Round working well main body structure and construction method thereof

Abstract

The invention discloses a circular working well main body structure and a construction method thereof. The circular working well main body structure structurally comprises a cylindrical hollow side wall, a top plate is arranged at the upper end of the side wall, a bottom plate is arranged at the lower end of the side wall, #-shaped crossed internal partition walls are arranged in the internal space of the side wall, and four shield launching and receiving holes are reserved in a lining wall on the inner side of the side wall; the construction method comprises the following steps: constructing the cylindrical enclosure structure and the upper support; the foundation pit is excavated to the plane below the bottom of the top plate ring beam, and the top plate ring beam is reversely built; excavating in sections, and inversely building the lining wall in layers; the foundation pit is excavated to the bottom of the foundation pit, and the last section of lining wall, the bottom plate and the bottom plate hidden cross beam are constructed at a time; longitudinal partition walls and transverse partition walls are constructed in sequence; breaking an enclosure structure in the range of the side wall tunnel portal; constructing a cross partition wall post-cast ring beam; constructing a middle partition wall and a top plate at a top plate hoisting hole in a use stage; and backfilling and earthing to finish the construction. The construction period is shortened; thickness of the enclosure structure and the lining wall is optimized, and the supporting structure is permanently and temporarily combined and is green and economical.

Description

Technical Field

[0001] The present invention belongs to the field of underground engineering structures, and in particular relates to a circular working shaft main structure and a construction method thereof. Background Art

[0002] When constructing long and large intercity railway tunnels in urban areas, it is necessary to set up working pits for segmented construction to speed up the construction progress. In order to avoid the dense existing subway network, the buried depth of intercity railway tunnels is generally large, resulting in a corresponding increase in the required working pit depth. The existing rectangular working pit "enclosure structure + internal bracing" support system cannot effectively adapt to the design and construction requirements of ultra-deep working pits. In terms of shield starting, receiving, and equipment hoisting, there are problems such as excessive structural size, low utilization rate of temporary internal supports, material waste, and inconvenient construction. After optimization design, ultra-deep working pits often use a quasi-circular enclosure structure. However, the circular working pit has a large number of shield starting and receiving portals, the structural opening area is large and the structure is a special-shaped structure. During construction, high requirements are placed on the safety and stability of the structure. During the use phase, the structure is buried deep and has high stress requirements. A circular working pit main structure is urgently needed to solve the above problems. Summary of the Invention

[0003] The present invention is proposed to solve the problems existing in the prior art, and its purpose is to provide a circular working pit main structure and a construction method thereof.

[0004] The technical solution of the present invention is: a circular working pit main structure, including a cylindrical hollow side wall, a top plate located at the top of the upper end of the side wall, a bottom plate located at the bottom of the lower end of the side wall, and a well-shaped cross internal partition wall in the internal space of the side wall. The internal partition wall divides the internal space, and the inner lining wall inside the side wall reserves four shield starting receiving openings.

[0005] Furthermore, the top plate includes a top plate ring beam connected to the side wall, and a longitudinal top plate longitudinal beam and a transverse top plate cross beam are arranged in the middle of the top plate ring beam. The top plate ring beam, the top plate longitudinal beam and the top plate cross beam form a top plate lifting hole.

[0006] Furthermore, after the shield is started or received, a top plate hidden cross beam is provided in the top plate, and the top plate hidden cross beam is located at the top plate lifting hole.

[0007] Furthermore, the side wall includes an external enclosure structure and an internal lining wall. The enclosure structure and the internal lining wall constitute a composite wall body, and a composite wall shear groove is provided at the composite interface between the two.

[0008] Furthermore, a spatially shaped pre-cast ring beam of the lining wall is provided in the lining wall, and the pre-cast ring beam of the lining wall is projected into a circle in the longitudinal direction of the tunnel, and the inner diameter of the projected circle is adapted to the diameter of the shield machine.

[0009] Furthermore, the internal partition wall includes a transverse transverse partition wall, which is connected to the top plate beam in an aligned manner. The transverse partition wall is provided with a transverse partition wall pre-cast ring beam, and the inner diameter of the transverse partition wall pre-cast ring beam is adapted to the diameter of the shield machine.

