Super-long span tie-arch underground composite structure and its construction method

Abstract

The present invention relates to an ultra-large span tie-arch underground composite structure and a construction method thereof. Large-span open-cut box-type tunnel structures have the problems of large structural dimensions, many structural cracks, complex internal stress distribution, and large uneven settlement and deformation. The present structure includes a box-type structure, a tie-arch structure, and a pile foundation. The tie-arch structure is located at the top of the box-type structure, and the pile foundation is located at the bottom of the box-type structure. The tie-arch structure includes a horizontal support plate, tie rods, and an arch top plate. The arch top plate is arched and located above the horizontal support plate, and the tie rods are vertically connected between the arch top plate and the horizontal support plate. The present invention adds a combined structure of a tie-arch structure, a longitudinal hidden beam, and a bottom pile foundation to the tunnel box-type structure. The engineering volume is small, the force system is clear, and the structural rigidity and stability are significantly improved, the size of the structural components and the deformation and settlement are reduced, and the structural safety is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of open-cut tunnel engineering construction, and in particular to an ultra-large-span tie-arch underground combined structure and a construction method thereof. Background Art

[0002] With the rapid development of rail transit, underground structures are often constrained by surrounding and internal conditions. To address these limitations, open-cut rectangular structures are often employed. When these constraints necessitate an increase in the span of a rectangular structure, a large-span or ultra-large-span open-cut rectangular structure is formed. These large-span or ultra-large-span open-cut rectangular structures are prone to increased internal forces and deformation, and are particularly susceptible to significant uneven settlement and deformation when located in soft, water-rich strata.

[0003] Unlike conventional open-cut tunnel box structures, when the structural span increases, the internal stress of the tunnel structure will increase accordingly and be unevenly distributed. The use of existing open-cut box tunnel structures will lead to an increase in structural size, an increase in structural cracks, and a complex internal force distribution that is uneconomical. Therefore, it is necessary to design a construction structure for ultra-large span underground box-type open-cut structures that can solve the above technical problems. Summary of the Invention

[0004] The purpose of the present invention is to provide an ultra-large span tie-arch underground composite structure and a construction method thereof, so as to solve the problems of large internal stress and uneven distribution when the large span open-cut tunnel box structure is located in soft soil and water-rich strata.

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

[0006] An ultra-large span tie-arch underground composite structure, comprising a box structure, a tie-arch structure, and a pile foundation, wherein the tie-arch structure is located at the top of the box structure, and the pile foundation is located at the bottom of the box structure;

[0007] The tie rod arch structure includes a horizontal support plate, a tie rod and an arch top plate. The arch top plate is arched and located above the horizontal support plate. The tie rod is vertically connected between the arch top plate and the horizontal support plate.

[0008] Furthermore, the bottom of the box-type structure is a bottom plate, both sides of the bottom plate are longitudinal bottom hidden beams, and the top of the bottom hidden beams is a vertical side wall.

[0009] Furthermore, the top of the side wall is a side wall hidden beam, and the horizontal support plate and the transverse ends of the arch top plate are respectively connected to the side wall hidden beams on both sides.

[0010] Furthermore, both lateral ends of the horizontal support plate have enlarged ends, and the horizontal support plate is connected to the side wall hidden beam through the enlarged ends.

[0011] Furthermore, foundation pit supports arranged vertically and in rows are provided on the outer sides of the side walls, and longitudinal beams are provided on the tops of the foundation pit supports.

[0012] Furthermore, a side platform is provided on the inner top of the bottom hidden beam, a drainage ditch is provided on the side platform, and a cover plate is provided above the drainage ditch.

[0013] Furthermore, a drainage pipe is provided in the side wall, one end of the drainage pipe passes through the side wall hidden beam and the horizontal support plate and is located above the horizontal support plate, and the other end of the drainage pipe passes through the bottom hidden beam and is connected to the drainage ditch.

[0014] In another aspect, a construction method for the ultra-large span tie-arch underground composite structure is provided, the method comprising:

[0015] Construct the open excavation pit support structure, construct the pile foundation simultaneously, and reserve connecting steel bars on the top of the pile foundation;

[0016] Excavate the foundation pit layer by layer down to the bottom plate elevation, expose the reserved steel bars on the top of the pile foundation, and carry out bottom plate waterproofing and cushion construction;

[0017] Tie the bottom plate reinforcement, securely anchor the bottom plate reinforcement and the reserved reinforcement at the top of the pile foundation, set the hidden beam reinforcement at the bottom hidden beam, and pour concrete in the formwork to form a combined structure of the bottom hidden beam and the bottom plate;

[0018] Arrange the side walls in layers and sections;

[0019] Tie up the side wall hidden beam reinforcement, erect the formwork and pour concrete, construct the side wall hidden beam and reserve connecting reinforcement on its top and inside;

[0020] Build a horizontal support plate, tie the steel bars of the horizontal support plate and the connecting steel bars reserved in the side wall hidden beam together, and build a tie rod;

[0021] Construct the arch top plate, and tie the steel bars of the arch top plate and the connecting steel bars reserved in the side wall hidden beams together.

