Construction method for cross-shaped subway transfer station with underneath pass of bunching type structure

Abstract

The invention discloses a construction method of an underpass subway cross transfer station by utilizing a bunching structure. The construction method comprises the following steps: 1, respectively constructing a bunching structure starting well and a bunching structure receiving well with the same depth as that of a newly-built underground station on two sides of an existing subway station and at positions corresponding to two ends of the newly-built underground station; 2, pipe joint jacking construction of a bunching structure is conducted in the soil body below the existing subway station; 3, under the condition that the soil body is not excavated, prestress tensioning construction of the bunching structure is completed; 4, soil in the bunching structure is excavated, and underpinning construction is conducted on the bunching structure; and 5, construction of the underpass section, located below the existing subway station, of the newly-built underground station is completed. The construction risk is better controlled, the engineering investment is reduced, the construction period is shortened, and the low-carbon and green construction requirements of the engineering construction process are met.

Description

Technical Field

[0001] The invention relates to the technical field of subway station construction, and in particular to a construction method for a subway cross transfer station using an underpass with a bundled structure. Background Art

[0002] An urban rail transit cross-transfer subway station is where two subway lines intersect, and the station presents a cross-shaped "zero-distance" transfer.

[0003] The conventional processing method in the prior art is to complete the construction of the deepest cross-transfer subway station node when the subway line is constructed first, and reserve the conditions for later access. The cross-transfer node area is generally three underground floors, and the remaining station areas are two underground floors. When the subway line is constructed later, it is only necessary to dig out the three-story underground station on both sides of the existing station, and use the reserved conditions to connect to complete the cross transfer.

[0004] However, in actual projects, due to urban development and the adjustment or addition of rail transit network planning, there will be already built subway stations that do not reserve conditions for future transfers and are generally only two underground floors. However, the surrounding environment and construction conditions require them to have the function of cross transfers, which leads to the need to construct a three-story underground structure under the existing two-story underground operating subway station.

[0005] This type of project has a great construction risk due to the strict deformation control and high protection requirements of operating subway stations. There are related cases in domestic soft soil areas, such as: Shanghai Metro Line 18 under Line 10, Tianjin Metro Line 8 under Line 1, and Hangzhou Metro Line 4 under Line 2. In order to reduce the impact on existing operating subway stations, they can only pass through the section underpass type, that is, "backfill after manual clearance of hidden excavation + shield secondary crossing" plan, which cannot achieve close underpass and cross transfer of two-span or three-span subway stations. In addition, in soft soil areas, the strata have the characteristics of high water content, low soil strength, and poor self-stabilization ability. Therefore, before manual clearance of hidden excavation, horizontal MJS or freezing method must be used to reinforce the soil. However, as a hidden project, the construction quality of such soil reinforcement measures is difficult to control and quality inspection is difficult.

[0006] As a result, the subsequent use of underground excavation methods such as the step method or CRD method to dig and clear obstacles under the existing station has great construction risks, and the construction sequence of first digging and then supporting makes deformation control difficult. At the same time, a large number of horizontal MJS+frozen reinforcement, underground excavation, and backfilling are temporary projects, with large project investments, complicated procedures, and long construction periods.

[0007] The bundled structure bundles the discrete, small-section rectangular steel pipes that are pushed forward longitudinally into an integral structure that can bear lateral forces by transversely tensioning the prestressed tendons. On the one hand, it solves the problem of dark excavation in soft soil areas without temporary support, soil reinforcement, full-section excavation, and integration of advance support and permanent structure; on the other hand, it uses the mature technology of small jacking pipes and prestressing to "break the whole into parts", first form a high-rigidity structure, then excavate, with good deformation control and low construction risk.

[0008] Therefore, how to better control construction risks, reduce project investment, shorten construction period, and achieve low-carbon and green construction requirements for engineering construction technology has become a technical problem that technical personnel in this field urgently need to solve. Summary of the invention

[0009] In view of the above-mentioned defects of the prior art, the present invention provides a construction method for a subway cross transfer station using an underpass with a bundled structure, the purpose of which is to better control construction risks, reduce project investment, shorten construction period, and meet the construction requirements of low-carbon and green engineering construction technology.

[0010] To achieve the above-mentioned purpose, the present invention discloses a construction method of a subway cross transfer station using a bundled structure, which is used to build a new underground station on the next floor of an existing subway station that has been completed, and the vertical projection is in a cross shape with the existing subway station;

[0011] The steps include:

[0012] Step 1: On both sides of the existing subway station, corresponding to the positions at both ends of the newly built underground station, a bundled structure starting well and a bundled structure receiving well with the same depth as that of the newly built underground station are respectively constructed;

[0013] Step 2: Perform jacking construction of pipe segments of the bundled structure in the soil below the existing subway station;

[0014] Step 3: completing the prestressing construction of the bundled structure without excavating the soil;

[0015] Step 4: excavating the soil in the bundled structure, and performing underpinning construction in the bundled structure;

[0016] Step 5: Complete the construction of the underpass section of the new underground station located below the existing subway station.

[0017] Preferably, step 1 is as follows:

[0018] Step 1.1, constructing a new underground wall of the starting well of the bundled structure and a new underground wall of the receiving well of the bundled structure at a position 1m±10% away from the outside of the existing underground wall of the existing subway station;

[0019] Step 1.2, constructing a sandwich soil reinforcement between the new underground wall of the starting well and the existing underground wall;

[0020] Constructing a sandwich soil reinforcement between the new underground wall of the receiving well and the existing underground wall;

[0021] Step 1.3, stripping off the top steel bars of the newly constructed underground wall of the starting well, the newly constructed underground wall of the receiving well and the existing underground wall, and respectively casting the starting well side top ring beam and the receiving well side top ring beam at the position where the top steel bars are stripped off.

[0022] Step 1.3, stripping off the top steel bars of the newly constructed underground wall of the starting well, the newly constructed underground wall of the receiving well and the existing underground wall, and respectively casting the starting well side ring beam and the receiving well top ring beam at the position where the top steel bars are stripped off.

[0023] More preferably, each floor slab of the starting well of the bundled structure is provided with a starting well hoisting hole; and each floor slab of the receiving well of the bundled structure is provided with a receiving well hoisting hole.

