A subway station support and construction method allowing a pipe jacking to cross a pipeline

Abstract

A kind of subway station support and construction method allowing pipeline pipe jacking to cross, comprising the following steps: making enclosure and enclosure structure, reserved pipe jacking interface on the interlocking pile, municipal pipeline pipe jacking crosses from the reserved pipe jacking interface;Make precipitation well, temporary center column, corbel and first support;Foundation pit excavation, make first waist beam and second support, second support is located above the interlocking pile breaking pile position;After foundation pit excavation to the bottom of municipal pipeline, make pipeline suspension measure;Foundation pit excavation, make second waist beam and third support, third support is located at the height of interlocking pile breaking pile;Foundation pit excavation, make third waist beam and fourth support;Make cushion, lay waterproof layer, pour bottom plate and side wall;Backfilling, remove first support and temporary center column, restore ground surface.The present application can realize municipal pipeline pipe jacking to cross subway station safely without avoiding, at the same time, make pipe jacking construction and station construction safety synchronization without conflict.

Description

Technical Field

[0001] This invention relates to the field of underground engineering construction technology, and in particular to a method for supporting and constructing subway stations that allows pipeline jacking to cross. Background Technology

[0002] Underground rail transit and urban pipeline networks, as two core systems of modern urban infrastructure, compete for limited underground space resources. Due to fragmented planning systems, asynchronous construction schedules, and information barriers, conflicts between the two often persist throughout the planning, construction, and operation processes. Therefore, their coordinated development directly impacts urban operational efficiency and sustainable development. With the advancement of urban construction, the coordinated planning of underground rail transit and urban pipeline networks faces multiple technical challenges and implementation difficulties. Subway stations are often built in densely populated areas where underground space is already occupied by various municipal pipelines, leading to serious conflicts between rail transit line layouts and existing pipeline networks. Current technologies often employ partial relocation or avoidance solutions, but these methods easily trigger secondary construction, increase construction costs, and may damage the stability of the original pipeline system. Therefore, for situations where pipeline networks and underground station halls cannot be avoided or where avoidance is costly, it is necessary to seek technical solutions for their coexistence and coordinated cooperation. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of the prior art and provide a subway station support and construction method that allows pipeline jacking to cross the station, enabling pipeline jacking and station support construction to be carried out simultaneously without interference and to complement each other.

[0004] This invention is achieved through the following technical solution: A method for supporting and constructing subway stations that allows for pipe jacking to cross, comprising the following steps: At the site of the subway station's foundation pit, a enclosure, guide wall, and retaining structure are constructed. The retaining structure includes several interlocking piles arranged in the direction of the municipal pipeline laying, i.e., the direction of the interlocking piles intersects with the direction of the municipal pipeline laying. The municipal pipeline passes through the interlocking piles. The interlocking piles have reserved jacking interfaces at the locations where the municipal pipeline jacking pipes cross. When the pipeline jacking pipes pass through the interlocking pile locations, they can pass quickly without manual removal. In municipal pipeline jacking construction, the pipeline crosses the retaining structure horizontally from the reserved jacking interface of the interlocking pile; Dewatering wells, temporary central columns, capping beams, and the first support were constructed at the excavation site. The pile foundation steel bars of the temporary central columns were anchored below the station structure floor slab. When the foundation pit is excavated to a certain depth near the municipal pipeline and below the bottom of the designed second support, the first waist beam and the second support are constructed. The first waist beam and the second support are located above the broken pile position caused by the municipal pipeline crossing. The positions of the first waist beam and the second support are set at the broken pile opening to restrain the deformation of the interlocking pile. After the foundation pit is excavated to the bottom of the municipal pipeline, pipeline suspension measures are implemented to fix the municipal pipeline. Each municipal pipeline must be provided with pipeline suspension measures. When the foundation pit is excavated to a certain depth below the bottom of the designed third support, the second waist beam and the third support are constructed. The second waist beam and the third support are located at the height of the interlocking pile broken due to the cross-section of municipal pipelines. When the foundation pit is excavated to a certain depth below the bottom of the designed fourth support, the third waist beam and the fourth support are constructed. The third waist beam and the fourth support are located below the bottom of the interlocking pile broken due to the cross-section of municipal pipelines, and are located between the bottom slab and the top slab of the station structure. The foundation pit is excavated to the base, a cushion layer is constructed, a waterproof layer is laid, and the bottom slab and part of the side walls are poured. When the concrete strength of the side wall reaches more than 80% of the design strength, steel bracing is installed on the foundation of the side wall, the fourth bracing is removed, and the remaining side wall and top slab are constructed. The steel supports will be removed when the concrete strength of the top slab and side walls reaches more than 80% of the design strength. Backfill the soil to below the first support, and remove the first support and the temporary central column; Continue backfilling and covering the soil, restore the ground surface, remove the barriers, dismantle the dewatering wells, and construct the station hall floor and internal structure.