[0010] Furthermore, the internal partition wall includes a longitudinal partition wall, which is connected to the longitudinal beam of the top plate in an aligned manner, and the longitudinal partition wall is disconnected in the middle of the working shaft.

[0011] Furthermore, after the shield is started or received, the internal partition wall also includes a partition wall in the use stage, and the partition wall in the use stage is perpendicular to the top plate hidden beam and the bottom plate hidden beam.

[0012] Furthermore, the bottom plate hidden beams are provided with hidden columns for partition walls during the use phase, and the hidden columns for partition walls during the use phase are connected to the top plate hidden beams and the bottom plate hidden beams in a corresponding position.

[0013] A construction method for a circular working pit main structure comprises the following steps: A. Construct cylindrical enclosure structure and provide upper support; B. Excavate the foundation pit to the plane below the bottom of the top plate ring beam, and build the top plate ring beam in reverse direction; C. Continue excavation in sections and build lining walls in layers; D. Excavate the foundation pit to the bottom and construct the last section of lining wall, bottom plate and bottom plate concealed beam at one time; E. Build longitudinal and transverse partition walls in sequence; F. Remove the enclosure structure and hidden ring beam of the inner lining wall within the scope of the side wall portal, and hoist, launch, receive and lift out the shield machine; G. Construction of post-cast ring beams for transverse diaphragm walls; H. The top plate of the partition wall and top plate hoisting holes during the construction and use stage; I. Backfill the soil to complete the construction.

[0014] The beneficial effects of the present invention are as follows: The invention forms a superimposed side wall by building a reverse circular lining wall and a retaining structure, thereby saving construction time; utilizing the circular arch effect and the superimposed structural system, the thickness of the retaining structure and the lining wall is optimized, and the amount of engineering materials used is reduced.

[0015] The cross-shaped internal longitudinal and transverse beam (wall) system of this invention provides high support rigidity, enhancing the stability of the multi-opening structure of the ultra-deep circular working shaft and effectively controlling ground deformation. The rational spatial layout of the longitudinal and transverse beam (wall) system reduces the slab span and forms a self-balancing spatial force system. Even at great burial depths, the top and bottom slabs are thin, and the slab surface is flat, eliminating the need for arching. The construction process is simple and controllable, and space utilization is more optimized.

[0016] The present invention adopts the cast-in-place reverse construction method through layered excavation from top to bottom and pouring construction layer by layer, which optimizes the construction process, combines permanent and temporary structural components, saves demolition work, and is green and low-carbon economic. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a three-dimensional diagram of the main structure of the circular working well in the present invention; Figure 2 This is a top view of the top plate of the main structure of the circular working pit in the present invention (construction stage); Figure 3 This is a top view of the top plate of the main structure of the circular working well in the present invention (in use stage); Figure 4 This is a cross-sectional view of the main structure of the circular working pit of the present invention from 1 / 2 height downward (construction stage); Figure 5 This is a cross-sectional view of the main structure of the circular working pit of the present invention from 1 / 2 height downward (in use stage); Figure 6 yes Figure 4 Sectional view of section 1-1; Figure 7 yes Figure 5 Sectional view of section 1-1; Figure 8 yes Figure 4 Sectional view of section 2-2; Figure 9 yes Figure 5 Sectional view of section 2-2; Figure 10 yes Figure 5 Sectional view of section 3-3; Figure 11 This is a three-dimensional model diagram of the main structure of the circular working pit (construction stage); Figure 12 It is a three-dimensional model diagram of the main structure of the circular working pit (in use stage); in: 1 top plate 2 side wall 3 Base plate 4 Internal partition wall 11 Roof ring beam 12 Roof longitudinal beam 13 Top plate crossbeam 14 Top plate lifting hole 15 Hidden beams on top plate 111 Top plate ring beam tongue and groove 121 Top plate longitudinal beam tongue and groove 131 Top beam tongue and groove 21 Enclosure structure 22 Lining wall 23 Composite wall shear groove 221 Precast ring beam for inner lining wall 222 Concealed ring beam for inner lining wall 31 Bottom plate hidden beam 41 longitudinal partition wall 42 transverse partition wall 43 Partition wall during use 421 Pre-cast ring beam for transverse diaphragm wall 422 Post-cast ring beam for transverse diaphragm wall 431 Concealed columns in partition walls during the use phase. DETAILED DESCRIPTION