[0024] More preferably, after the construction of the bundling structure is completed, a starting shaft connecting layer and a receiving shaft connecting layer are respectively set between the underground first floor of the existing subway station and the starting shaft and the underground first floor of the bundling structure receiving shaft, and the underground first floor of the existing subway station is connected through the corresponding starting shaft connecting layer or the corresponding receiving shaft connecting layer.

[0025] Preferably, step 2 is as follows:

[0026] Step 2.1, in the starting well of the bundled structure and the receiving well of the bundled structure, grooves are cut step by step to break all the pipe joint jacking ranges at the top, bottom and sides of the bundled structure, and the new underground wall of the starting well, the new underground wall of the receiving well, and the existing underground wall within the range of the ring frame beam of the outer circumference of the bundled structure;

[0027] Step 2.2, completing the construction of the ring frame beam and the embedded steel ring inside the ring frame beam on the starting well side of the bundled structure and the receiving well side of the bundled structure;

[0028] Step 2.3, completing the jacking construction of each pipe segment of the bundled structure, and welding them to the embedded steel ring on the inner side of the ring frame beam;

[0029] Step 2.4, temporary steel supports are set up at the end wall frames of the starting shaft of the bundled structure and the receiving shaft of the bundled structure close to the existing subway station side.

[0030] More preferably, the pipe sections at the top and bottom of the bundled structure include A-type standard pipes and C-type longitudinal beam standard pipes;

[0031] The C-shaped longitudinal beam standard tubes are arranged in pairs at the top steel support column and the bottom steel support column of the bundled structure;

[0032] The pipe sections on the side of the bundled structure all include the A-type standard pipe and the B1-type working pipe;

[0033] The B1 type working tubes are all arranged at the corners between the side and the top of the bundled structure;

[0034] The pipe sections of the middle wall of the bundled structure include A1 type pipe sections, B2 type standard pipes and A2 type pipe sections;

[0035] On the outside of each pipe section, two sets of matching male and female lock buckles are provided at the same positions on both sides of the connecting surface as those of another adjacent pipe section;

[0036] Each of the pipe segment walls at the top, bottom and side of the bundled structure and the inner sides of the two groups of male and female lock buckles near the two sides of the connecting surface of another adjacent pipe segment are provided with reserved openings for passing prestressed steel strands;

[0037] Each of the B1 type working pipes is used for tensioning and anchoring the prestressed steel strands, and is provided with reinforcing ribs on the inner side close to another adjacent pipe segment;

[0038] Each of the A1-type pipe sections is used to connect the bottom or top of the bundled structure with the B2-type standard pipe at the lower end or upper end of the corresponding middle wall, and is fixed by a plurality of high-strength bolts on the inner sides of the two groups of male and female lock buckles near both sides of the connecting surface between the side facing the middle wall and the adjacent B2-type standard pipe;

[0039] Each of the A2-type pipe sections is located between two of the B2-type standard pipes and is fixed by a plurality of high-strength bolts on the inner sides of the two groups of male and female lock buckles close to both sides of the connecting surface.

[0040] When the newly built underground wall of the starting shaft and the corresponding existing underground wall of the bundled structure within the range of the ring frame beam on one side of the starting shaft of the bundled structure are removed in step 2.1, the newly built underground wall of the starting shaft needs to be completely removed and the steel bars on both sides are stripped out, and the corresponding existing underground wall only has the inner half removed and the inner steel bars are stripped out;

[0041] More preferably, when the newly built underground wall of the starting shaft, the newly built underground wall of the receiving shaft and the corresponding existing underground wall within the range of the ring frame beam are broken step by step in step 2.1, the newly built underground wall of the starting shaft and the newly built underground wall of the receiving shaft need to be completely broken and stripped out to reveal a total of 2 rows of steel bars on both sides, and the corresponding existing underground wall only has the inner half broken and a total of 1 row of inner side steel bars stripped out.

[0042] More preferably, step 2.2 is as follows:

[0043] Step 2.2.1, the two rows of stripped steel bars of the newly built underground wall of the starting well and the one row of steel bars of the existing underground wall on the corresponding side are anchored into the ring frame beam, and connected to the remaining half of the existing underground wall on the corresponding side through horizontal planting of steel bars to form a whole; the three rows of stripped steel bars of the newly built underground wall of the receiving well and the existing underground wall on the corresponding side are treated in the same way;

[0044] Step 2.2.2, the contact surface treatment is performed on the joint surfaces of the ring frame beam and the starting well of the bundled structure, the working well structure of the receiving well of the bundled structure, the newly built underground wall of the corresponding starting well, the newly built underground wall of the corresponding receiving well, or the remaining half of the corresponding existing underground wall;

[0045] Pre-embedded waterproof sealant is provided on the horizontal joint surface between the ring frame beam and the corresponding newly-built underground wall of the starting well or the corresponding newly-built underground wall of the receiving well, and the vertical joint surface between the corresponding existing underground wall;

[0046] The contact surface treatment refers to roughening the concrete and applying cement-based penetrating crystalline waterproof coating;

[0047] The waterproof sealant is a single-component water-swellable polyurethane sealant or a single-component extrusion type water-swellable polyurethane sealant;

[0048] Preferably, step 3 is as follows:

[0049] Step 3.1, inserting prestressed steel strands into all the pipe sections at the top, bottom and sides of the bundled structure;

[0050] Step 3.2, in all the pipe segments of the middle wall of the bundled structure, high-strength bolts are used to fasten and complete the connection between the A1 pipe segment, the B2 standard pipe and the A2 pipe segment;

[0051] Step 3.3, pouring concrete inside and between all the pipe sections except the B1 type working pipe;

[0052] Step 3.4, tensioning the prestressed steel strand in the B1 type working tube;

[0053] The order of tensioning the prestressed steel strands is: following the same cross section, symmetry, internal and external synchronization, long strands first and short strands later tensioning principle;

[0054] Step 3.5, anchoring the two ends of the tensioned prestressed steel strand in the corresponding B1 type working tube and filling it with concrete to form a structure that can bear overall lateral force.

