaped plug segments, L-shaped joint segments, and adjacent block segments 6. The L-shaped plug segments include top L-shaped plug segments 2 and bottom L-shaped plug segments 4, each consisting of a segment with a curvature radius consistent with that of the shield tunnel and a large plug protruding inward at the end of the segment. The L-shaped joint segments include top L-shaped joint segments 3 and bottom L-shaped joint segments 5, each consisting of a segment with a curvature radius consistent with that of the shield tunnel and a small joint protruding inward at the end of the segment, with an L-shaped cross-section.

[0084] The top L-shaped plug segment 2 and the top L-shaped joint segment 3 are arranged on both sides of the tunnel arch, and the small joint of the top L-shaped joint segment 3 is connected to the back of the large plug of the top L-shaped plug segment 2, and the joint position is located at the tunnel arch; the bottom L-shaped plug segment 4 and the bottom L-shaped joint segment 5 are arranged on both sides of the tunnel arch, and the small joint of the bottom L-shaped joint segment 5 is connected to the back of the large plug of the bottom L-shaped plug segment 4, and the joint position is located at the tunnel arch.

[0085] The adjacent block segments 6 are arc-shaped structures. Multiple adjacent block segments 6 are respectively connected between the top L-shaped plug segment 2 and the bottom L-shaped plug segment 4, and between the top L-shaped joint segment 3 and the bottom L-shaped joint segment 5. The segment blocks are connected by traditional bolts and are circumferentially closed into a ring.

[0086] The shield tunnel has a temporary support structure inside, including temporary vertical supports 10 and temporary transverse supports 11. Specifically, temporary vertical supports 10 are installed between the large plug of the top L-shaped plug segment 2 and the large plug of the bottom L-shaped plug segment 4. Temporary transverse supports 11 are also installed in the middle of the system, with both ends of temporary transverse supports 11 tightly abutting the adjacent segments 6 on either side.

[0087] like Figure 1 There is a wedge-shaped space between the large plug of the L-shaped plug segment and the small joint of the L-shaped joint segment and it is filled with triangular foam boards. They are pasted to the corresponding positions of the L-shaped plug segment and the L-shaped joint segment before assembly after the prefabricated segments.

[0088] In addition, an oblique jack servo device 9 is provided between the inner side of the large plug of the L-shaped plug segment and the adjacent block segment 6 on that side. The device is distributed on the side of the shield tunnel away from the station, and one is arranged above and below to provide support for the tunnel vault and arch bottom, effectively controlling the deformation trend of the tunnel vault and arch bottom. The present invention sets L-shaped segments and oblique jack devices on the vault and arch bottom of the shield tunnel. Before the shield tunnel is horizontally expanded and the lining is removed, the L-shaped segment is effectively connected to the arch cover lining and the arch bottom lining based on the wedge-shaped space reserved on the outside of the L-shaped segment. The load servo device is used to perform horizontal active loading, realizing the active conversion of the horizontal bearing system before the segment lining is removed.

[0089] All segments, including L-shaped plug segments, L-shaped joint segments and adjacent block segments 6, are provided with longitudinal bolt connection holes for inserting longitudinal bolts during longitudinal splicing to connect the circumferential joints and longitudinal joints of the segments.

[0090] The technical core of the method of the present invention is the L-shaped plug segments and L-shaped joint segments set on the tunnel vault and arch bottom. On the one hand, wedge-shaped space is reserved for the outer side of the tunnel vault and arch bottom, providing conditions for the connection of the arch cover lining 16, arch bottom lining 18 and the segment lining in the later stage. On the other hand, a structural contour force system including the station range can be formed before the segment lining is broken. The load servo device based on the jack can realize "erecting first and then breaking", thereby minimizing the risk of ground deformation caused by the breaking of the segment lining.

[0091] In the structural system of the present invention, conventional reinforced concrete lining is used for the various segments, arch cap lining, and arch base lining. The arch primary supports 15 and arch base 17 are constructed using a mixture of wire mesh and C25 sprayed concrete. The steel top block 12, steel bottom block 13, temporary vertical supports 10, temporary horizontal supports 11, wedge-shaped I-beams 21, and jack load servo device 9 are all constructed using steel structures, such as Q345 steel plates. The wedge-shaped spaces at the top and bottom of the tunnel are pre-sealed with foam board. The station's internal structure utilizes conventional reinforced concrete, and the backfill concrete at the station base is C25 concrete.

[0092] The distance between the two lines of shield tunnel 1 must meet the requirements of the station platform span and the subsequent expansion excavation process. The size and curvature of the top advance support 14 and the arch cover lining 15 must be determined comprehensively based on the stratum conditions, excavation method and stratum settlement control requirements. The rise-to-span ratio of the arch cover lining 15 should not be less than 1 / 5.