[0005] Furthermore, the municipal pipeline includes rainwater pipes and sewage pipes arranged vertically, and the third support is located at the depth between the rainwater pipes and the sewage pipes; After the foundation pit is excavated to the bottom of the municipal pipeline (such as rainwater pipe) located above, pipeline suspension measures are implemented on the second support to fix the municipal pipeline located above on the second support; After the foundation pit is excavated to the bottom of the municipal pipeline (such as a sewage pipe) located below, pipeline suspension measures are implemented on the third support to fix the municipal pipeline located below to the third support.

[0006] Furthermore, the method for implementing pipeline suspension measures is as follows: steel plates are pre-embedded on the support beams of the second or third support, and channel steel is welded onto the pre-embedded steel plates. The channel steels are welded together to form a frame that can accommodate municipal pipelines.

[0007] Furthermore, the interlocking piles include solid piles and plain piles, and the municipal pipelines include rainwater pipes and sewage pipes. The rainwater pipes and sewage pipes are arranged in a staggered manner, and a complete solid pile is retained between the rainwater pipes and the sewage pipes.

[0008] Furthermore, the method for reserving the pipe jacking interface on the interlocking pile is to use glass fiber reinforcement instead of steel reinforcement at the location where municipal pipelines pass through the interlocking pile.

[0009] Furthermore, the retaining structure includes not only interlocking piles, but also pile banks and diaphragm walls; the guide wall is made of C25 concrete, and the thickness of the protective layer for the reinforcing steel is not less than 25mm.

[0010] Furthermore, the temporary central column adopts a lattice-type central column, and the foundation of the temporary central column adopts C30 underwater concrete and a bored pile with a diameter of 1200.

[0011] Furthermore, the first support covers the entire area of ​​the foundation pit and includes a first reinforced concrete support beam, a first connecting beam, and a first diagonal brace. The first reinforced concrete support beam and the first connecting beam are connected to the temporary central column support. The two ends of the first reinforced concrete support beam are connected to the cap beam and are perpendicular to the direction of the interlocking piles. The first diagonal brace is set between the first reinforced concrete support beam and the cap beam and has an angle of 45 degrees with the direction of the interlocking piles. The first connecting beam is set between the first reinforced concrete support beams.

[0012] Furthermore, the second support covers the entire excavation pit and includes a second reinforced concrete support beam, a second connecting beam, and a second diagonal brace. The second reinforced concrete support beam and the second connecting beam are connected to the temporary central column support. The two ends of the two reinforced concrete support beams are connected to the first waist beam. The second reinforced concrete support beams near the municipal pipelines are parallel to the municipal pipelines, while the other second reinforced concrete support beams are perpendicular to the direction of the interlocking piles and are fixed by the second diagonal brace. The angle between the second diagonal brace and the direction of the interlocking piles is 45 degrees. The second connecting beam is set between the second reinforced concrete support beams.

[0013] Furthermore, the third support only covers the area where the municipal pipeline is located, and includes a third reinforced concrete support beam and a third connecting beam. The third reinforced concrete support beam and the third connecting beam are connected to the temporary central column support. The two ends of the third reinforced concrete support beam are connected to the second waist beam and are parallel to the municipal pipeline. The third connecting beam is set between the third reinforced concrete support beams.

[0014] Furthermore, the fourth support covers the entire excavation pit and includes a fourth reinforced concrete support beam and a fourth connecting beam. The fourth reinforced concrete support beam and the fourth connecting beam are connected to the temporary central column support. The two ends of the fourth reinforced concrete support beam are connected to the third waist beam and are perpendicular to the direction of the interlocking piles. The fourth connecting beam is arranged between the fourth reinforced concrete support beams.

[0015] Furthermore, when constructing the roof slab, it is necessary to avoid municipal pipelines and form a protective structure for them.