[0055] Preferably, step 4 is as follows:

[0056] Step 4.1, constructing a well joint of the bundle structure in the starting well of the bundle structure and the receiving well of the bundle structure;

[0057] Step 4.2, the existing underground wall within the scope of the bundled structure, the newly built underground wall of the starting well and the newly built underground wall of the receiving well are demolished as they are excavated;

[0058] Step 4.3, excavating the soil in the bundled structure in full section;

[0059] Step 4.4, arranging a steel underpinning column in the bundled structure;

[0060] Step 4.5: Clear all the middle walls in the bundled structure to complete the underpinning construction.

[0061] More preferably, waterproof sealant and grouting pipes are provided at the interface between the well joint and each pipe section of the bundled structure, and the working well structure of the starting well of the bundled structure or the receiving well of the bundled structure.

[0062] More preferably, each well joint is provided with well joint reinforcement on the outside thereof;

[0063] Each of the well joint steel bars is composed of an inverted L-shaped steel bar and a C-shaped steel bar;

[0064] After the jacking construction of the pipe segment of the bundled structure is completed, one end of each inverted L-shaped steel bar is welded and fixed to the inner wall of the pipe segment at the corresponding position, and is bent downward to form an L shape, and the other end is welded to the reserved steel bar at the corresponding position of the corresponding bundled structure starting well or the corresponding bundled structure receiving well during construction;

[0065] After the jacking construction of the pipe segment of the bundled structure is completed, one end of each C-shaped steel bar is welded and fixed to the inner wall of the pipe segment at the corresponding position, and is bent downward twice to form a C shape, and the other end is welded to the steel bar reserved at the corresponding position of the ring frame beam during construction.

[0066] More preferably, after all the middle walls in the bundled structure are removed, the whole wall is hoisted out, or it is hoisted out after being cut into pieces, by cutting off the male and female lock buckles and high-strength bolts between the B2-type standard tube and the corresponding A1-type tube.

[0067] More preferably, each of the steel underpinning columns is disposed between two C-shaped longitudinal beam standard tubes;

[0068] The column foot of each of the steel-type underpinning columns comprises an end plate and column foot stiffening ribs;

[0069] Each end plate has reserved reinforcement openings on the outer circumference of the corresponding steel support column, and is fixed to the corresponding C-shaped longitudinal beam standard tube by fillet welds;

[0070] Each of the C-shaped longitudinal beam standard tubes is provided with openings of the same specifications and quantity corresponding to each of the reinforcement openings;

[0071] Before pouring concrete in any of the steel support columns, first reserve dowel bars at the column;

[0072] The reserved dowel bars at the column of each of the steel-type underpinning columns pass through the corresponding end plates through the corresponding reserved reinforcement openings;

[0073] Each pipe segment connected to the steel support column is provided with a plug welding hole corresponding to each of the reserved reinforcement openings, and the internally reserved inserted reinforcements are passed through the corresponding plug welding holes and the corresponding reserved reinforcement openings to fix the corresponding pipe segment and the corresponding end plate through-hole plug welding;

[0074] Each of the pipe sections connected to the steel underpinning column is fixed to the corresponding end plate by welding through a fillet weld.

[0075] More preferably, step 5 is as follows:

[0076] Step 5.1, construct steel concrete columns;

[0077] Step 5.2: construct the secondary structure of the station including lining, platform slab and backfill of plain concrete;

[0078] Step 5.3, closing the starting well hoisting hole and the receiving well hoisting hole in the starting well of the bundle structure and the receiving well of the bundle structure;

[0079] More preferably, step 5.1 is as follows:

[0080] Step 5.1.1, tying steel concrete column reinforcement around the outer circumference of the steel underpinning column;

[0081] Step 5.1.2, the steel bars of the steel concrete column are aligned one by one with the reserved dowel bars reserved in the standard tube of the C-shaped longitudinal beam and are welded together;

[0082] Step 5.1.2, setting the formwork and pouring concrete to form the steel-concrete column.

[0083] Preferably, the newly built underground station is built together with the receiving shaft of the bundled structure.

[0084] Beneficial effects of the present invention:

[0085] The present invention can better control construction risks, reduce project investment, shorten construction period, and realize low-carbon and green construction requirements of engineering construction technology.

[0086] The present invention replaces hardened soft soil with a bundled structure, the construction is visible and controllable, the quality inspection is easy to operate, and the rectangular small jacking pipe and prestressed tensioning are conventional processes. The formed structure has high rigidity, good force performance, small controlled deformation and low construction risk.

[0087] The present invention optimizes a large number of abandoned projects such as soil reinforcement and temporary support, combines permanent and temporary projects, and is green and environmentally friendly. Compared with the traditional method of "backfilling after hidden excavation and manual obstacle clearing + secondary shield crossing" in the prior art, it has better economic and social benefits.

[0088] The concept, specific structure and technical effects of the present invention will be further described below in conjunction with the accompanying drawings to fully understand the purpose, characteristics and effects of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0089] Figure 1 A plan view of a cross-transfer subway station in accordance with an embodiment of the present invention is shown.

[0090] Figure 2 A schematic longitudinal section diagram of construction step 1 in one embodiment of the present invention is shown.

[0091] Figure 3 A schematic longitudinal section diagram of construction step 2 in one embodiment of the present invention is shown.

[0092] Figure 4 A cross-sectional schematic diagram of construction step 2 in one embodiment of the present invention is shown.

[0093] Figure 5 A schematic cross-sectional view of a type A standard tube in one embodiment of the present invention is shown.

[0094] Figure 6 A schematic cross-sectional view of a B1 type standard tube in one embodiment of the present invention is shown.

[0095] Figure 7 A cross-sectional schematic diagram of a C-shaped longitudinal beam standard tube in one embodiment of the present invention is shown.

[0096] Figure 8 A partial cross-sectional schematic diagram of the connection between the top of the bundled structure and the middle wall in one embodiment of the present invention is shown.

[0097] Fig. 9 A schematic diagram of a ring frame beam construction method in one embodiment of the present invention is shown.

[0098] Fig.10 A schematic longitudinal section diagram of construction step 3 in one embodiment of the present invention is shown.

[0099] Fig.11 A cross-sectional schematic diagram of construction step 3 in one embodiment of the present invention is shown.

[0100] Fig.12 A schematic longitudinal section diagram of construction step 4 in one embodiment of the present invention is shown.

[0101] Fig.13 A cross-sectional schematic diagram of construction step 4 in one embodiment of the present invention is shown.

[0102] Fig.14 A schematic diagram of a well joint construction method in one embodiment of the present invention is shown.