[0018] Hereinafter, the present invention will be described in detail with reference to the accompanying drawings and embodiments: like Figures 1 to 12 As shown, a circular working shaft main structure includes a cylindrical hollow side wall 2, the upper end of the side wall 2 is provided with a top plate 1 located at the top, the lower end of the side wall 2 is provided with a bottom plate 3 located at the bottom, and the internal space of the side wall 2 is provided with a well-shaped cross internal partition wall 4. The internal partition wall 4 divides the internal space, and the inner lining wall 22 on the inner side of the side wall 2 reserves four shield starting receiving holes.

[0019] The roof 1 includes a roof ring beam 11 connected to the side wall 2, and a longitudinal roof longitudinal beam 12 and a transverse roof cross beam 13 are arranged in the middle of the roof ring beam 11. The roof ring beam 11, the roof longitudinal beam 12, and the roof cross beam 13 enclose a roof hoisting hole 14.

[0020] After the shield is started or received, a top plate hidden cross beam 15 is provided in the top plate 1 , and the top plate hidden cross beam 15 is located at the top plate hoisting hole 14 .

[0021] The side wall 2 includes an external enclosure structure 21 and an internal lining wall 22 . The enclosure structure 21 and the internal lining wall 22 constitute a composite wall body, and a composite wall shear groove 23 is provided at the composite interface between the two.

[0022] The lining wall 22 is provided with a spatially shaped lining wall precast ring beam 221. The lining wall precast ring beam 221 is projected into a circle in the longitudinal direction of the tunnel, and the inner diameter of the projected circle is adapted to the diameter of the shield machine.

[0023] The internal partition wall 4 includes a transverse transverse partition wall 42, which is connected to the top plate beam 13 in an aligned manner. A transverse partition wall pre-cast ring beam 421 is provided in the transverse partition wall 42, and the inner diameter of the transverse partition wall pre-cast ring beam 421 is adapted to the diameter of the shield machine.

[0024] The internal partition wall 4 includes a longitudinal partition wall 41, which is connected to the top plate longitudinal beam 12 in an aligned manner. The longitudinal partition wall 41 is disconnected in the middle of the working shaft, providing a more convenient space for left and right line shield construction.

[0025] After the shield is started or received, the internal partition wall 4 further includes a partition wall 43 in the use phase, and the partition wall 43 in the use phase is perpendicular to the top plate hidden beam 15 and the bottom plate hidden beam 31.

[0026] The bottom plate hidden cross beam 31 is provided with a partition wall hidden column 431 during the use phase. The partition wall hidden column 431 during the use phase is aligned and connected to the top plate hidden cross beam 15 and the bottom plate hidden cross beam 31.

[0027] Specifically, the top plate 1, side walls 2, bottom plate 3, and internal partition walls 4 are combined to form a cylindrical spatial composite frame structure.

[0028] As a preferred implementation, the outer diameter of the main structure of the cylindrical working shaft is 36m, which is suitable for the starting and receiving space requirements of two 9.13m diameter shield machines in the double-track tunnel of the intercity railway.

[0029] Specifically, the roof ring beam 11 , the roof longitudinal beams 12 and the roof transverse beams 13 in the roof 1 form a cross-shaped mesh structure in a circular ring.

[0030] Specifically, a top plate hoisting hole 14 is reserved in the top plate 1, and the concrete poured later in the range of the top plate hoisting hole 14 is interlocked with the pre-cast top plate ring beam 11, top plate longitudinal beam 12 and top plate transverse beam 13 through the reserved top plate ring beam tongue 111, top plate longitudinal beam tongue 121 and top plate transverse beam tongue 131.

[0031] At the same time, the cutoff parts of the opening steel bars are connected by steel bar connectors. The tongue and groove 111 of the top plate ring beam is set on the inner side of the whole ring and is disconnected at the cross beam position. The tongue and groove 121 of the top plate longitudinal beam and the tongue and groove 131 of the top plate cross beam are set towards the larger top plate hoisting hole 14. The post-poured concrete of the top plate hoisting hole 14 adopts micro-expansion concrete with a strength grade one level higher than that of the pre-poured structure such as the longitudinal beam, and is applied after the shield is started and received.