[0016] This invention addresses situations where municipal pipelines need to cross station entrances. It coordinates pipeline jacking with the entire station concourse construction process, ensuring both construction and safety. Specifically: before jacking, interface conditions are pre-reserved in the subway station's retaining structure for pipeline passage. This allows for rapid pipeline jacking, eliminating the need for forceful demolition and avoiding unpredictable impacts on the retaining structure caused by such demolition, thus keeping the impact of jacking within a manageable range. For broken piles formed when the pipeline jacking machine crosses interlocking piles, a wainscoting beam and support are installed above the broken pile. The broken pile is connected to the surrounding interlocking piles via the wainscoting beam, enhancing the bending resistance of the interlocking piles at the broken pile location, ensuring the overall strength of the retaining structure, and without affecting the original foundation pit support structure. Only slight adjustments to the original foundation pit support position are required. The support can be placed directly and retained during subsequent backfilling to strengthen the overall maintenance structure. Simultaneously, an additional lintel and support (a third layer of support) are added at the broken pile location. This support only covers the pipeline area, further reinforcing the broken pile location. After the foundation pit support is removed, this support will be retained to continuously support the pipeline and station hall enclosure without affecting the construction of the station's main structure. When arranging interlocking piles, interlocking piles are placed in the middle of the pipeline to ensure the strength of the enclosure structure at the pipeline location. Municipal pipelines are suspended, avoiding the pipelines during station roof construction and providing protection for them, ensuring spatial coordination between the municipal pipelines and the station. The overall scheme achieves mutual coordination between pipeline jacking and station construction, without conflict, and ensures the safety of the entire construction process and the final structure. Attached Figure Description

[0017] Figure 1 This is a cross-sectional view of the engineering location in an embodiment of the present invention.

[0018] Figure 2 This is a schematic diagram of the overall construction process of an embodiment of the present invention.

[0019] Figure 3 This is a schematic diagram of the first step of construction in an embodiment of the present invention.

[0020] Figure 4 This is a schematic diagram of the second step of construction in an embodiment of the present invention.

[0021] Figure 5 This is a plan view of the municipal pipeline jacking in an embodiment of the present invention.

[0022] Figure 6 This is a schematic diagram of the third step of construction in an embodiment of the present invention.

[0023] Figure 7 This is a planar schematic diagram of the first support in an embodiment of the present invention.

[0024] Figure 8 This is a schematic diagram of the fourth step of construction in an embodiment of the present invention.

[0025] Figure 9 This is a planar schematic diagram of the second support in an embodiment of the present invention.

[0026] Figure 10 This is a schematic diagram of the fifth step of the construction in an embodiment of the present invention.

[0027] Figure 11 This is a schematic diagram of the first pipeline suspension measure in an embodiment of the present invention.

[0028] Figure 12 This is a schematic diagram of the sixth step of the construction in an embodiment of the present invention.

[0029] Figure 13 This is a planar schematic diagram of the third support in an embodiment of the present invention.

[0030] Figure 14 This is a schematic diagram of the seventh step of the construction in an embodiment of the present invention.

[0031] Figure 15 This is a schematic diagram of the second pipeline suspension measure in an embodiment of the present invention.

[0032] Figure 16 This is a schematic diagram of the eighth step of the construction in an embodiment of the present invention.

[0033] Figure 17 This is a planar schematic diagram of the fourth support in an embodiment of the present invention.

[0034] Figure 18 This is a schematic diagram of the ninth step of the construction process in an embodiment of the present invention.

[0035] Figure 19 This is a schematic diagram of the tenth step of the construction in an embodiment of the present invention.

[0036] Figure 20 This is a schematic diagram of the eleventh step in the embodiment of the present invention.

[0037] Figure 21 This is a construction diagram of steps eleven and twelfth in an embodiment of the present invention.

[0038] Attached reference numerals: 1-Interlocking pile; 2-Pipe jacking interface; 3-Rainwater pipe; 4-Sewage pipe; 5-Temporary central column; 6-Dewatering well; 7-First support; 8-Cover beam; 9-Second support; 10-Enclosure; 11-First wainscoting beam; 12-First pipeline suspension measure; 13-Third support; 14-Second wainscoting beam; 15-Second pipeline suspension measure; 16-Fourth support; 17-Third wainscoting beam; 18-Base slab; 19-Side wall; 20-Steel replacement support; 21-Top slab; 71-First reinforced concrete support beam; 72-First connecting beam; 73-First diagonal brace; 91-Second reinforced concrete support beam; 92-Second connecting beam; 93-Second diagonal brace; 131-Third reinforced concrete support beam; 132-Third connecting beam; 161-Fourth reinforced concrete support beam; 162-Fourth connecting beam. Detailed Implementation

[0039] This invention discloses a subway station support and construction method that allows pipeline jacking to cross the subway station. It is mainly for situations where municipal pipelines cross the subway station. The interlocking piles of the subway station retaining structure are constructed first, while reserving conditions for pipeline jacking construction. Then, rainwater and sewage pipelines are constructed in the station foundation pit state, minimizing the impact of station construction on the pipeline construction period. In order to reduce the impact of interlocking pile breakage caused by pipeline jacking, structural reinforcement measures are taken at the broken piles, increasing structural supports and replacing supports. At the same time, the position of the original supports is adjusted, and the municipal pipelines are protected in conjunction with the station structure construction.

