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

Abstract

The present application relates to a kind of tunnel station integrated construction method and its special-shaped segment load servo support system, shield tunneling stage carries out segment lining assembly operation;Erect temporary support, install jack servo device between L-shaped plug segment and adjoining block segment;The intermediate soil body between two-line shield tunnel is excavated in steps, and station structure is formed by supporting and lining;Temporary transverse support, adjoining block segment close to station structure, temporary vertical support, lower jack load servo device are removed in sequence, arch bottom area is backfilled, and station internal structure is applied, and L-shaped plug segment plug is used as the suspension support point of contact net system.The method of the present application is based on the concept of "reserved joint, active conversion", "first stand then break, first support then remove", forms a new type of tunnel station integrated construction method, meets the actual demand of station, interval using shield continuous tunneling, and provides more flexible selection space for urban rail transit engineering construction.

Description

Technical Field

[0001] This invention relates to the field of underground engineering construction technology, specifically to an integrated tunnel-station construction method and its irregular segment load servo support system. Background Technology

[0002] Currently, as urban rail transit develops towards greater depth, larger cross-sections, and more spatial dimensions, the surrounding environment of station projects is becoming increasingly complex due to urban development and existing structures. According to the overall project plan, station construction is typically carried out first (providing access to the tunnel sections for either cut-and-cover excavation or shield tunneling at both ends of the station), followed by tunnel construction. However, due to constraints from the surrounding environment, station projects in core urban areas face severe challenges related to traffic diversion, pipeline relocation, and the protection of existing structures, leading to delays in station construction and the inability to meet the needs of shield tunneling launch or reception. In such cases, it is necessary to consider first constructing the tunnel using cut-and-cover methods, and then expanding the existing tunnel to form the station.

[0003] In the past, the expansion process based on existing shield tunnels required the removal of the segment lining first, followed by the connection of the old and new lining structures. Only then could an effective stress transfer or load transfer path be formed. This resulted in problems such as unclear load transfer paths and ineffective control of ground settlement. Furthermore, it required complex ground pre-reinforcement measures and internal support systems, leading to high costs and uncontrollable risks. Therefore, it is urgent to break away from the traditional approach and develop a segment lining construction method that can effectively improve the efficiency of shield tunnel expansion and the effectiveness of risk management. Summary of the Invention

[0004] The purpose of this invention is to provide a method for integrated construction of tunnel stations and its load servo support system for irregularly shaped tunnel segments, so as to solve the problems of unclear load conversion path, uncontrollable ground settlement, and the need to set up complex internal supports in the existing shield tunnel expansion process.

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

[0006] A load-servo support system for irregularly shaped segments is provided in the integrated construction method of tunnel and station. The system includes 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 consists of segments with a radius of curvature consistent with the shield tunnel and large plugs protruding inward at the ends of the segments, with an L-shaped cross-section.

[0008] The L-shaped joint segment includes a top L-shaped joint segment and a bottom L-shaped joint segment, which consists of segments with a radius of curvature consistent with the shield tunnel and small joints protruding inward at the ends of the segments, with an L-shaped cross-section.

[0009] The top L-shaped plug segment and the top L-shaped connector segment are arranged on the left and right sides of the tunnel arch. The small connector of the top L-shaped connector segment is connected to the back of the large plug of the top L-shaped plug segment, and the connector position is located at the tunnel arch. The bottom L-shaped plug segment and the bottom L-shaped connector segment are arranged on the left and right sides of the tunnel arch bottom. The small connector of the bottom L-shaped connector segment is connected to the back of the large plug of the bottom L-shaped plug segment, and the connector position is located at the tunnel arch bottom.

[0010] The adjacent block tube segment has an arc-shaped structure, and multiple adjacent block tube segments are respectively connected between the top L-shaped plug tube segment and the bottom L-shaped plug tube segment, as well as between the top L-shaped connector tube segment and the bottom L-shaped connector tube segment, forming a circumferential closed 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 lateral support is also provided in the middle of the system, and the two ends of the temporary lateral support are tightly abutted against the adjacent block segments on both sides.

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

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

[0015] Furthermore, an inclined 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, the L-shaped plug segment, the L-shaped connector segment, and the adjacent block segment are all provided with longitudinal bolt connection holes for connecting the circumferential joints and longitudinal joints of the segments.