[0022] Furthermore, the method further comprises:

[0023] While constructing the open excavation foundation pit support structure, vertical and column-arranged foundation pit supports are constructed outside the designed position of the side wall, and longitudinal beams are constructed on the top of the foundation pit supports to form longitudinal connections at the top of each foundation pit support.

[0024] Furthermore, the method further comprises:

[0025] After the box structure is completed, a side platform is constructed on the inner top of the bottom hidden beam, a drainage ditch is constructed on the side platform, and a cover plate is added;

[0026] When constructing the bottom hidden beam, side wall, side wall hidden beam, and horizontal support plate, reserve passages for drainage pipes. After the structural construction is completed, lay drainage pipes in the passages.

[0027] One end of the drainage pipe is located above the horizontal support plate, and the other end is connected to the drainage ditch to drain the accumulated water in the tie-rod arch structure.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] The present invention adds a combined structure of a tie-rod arch structure, a ribbed longitudinal hidden beam and a bottom pile foundation to the tunnel box structure. The engineering workload is small, the force system is clear, and the structural rigidity and stability are significantly improved, the deformation and settlement of the structure are reduced, and the structural safety is improved.

[0030] During the structural construction process of the present invention, the box size can be reduced by arranging the tie-rod arch structure and the ribbed hidden beams, thereby reducing the structural engineering workload and improving the structural integrity, safety and reliability.

[0031] The present invention sets a pile foundation at the bottom of the tunnel box structure, which provides sufficient support for the box structure, improves the overall settlement and uneven settlement deformation of the tunnel under soft soil and water-rich strata conditions, and improves the overall safety of the structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, without paying any creative work, they can also obtain drawings of other embodiments based on these drawings.

[0033] Figure 1 It is an elevation view of the structure of the present invention.

[0034] The symbols in the figure are:

[0035] 1-pile foundation, 2-bottom plate, 3-bottom hidden beam, 4-side wall, 5-side wall hidden beam, 6-horizontal support plate, 7-pull rod, 8-arch top plate, 9-longitudinal beam, 10-foundation pit support, 11-drainage pipe, 12-drainage ditch, 13-cover plate, 14-side platform. DETAILED DESCRIPTION

[0036] To facilitate understanding of the present invention, the present invention will be described more fully below with reference to the accompanying drawings. The accompanying drawings illustrate preferred embodiments of the present invention. However, the present invention may be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and comprehensive understanding of the present disclosure.

[0037] In the description of this patent, it should be understood that the terms "up", "down", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings. They are only for the convenience of describing this patent and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they should not be understood as limitations on this patent.

[0038] In the description of this patent, it should be noted that, unless otherwise expressly specified or limited, the terms "connected" and "disposed" should be understood broadly. For example, they can refer to fixed connection or disposition, detachable connection or disposition, or integral connection or disposition. Those skilled in the art will understand the specific meanings of the above terms in this patent based on the specific circumstances.

[0039] In a specific embodiment, the line direction is defined as the longitudinal direction, and the direction perpendicular to the line direction is defined as the transverse direction.

[0040] like Figure 1 The present invention provides an ultra-long-span tie-arch underground composite structure suitable for construction of open-cut rectangular structures with a span greater than 16.5 meters in soft, water-rich strata. The structure comprises a box structure, a tie-arch structure, and pile foundations (1). The tie-arch structure is located at the top of the box structure, and the pile foundations (1) are located at the bottom of the box structure.

[0041] The tie rod arch structure includes a horizontal support plate 6, a tie rod 7 and an arch top plate 8. The arch top plate 8 is arched and located above the horizontal support plate 6. The tie rod 7 is vertically connected between the arch top plate 8 and the horizontal support plate 6. The horizontal support plate 6 and the arch top plate 8 form an arched structure covering the top of the box structure.