[0103] Fig.15 A schematic diagram of an inverted L-shaped steel bar of a well joint in one embodiment of the present invention is shown.

[0104] Fig.16 A schematic diagram of a C-shaped steel bar of a well joint in one embodiment of the present invention is shown.

[0105] Fig.17 A schematic diagram of the column foot structure of a medium-sized steel underpinning column in one embodiment of the present invention is shown.

[0106] Fig.18 A schematic diagram showing the connection between the column foot of a section steel underpinning column and a standard tube of a C-shaped longitudinal beam in one embodiment of the present invention is shown.

[0107] Fig.19 A schematic longitudinal section diagram of construction step 5 in one embodiment of the present invention is shown.

[0108] Fig. 20 A cross-sectional schematic diagram of construction step 5 in one embodiment of the present invention is shown.

[0109] Fig.21 A schematic structural diagram of a medium-sized steel concrete column in one embodiment of the present invention is shown.

[0110] Fig. 22 A schematic diagram showing the connection between a steel concrete column and a C-shaped longitudinal beam standard pipe and an inner lining according to an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0111] Example

[0112] like Figures 1 to 22 As shown, a construction method of a subway cross transfer station using a bundled structure is used to construct a new underground station 4 on the next floor of an existing subway station 1 that has been completed, and the vertical projection is in a cross shape with the existing subway station 1, including the following steps:

[0113] Step 1: On both sides of the existing subway station 1, corresponding to the positions at both ends of the new underground station 4, a bundled structure starting shaft 2 and a bundled structure receiving shaft 3 with the same depth as the new underground station 4 are respectively constructed;

[0114] Step 2: Perform pipe segment jacking construction of the bundled structure 5 in the soil below the existing subway station 1;

[0115] Step 3: Complete the prestressing construction of the bundled structure 5 without excavating the soil;

[0116] Step 4: excavate the soil in the bundled structure 5 and perform underpinning construction on the bundled structure 5;

[0117] Step 5: Complete the construction of the underpass section of the new underground station 4 located below the existing subway station 1.

[0118] In the application of the embodiment, see the attached Figure 1 The existing east-west subway station 1 has two underground floors, and the bundled structure departure shaft 2 and bundled structure receiving shaft 3 on both sides of the north-south direction are both three underground floors.

[0119] In this embodiment, the bundled structure receiving shaft 3 on the north side and the newly built underground station 4 are built together, both of which are three underground floors. The bundled structure starting shaft 2 on the south side is also part of the newly built subway station 4.

[0120] After the construction of the bundle structure starting shaft 2 and the bundle structure receiving shaft 3 is completed, the construction of the bundle structure 5 can be carried out under the existing subway station 1.

[0121] After the construction of the bundle structure 5 is completed, the underground layer of the bundle structure starting shaft 2 and the bundle structure receiving shaft 3 is connected with the existing subway station 1, thereby realizing cross transfer.

[0122] In other embodiments, the arrangement of the bundled structure departure shaft 2 and the bundled structure receiving shaft 3 may be adjusted in combination with the architectural plan of the new underground station 4 .

[0123] like Figure 2 As shown, step 1 is as follows:

[0124] Step 1.1, constructing a new underground wall 201 of the starting shaft of the bundled structure starting shaft 2 and a new underground wall 301 of the receiving shaft of the bundled structure receiving shaft 3 at a position 1m±10% outside the existing underground wall 101 of the existing subway station 1;

[0125] Step 1.2, constructing a starting well ground wall sandwich soil reinforcement 202 between the new starting well underground wall 201 and the existing underground wall 101;

[0126] Constructing a receiving well ground wall sandwich soil reinforcement 302 between the newly built receiving well underground wall 301 and the existing underground wall 101;

[0127] Step 1.3, strip the top steel bars of the newly constructed underground wall 201 of the starting well, the newly constructed underground wall 301 of the receiving well and the existing underground wall 101, and cast the starting well side ring beam 203 and the receiving well top ring beam 303 respectively at the position where the top steel bars are stripped.

[0128] The arrangement of the starting shaft side ring beam 203 and the receiving shaft top ring beam 303 can avoid differential settlement during construction.

[0129] In some embodiments, each floor slab of the starting well 2 of the bundled structure is provided with a starting well hoisting hole 205; each floor slab of the receiving well 3 of the bundled structure is provided with a receiving well hoisting hole 305.

[0130] The starting well hoisting hole 205 and the receiving well hoisting hole 305 can be used for hoisting in and out of the equipment and materials in the subsequent bundling structure construction.

[0131] In some embodiments, after the construction of the bundling structure 5 is completed, a starting shaft connecting layer 204 and a receiving shaft connecting layer 304 are respectively set between the underground first floor of the bundling structure starting shaft 2 and the bundling structure receiving shaft 3 and the underground first floor of the existing subway station 1, and the underground first floor of the existing subway station 1 is connected through the corresponding starting shaft connecting layer 204 or the corresponding receiving shaft connecting layer 304.

[0132] In practical applications, the method of connecting the originating well layer 204 and the receiving well layer 304 is an existing mature method and will not be described in detail.

[0133] like Figure 3 and Figure 4 As shown, step 2 is as follows:

[0134] Step 2.1, in the starting well 2 of the bundled structure and the receiving well 3 of the bundled structure, the new underground wall 201 of the starting well, the new underground wall 301 of the receiving well, and the existing underground wall 101 of the ring frame beam 501 of the outer circumference of the bundled structure 5 are constructed by step-by-step trenching to break all the pipe joint jacking ranges of the top, bottom and sides of the bundled structure 5;

[0135] Step 2.2, completing the construction of the ring frame beam 501 and the embedded steel ring 502 inside the ring frame beam 501 on the starting well 2 side of the bundled structure and the receiving well 3 side of the bundled structure;

[0136] Step 2.3, completing the jacking construction of each pipe segment of the bundled structure 5, and welding it to the embedded steel ring 502 on the inner side of the ring frame beam 501;

[0137] Step 2.4, temporary steel supports 503 are set up at the end wall frames of the bundled structure starting shaft 2 and the bundled structure receiving shaft 3 close to the existing subway station 1.

[0138] Temporary steel supports 503 are set up on the end wall frames close to the existing subway station 1 to enhance the overall stability of each pipe section during the construction phase.