[0040] The specific technical solution of the present invention is illustrated below with a specific project example. The actual engineering project in this embodiment is the construction of a new city... Figure 1 As shown, the municipal pipelines need to cross the wiring area of ​​the subway station. The station is a single-level underground arched structure with a structural clearance of approximately 27m and a structural slab 18 buried at a depth of approximately 20m. The municipal pipelines are DN1800mm rainwater pipe 3 and DN2200mm sewage pipe 4. Rainwater pipe 3 has a bottom burial depth of approximately 10.6m and a structural clearance of approximately 0.2m between it and the station roof slab 21. Sewage pipe 4 has a bottom burial depth of approximately 7.1m and a structural clearance of approximately 3.7m between it and the station roof slab 21. The clearance between the pipelines is only 1.3m. During the original subway station excavation phase, two layers of concrete supports and one layer of steel supports were used for shoring. After the completion of the jacking construction of rainwater pipe 3 and sewage pipe 4, the original interlocking piles 1 were damaged, resulting in multiple broken piles within a small vertical area, severely weakening the overall strength of the retaining structure. Calculations confirmed that the deformation of interlocking pile 1 at the broken pile locations was excessive, and the original supports could not meet the safety requirements of the excavation pit. Measures need to be taken to reduce the deformation of the retaining structure. This invention proposes a series of reinforcement measures for interlocking pile foundation pits, multi-pipeline and small-spacing pipe jacking construction, which damages the strength of the retaining structure. The overall construction structure is as follows: Figure 2 As shown, the specific steps include the following: Step 1: Construction preparation, pipeline relocation, traffic diversion, and construction of fencing, guide walls, and retaining structures at the subway station's foundation pit location, such as... Figure 3 As shown, the retaining structure includes several interlocking piles 1 arranged facing the direction of the municipal pipeline laying. That is, the direction of the interlocking piles 1 intersects the direction of the municipal pipeline laying. The municipal pipeline passes through the interlocking piles 1, either perpendicularly or non-perpendicularly depending on the actual project conditions. The interlocking piles 1 have pre-reserved jacking interface 2 at the locations where the municipal pipeline jacking crosses. When the pipeline jacking passes through the interlocking piles 1, it can pass quickly without manual removal. The guide wall is made of C25 concrete, and the protective layer thickness of the reinforcing steel is not less than 25mm. The retaining structure, in addition to the interlocking piles 1, also includes pile banks and diaphragm walls. Specifically, in this embodiment, the retaining structure along axes 1-15 uses D1000mm@1200mm pile banks + three internal supports (partially four supports); axes 15-30 use an 800mm thick diaphragm wall + three internal supports; axes 30-36 use D1000mm@1400mm interlocking piles 1 + three internal supports; axes 36-45 use an 800mm thick diaphragm wall + three internal supports; axes 45-60 use a 1000mm thick diaphragm wall + three internal supports; and axes 60-79 use D1200mm@1400mm pile banks + three internal supports. The concrete strength grade of the retaining structure is C35, P8 underwater concrete.

[0041] The method for reserving the pipe jacking interface 2 on the interlocking pile 1 is as follows: glass fiber reinforcement is used instead of steel reinforcement at the location where municipal pipelines pass through the interlocking pile 1.

[0042] The interlocking pile 1 includes solid piles and plain piles. The municipal pipelines include rainwater pipes 3 and sewage pipes 4. The rainwater pipes 3 and sewage pipes 4 are staggered, with a certain gap between them, so that complete solid piles are maintained between the rainwater pipes 3 and sewage pipes 4 to ensure the stability of the retaining structure. Specifically, in this embodiment, as follows... Figure 5 As shown, A1-A14 are solid piles, and B1-B12 are plain piles. After the jacking construction of rainwater pipe 3 and sewage pipe 4, broken piles A2, A3, A5, A6, A9, A10, A12, and A13 are formed, while complete solid piles A4 and A11 are retained in the middle of the pipeline.

[0043] When laying out the enclosure structure, the enclosure structure should be laid out according to the coordinates of the enclosure structure and the dimensions of the construction drawings, taking into account the control requirements such as construction error and maximum allowable horizontal displacement, to ensure the building clearance and the thickness of the inner lining wall.

[0044] When constructing diaphragm walls, the number of sections can be adjusted according to the specific conditions of the equipment, but approval from the relevant authorities is required.