[0017] On the other hand, a method for integrated tunnel-station construction based on the aforementioned irregular segment load servo support system is provided, the method comprising:

[0018] Precast tunnel segments, including L-shaped end cap segments, L-shaped joint segments, and adjacent block segments;

[0019] During the shield tunnel excavation stage, segment lining assembly work is carried out, with the two lines constructed separately.

[0020] Temporary vertical and lateral supports are erected inside the shield tunnel;

[0021] A jack servo device is installed between the inner side of the large plug of the L-shaped plug segment and the adjacent block segment on that side.

[0022] The soil between the two shield tunnels was excavated in stages, and support and lining were carried out in a timely manner to form the station structure.

[0023] The temporary horizontal supports, adjacent pipe segments near the station structure, and temporary vertical supports were removed in sequence.

[0024] Remove the lower jack load servo device, backfill the bottom of the station structure with low-grade concrete, and carry out the construction of the internal structure of the station. Use the large end of the L-shaped end cap segment as the suspension support point of the contact network system.

[0025] Furthermore, during the prefabrication of shield tunnel segments, longitudinal bolt connection holes are prefabricated on L-shaped plug segments, L-shaped joint segments, and adjacent block segments, and triangular foam boards are glued to the corresponding wedge-shaped spaces on 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, the bottom L-shaped joint pipe segments are assembled, and then the adjacent block pipe segments, the top L-shaped plug pipe segments and the top L-shaped joint pipe segments are assembled in an alternating left and right upward manner.

[0029] All tunnel segments within the station area are assembled using continuous joints.

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

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

[0032] A steel top block is welded below the L-shaped plug segment at the top of the shield tunnel, and a steel bottom block is welded inside the L-shaped plug segment at the bottom.

[0033] Temporary vertical supports are erected between the steel top block and the steel bottom block;

[0034] Temporary lateral supports were erected, and wedges were used at both ends to hold the pipe segments in place with the adjacent pipe segments on both sides;

[0035] Temporary vertical supports and temporary horizontal supports are installed at intervals along the longitudinal direction of the tunnel, according to the requirement of one support per ring segment.

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

[0037] On the outer upper section of the shield tunnel, one end of the jack load servo device is pressed against the inner side of the top L-shaped plug segment, and the other end is pressed against the adjacent block segment to apply prestress and ensure that the shield tunnel arch has an upward displacement tendency.

[0038] On the lower section outside the shield tunnel, one end of the jack load servo device is used to support one side of the steel bottom block, and the other end is used to support the adjacent segment to apply prestress, ensuring that the bottom L-shaped plug segment of the shield tunnel can withstand the horizontal force.

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

[0040] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0041] This invention provides an integrated tunnel-station construction method and its irregular segment load-servoing support system. L-shaped end-cap segments, L-shaped joint segments, and adjacent segment blocks are prefabricated in a factory according to design requirements. Based on the work schedule, the excavation of the left and right shield tunnels is completed sequentially. Within the station area, the segment lining adopts continuous joint assembly to ensure that the wedge-shaped space on the outside of the L-shaped segments is located at the tunnel arch crown and arch bottom, achieving the purpose of "reserved joints and active conversion." The reserved wedge-shaped spaces and connecting end-cap segments at the arch crown and arch bottom of the shield tunnel provide working space for the effective connection between the top and bottom lining structures of the excavated area and the shield tunnel segment lining, realizing the active conversion of the load system before the segment lining is removed. Meanwhile, the jack load servo device connected to the L-shaped tunnel segments can actively load and control the settlement and deformation of the tunnel top as needed, further realizing the principle of "establishing before breaking and supporting before dismantling". That is, after the load conversion system is completed, the shield tunnel segment lining is broken and the temporary support inside the tunnel is removed. This effectively overcomes the drawback of the past, which required the segment lining to be removed before a complete load conversion system could be established. It effectively controls ground settlement, and the internal support is simple and effective. At the same time, it also solves the risk of water leakage at the junction of the old and new structures in conventional excavation processes, resulting in significant economic and social benefits. Attached Figure Description

[0042] 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.

[0043] Figure 1The diagram shows the single-line shield tunnel excavation and segment lining assembly provided in the embodiments of the present invention.

[0044] Figure 2 The diagram shows the excavation and segment lining assembly of a double-line shield tunnel, as provided in an embodiment of the present invention.