[0032] Specifically, the overlapping interface of the enclosure structure 21 and the inner lining wall 22 is coated with a cement-based penetrating crystalline waterproof coating to enhance the waterproofing of the overlapping wall.

[0033] Specifically, the inner lining wall 22 is further provided with an inner lining wall hidden ring beam 222 , and the vertical position of the inner lining wall hidden ring beam 222 is within the range of the inner lining wall pre-cast ring beam 221 .

[0034] Specifically, the top plate ring beam 11 and the enclosure structure 21 are fixedly connected by steel bar connectors or embedded steel bars reserved in the enclosure structure.

[0035] More specifically, when using steel bar connectors for connection, the connectors must be embedded when the reinforcement cage of the retaining structure is installed. When using embedded reinforcement for connection, the connection can be made according to the embedded reinforcement requirements when the foundation pit is excavated to the corresponding position and the corresponding structure is constructed.

[0036] Specifically, the bottom plate concealed cross beam 31 in the bottom plate 3 is connected to the top plate concealed cross beam 15 by using the intermediate partition wall concealed columns 431. The bottom plate 3 is fixedly connected to the enclosure 21 by using a pre-reinforcement connector or embedded rebar within the enclosure. The bottom plate concealed cross beam 31 is installed simultaneously with the bottom plate reinforcement, and the bottom plate 3 and bottom plate concealed cross beam 31 are cast at one time.

[0037] Specifically, the internal partition wall 4 includes a longitudinal partition wall 41, a transverse partition wall 42 and an intermediate partition wall 43 during use. The longitudinal partition wall 41, the transverse partition wall 42 and the intermediate partition wall 43 during use form a three-dimensional grid structure.

[0038] Specifically, the transverse diaphragm 42 is provided with a pre-cast ring beam 421 and a post-cast ring beam 422. The two transverse diaphragm walls 42 intersect the four middle diaphragm walls perpendicularly. The longitudinal diaphragm 41 is disconnected in the middle of the working shaft, with only the large and small mileage ends of the working shaft being installed. The transverse diaphragm 42 is arranged horizontally and is connected. Two shield launching and receiving portals are set on each wall. The longitudinal beam 12 of the top plate above the longitudinal diaphragm 41 and the transverse beam 13 of the top plate above the transverse diaphragm 42 are both connected.

[0039] A construction method for a circular working pit main structure comprises the following steps: A. Construct the cylindrical enclosure structure 21 and provide upper support; B. Excavate the foundation pit to the plane below the bottom of the top plate ring beam, and build the top plate ring beam 11 in reverse direction; C. Continue excavation in sections and build lining walls 22 in layers; D. Excavate the foundation pit to the bottom and construct the last section of the lining wall 22, the bottom plate 3, and the bottom plate hidden beam 31 at one time; E. Build longitudinal partition wall 41 and transverse partition wall 42; F. Remove the enclosure structure 21 and the inner lining wall hidden ring beam 222 within the area of the side wall portal, and hoist, launch, receive, and lift out the shield machine; G. Construction of post-cast ring beam 422 for transverse diaphragm wall; H. The partition wall 43 and the top plate at 14 top plate hoisting holes during the construction and use phase; I. Backfill the soil to complete the construction.

[0040] Specifically, step A is to construct the cylindrical enclosure structure 21 and provide upper support, as follows: First, the cylindrical enclosure structure 21 is constructed; Then, excavate from top to bottom and construct supports up to the top plate 1 of the main structure.

[0041] Specifically, in step B, the foundation pit is excavated to the plane below the bottom of the top plate ring beam, and the top plate ring beam 11 is built in reverse, as follows: First, excavate the foundation pit to 0.5m below the top plate ring beam 11; Then, the top plate ring beam 11 is built upside down and fixedly connected to the enclosure structure 21 .