[0139] In some embodiments, the top and bottom pipe sections of the bundled structure 5 both include A-type standard pipes 504 and C-type longitudinal beam standard pipes 507;

[0140] The C-shaped longitudinal beam standard tubes 507 are located at both ends of the steel support columns 515 between the top and the bottom of the bundled structure 5, and are arranged in pairs corresponding to each steel support column 515;

[0141] The pipe sections at the side of the bundled structure 5 include type A standard pipes 504 and type B1 working pipes 508;

[0142] The B1 type working tubes 508 are all arranged at the corners between the side and the top of the bundle structure 5;

[0143] The pipe segments of the middle wall 513 of the bundled structure 5 all include A1 type pipe segments 505, B2 type standard pipes 509 and A2 type pipe segments 506;

[0144] like Figures 5 to 8 As shown, on the outside of each pipe section, two sets of matching male and female lock buckles 12 are provided at the same positions on both sides of the adjacent pipe section near the connecting surface;

[0145] Each pipe segment wall at the top, bottom and side of the bundled structure 5 and the adjacent pipe segment are provided with reserved openings 11 for passing the prestressed steel strands 510 on the inner sides of the two sets of male and female lock buckles 12 near the two sides of the connecting surface;

[0146] Each B1 type working pipe 510 is used for tensioning and anchoring the prestressed steel strand 510, and is provided with a reinforcing rib 13 on the inner side close to another adjacent pipe segment;

[0147] Each A1 type pipe section 505 is used to connect the bottom or top of the bundle structure 5 with the B2 type standard pipe 509 at the lower end or upper end of the corresponding middle wall 513, and is fixed by a plurality of high-strength bolts 14 between the side facing the middle wall 513 and the adjacent B2 type standard pipe 509, on the inner side of two sets of male and female lock buckles 12 near both sides of the connecting surface;

[0148] Each A2 type pipe section 506 is located between two B2 type standard pipes 509 and is fixed by a plurality of high-strength bolts 14 on the inner side of two sets of male and female lock buckles 12 near both sides of the connecting surface.

[0149] The outer dimensions and wall thickness of the pipe segment of the bundled structure underpass section 5 are determined by actual calculation.

[0150] When the newly built underground wall 201 of the starting shaft, the newly built underground wall 301 of the receiving shaft and the corresponding existing underground wall 101 within the range of the ring frame beam 501 are removed step by step in step 2.1, the newly built underground wall 201 of the starting shaft and the newly built underground wall 301 of the receiving shaft need to be completely removed and two rows of steel bars on both sides need to be stripped out, and the corresponding existing underground wall 101 only needs to remove the inner half and strip out one row of inner side steel bars.

[0151] In practical applications, the above steps can facilitate shielding of water and soil outside the bundled structure 5 .

[0152] like Fig. 9 As shown, step 2.2 is as follows:

[0153] Step 2.2.1, the two rows of stripped steel bars of the newly built underground wall 201 of the starting well and the one row of steel bars of the existing underground wall 101 on the corresponding side are anchored into the ring frame beam 501, and connected to the remaining half of the existing underground wall 101 on the corresponding side through the horizontal planting bar 10 to form a whole; the three rows of stripped steel bars of the newly built underground wall 301 of the receiving well and the existing underground wall 101 on the corresponding side are treated in the same way;

[0154] Step 2.2.2, the contact surface treatment is performed on the joint surfaces of the ring frame beam 501 and the starting shaft 2 of the bundled structure, the working shaft structure of the receiving shaft 3 of the bundled structure, the corresponding newly built underground wall 201 of the starting shaft, the corresponding newly built underground wall 301 of the receiving shaft or the remaining half of the corresponding existing underground wall 101;

[0155] Pre-embedded waterproof sealant is provided on the horizontal joint surface between the ring frame beam 501 and the corresponding newly built underground wall 201 of the starting well or the corresponding newly built underground wall 301 of the receiving well, and the vertical joint surface between the corresponding existing underground wall;

[0156] Contact surface treatment 8 refers to roughening the concrete and applying cement-based penetrating crystalline waterproof coating;

[0157] The waterproof sealant 9 is a single-component water-swellable polyurethane sealant or a single-component extrusion type water-swellable polyurethane sealant;

[0158] Step 2.2.3: Each pipe segment at the top, bottom and side of the bundled structure 5 is welded to the embedded steel ring 502 on each ring frame beam 501 .

[0159] like Fig.10 and Fig.11 As shown, step 3 is as follows:

[0160] Step 3.1, inserting prestressed steel strands 510 into all pipe sections at the top, bottom and sides of the bundled structure 5;

[0161] Step 3.2, in all the pipe sections of the middle wall 513 of the bundled structure 5, high-strength bolts are used to fasten and complete the connection between the A1 pipe section 505, the B2 standard pipe 509 and the A2 pipe section 506;

[0162] Step 3.3, pouring concrete inside and between all pipe sections except the B1 type working pipe;

[0163] Step 3.4, tensioning the prestressed steel strand 510 in the B1 type working tube;

[0164] The order of tensioning the prestressed steel strand 510 is: following the tensioning principle of the same cross section, symmetry, internal and external synchronization, first long strands and then short strands;

[0165] Step 3.5: Anchor both ends of the tensioned prestressed steel strand 510 in the corresponding B1 type working pipe and fill it with concrete 512 to form a structure that can bear overall lateral force.

[0166] The pulling of the corrugated pipe before pulling the prestressed steel strand 510, the tensioning of the prestress, the grouting in the corrugated pipe and the anchoring are all conventional operations of post-tensioning prestressing construction and will not be described in detail.

[0167] like Fig.12 and Fig.13 As shown, step 4 is as follows:

[0168] Step 4.1, constructing a well joint 514 of the bundle structure 5 in the bundle structure starting well 2 and the bundle structure receiving well 3;

[0169] Step 4.2, the existing underground wall 101, the newly built underground wall 201 of the starting well and the newly built underground wall 301 of the receiving well within the scope of the bundled structure 5 are demolished as they are excavated;

[0170] Step 4.3, excavating the soil in the bundled structure 5 in full section;

[0171] Step 4.4, setting a steel underpinning column 515 in the bundled structure 5;

[0172] Step 4.5: Clear all the middle walls 513 in the bundled structure 5 to complete the underpinning construction.