[0045] In this embodiment, the foundation pit base is primarily located in strongly weathered and moderately weathered layers. The insertion depth of the retaining structure is, in principle, not less than the design calculation depth and must meet the following requirements: no less than 5.5m into completely weathered strata, no less than 4.0m into strongly weathered strata, no less than 2.5m into moderately weathered strata, and no less than 1.5m into slightly weathered strata. The construction unit should strengthen the verification of geology. If any discrepancies are found between the geology and the design in this drawing during construction, the relevant units should be notified promptly to adjust the embedment depth of the retaining structure.

[0046] Unless otherwise specified, the locations of the water collection well and the downlift beam are generally located in strongly weathered rock layers with a slope ratio of 1:0.5. Construction can only proceed after their locations have been verified against the architectural construction drawings.

[0047] The location of the dewatering well 6 can be adjusted appropriately according to the site conditions. The construction of the foundation must be carried out under the premise of dewatering, and the dewatering depth should reach 1.0m below the foundation or 0.5m below the moderately or slightly weathered rock layer.

[0048] The construction project in this embodiment is located in a karst development zone. The embedment depth of the retaining structure needs to be verified based on the geological data from the advance drilling before construction can proceed. Each diaphragm wall is equipped with 1-2 advance drilling holes, and the bored piles and column piles are single piles with single holes.

[0049] Before constructing the retaining structure, any underground pipelines of unknown or unknown origin should be probed to avoid damage during trenching. During the excavation of the foundation pit, pipelines near the pit should be strictly monitored to ensure their safety. Simultaneously, concrete water barriers and drainage ditches should be constructed around the pit to prevent flooding and surface water from flowing into it.

[0050] Step 2: As Figure 4 , Figure 5 As shown, the municipal pipeline jacking construction involves crossing the retaining structure from the reserved jacking interface 2 of the interlocking pile 1.

[0051] Step 3: As Figure 6 As shown, a dewatering well 6, a temporary central column 5, a capping beam 8, and a first support 7 are constructed at the location of the foundation pit. The pile foundation steel bars of the temporary central column 5 are anchored into the station structure bottom slab 18 and below.

[0052] The temporary central support column 5 is a lattice-type central support column, and its foundation is made of C30 underwater concrete and 1200mm diameter bored piles. The number and location of the temporary central support columns 5 are determined according to the actual project requirements. In this embodiment, the temporary central support columns 5 are as follows: Figure 7 Deployment.

[0053] like Figure 7As shown, the first support 7 covers the entire area of ​​the foundation pit. The first support 7 is made of reinforced concrete and includes a first reinforced concrete support beam 71, a first connecting beam 72, and a first diagonal brace 73. The first reinforced concrete support beam 71 and the first connecting beam 72 are connected to the temporary central column 5. The two ends of the first reinforced concrete support beam 71 are connected to the capping beam 8 and are perpendicular to the direction of the interlocking piles 1. The first diagonal brace 73 is located between the first reinforced concrete support beam 71 and the capping beam 8 and has an angle of 45 degrees with the direction of the interlocking piles 1. The first connecting beam 72 is located between the first reinforced concrete support beams 71.

[0054] In this embodiment, the first reinforced concrete support beam 71 has a cross-section of 800×1000, the capping beam 8 has dimensions of 800×1000+1000×1000+1200×1000, and the coping beam has dimensions of 600×800. The cover plate is 300mm thick, the cover beam KL1 has a cross-section of 800×1000, and the bottom wall thickness of the crash barrier is 500mm.

[0055] During construction, the support should be erected in a timely manner. At the same time, during the excavation of the foundation pit, attention should be paid to monitoring the displacement of the retaining structure and the changes in the axial force of the support. If any abnormality is found in the displacement of the retaining structure or the axial force of the support, effective remedial measures should be taken immediately, and the relevant units should be notified immediately for handling.

[0056] The capping beam, concrete supports, slab supports, retaining walls, and crash barriers are all made of C30 concrete, while the capping beam is made of C35 underwater concrete. For concrete supports with a span L ≥ 8m, camber should be applied at L / 400. Further excavation and dewatering work is not permitted until the first layer of reinforced concrete supports has reached 80% of its design strength.

[0057] Step 4: As Figure 8 As shown, when the excavation pit reaches a certain depth (0.5m) below the bottom of the designed second support 9 and is close to the municipal pipeline, the first wainscoting 11 and the second support 9 are constructed. The first wainscoting 11 and the second support 9 are located above the broken pile position of the interlocking pile 1 caused by the municipal pipeline crossing. Positioning the second support 9 at the broken pile opening can restrain the deformation of the interlocking pile 1.