[0042] Specifically, step C continues to excavate in sections and build the lining wall 22 in reverse layers, as follows: First, depending on the height of the main structure, excavate the bottom plane of the foundation pit in sections to below the bottom of the Nth section of the lining wall; Then, the lining wall 22 is built up in reverse layers in sequence; Finally, grouting pipes are embedded in the segment joints for grouting and water-stopping, and water-stopping steel plates are installed.

[0043] As a specific implementation, this embodiment excavates and builds the lining wall 22 in sections at a height of 3m, and arranges a composite wall shear groove 23 on the outer side of the lining wall below the top plate ring beam 11 and embeds it into the retaining structure 21. The composite wall shear groove 23 is cut off when encountering an opening, and concrete is not poured when the opening position of the lining wall 22 is built in reverse. The space is reserved for the special-shaped lining wall first-cast ring beam 221 and the lining wall hidden ring beam 222. The steel cage installation of the lining wall 22, the lining wall first-cast ring beam 221, and the lining wall hidden ring beam 222 are constructed together with the concrete pouring.

[0044] Specifically, in step D, the foundation pit is excavated to the bottom of the foundation pit, and the last section of the lining wall 22, the bottom plate 3, and the bottom plate hidden beam 31 are constructed at one time, as follows: First, excavate the foundation pit to the base, and apply the cushion layer and the top and bottom slab waterproof layer; Then, the last section of the lining wall 22 , the bottom plate 3 , and the bottom plate hidden cross beam 31 are cast at one time, and the bottom plate is fixedly connected to the enclosure structure 21 .

[0045] Specifically, step E is to build the longitudinal partition wall 41 and the transverse partition wall 42 in sequence as follows: The longitudinal partition walls 41, transverse partition walls 42, top plate longitudinal beams 12 and top plate transverse beams 13 inside the main structure are built sequentially, and the ring beam 421 of the transverse partition wall is first cast together with the transverse partition wall.

[0046] Specifically, step F involves removing the enclosure structure 21 and the inner lining wall hidden ring beam 222 within the scope of the side wall portal, and hoisting, launching, receiving, and hoisting out the shield machine as follows: The retaining structure 21 and the inner lining wall hidden ring beam 222 in the side wall portal area are removed, and the shield is hoisted, started, received and hoisted out.

[0047] Specifically, step G is to construct the post-cast ring beam 422 of the diaphragm wall as follows: After the shield machine starts or receives the completed segment assembly construction, the transverse diaphragm post-cast ring beam 422 is constructed.

[0048] Specifically, in the construction and use phase of step H, the partition wall 43 and the top plate at the top plate hoisting holes 14 are as follows: Cast the four internal partition walls 43 during the use phase, the top plate 1 within the range of the top plate hanging holes 14, and the top plate hidden beams 15.

[0049] Specifically, step 1 is backfilling and covering soil to complete the construction, which is as follows: After applying the top plate waterproof layer and fine stone concrete protective layer, backfill the soil to complete the construction.

[0050] The circular working shaft main structure and its construction method are used in multiple ultra-deep working shafts (over 40 meters deep) on the Shenzhen-Dalian Intercity Railway. The circular working shaft main structure has an outer diameter of 36 meters, and the inner lining of the composite wall is 1 meter thick, which is nearly 50% thinner than the side wall thickness of a conventional rectangular working shaft (2 meters). The circular inner lining is constructed using a reverse construction method, and combined with an internal longitudinal and transverse beam (wall) system, this reduces structural material usage while ensuring the stability and safety of the multi-hole structure required for shield tunneling.

[0051] The invention forms a superimposed side wall by building a reverse circular lining wall and a retaining structure, thereby saving construction time; utilizing the circular arch effect and the superimposed structural system, the thickness of the retaining structure and the lining wall is optimized, and the amount of engineering materials used is reduced.

[0052] The cross-shaped internal longitudinal and transverse beam (wall) system of this invention provides high support rigidity, enhancing the stability of the multi-opening structure of the ultra-deep circular working shaft and effectively controlling ground deformation. The rational spatial layout of the longitudinal and transverse beam (wall) system reduces the slab span and forms a self-balancing spatial force system. Even at great burial depths, the top and bottom slabs are thin, and the slab surface is flat, eliminating the need for arching. The construction process is simple and controllable, and space utilization is more optimized.