[0173] like Fig.14 As shown, waterproof sealant 9 and grouting pipe 17 are provided at the interface between the well joint 514 and each pipe section of the bundled structure 5, and the working well structure 7 of the bundled structure starting well 2 or the bundled structure receiving well 3, to ensure that no water leakage occurs during the permanent use stage.

[0174] In some embodiments, each well joint 514 is provided with a well joint reinforcement 15 on the outside;

[0175] Each well joint reinforcement 15 is composed of an inverted L-shaped reinforcement and a C-shaped reinforcement. Fig.15 and Fig.16 As shown;

[0176] After the jacking construction of the pipe segment of the bundled structure 5 is completed, one end of each inverted L-shaped steel bar is welded and fixed to the inner wall of the pipe segment at the corresponding position, and is bent downward to form an L shape, and the other end is welded to the reserved steel bar at the corresponding position of the corresponding bundled structure starting well 2 or the corresponding bundled structure receiving well 3 during construction;

[0177] After the jacking construction of the pipe segment of the bundled structure 5 is completed, one end of each C-shaped steel bar is welded to the inner wall of the pipe segment at the corresponding position and bent downward twice to form a C shape, and the other end is welded to the steel bar reserved at the corresponding position of the ring frame beam 501 during construction.

[0178] In some embodiments, after all the middle walls 513 in the bundled structure 5 are removed, the entire wall is hoisted out, or the wall is hoisted out after being cut into pieces, by cutting off the male and female lock buckles 12 and high-strength bolts 14 between the B2-type standard tube and the corresponding A1-type tube.

[0179] like Fig.13 As shown, each steel support column 515 is disposed between two C-shaped longitudinal beam standard tubes 507;

[0180] like Fig.17 and Fig.18 As shown, the column base of each steel underpinning column 515 includes an end plate 18 and a column base stiffening rib 19;

[0181] Each end plate 18 has a reinforcement opening 20 reserved on the outer circumference of the corresponding steel support column 515, and is fixed to the corresponding C-shaped longitudinal beam standard tube 507 by fillet welding;

[0182] Each C-shaped longitudinal beam standard tube 507 is provided with openings of the same specification and quantity corresponding to each reinforcement opening 20;

[0183] Before pouring concrete in any steel support column 515, first reserve dowel bars 21 at the column;

[0184] The reserved dowel bars 21 at the column of each steel support column 515 pass through the corresponding end plate 18 through the corresponding reserved reinforcement opening 20;

[0185] Each pipe segment connected to the steel support column 515 is provided with a plug welding hole corresponding to each corresponding reserved reinforcement opening 20, and the internal reserved inserted reinforcement 21 passes through the corresponding plug welding hole and the corresponding reserved reinforcement opening 20 to fix the corresponding pipe segment and the corresponding end plate 18 by plug welding;

[0186] Each pipe segment connected to the steel underpinning column 515 is fixed to the corresponding end plate 18 by means of fillet welds.

[0187] The specifications, quantity and arrangement of the end plate 18 and the column foot stiffening ribs 19 are determined by the force calculation during the temporary underpinning construction stage;

[0188] The size, quantity and arrangement of the reserved openings of the aligned end plates and the reserved openings of the C-type longitudinal beam standard tube 507 are determined by the outer peripheral ring reinforcement of the steel-concrete column 516 of the steel-wrapped underpinning column 515 to be constructed later;

[0189] The outer ring reinforcement of the steel-concrete column is determined by the force calculation of the steel-concrete column during the permanent use stage.

[0190] like Fig.19 and Fig. 20 As shown, step 5 is as follows:

[0191] Step 5.1, constructing steel concrete column 516;

[0192] Step 5.2, construct the secondary structure of the station including the inner lining 22, the platform slab 23, and the backfilled plain concrete 24;

[0193] Step 5.3, closing the starting well hoisting hole 205 and the receiving well hoisting hole 305 in the starting well 2 and the receiving well 3 of the bundle structure;

[0194] Step 5.4: Complete the construction of the new underground station 4, backfill with soil, and close the precipitation well.

[0195] like Fig.21 and Fig. 22 As shown, step 5.1 is as follows:

[0196] Step 5.1.1, tying steel concrete column reinforcement 25 around the outer circumference of the steel underpinning column 515;

[0197] Step 5.1.2, the steel concrete column reinforcement bars 25 are aligned one by one with the reserved dowel bars 21 reserved in the C-shaped longitudinal beam standard tube 507 and welded together;

[0198] Step 5.1.2: Set up the formwork and pour concrete to form the steel-concrete column 516.

[0199] In some embodiments, a new underground station 4 is built together with the bundled structure receiving shaft 3 .

[0200] The preferred specific embodiments of the present invention are described in detail above. It should be understood that a person skilled in the art can make many modifications and changes based on the concept of the present invention without creative work. Therefore, any technical solution that can be obtained by a person skilled in the art through logical analysis, reasoning or limited experiments based on the concept of the present invention on the basis of the prior art should be within the scope of protection determined by the claims.

Claims

1. A method for constructing a subway cross transfer station using a bundled structure; used to construct a new underground station (4) on the next floor of an existing subway station (1) that has been completed, the vertical projection of which is in the shape of a cross with the existing subway station (1); characterized in that: The steps include: Step 1: On both sides of the existing subway station (1), corresponding to the positions at both ends of the newly built underground station (4), a bundled structure starting well (2) and a bundled structure receiving well (3) with the same depth as that of the newly built underground station (4) are respectively constructed; Step 2: performing pipe segment jacking construction of the bundled structure (5) in the soil below the existing subway station (1); Step 3, completing the prestressing construction of the bundled structure (5) without excavating the soil; Step 4: excavating the soil in the bundled structure (5), and performing underpinning construction on the bundled structure (5); Step 5: Complete the construction of the underpass section of the new underground station (4) located below the existing subway station (1).