[0058] Because the spacing between the interlocking piles 1 is relatively large, the water-stopping pile in the middle of the interlocking piles 1 cannot form a bending resistance against the water and soil pressure on the outside of the foundation pit. When the foundation pit is excavated to the pipeline location, the deformation at the broken pile is too large, affecting the safety of the foundation pit. In its design scheme, this invention cleverly proposes to erect a waist beam and support at the broken pile location. The broken pile and the surrounding interlocking piles 1 are connected as a whole through the waist beam, which enhances the bending resistance of the interlocking piles 1 at the broken pile location.

[0059] like Figure 9As shown, the second support 9 covers the entire excavation pit and is made of reinforced concrete. It includes a second reinforced concrete support beam 91, a second connecting beam 92, and a second diagonal brace 93. The second reinforced concrete support beam 91 and the second connecting beam 92 are connected to the temporary central column 5. The two ends of the second reinforced concrete support beam 91 are connected to the first waist beam 11. The second reinforced concrete support beam 91 near the municipal pipeline is parallel to the municipal pipeline. The other second reinforced concrete support beams 91 are perpendicular to the direction of the interlocking piles 1 and are fixed by the second diagonal brace 93. The angle between the second diagonal brace 93 and the direction of the interlocking piles 1 is 45 degrees. The second connecting beam 92 is arranged between the second reinforced concrete support beams 91.

[0060] The second reinforced concrete support beam 91 has a cross-section of 1000×1200, and the lintel beam YL1 has dimensions of 1000×1200. The lintel beam, concrete supports, and slab supports are all made of C30 concrete. For concrete supports with a span L≥8m, camber should be applied at L / 400. Further excavation and dewatering work is not permitted until the second reinforced concrete support has reached 80% of its design strength.

[0061] During the construction of the foundation pit and main structure, concrete water retainers and drainage ditches should be constructed around the foundation pit to prevent flooding and surface water from flowing into it.

[0062] Step 5: As Figure 10 As shown, after the foundation pit is excavated to the bottom of the municipal pipeline (rainwater pipe 3), the first pipeline suspension measure 12 is implemented to fix the municipal pipeline.

[0063] In this embodiment, the rainwater pipe 3 and the sewage pipe 4 are arranged in a staggered manner, with the rainwater pipe 3 on top and the sewage pipe 4 on the bottom. The second support 9 is located at the broken pile opening above the rainwater pipe 3, and the third support 13 is located at the depth between the rainwater pipe 3 and the sewage pipe 4.

[0064] Specifically, after the excavation of the foundation pit reaches the bottom of the upper rainwater pipe 3, the first pipeline suspension measure 12 is implemented on the second support 9 to fix the municipal pipeline on the second support 9. For example... Figure 11 As shown, the specific construction method of the first pipeline suspension measure 12 is as follows: steel plates are pre-embedded on the support beams of the second support 9 or the third support 13, and channel steel is welded on the pre-embedded steel plates. The channel steels are welded together to form a frame that can accommodate the municipal pipeline, thus providing support for the municipal pipeline.

[0065] Step 6: As Figure 12 As shown, when the foundation pit is excavated to a certain depth (0.5m) below the bottom of the designed third support 13, the second waist beam 14 and the third support 13 are constructed. The second waist beam 14 and the third support 13 are located at the height of the broken pile of the interlocking pile 1 caused by the cross-section of the municipal pipeline.

[0066] like Figure 13 As shown, the third support 13 only covers the area where the municipal pipeline is located, further reinforcing the broken pile position of the interlocking pile 1, and providing continuous protection after the foundation pit support is removed. The third support 13 includes a third reinforced concrete support beam 131 and a third connecting beam 132. The third reinforced concrete support beam 131 and the third connecting beam 132 are connected to the temporary central column 5. The two ends of the third reinforced concrete support beam 131 are connected to the second waist beam 14 and are parallel to the municipal pipeline. The third connecting beam 132 is arranged between the third reinforced concrete support beams 131. As shown in the figure, the three third reinforced concrete support beams 131 are only arranged at the positions of the A1-A14 plain piles and the B1-B12 plain piles, with a cross-section of 1000×1200, and are connected by two third connecting beams 132.

[0067] Step 7: As Figure 14 As shown, after the foundation pit is excavated to the bottom of the municipal pipeline (sewage pipe 4), a second pipeline suspension measure 15 is implemented to fix the municipal pipeline.

[0068] Specifically, after the excavation pit reaches the bottom of the sewage pipe 4 located at the lower level, a second pipeline suspension measure 15 is implemented on the third support 13 to fix the municipal pipeline to the third support 13. For example... Figure 15 As shown, the pipeline suspension measures are the same as the suspension scheme of the previous rainwater pipe 3.