[0045] Figure 3 This is a diagram illustrating the pre-support of the soil sandwiched body and the excavation and lining of the upper step, as provided in an embodiment of the present invention.

[0046] Figure 4 This is a diagram illustrating the excavation and lining operation of the lower step of the soil sandwiched in an embodiment of the present invention.

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

[0048] Figure 6 The diagram shows the segment lining and temporary support removal provided in the embodiment of the present invention.

[0049] Figure 7 The following are construction drawings of the station's internal structure, such as bottom backfill and platform slab, provided for embodiments of the present invention.

[0050] The diagram is labeled as follows:

[0051] 1-Shield tunnel, 2-Top L-shaped end cap segment, 3-Top L-shaped joint segment, 4-Bottom L-shaped end cap 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 horizontal support, 12-Steel top block, 13-Steel bottom block, 14-Advanced support, 15-Arch-shaped initial support, 16-Arch cover lining, 17-Arch bottom initial support, 18-Cast-in-place arch bottom lining, 19-Backfill layer, 20-Platform slab, 21-Wedge-shaped I-beam, 22-Contact wire system, 23-Track bed, 24-Vehicle, 25-Upper step, 26-Middle step, 27-Lower step. Detailed Implementation

[0052] 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.

[0053] In the description of this invention, it should be understood that the terms "upper", "lower", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", 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.

[0054] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "installation," etc., should be interpreted broadly. For example, they can refer to a fixed connection or installation, a detachable connection or installation, or an integral connection or installation. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0055] 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.

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

[0057] In engineering practice, tunnels are first excavated using the cut-and-cover method, and then the station is formed by widening the excavation on the basis of the completed tunnel. This is the tunnel widening construction process. To overcome the problems existing in the current tunnel widening construction process, such as the lining structure being demolished before reconstruction, the load transfer system being built in a delayed manner, the ground settlement caused by widening construction being difficult to control effectively, and the inability to meet the safety protection requirements of the widening construction itself and the surrounding environment, this invention provides a tunnel-station integrated construction method based on a non-circular segment load servo support system. The method specifically includes the following steps:

[0058] S1: Prefabricate the lining structure, including L-shaped joint segments, and construct the tunnel boring machine.

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

[0060] The shield tunneling method is used for continuous excavation of urban rail transit tunnels and station areas. According to the design scheme and project planning requirements, the shield tunneling of the left and right lines of the tunnel is completed in sequence. The two lines are constructed at a certain distance along the longitudinal direction. The net distance between the two tunnel lines should generally not be less than one tunnel diameter. Based on the smoothness of the outline and the stress requirements, the cut-and-cover outline and range between the left and right tunnel lines are given.

[0061] During the shield tunneling stage, segment lining assembly is carried out according to design requirements. The assembly of the bottom L-shaped end cap segment 4 should be performed first, and the entire ring of segments should be positioned using this assembly. Next, the bottom L-shaped joint segment 5 should be assembled. Finally, the adjacent segment block 6, the top L-shaped end cap segment 2, and the top L-shaped joint segment 3 should be assembled, alternating left and right upwards. All shield segments within the station area are assembled using continuous joints. The last assembled L-shaped joint segment 3 is wedge-shaped (transverse to the tunnel, with inconsistent arc lengths on the front and rear sides), and its construction method is similar to that of conventional shield tunnel segment capping blocks.

[0062] The height of the large plug of the L-shaped plug segment must be greater than the sum of the height of the top and bottom wedge-shaped spaces and the thickness of the L-shaped joint segment lining. The thickness of the large plug (≥700mm) can generally be considered as twice the thickness of the segment lining (≥350mm). The side dimension of the plug in the top wedge-shaped space 7 is generally not less than 600mm, which must meet the construction conditions of the initial arch support 15 and the arch cover lining 16, and at the same time ensure 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 in the bottom wedge-shaped space 8 is generally not less than 800mm, which must meet the construction conditions of the initial arch support 17 and the arch bottom lining 18, and at the same time ensure 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 glued to their back sides according to the requirements of the outer contour of the shield tunnel, filling the top and bottom wedge-shaped spaces and meeting the requirements of the smoothness of the outer contour of the shield tunnel.

[0064] In the cross-sectional direction of the shield tunnel, i.e. on the lining ring surface of the segment, longitudinal bolt connection holes are evenly set at a 360° angle. They can be evenly set at intervals of about 20°, and at the same time, they need to maintain a certain distance from the longitudinal joint of the cross-section segment.