2. The construction method of a subway cross transfer station using a bundled structure underpass according to claim 1 is characterized in that: Step 1 is as follows: Step 1.1, constructing a new underground wall (201) of the starting shaft of the bundled structure starting shaft (2) and a new underground wall (301) of the receiving shaft of the bundled structure receiving shaft (3) at a position 1m±10% outside the existing underground wall (101) of the existing subway station (1); Step 1.2, constructing a starting well ground wall sandwich soil reinforcement (202) between the newly built underground wall (201) of the starting well and the existing underground wall (101); Constructing a receiving well ground wall sandwich soil reinforcement (302) between the newly constructed receiving well underground wall (301) and the existing underground wall (101); Step 1.3, stripping off the top steel bars of the newly constructed underground wall (201) of the starting well, the newly constructed underground wall (301) of the receiving well and the existing underground wall (101), and casting the starting well side ring beam (203) and the receiving well top ring beam (303) at the position where the top steel bars are stripped off.

3. The construction method of a subway cross transfer station using a bundled structure underpass according to claim 2 is characterized in that: Each floor slab of the starting well (2) of the bundled structure is provided with a starting well hoisting hole (205); and each floor slab of the receiving well (3) of the bundled structure is provided with a receiving well hoisting hole (305).

4. The construction method of a subway cross transfer station using a bundled structure underpass according to claim 2 is characterized in that: After the construction of the bundling structure (5) is completed, a starting shaft connecting layer (204) and a receiving shaft connecting layer (304) are respectively arranged between the underground first floor of the existing subway station (1) of the starting shaft (2) and the underground first floor of the receiving shaft (3) of the bundling structure, and the underground first floor of the existing subway station (1) is connected through the corresponding starting shaft connecting layer (204) or the corresponding receiving shaft connecting layer (304).

5. The construction method of a subway cross transfer station using a bundled structure underpass according to claim 1 is characterized in that: Step 2 is as follows: Step 2.1, in the starting well (2) and the receiving well (3) of the bundled structure, grooves are cut step by step to break all the pipe sections of the top, bottom and side of the bundled structure (5), and the newly built underground wall (201) of the starting well, the newly built underground wall (301) of the receiving well, and the existing underground wall (101) within the range of the ring frame beam (501) of the outer circumference of the bundled structure (5); Step 2.2, completing the construction of the ring frame beam (501) and the embedded steel ring (502) inside the ring frame beam (501) on the starting well (2) side of the bundled structure and the receiving well (3) side of the bundled structure; Step 2.3, completing the jacking construction of each pipe segment of the bundled structure (5), and welding them to the embedded steel ring (502) inside the ring frame beam (501); Step 2.4, temporary steel supports (503) are set up on the end wall frames of the bundled structure starting shaft (2) and the bundled structure receiving shaft (3) close to the existing subway station (1).

6. The construction method of a subway cross transfer station using a bundled structure underpass according to claim 5 is characterized in that: The pipe sections at the top and bottom of the bundled structure (5) both include A-type standard pipes (504) and C-type longitudinal beam standard pipes (507); The C-shaped longitudinal beam standard tubes (507) are located at both ends of the steel underpinning columns (515) between the top and the bottom of the bundled structure (5), and are arranged in pairs corresponding to each of the steel underpinning columns (515); The pipe sections on the side of the bundled structure (5) all include the A-type standard pipe (504) and the B1-type working pipe (508); The B1 type working tubes (508) are all arranged at the corners between the side and the top of the bundled structure (5); The pipe sections of the middle wall (513) of the bundled structure (5) all include A1-type pipe sections (505), B2-type standard pipes (509) and A2-type pipe sections (506); On the outside of each pipe section, two sets of matching male and female lock buckles (12) are provided at the same positions near both sides of the connecting surface as those of another adjacent pipe section; Each of the pipe segment walls at the top, bottom and side of the bundled structure (5) and the inner sides of two groups of male and female lock buckles (12) close to the two sides of the connecting surface of another adjacent pipe segment are provided with reserved openings (11) for passing prestressed steel strands (510); Each of the B1 type working pipes (510) is used for tensioning and anchoring the prestressed steel strands (510), and is provided with reinforcing ribs (13) inside the pipe near another adjacent pipe segment; Each of the A1-type pipe sections (505) is used to connect the bottom or top of the bundled structure (5) with the B2-type standard pipe (509) at the lower end or upper end of the corresponding middle wall (513), and is fixed by a plurality of high-strength bolts (14) between the side facing the middle wall (513) and the adjacent B2-type standard pipe (509) on the inner side of the two groups of male and female lock buckles (12) close to both sides of the connecting surface; Each of the A2-type pipe sections (506) is located between two of the B2-type standard pipes (509) and is fixed by a plurality of high-strength bolts (14) on the inner sides of two groups of male and female lock buckles (12) near the two sides of the connecting surface.

7. The construction method of a subway cross transfer station using a bundled structure underpass according to claim 5, characterized in that: When the newly built underground wall (201) of the starting shaft, the newly built underground wall (301) of the receiving shaft and the corresponding existing underground wall (101) within the range of the ring frame beam (501) are removed step by step in step 2.1, the newly built underground wall (201) of the starting shaft and the newly built underground wall (301) of the receiving shaft need to be completely removed and two rows of steel bars on both sides need to be stripped out, and the corresponding existing underground wall (101) only needs to remove the inner half and strip out one row of inner side steel bars.

8. The construction method of a subway cross transfer station using a bundled structure underpass according to claim 7 is characterized in that: Step 2.2 is as follows: Step 2.2.1, the two rows of stripped steel bars of the newly built underground wall (201) of the starting well and the one row of steel bars of the existing underground wall (101) on the corresponding side are anchored into the ring frame beam (501), and connected to the remaining half of the existing underground wall (101) on the corresponding side through horizontal embedded reinforcement (10) to form a whole; the three rows of stripped steel bars of the newly built underground wall (301) of the receiving well and the existing underground wall (101) on the corresponding side are treated in the same way; Step 2.2.2, the contact surface treatment is performed on the joint surfaces of the ring frame beam (501) and the starting well (2) of the bundled structure, the working well structure of the receiving well (3) of the bundled structure, the corresponding newly built underground wall (201) of the starting well, the corresponding newly built underground wall (301) of the receiving well, or the remaining half of the corresponding existing underground wall (101); Pre-embedded waterproof sealant is provided on the horizontal joint surface between the ring frame beam (501) and the corresponding newly built underground wall (201) of the starting well or the corresponding newly built underground wall (301) of the receiving well, and the vertical joint surface of the corresponding existing underground wall; The contact surface treatment (8) refers to roughening the concrete and applying a cement-based penetrating crystalline waterproof coating; The waterproof sealant (9) is a single-component water-swellable polyurethane sealant or a single-component extrusion type water-swellable polyurethane sealant; Step 2.2.3, each of the pipe sections at the top, bottom and side of the bundled structure (5) is welded to the embedded steel ring (502) on each of the ring frame beams (501).