[0069] Step 8: As Figure 16 As shown, when the foundation pit is excavated to a certain depth (0.5m) below the bottom of the designed fourth support 16, the third waist beam 17 and the fourth support 16 are constructed. The third waist beam 17 and the fourth support 16 are located below the bottom of the broken pile of the interlocking pile 1 caused by the cross-section of the municipal pipeline, and are located between the bottom slab 18 and the top slab 21 of the station structure.

[0070] The fourth support 16 is disposed between the structural base plate 18 and the structural top plate 21, such as Figure 17 As shown, the fourth support 16 covers the entire area of ​​the foundation pit, including a fourth reinforced concrete support beam 161 and a fourth connecting beam 162. The fourth reinforced concrete support beam 161 and the fourth connecting beam 162 are connected to the temporary central column 5. The two ends of the fourth reinforced concrete support beam 161 are connected to the third waist beam 17 and are perpendicular to the direction of the interlocking piles 1. The fourth connecting beam 162 is arranged between the fourth reinforced concrete support beams 161.

[0071] Step 9: As Figure 18 As shown, the foundation pit is excavated to the base, a cushion layer is constructed, a waterproof layer is laid, and the base slab 18 and part of the side walls 19 are poured.

[0072] Step 10: As Figure 19As shown, when the concrete strength of the side wall 19 reaches more than 80% of the design strength, steel replacement support 20 is constructed on the basis of the side wall 19, the fourth support 16 is removed, and the remaining side wall 19 and top plate 21 are constructed.

[0073] When constructing the roof slab 21, it is necessary to avoid municipal pipelines. In this embodiment, the structural roof slab 21 forms a convex structure to avoid the jacking pipe. Since the third support 13 only covers the area where the pipeline is located, retaining the third support 13 will not affect the construction of the roof slab 21 and the side wall 19, and can also provide continuous support for the municipal pipeline and the station maintenance structure.

[0074] Step 11: As Figure 20 , Figure 21 As shown, when the concrete strength of the top slab 21 and side wall 19 reaches more than 80% of the design strength, the steel replacement support 20 is removed, the backfill soil is filled to below the first support 7, and the first support and temporary central column 5 are removed.

[0075] Step 12: As Figure 21 As shown, continue backfilling and covering with soil to restore the ground surface, remove 10 barriers, remove 6 dewatering wells, and construct the station hall floor and internal structure.

[0076] The above detailed description is a specific description of feasible embodiments of the present invention. These embodiments are not intended to limit the patent scope of the present invention. All equivalent implementations or modifications that do not depart from the present invention should be included in the patent scope of this case.

Claims

1. A method for supporting and constructing subway stations that allows for pipe jacking, characterized in that, Includes the following steps: At the site of the foundation pit of the subway station, a barrier, guide wall and retaining structure are constructed. The retaining structure includes a number of interlocking piles arranged in the direction of the municipal pipeline laying. The interlocking piles have reserved jacking interfaces at the locations where the municipal pipeline jacking crosses the site. In municipal pipeline jacking construction, the pipes pass horizontally through the retaining structure from the reserved jacking interface of the interlocking piles. Dewatering wells, temporary central columns, capping beams, and the first support were constructed at the excavation site. The pile foundation steel bars of the temporary central columns were anchored below the station structure floor slab. When the foundation pit is excavated to a certain depth near the municipal pipeline and below the bottom of the designed second support, the first waist beam and the second support are constructed, and the first waist beam and the second support are located above the location of the broken interlocking pile caused by the crossing of the municipal pipeline. After the foundation pit is excavated to the bottom of the municipal pipeline, pipeline suspension measures are implemented to fix the municipal pipeline. Each municipal pipeline must be provided with pipeline suspension measures. When the foundation pit is excavated to a certain depth below the bottom of the designed third support, the second waist beam and the third support are constructed. The second waist beam and the third support are located at the height of the interlocking pile broken due to the cross-section of municipal pipelines. When the foundation pit is excavated to a certain depth below the bottom of the designed fourth support, the third waist beam and the fourth support are constructed. The third waist beam and the fourth support are located below the bottom of the interlocking pile broken due to the cross-section of municipal pipelines, and are located between the bottom slab and the top slab of the station structure. The foundation pit was excavated to the base, a cushion layer was constructed, a waterproof layer was laid, and the station structure base slab and part of the side walls were poured. When the concrete strength of the side wall reaches more than 80% of the design strength, steel bracing is installed on the foundation of the side wall, the fourth bracing is removed, and the remaining side wall and top slab are constructed. The steel supports will be removed when the concrete strength of the top slab and side walls reaches more than 80% of the design strength. Backfill the soil to below the first support, and remove the first support and the temporary central column; Continue backfilling and covering the soil, restore the ground surface, remove the barriers, dismantle the dewatering wells, and construct the station hall floor and internal structure.