[0042] The bottom of the box-type structure is the base plate 2, flanked by longitudinal bottom concealed beams 3. The tops of the bottom concealed beams 3 are the vertical side walls 4. The horizontal support plate 6 of the tie-arch structure also serves as the top plate of the box-type structure. The tops of the side walls 4 are connected to the side wall concealed beams 5. The horizontal support plate 6 and the arch top plate 8 are connected to the side wall concealed beams 5 at both ends, with internal reinforcement tied to each other. The horizontal support plate 6 has enlarged ends at both ends, connecting to the side wall concealed beams 5 through the enlarged ends, increasing the joint stiffness.

[0043] In some embodiments, in order to further increase the overall lateral compressive resistance of the structure, vertical and columnar foundation pit supports 10 can be set on the outside of the side wall 4, and longitudinal beams 9 are set on the top of the foundation pit supports 10 to form a longitudinal connection at the top of the foundation pit supports 10.

[0044] In some embodiments, this structure can be equipped with a drainage system to drain accumulated water within the tie-arch structure. A side platform 14 is provided on the inner top of the bottom concealed beam 3. A drainage ditch 12 is provided on this platform, and a cover plate 13 is installed above the drainage ditch 12. A drainage pipe 11 is installed in the side wall 4. One end of the drainage pipe 11 passes through the side wall concealed beam 5 and the horizontal support plate 6, and is located above the horizontal support plate 6. The other end of the drainage pipe 11 passes through the bottom concealed beam 3 and connects to the drainage ditch 12.

[0045] The construction method of the above-mentioned ultra-large span tie-arch underground composite structure specifically includes the following steps:

[0046] S1: Construct the open excavation foundation pit support structure, construct pile foundation 1 simultaneously, and reserve connecting steel bars on the top of pile foundation 1;

[0047] S2: Excavate the foundation pit layer by layer downward to the elevation of bottom plate 2, expose the reserved steel bars on the top of pile foundation 1, and carry out waterproofing and cushion construction of bottom plate 2;

[0048] S3: Tie the bottom plate 2 steel bars, reliably anchor the bottom plate 2 steel bars and the reserved steel bars on the top of the pile foundation 1, and set the hidden beam steel bars at the bottom hidden beam 3, and pour concrete in the formwork to form a combined structure of the bottom hidden beam 3 and the bottom plate 2;

[0049] S4: Layered and segmented side wall 4;

[0050] S5: Tie the side wall hidden beam 5 reinforcement, set up the formwork and pour concrete, build the side wall hidden beam 5 and reserve connecting reinforcement on its top and inside;

[0051] S6: Build a horizontal support plate 6, tie the steel bars of the horizontal support plate 6 to the connecting steel bars reserved in the side wall hidden beam 5, and build a tie rod 7;

[0052] S7: construct the arch top plate 8, and tie the steel bars of the arch top plate 8 and the connection steel bars reserved in the side wall hidden beam 5 into one.

[0053] The above method further comprises the following steps:

[0054] 1. While constructing the open excavation foundation pit support structure, vertical foundation pit supports 10 arranged in rows are constructed outside the designed position of the side wall 4, and longitudinal beams 9 are constructed on the top of the foundation pit supports 10 to form a longitudinal connection at the top of each foundation pit support 10.

[0055] 2. After the box structure is completed, a side platform 14 is constructed on the inner top of the bottom hidden beam 3, a drainage ditch 12 is constructed on the side platform 14, and a cover plate 13 is added;

[0056] When constructing the bottom hidden beam 3, side wall 4, side wall hidden beam 5, and horizontal support plate 6, respectively reserve passages for the drainage pipe 11. After the structural construction is completed, the drainage pipe 11 is laid in the passages.

[0057] One end of the drainage pipe 11 is located above the horizontal support plate 6, and the other end is connected to the drainage ditch 12 to drain the accumulated water in the tie rod arch structure.

[0058] This structure, a super-long-span box structure, a tie-arch structure, ribbed concealed beams, and a pile foundation, form a super-long-span tie-arch box structure. This prevents uneven stress distribution, low rigidity, poor integrity, large structural deformation, large settlement, and poor safety in super-long-span underground box structures. This structure ensures the stability of internal forces and deformations of super-long-span underground box structures when subjected to overhead loads, making it particularly suitable for the design of super-long-span open-cut box tunnel structures.

[0059] The above examples are used to illustrate the present invention, which are only used to help understand the present invention and are not intended to limit the present invention. Those skilled in the art can make several simple deductions, modifications or substitutions based on the concept of the present invention.