9. The construction method of a subway cross transfer station using a bundled structure underpass according to claim 1, characterized in that: Step 3 is as follows: Step 3.1, inserting prestressed steel strands (510) into all the pipe sections at the top, bottom and sides of the bundled structure (5); Step 3.2, in all the pipe segments of the middle wall (513) of the bundled structure (5), high-strength bolts are used to fasten and complete the connection between the A1 type pipe segment (505), the B2 type standard pipe (509) and the A2 type pipe segment (506); Step 3.3, pouring concrete inside and between all the pipe sections except the B1 type working pipe; Step 3.4, tensioning the prestressed steel strand (510) in the B1 type working tube; The order of tensioning the prestressed steel strands (510) is: following the same cross section, symmetry, internal and external synchronization, first long strands and then short strands tensioning principles; Step 3.5, anchoring the two ends of the tensioned prestressed steel strand (510) in the corresponding B1 type working pipe, and filling it with concrete (512) to form a structure that can bear overall lateral force.

10. The construction method of a subway cross transfer station using a bundled structure underpass according to claim 1, characterized in that: Step 4 is as follows: Step 4.1, constructing the well joint (514) of the bundle structure (5) in the bundle structure starting well (2) and the bundle structure receiving well (3); Step 4.2, the existing underground wall (101) within the range of the bundled structure (5), the newly built underground wall (201) of the starting well and the newly built underground wall (301) of the receiving well are demolished as they are excavated; Step 4.3, excavating the soil in the bundled structure (5) in full section; Step 4.4, arranging a steel underpinning column (515) in the bundled structure (5); Step 4.5: Clear all the middle walls (513) in the bundled structure (5) to complete the underpinning construction.

11. The construction method of a subway cross transfer station using a bundled structure underpass according to claim 10, characterized in that: Waterproof sealant (9) and grouting pipes (17) are provided at the interface between the well joint (514) and each pipe section of the bundled structure (5), and the working well structure (7) of the bundled structure starting well (2) or the bundled structure receiving well (3).

12. The construction method of a subway cross transfer station using a bundled structure underpass according to claim 10, characterized in that: The outer side of each well joint (514) is provided with a well joint steel bar (15); Each of the well joint steel bars (15) is composed of an inverted L-shaped steel bar and a C-shaped steel bar; After the jacking construction of the pipe segment of the bundled structure (5) is completed, one end of each inverted L-shaped steel bar is welded and fixed to the inner wall of the pipe segment at the corresponding position, and is bent downward to form an L shape, and the other end is welded to the steel bar reserved at the corresponding position of the corresponding bundled structure starting well (2) or the corresponding bundled structure receiving well (3) during construction; After the jacking construction of the pipe segment of the bundled structure (5) is completed, one end of each C-shaped steel bar is welded to the inner wall of the pipe segment at the corresponding position and bent downward twice to form a C shape, and the other end is welded to the steel bar reserved at the corresponding position of the ring frame beam (501) during construction.

13. The construction method of a subway cross transfer station using a bundled structure underpass according to claim 10, characterized in that: After all the middle walls (513) in the bundled structure (5) are removed, the entire wall is hoisted out, or the wall is hoisted out after being cut into pieces, by cutting off the male and female lock buckles (12) and high-strength bolts (14) between the B2-type standard tube and the corresponding A1-type tube.

14. The construction method of a subway cross transfer station using a bundled structure underpass according to claim 10, characterized in that: Each of the steel support columns (515) is arranged between two C-shaped longitudinal beam standard tubes (507); The column foot of each of the steel support columns (515) comprises an end plate (18) and column foot stiffening ribs (19); Each of the end plates (18) is provided with a reinforcement opening (20) at the outer circumference of the corresponding section steel underpinning column (515), and is fixed to the corresponding C-shaped longitudinal beam standard tube (507) by fillet welding; Each of the C-shaped longitudinal beam standard tubes (507) is provided with openings of the same specification and quantity corresponding to each of the reinforcement openings (20); Before pouring concrete in any of the steel support columns (515), a reserved dowel bar (21) is first constructed at the column. The reserved dowel bars (21) at the column of each of the steel support columns (515) pass through the corresponding end plates (18) through the corresponding reserved reinforcement openings (20); Each pipe segment connected to the steel support column (515) is provided with a plug welding hole corresponding to each of the reserved reinforcement openings (20), and the internally reserved inserted reinforcement (21) passes through the corresponding plug welding hole and the corresponding reserved reinforcement opening (20) to fix the corresponding pipe segment and the corresponding end plate (18) by plug welding; Each of the pipe sections connected to the steel underpinning column (515) is fixed to the corresponding end plate (18) by means of fillet welds.

15. The construction method of a subway cross transfer station using a bundled structure underpass according to claim 14, characterized in that: Step 5 is as follows: Step 5.1, constructing steel concrete columns (516); Step 5.2, constructing the secondary structure of the station including the inner lining (22), the platform slab (23), and the backfill of plain concrete (24); Step 5.3, closing the starting well hoisting hole (205) and the receiving well hoisting hole (305) in the starting well (2) and the receiving well (3) of the bundle structure; Step 5.4, completing the construction of the new underground station (4), backfilling with soil, and closing the precipitation well.

16. The construction method of a subway cross transfer station using a bundled structure underpass according to claim 15, characterized in that: Step 5.1 is as follows: Step 5.1.1, tying steel-concrete column reinforcement (25) around the outer circumference of the steel underpinning column (515); Step 5.1.2, the steel-concrete column reinforcement bars (25) are aligned one by one with the reserved dowel bars (21) reserved in the C-shaped longitudinal beam standard tube (507) and connected by welding; Step 5.1.2, setting a formwork and pouring concrete to form the steel-concrete column (516).

17. The construction method of a subway cross transfer station using a bundled structure underpass according to claim 1, characterized in that: The newly built underground station (4) is built together with the bundled structure receiving shaft (3).

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