[0065] S2: Construct the internal support system for the shield tunnel.

[0066] like Figure 1A steel top block 12 is welded below the L-shaped end cap segment 2 at the top of the shield tunnel, and a steel bottom block 13 is welded inside the L-shaped end cap segment 4 at the bottom. Then, a temporary vertical support 10 is erected between the steel top block 12 and the steel bottom block 13. Next, a temporary horizontal support 11 is erected, with both ends secured to the segment lining using wedges. The temporary vertical supports 10 and temporary horizontal supports 11 are spaced apart according to the requirement of one support per ring of segments, with the longitudinal spacing consistent with the ring width of the segments.

[0067] Load servo devices, mainly composed of inclined jacks, are installed at both the tunnel arch and the tunnel bottom. Specifically, on the upper left section of the tunnel, one end of the jack load servo device 9 is used to support the inner side of the L-shaped plug segment, and the other end is used to support the adjacent block segment 6, and a certain prestress is applied to ensure that the tunnel arch has a certain upward displacement tendency; on the lower left section of the tunnel, one end of the jack load servo device 9 is used to support one side of the steel block 13, and the other end is used to support the adjacent block segment 6, and a certain prestress is applied to ensure that the L-shaped plug segment 4 at the bottom of the tunnel bears a certain horizontal force.

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

[0069] like Figure 2 After the tunnel boring machine (TBM) has completed the excavation of the two shield tunnels, the segment assembly and the internal support system erection, the excavation of the intermediate soil is carried out. The soil area is first divided into three parts: upper step 25, middle step 26 and lower step 27. Alternatively, it can be divided into four steps from top to bottom according to the geological conditions.

[0070] like Figure 3 First, pre-reinforcement of the strata outside the excavation outline of the upper step 25 is carried out. The pre-support 14 can adopt large pipe shed or pipe curtain as appropriate. The diameter and spacing of the large pipe shed or pipe curtain are determined according to the settlement and deformation control requirements 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 as 300-500mm, the longitudinal length should generally not be less than 15m, the longitudinal overlap length should generally not be less than 3m, and the elevation angle along the tunnel longitudinal direction should be considered at about 15°. 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 on the back side of the top L-shaped plug segment 2 to the reinforcing steel of the arch lining 16.

[0071] Under the protection of the advanced support measures, the soil of the upper step 25 is excavated according to the design requirements. Full-section excavation or a pre-reserved core soil excavation method can be adopted depending on the situation. That is, the annular step of the arch is excavated first to meet the construction needs of the initial arch support 15 and the arch lining 16. After the arch lining reaches the design strength requirements, the remaining soil of the upper step 25 is excavated. The advanced support 14 must cover the wedge-shaped space behind the L-shaped end cap segment. Simultaneously, the foam boards at the corresponding locations must be removed during the initial support and secondary lining construction.

[0072] After the arch 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 lining 16, the top L-shaped plug segment 2 and the jack servo device 9. At the same time, it should be ensured that the arch lining 16 bears a certain "pre-stress" and shows 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 bench 25, the lower bench 27 is excavated. The top height of the lower bench 27 should not exceed the height of the temporary transverse support 11 inside the tunnel. Depending on the stability of the strata, cross-sectional segmented excavation can be adopted, and the initial support 17 and the arch bottom lining 18 should be constructed in a timely manner. After the excavation of the lower bench 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, which is pre-embedded on the back side of the bottom L-shaped plug segment 4, to the reinforcing steel of the arch bottom lining 18. The design of the pre-embedded steel plate meets the waterproofing requirements of the joint at the cold joint of the structure. More importantly, it effectively avoids the conventional process of widening excavation that requires first breaking the segment lining and disrupting the existing stress balance system. It achieves effective load transfer first, and then the segment lining is broken and widening excavation is carried out.

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

[0075] During the excavation of the interlayer soil, after the arch lining 16 is poured and reaches the design strength, the support force of the upper load servo device of the shield tunnel should be appropriately increased if necessary, based on the monitoring of ground displacement and settlement, so that the arch lining 16 will show a certain upward arching trend and suppress the settlement and deformation of the upper strata.

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

[0077] S4: Removal of shield tunnel segment lining and construction of station structure.