2. The method for supporting and constructing a subway station that allows for pipe jacking to cross, as described in claim 1, is characterized in that... The municipal pipelines include rainwater pipes and sewage pipes arranged vertically, and the third support is located at the depth between the rainwater pipes and the sewage pipes; After the foundation pit is excavated to the bottom of the municipal pipeline located above, pipeline suspension measures are implemented on the second support to fix the municipal pipeline located above to the second support; After the foundation pit is excavated to the bottom of the municipal pipeline located below, pipeline suspension measures are implemented on the third support to fix the municipal pipeline located below to the third support.

3. The method for supporting and constructing a subway station that allows for pipe jacking to cross, as described in claim 1, is characterized in that... The method for implementing pipeline suspension measures is as follows: steel plates are pre-embedded on the support beams of the second or third support, and channel steel is welded onto the pre-embedded steel plates. The channel steels are welded together to form a frame that can accommodate municipal pipelines.

4. A method for supporting and constructing a subway station that allows for pipe jacking to cross, as described in claim 1, is characterized in that... The interlocking piles include solid piles and plain piles, and the municipal pipelines include rainwater pipes and sewage pipes. The rainwater pipes and sewage pipes are arranged in a staggered manner, and a complete solid pile is retained between the rainwater pipes and the sewage pipes.

5. A method for supporting and constructing a subway station that allows for pipe jacking to cross, as described in claim 1, is characterized in that... The method for reserving the pipe jacking interface on the interlocking pile is to use glass fiber reinforcement instead of steel reinforcement at the location where municipal pipelines pass through the interlocking pile.

6. A method for supporting and constructing a subway station that allows for pipe jacking to cross, as described in claim 1, is characterized in that... The retaining structure includes interlocking piles, pile banks, and diaphragm walls. The guide wall is made of C25 concrete, and the thickness of the protective layer for the reinforcing steel is not less than 25mm. The temporary central column adopts a lattice-type central column, and the foundation of the temporary central column adopts C30 underwater concrete and a bored pile with a diameter of 1200.

7. A method for supporting and constructing a subway station that allows for pipe jacking to cross, as described in claim 1, is characterized in that... The first support covers the entire excavation pit and includes a first reinforced concrete support beam, a first connecting beam, and a first diagonal brace. The first reinforced concrete support beam and the first connecting beam are connected to the temporary central column support. The two ends of the first reinforced concrete support beam are connected to the cap beam and are perpendicular to the direction of the interlocking piles. The first diagonal brace is located between the first reinforced concrete support beam and the cap beam and forms an angle of 45 degrees with the direction of the interlocking piles. The first connecting beam is located between the first reinforced concrete support beams.

8. A method for supporting and constructing a subway station that allows for pipe jacking to cross, as described in claim 1, is characterized in that... The second support covers the entire excavation pit and includes a second reinforced concrete support beam, a second connecting beam, and a second diagonal brace. The second reinforced concrete support beam and the second connecting beam are connected to the temporary central column support. The two ends of the second reinforced concrete support beam are connected to the first waist beam. The second reinforced concrete support beam near the municipal pipeline is parallel to the municipal pipeline, while the other second reinforced concrete support beams are perpendicular to the direction of the interlocking piles and are fixed by the second diagonal brace. The angle between the second diagonal brace and the direction of the interlocking piles is 45 degrees. The second connecting beam is set between the second reinforced concrete support beams.

9. A method for supporting and constructing a subway station that allows for pipe jacking to cross, as described in claim 1, is characterized in that... The third support only covers the area where the municipal pipeline is located. It includes a third reinforced concrete support beam and a third connecting beam. The third reinforced concrete support beam and the third connecting beam are connected to the temporary central column support. The two ends of the third reinforced concrete support beam are connected to the second waist beam and are parallel to the municipal pipeline. The third connecting beam is set between the third reinforced concrete support beams. The fourth support covers the entire excavation pit and includes a fourth reinforced concrete support beam and a fourth connecting beam. The fourth reinforced concrete support beam and the fourth connecting beam are connected to the temporary central column support. The two ends of the fourth reinforced concrete support beam are connected to the third waist beam and are perpendicular to the direction of the interlocking piles. The fourth connecting beam is arranged between the fourth reinforced concrete support beams.

10. A method for supporting and constructing a subway station that allows for pipe jacking to cross, as described in claim 1, characterized in that, When constructing the roof slab, municipal pipelines must be avoided.

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