[0093] During implementation of the method provided by the present invention, it is necessary to pay attention to the following:

[0094] 1. The wedge-shaped spaces at the top and bottom of the shield tunnel 1 are primarily formed by the "M"-shaped connection of the L-shaped plug segments and the L-shaped joint segments. The wedge-shaped spaces are relatively fixed in position, and their size must meet the connection requirements of the arch cover lining 16 and the arch bottom lining 18. Simultaneously, these spaces are filled with foam boards during segment assembly.

[0095] 2. The jack load servo device 9 installed inside the shield tunnel 1 is directly connected to the top L-shaped plug segment 2 and the steel bottom block 13, thereby applying a certain pre-loading force to the tunnel vault and arch cover lining 16. However, the magnitude of the pre-loading force must be strictly controlled. If it is too small, it may cause the tunnel vault and stratum to sink and deform, while if it is too large, it may cause damage to the segment lining. Generally, it can be controlled by ensuring that the L-shaped plug segment 2 at the vault position is subject to a certain upward displacement trend;

[0096] 3. Within the station structure, the shield tunnel 1 segment lining must be assembled with through-seam assemblies to ensure that relatively fixed wedge-shaped spaces are formed at the tunnel vault and vault bottom.

[0097] 4. Within the station structure, the clear distance between the left and right tunnels should generally be no less than 1 shield diameter. The soil between the two lines should be divided into at least three steps, from top to bottom, based on ground conditions and the surrounding environment. Before excavating the upper step, advance support should be implemented as appropriate. The top of the lower step should not exceed the height of the temporary lateral support 11 within the shield tunnel 1. Excavation of the soil between the two lines should be carried out simultaneously, followed by removal of the segmental lining and construction of the station's internal structure.

[0098] The structure of the present invention has the following characteristics and advantages:

[0099] 1) Based on the concept of "reserving space for active load conversion," this invention uses a special L-shaped plug segment and L-shaped joint segment combination to form a relatively fixed wedge-shaped space at the tunnel vault and vault base. This space provides an effective connection between the vault cover lining, vault base lining, and shield tunnel segment lining. This not only achieves active load conversion but also completely solves the problems of tunnel vault and vault base destruction and structural cold joint leakage.

[0100] 2) The "build first, demolish later, support first, demolish later" concept proposed in this invention is primarily aimed at: after the excavation of the soil between the left and right shield tunnels within the station area is completed, and the top arch lining and bottom lining of the station area are poured, forming a complete load-bearing system around the station outline, then the segmental lining in the shield tunnel expansion area and the temporary supports inside the tunnel can be removed;

[0101] 3) The wedge-shaped reserved space formed by the L-shaped segments in this invention can provide a reference for the expansion and construction of various underground spaces, especially for the development and construction of plots along urban rail transit lines and the development and construction of TOD stations, effectively supporting urban construction and development;

[0102] 4) The "active conversion, erection before demolition" method based on the "L-shaped segments" provided by the present invention has a clear concept, simple process, and easy construction. It has high economic and social benefits and has broad application prospects in tunnel projects involving urban underground space development, rail transit, railway projects, etc.

[0103] The above examples are used to illustrate the present invention, which are only used to help understand the present invention and are not intended to limit the present invention. Those skilled in the art can make several simple deductions, modifications or substitutions based on the concept of the present invention.

Claims

1. The load servo support system for special-shaped segments in the tunnel-station integrated construction method is characterized by: The system comprises an L-shaped plug segment, an L-shaped joint segment and an adjacent block segment (6); The L-shaped plug segment comprises a top L-shaped plug segment (2) and a bottom L-shaped plug segment (4), which is composed of a segment having a curvature radius consistent with that of the shield tunnel (1) and a large plug protruding inwardly at the end of the segment, and has an L-shaped cross section; The L-shaped joint segments include a top L-shaped joint segment (3) and a bottom L-shaped joint segment (5), each consisting of a segment having a curvature radius consistent with that of the shield tunnel (1) and a small joint protruding inwardly at the end of the segment, and having an L-shaped cross section; The top L-shaped plug segment (2) and the top L-shaped joint segment (3) are arranged on both sides of the tunnel vault, the small joint of the top L-shaped joint segment (3) is connected to the back of the large plug of the top L-shaped plug segment (2), and the joint position is located at the tunnel vault; the bottom L-shaped plug segment (4) and the bottom L-shaped joint segment (5) are arranged on both sides of the tunnel vault, the small joint of the bottom L-shaped joint segment (5) is connected to the back of the large plug of the bottom L-shaped plug segment (4), and the joint position is located at the tunnel vault; The adjacent block segments (6) are of an arc-shaped structure, and a plurality of the adjacent block segments (6) are respectively connected between the top L-shaped plug segment (2) and the bottom L-shaped plug segment (4), and between the top L-shaped joint segment (3) and the bottom L-shaped joint segment (5), and are circumferentially closed into a ring.