[0078] After the excavation of the soil between the left and right shield tunnels is completed, the entire station outline structure has been constructed. At this time, the circular outline force system of the shield tunnel has been transformed into an integrated elliptical outline force system of the tunnel and 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 The temporary horizontal support 11, adjacent segment 6, and temporary vertical support 10 are removed in sequence, one ring at a time along the longitudinal direction of the tunnel. During the removal process, the settlement trend of the tunnel arch must be monitored at all times.

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

[0081] Subsequently, according to the requirements for the overhead contact line above vehicle 24, the steel top block 12 at the top of the vertical temporary support 10 in the shield tunnel 1 is used to fix the wedge-shaped I-beam 21 below the steel top block 12 with bolts. The wedge-shaped I-beam 21 can provide a suspension support point for the overhead contact line system 22.

[0082] The method of this invention is based on the concepts of "pre-reserved joints and active conversion" and "establish before breaking and support before dismantling", forming a new "tunnel-station integrated" construction method. It meets the actual needs of continuous shield tunneling for stations and sections, and provides more flexible options for urban rail transit engineering construction.

[0083] The aforementioned construction method involves a special structure for a special type of segment load-servoing support system, comprising three main categories of segments: L-shaped end cap segments, L-shaped joint segments, and adjacent block segments 6. Specifically, the L-shaped end cap segments include a top L-shaped end cap segment 2 and a bottom L-shaped end cap segment 4, consisting of segments with a curvature radius consistent with the shield tunnel and large end caps protruding inwards at the ends of the segments. The L-shaped joint segments include a top L-shaped joint segment 3 and a bottom L-shaped joint segment 5, consisting of segments with a curvature radius consistent with the shield tunnel and small joints protruding inwards at the ends of the segments, with an L-shaped cross-section.

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

[0085] The adjacent block segment 6 has an arc-shaped structure. Multiple adjacent block segments 6 are connected between the top L-shaped plug segment 2 and the bottom L-shaped plug segment 4, as well as between the top L-shaped connector segment 3 and the bottom L-shaped connector segment 5. The segments are connected by traditional bolts and are closed in a ring.

[0086] The shield tunnel has a temporary support structure inside, including temporary vertical supports 10 and temporary horizontal supports 11. Specifically, a temporary vertical support 10 is installed between the large end cap of the top L-shaped end cap segment 2 and the large end cap of the bottom L-shaped end cap segment 4. A temporary horizontal support 11 is also installed in the middle of the system, with both ends of the temporary horizontal support 11 abutting against the adjacent block segments 6 on both sides.

[0087] like Figure 1 The L-shaped plug segment has a wedge-shaped space between its large plug and the small joint of its L-shaped connector segment, which is filled with triangular foam board. This space is attached to the corresponding positions of the L-shaped plug segment and the L-shaped connector segment after the prefabrication of the segments and before assembly.

[0088] In addition, inclined jack servo devices 9 are installed between the inner side of the large plug of the L-shaped plug segment and the adjacent block segment 6 on the same side. These devices are distributed on the side of the shield tunnel away from the station, with one device above and one below, to provide support force for the tunnel arch and arch bottom, effectively controlling the deformation trend of the tunnel arch and arch bottom. This invention sets up L-shaped segments and inclined jack devices at the arch and arch bottom of the shield tunnel. Before the transverse excavation and lining removal of the shield tunnel, based on the wedge-shaped space reserved on the outside of the L-shaped segments, the L-shaped segments are effectively connected to the arch cover lining and the arch bottom lining. Horizontal active loading is achieved through the load servo device, realizing the active conversion of the horizontal load-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 segments with circumferential and longitudinal joints.

[0090] The core technology of this invention is the L-shaped plug segments and L-shaped joint segments set at the tunnel arch top and bottom. On the one hand, it provides wedge-shaped space on the outside of the tunnel arch top and bottom, providing conditions for the later connection between the arch cover lining 16, the arch bottom lining 18 and the segment lining. On the other hand, it also enables the formation of a structural outline force system covering the station area before the segment lining is broken. Based on the load servo device of the jack, the "erect first, break later" approach can be achieved, minimizing the risk of ground deformation caused by the breaking of the segment lining.