Claims

1. The ultra-large span tie-arch underground composite structure is characterized by: The structure comprises a box-type structure, a tie-rod arch structure and a pile foundation (1), wherein the tie-rod arch structure is located at the top of the box-type structure, and the pile foundation (1) is located at the bottom of the box-type structure; The tie rod arch structure comprises a horizontal support plate (6), a tie rod (7) and an arch top plate (8), wherein the arch top plate (8) is arched and located above the horizontal support plate (6), and the tie rod (7) is vertically connected between the arch top plate (8) and the horizontal support plate (6); The bottom of the box-shaped structure is a bottom plate (2), both sides of the bottom plate (2) are longitudinal bottom hidden beams (3), and the top of the bottom hidden beams (3) is a vertical side wall (4); The top of the side wall (4) is a side wall hidden beam (5), and the horizontal support plate (6) and the lateral ends of the arch top plate (8) are respectively connected to the side wall hidden beam (5) on both sides.

2. The ultra-large span tie-arch underground composite structure according to claim 1, characterized in that: Both transverse ends of the horizontal support plate (6) are provided with enlarged ends, and the horizontal support plate (6) is connected to the side wall concealed beam (5) via the enlarged ends.

3. The ultra-large span tie-arch underground composite structure according to claim 2, characterized in that: Foundation pit supports (10) arranged vertically and in rows are provided on the outside of the side walls (4), and longitudinal beams (9) are provided on the tops of the foundation pit supports (10).

4. The ultra-large span tie-arch underground composite structure according to claim 3, characterized in that: A side platform (14) is provided on the inner top of the bottom hidden beam (3), a drainage ditch (12) is provided on the side platform (14), and a cover plate (13) is provided above the drainage ditch (12).

5. The ultra-large span tie-arch underground composite structure according to claim 4 is characterized in that: A drainage pipe (11) is provided in the side wall (4), one end of the drainage pipe (11) passes through the side wall concealed beam (5) and the horizontal support plate (6) and is located above the horizontal support plate (6), and the other end of the drainage pipe (11) passes through the bottom concealed beam (3) and is connected to the drainage ditch (12).

6. The construction method of the ultra-large span tie-arch underground composite structure according to claim 5, characterized in that: The method comprises: Constructing an open excavation foundation pit support structure, constructing a pile foundation (1) simultaneously, and reserving connecting steel bars on the top of the pile foundation (1); Excavate the foundation pit layer by layer downward to the elevation of the bottom plate (2), expose the reserved steel bars on the top of the pile foundation (1), and carry out waterproofing and cushion construction of the bottom plate (2); Tie the bottom plate (2) steel bars, reliably anchor the bottom plate (2) steel bars and the reserved steel bars on the top of the pile foundation (1), set hidden beam steel bars at the bottom hidden beam (3), and cast concrete in a formwork to form a combined structure of the bottom hidden beam (3) and the bottom plate (2); Layered and segmented side walls (4); Tie up the side wall hidden beam (5) reinforcement, set up the formwork and pour concrete, construct the side wall hidden beam (5) and reserve connecting reinforcement at its top and inside; A horizontal support plate (6) is constructed, the steel bars of the horizontal support plate (6) are tied together with the connection steel bars reserved for the side wall hidden beam (5), and a tie rod (7) is constructed; The arch top plate (8) is constructed, and the steel bars of the arch top plate (8) and the connection steel bars reserved for the side wall hidden beam (5) are tied together as a whole.

7. The construction method of the ultra-large span tie-arch underground composite structure according to claim 6 is characterized by: The method further comprises: While constructing the open excavation foundation pit support structure, foundation pit supports (10) arranged vertically and in rows are constructed outside the designed position of the side wall (4), and longitudinal beams (9) are constructed on the top of the foundation pit supports (10) to form a longitudinal connection at the top of each foundation pit support (10).

8. The construction method of the ultra-large span tie-arch underground composite structure according to claim 7, characterized in that: The method further comprises: After the box structure is completed, a side platform (14) is constructed on the inner top of the bottom hidden beam (3), a drainage ditch (12) is constructed on the side platform (14), and a cover plate (13) is added; When constructing the bottom hidden beam (3), the side wall (4), the side wall hidden beam (5), and the horizontal support plate (6), respectively, holes for the drainage pipe (11) to pass through are reserved. After the structural construction is completed, the drainage pipe (11) is laid in the holes; One end of the drainage pipe (11) is located above the horizontal support plate (6), and the other end is connected to the drainage ditch (12) to drain the accumulated water in the tie-rod arch structure.

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