[0053] The present invention adopts the cast-in-place reverse construction method through layered excavation from top to bottom and pouring construction layer by layer, which optimizes the construction process, combines permanent and temporary structural components, saves demolition work, and is green and low-carbon economic.

Claims

1. A circular working pit main structure, characterized by: The utility model comprises a cylindrical hollow side wall (2), wherein the upper end of the side wall (2) is provided with a top plate (1) located at the top, and the lower end of the side wall (2) is provided with a bottom plate (3) located at the bottom. The internal space of the side wall (2) is provided with a well-shaped cross internal partition wall (4), and the internal partition wall (4) divides the internal space. The inner lining wall (22) inside the side wall (2) is reserved for four shield starting receiving openings.

2. The circular working pit main structure according to claim 1, characterized in that: The top plate (1) comprises a top plate ring beam (11) connected to the side wall (2), a longitudinal top plate longitudinal beam (12) and a transverse top plate cross beam (13) are arranged in the middle of the top plate ring beam (11), and a top plate hoisting hole (14) is formed between the top plate ring beam (11), the top plate longitudinal beam (12) and the top plate cross beam (13).

3. The circular working pit main structure according to claim 2, characterized in that: After the shield is started or received, a top plate hidden crossbeam (15) is provided in the top plate (1), and the top plate hidden crossbeam (15) is located at the top plate hoisting hole (14).

4. The circular working pit main structure according to claim 1, characterized in that: The side wall (2) comprises an external enclosure structure (21) and an internal lining wall (22); the enclosure structure (21) and the internal lining wall (22) constitute a composite wall body, and a composite wall shear groove (23) is provided at the composite interface between the two.

5. The circular working pit main structure according to claim 1, characterized in that: The inner lining wall (22) is provided with a spatially shaped inner lining wall precast ring beam (221), and the inner lining wall precast ring beam (221) is projected into a circle in the longitudinal direction of the tunnel, and the inner diameter of the projected circle is adapted to the diameter of the shield machine.

6. The circular working pit main structure according to claim 2, characterized in that: The internal partition wall (4) comprises a transverse transverse partition wall (42), the transverse partition wall (42) being connected to the top plate cross beam (13) in alignment, and a transverse partition wall precast ring beam (421) being provided in the transverse partition wall (42), the inner diameter of the transverse partition wall precast ring beam (421) being adapted to the diameter of the shield machine.

7. The circular working pit main structure according to claim 2, characterized in that: The internal partition wall (4) comprises a longitudinal partition wall (41), the longitudinal partition wall (41) is connected to the top plate longitudinal beam (12) in an aligned manner, and the longitudinal partition wall (41) is disconnected in the middle of the working shaft.

8. The circular working pit main structure according to claim 3, characterized in that: After the shield is started or received, the internal partition wall (4) further includes a partition wall (43) in the use phase, and the partition wall (43) in the use phase is perpendicular to the top plate hidden beam (15) and the bottom plate hidden beam (31).

9. The circular working pit main structure according to claim 8, characterized in that: The bottom plate hidden crossbeam (31) is provided with a partition wall hidden column (431) during the use phase. The partition wall hidden column (431) during the use phase is connected in position with the top plate hidden crossbeam (15) and the bottom plate hidden crossbeam (31).

10. The construction method of a circular working pit main structure according to claim 1, characterized in that: The following steps are involved: A. Construct the cylindrical enclosure structure (21) and provide upper support; B. Excavate the foundation pit to the plane below the bottom of the top plate ring beam, and build the top plate ring beam in reverse (11); C. Continue excavation in sections and build the lining wall in layers (22); D. Excavate the foundation pit to the bottom of the foundation pit and construct the last section of the lining wall (22), the bottom plate (3), and the bottom plate hidden beam (31) at one time; E. Build longitudinal partition wall (41) and transverse partition wall (42) in sequence; F. Remove the enclosure structure (21) and the inner lining wall hidden ring beam (222) within the scope of the side wall portal, and hoist, launch, receive and lift out the shield machine; G. Construction of post-cast ring beams for transverse diaphragm walls (422); H. The partition wall (43) and the top plate at the top plate hoisting hole (14) during the construction and use phase; I. Backfill the soil to complete the construction.

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