[0091] In the structural system of this invention, various tunnel segments, arch linings, and arch bottom linings mainly adopt conventional reinforced concrete lining structures. The initial arch support 15 and the initial arch bottom support 17 use wire mesh and C25 shotcrete. The steel top block 12, steel bottom block 13, temporary vertical support 10, temporary horizontal support 11, wedge-shaped I-beams 21, and jack load servo devices 9 all use steel structures, such as Q345 steel plates. The wedge-shaped spaces at the top and bottom of the tunnel are pre-sealed with foam boards. The internal structure of the station adopts a conventional reinforced concrete structure, and the backfill concrete at the bottom of the station uses C25 concrete.

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

[0093] The method provided by this invention requires the following attention during implementation:

[0094] 1. The wedge-shaped spaces at the top and bottom of the shield tunnel 1 are mainly formed by the “M” connection of L-shaped plug segments and L-shaped joint segments. The position of the wedge-shaped space is relatively fixed, and its size must meet the connection requirements of the arch cover lining 16 and the arch bottom lining 18. At the same time, this space is filled with foam board during the 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, which can apply a certain pre-jacking force to the tunnel arch and the arch cover lining 16. However, the size of the pre-jacking force needs to be strictly controlled. If it is too small, it may cause settlement and deformation of the tunnel arch and the stratum. If it is too large, it may cause damage to the segment lining. Generally, it can be controlled according to the upward displacement trend of the L-shaped plug segment 2 at the arch position.

[0096] 3. Within the scope of the station structure, the lining of the shield tunnel segment 1 must be assembled with continuous joints to ensure that a relatively fixed wedge-shaped space is formed at the tunnel arch and arch bottom.

[0097] 4. Regarding the station's structural scope, the clear distance between the left and right tunnels should generally not be less than one shield diameter. The soil between the two lines should be divided into at least three steps, from top to bottom, based on geological conditions and the surrounding environment. Advance support should be implemented before excavating the upper step, and the top of the lower step should not exceed the height of the temporary transverse support 11 inside the shield tunnel. Excavation of the soil between the two lines should be carried out simultaneously, followed by the removal of the segment lining and the construction of the station's internal structure.

[0098] The structure of this invention has the following features and advantages:

[0099] 1) Based on the concept of “reserving space and active conversion”, this invention forms a relatively fixed wedge-shaped space at the top and bottom of the tunnel arch by combining special L-shaped plug segments and L-shaped joint segments. This space provides an effective connection between the arch cover lining, the arch bottom lining and the shield tunnel segment lining, which not only realizes the active conversion of load, but also completely solves the problems of tunnel arch top and arch bottom breaking and structural cold joint leakage.

[0100] 2) The concept of "establishing before breaking, supporting before dismantling" proposed in this invention is mainly aimed at: after the excavation of the soil between the left and right shield tunnels in the station area is completed, and the top arch lining and bottom lining of the station area are poured, forming a complete stress system around the station outline, the segment lining in the shield tunnel expansion area and the temporary support inside the tunnel are dismantled.

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

[0102] 4) The "active conversion, first erect and then break" method based on "L-shaped segments" 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.

[0103] 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. The irregular segment load servo support system in the integrated tunnel-station construction method is characterized by: The system includes L-shaped plug segments, L-shaped joint segments and adjacent block segments (6). The L-shaped plug segment includes a top L-shaped plug segment (2) and a bottom L-shaped plug segment (4), which consists of a segment with a curvature radius consistent with the shield tunnel (1) and a large plug protruding inward at the end of the segment, and has an L-shaped cross-section. The L-shaped joint segment includes a top L-shaped joint segment (3) and a bottom L-shaped joint segment (5), which consists of segments with a curvature radius consistent with the shield tunnel (1) and small joints protruding inward at the ends of the segments, with an L-shaped cross-section. The top L-shaped plug segment (2) and the top L-shaped connector segment (3) are arranged on the left and right sides of the tunnel arch. The small connector of the top L-shaped connector segment (3) is connected to the back of the large plug of the top L-shaped plug segment (2). The connector is located at the tunnel arch. The bottom L-shaped plug segment (4) and the bottom L-shaped connector segment (5) are arranged on the left and right sides of the tunnel arch bottom. The small connector of the bottom L-shaped connector segment (5) is connected to the back of the large plug of the bottom L-shaped plug segment (4). The connector is located at the tunnel arch bottom. The adjacent block tube segment (6) has an arc-shaped structure. Multiple adjacent block tube segments (6) are respectively connected between the top L-shaped plug tube segment (2) and the bottom L-shaped plug tube segment (4), and between the top L-shaped connector tube segment (3) and the bottom L-shaped connector tube segment (5), forming a circumferential closed ring.