2. The load servo support system for special-shaped segments in the tunnel-station integrated construction method according to claim 1 is characterized by: A temporary vertical support (10) is provided between the large plug of the top L-shaped plug segment (2) and the large plug of the bottom L-shaped plug segment (4); A temporary transverse support (11) is also provided in the middle of the system, and both ends of the temporary transverse support (11) are tightly against the adjacent tube segments (6) on both sides; The temporary vertical supports (10) and the temporary horizontal supports (11) are arranged at intervals along the longitudinal direction according to the ring width of the shield tunnel (1).

3. The load servo support system for special-shaped segments in the tunnel station integrated construction method according to claim 2 is characterized by: A wedge-shaped space is provided between the large plug of the L-shaped plug pipe segment and the small joint of the L-shaped joint pipe segment and is filled with foam.

4. The load servo support system for special-shaped segments in the tunnel-station integrated construction method according to claim 3 is characterized by: An oblique jack servo device (9) is provided between the inner side of the large plug of the L-shaped plug segment and the adjacent block segment (6) on that side.

5. The load servo support system for special-shaped segments in the tunnel station integrated construction method according to claim 4 is characterized by: The L-shaped plugging segment, the L-shaped joint segment and the adjacent block segment (6) are all provided with longitudinal bolt connection holes for connecting the circumferential joints and longitudinal joints of the segments.

6. A method for constructing an integrated tunnel station based on the special-shaped segment load servo support system according to claim 5, characterized in that: The method comprises: Prefabricated shield segments, including L-shaped plug segments, L-shaped joint segments and adjacent block segments (6); During the shield tunneling phase, segment lining assembly work is carried out, with two lines constructed separately; Setting up temporary vertical supports (10) and temporary horizontal supports (11) inside the shield tunnel; A jack servo device (9) is installed between the inner side of the large plug of the L-shaped plug segment and the adjacent block segment (6) on that side; Excavate the soil between the two shield tunnels in steps, and promptly apply support and lining to form the station structure. Remove the temporary transverse supports (11), the adjacent segments (6) close to the station structure and the temporary vertical supports (10) in sequence; The lower jack load servo device (9) is removed, low-grade concrete is used to backfill the bottom of the station structure, and the internal structure of the station is constructed. The large plug of the L-shaped plug segment is used as the suspension support point of the contact network system (22).

7. The method for constructing an integrated tunnel station based on a special-shaped segment load servo support system according to claim 6, characterized in that: When prefabricating shield segments, longitudinal bolt connection holes are prefabricated on the L-shaped plug segments, the L-shaped joint segments and the adjacent block segments (6), and triangular foam plates are pasted on the L-shaped plug segments and the L-shaped joint segments at positions corresponding to the wedge-shaped spaces.

8. The method for constructing an integrated tunnel station based on a special-shaped segment load servo support system according to claim 7, characterized in that: Segment lining assembly operations include: First, assemble the bottom L-shaped plug segment (4), and position the full-ring segment lining through the assembly of the bottom L-shaped plug segment (4); Then, the bottom L-shaped joint segment (5) is assembled, and then the adjacent block segment (6), the top L-shaped plug segment (2) and the top L-shaped joint segment (3) are assembled in an alternating manner from left to right. All shield segments within the station area are assembled with through-seam technology; The top L-shaped joint segment (3) is wedge-shaped along the longitudinal direction of the tunnel.

9. The method for constructing an integrated tunnel station based on a special-shaped segment load servo support system according to claim 8, characterized in that: Temporary vertical supports (10) and temporary horizontal supports (11) are set up inside the shield tunnel, including: A steel top block (12) is welded below the L-shaped plug segment (2) at the top of the shield tunnel, and a steel bottom block (13) is welded inside the L-shaped plug segment (4) at the bottom; A temporary vertical support (10) is erected between the steel top block (12) and the steel bottom block (13); Temporary transverse supports (11) are erected, and wedges are used at both ends to lock the adjacent segments (6) on both sides; Temporary vertical supports (10) and temporary transverse supports (11) are arranged at intervals along the longitudinal direction of the tunnel according to the requirement of arranging one ring of segments at one location.

10. The method for constructing an integrated tunnel station based on a special-shaped segment load servo support system according to claim 9, characterized in that: Install the jack servo assembly (9), including: On the outer upper section of the shield tunnel, one end of a jack load servo device (9) is used to press against the inner side of the top L-shaped plug segment (2), and the other end is used to press against the adjacent segment (6), applying prestress to ensure that the shield tunnel vault has an upward displacement trend; At the lower section outside the shield tunnel, one end of a jack load servo device (9) is used to support one side of the steel bottom block (13), and the other end is used to support the adjacent block segment (6), applying prestress to ensure that the bottom L-shaped plug segment (4) of the shield tunnel withstands the horizontal force; After the station structure is formed, the circular profile force-bearing system of the shield tunnel is converted into an integrated elliptical profile force-bearing system of the tunnel station consisting of the arch cover lining (16), the top L-shaped plug segment (2), the adjacent block segment (6), the jack servo device (9), the bottom L-shaped plug segment (4) and the arch bottom lining (18) of the station structure.

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