2. The irregular segment load servo support system in the tunnel-station integrated construction method according to claim 1, characterized in that: 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 lateral support (11) is also provided in the middle of the system, and the two ends of the temporary lateral support (11) are closely abutting the adjacent block segments (6) on both sides. The temporary vertical support (10) and the temporary horizontal support (11) are arranged longitudinally at intervals according to the ring width of the shield tunnel (1).

3. The irregular segment load servo support system in the tunnel-station integrated construction method according to claim 2, characterized in that: There is a wedge-shaped space between the large plug of the L-shaped plug segment and the small joint of the L-shaped connector segment, which is filled with foam.

4. The irregular segment load servo support system in the tunnel-station integrated construction method according to claim 3, characterized in that: 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 the same side.

5. The irregular segment load servo support system in the tunnel-station integrated construction method according to claim 4, characterized in that: The L-shaped plug segment, the L-shaped connector 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 integrated tunnel and station construction based on the irregular segment load servo support system described in claim 5, characterized in that: The method includes: Precast shield tunnel segments, including L-shaped plug segments, L-shaped joint segments and adjacent block segments (6). During the shield tunnel excavation stage, segment lining assembly work is carried out, with the two lines constructed separately. Temporary vertical supports (10) and temporary horizontal supports (11) are erected 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. The soil between the two shield tunnels was excavated in stages, and support and lining were carried out in a timely manner to form the station structure. The temporary horizontal support (11), the adjacent block segment (6) near the station structure, and the temporary vertical support (10) were removed in sequence. Remove the lower jack servo device (9), backfill the bottom of the station structure with low grade concrete, and carry out the construction of the station's internal structure. Use the large end of the L-shaped end cap segment as the suspension support point of the contact network system (22).

7. A method for integrated tunnel and station construction based on the irregular segment load servo support system as described in claim 6, characterized in that: When prefabricating shield tunnel segments, longitudinal bolt connection holes are prefabricated on L-shaped plug segments, L-shaped joint segments and adjacent block segments (6), and triangular foam boards are pasted on the L-shaped plug segments and L-shaped joint segments at the positions corresponding to the wedge-shaped spaces.

8. A method for integrated tunnel and station construction based on the irregular segment load servo support system as described in claim 7, characterized in that: The segment lining assembly operation includes: First, the bottom L-shaped plug segment (4) is assembled, and the positioning of the full ring segment lining is achieved through the assembly of the bottom L-shaped plug segment (4). Then, the bottom L-shaped connector segment (5) is assembled, and then the adjacent block segment (6), the top L-shaped plug segment (2) and the top L-shaped connector segment (3) are assembled in an alternating left and right upward manner. All tunnel segments within the station area are assembled using continuous joints. The top L-shaped joint segment (3) is wedge-shaped along the longitudinal direction of the tunnel.

9. A method for integrated tunnel and station construction based on the irregular segment load servo support system as described in claim 8, characterized in that: Temporary vertical supports (10) and temporary horizontal supports (11) are erected 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. Temporary vertical supports (10) are 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 hold the adjacent pipe segments (6) on both sides in place; Temporary vertical supports (10) and temporary horizontal supports (11) are set at intervals along the longitudinal direction of the tunnel according to the requirement of one set of one ring segment.

10. A method for integrated tunnel and station construction based on the irregular segment load servo support system as described in claim 9, characterized in that: Install the jack servo device (9), including: On the outer upper section of the shield tunnel, one end of the jack servo device (9) is pressed against the inner side of the top L-shaped plug segment (2), and the other end is pressed against the adjacent block segment (6) to apply prestress and ensure that the arch of the shield tunnel has an upward displacement tendency. On the lower section outside the shield tunnel, one end of the jack servo device (9) is pressed against one side of the steel bottom block (13), and the other end is pressed against the adjacent block segment (6) to apply prestress and ensure that the bottom L-shaped plug segment (4) of the shield tunnel is subjected to horizontal force. After the station structure is formed, the circular outline force system of the shield tunnel is transformed into an integrated elliptical outline force system of the tunnel and 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).

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