Box culvert foundation pit supporting structure over-crossing underground structure

Abstract

The utility model relates to a box culvert foundation pit supporting structure crossing an underground structure, which comprises a box culvert main body arranged in a foundation pit, a gap is formed between the bottom of the box culvert main body and the bottom wall of the foundation pit, and a bottom sealing structure is arranged in the gap. A plurality of high-pressure jet grouting piles are arranged between the outer side walls of the two sides of the box culvert body and the inner side walls of the two corresponding sides of the foundation pit, and every two adjacent high-pressure jet grouting piles are arranged in an engaged mode. The high-pressure jet grouting piles are arranged on the inner side walls of the two sides of the foundation pit respectively, so that soil bodies can be isolated, deformation of surrounding soil bodies is further reduced, influence on surrounding buildings is small, construction risks are reduced, safety of the surrounding buildings is guaranteed, soil is excavated between the high-pressure jet grouting piles on the two sides, the box culvert body sinks to the designed elevation, and construction efficiency is improved. The foundation pit supporting structure can be prevented from being constructed firstly when the box culvert structure is constructed, the construction problem of a space limited area is solved, the engineering cost and the construction period are saved, the box culvert structure is high in overall rigidity, and deformation of the structure and surrounding soil is small.

Description

Technical Field

[0001] The utility model relates to the technical field of underground structure construction, in particular to a box culvert foundation pit supporting structure which spans an underground structure. Background Art

[0002] With the continuous development of urbanization, there is an increasing demand for the construction of box culvert structures such as underground drainage structures and pedestrian walkways. When constructing box culvert structures on existing urban roads, if there are previously built underground structures such as subways, tunnels, and pipe galleries below, it is impossible to use the method of driving support piles for foundation pit excavation; the existing road traffic volume is large and it is not suitable to use slope excavation. Box culvert structures are generally shallowly covered with soil and are not suitable for non-excavation methods such as jacking, and the cost of rectangular jacking is relatively high. Summary of the invention

[0003] The technical problem to be solved by the utility model is to provide a box culvert foundation pit supporting structure which crosses an underground structure in view of the deficiencies of the above-mentioned prior art.

[0004] The utility model provides a technical solution to the above-mentioned technical problem as follows: a box culvert foundation pit support structure spanning an underground structure, comprising a box culvert main body arranged in the foundation pit, a gap being formed between the bottom of the box culvert main body and the bottom wall of the foundation pit, a bottom sealing structure being arranged in the gap, a plurality of high-pressure rotary jet piles being arranged between the outer side walls on both sides of the box culvert main body and the inner side walls on both sides corresponding to the foundation pit, and two adjacent high-pressure rotary jet piles being arranged to be interlocked.

[0005] The beneficial effects of the utility model are as follows: the box culvert foundation pit support structure of the utility model that crosses the underground structure can isolate the soil by respectively arranging high-pressure rotary jet piles on the inner walls on both sides of the foundation pit, further reducing the deformation of the surrounding soil and the impact on the surrounding buildings, reducing the construction risk, and ensuring the safety of the surrounding buildings. The soil is excavated between the high-pressure rotary jet piles on both sides so that the box culvert body is sunk to the designed elevation, which can avoid the construction of the foundation pit support structure first when constructing the box culvert structure, solves the construction problem in the space-constrained area, saves engineering costs and construction period, and the box culvert structure has high overall rigidity, and the deformation of the structure itself and the surrounding soil is small.

[0006] On the basis of the above technical solution, the present invention can also be improved as follows:

[0007] Further: the box culvert body includes side walls adjacently arranged on the inner walls on the left and right sides of the foundation pit, an upper support beam is arranged between the upper ends of the inner walls of the side walls on the left and right sides, a top plate is arranged between the tops of the side walls on the left and right sides, a plurality of lower support beams are arranged between the lower ends of the inner walls of the side walls on the left and right sides, and a bottom plate is arranged between two adjacent lower support beams, a bottom sealing structure is arranged at the lower part of the bottom plate, a blade foot is arranged on the inner side of the bottom of the side wall, the top of the side walls on the left and right sides are respectively connected to the left and right ends of the top plate, and the bottom of the side walls on the left and right sides are respectively connected to the left and right ends of the bottom plate.

[0008] The beneficial effect of the above further scheme is that by arranging the side walls, the upper support beams, the lower support beams, the bottom plate and the top plate, a box culvert body with a stable structure is formed in this way, thereby ensuring the safety of the entire box culvert body when sinking.

[0009] Further: main reinforcement is arranged in the side wall, and the upper end of the main reinforcement extends out of the top of the side wall, and the upper end of the main reinforcement extends into the top plate to form reserved reinforcement for the top plate.

[0010] The beneficial effect of the above further scheme is: by setting the main reinforcement, on the one hand, the structural strength of the side wall can be enhanced, and on the other hand, the upper end of the main reinforcement can extend into the top plate and form a reserved reinforcement for the top plate, which facilitates the connection and fixation of the side wall and the top plate.

[0011] Further: the side wall is provided with transverse connecting steel bars along the longitudinal direction of the box culvert body, the lower support beam and longitudinal connecting steel bars are provided along the transverse direction of the box culvert body, and the transverse connecting steel bars are connected and fixed to the side wall, and the longitudinal connecting steel bars are respectively connected and fixed to the lower support beam and the bottom plate.

[0012] The beneficial effect of the above further scheme is that by arranging the transverse connecting steel bars and the longitudinal connecting steel bars, it can be ensured that the main reinforcement of the bottom plate made later is connected with the main reinforcement of the side wall and the lower support beam, and the structure can be connected as one.

[0013] Furthermore: the cross-sectional dimensions of the upper support beam and the lower support beam are the same, both are square, the lower support beam and the bottom plate are arranged at the same height, and the thickness of the two are the same.

[0014] The beneficial effect of the above further scheme is: by making the cross-sectional dimensions of the upper support beam and the lower support beam the same, both are square, so that the upper support beam and the lower support beam can ensure the safety of the foundation pit when the box culvert sinks, and the lower support beam and the bottom plate are set at the same height, which is convenient for construction on the one hand, and can make the lower support beam and the bottom plate synchronously and evenly stressed on the other hand.

[0015] Further: the bottom plate is a reinforced concrete slab arranged in the area surrounded by the side walls and each of the lower support beams, and the bottom plate is connected to the side walls through transverse connecting steel bars, and the bottom plate is connected to the lower support beams through longitudinal connecting steel bars.

[0016] The beneficial effects of the above further scheme are: the reinforced concrete slab has high structural strength, is easy to construct, and is convenient for the early reservation or later planting of the transverse connecting steel bars and the longitudinal connecting steel bars.

[0017] Further: the engagement between two adjacent high-pressure jet grouting piles is 0.1-0.2m, the distance between the pile body of the high-pressure jet grouting pile and the side wall is 0.2m, the top of the high-pressure jet grouting pile is at the same height as the ground, and the bottom elevation of the high-pressure jet grouting pile is the same as the bottom elevation of the blade foot.

[0018] The beneficial effect of the above further scheme is that by interlocking the pile bodies of two adjacent high-pressure jet grouting piles, all the high-pressure jet grouting piles on each side can form a whole, thereby ensuring the overall supporting strength and thus ensuring construction safety.

[0019] Furthermore: the lower part of the bottom cover structure is a sand and gravel mixture with a thickness of 0.3m, and the upper part is a C20 plain concrete with a thickness of 0.3m.

[0020] Further: the side walls, upper support beams, lower support beams, blade feet, bottom plates and top plates are all reinforced concrete structures, and the overall length is 10-30m. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic structural cross-sectional view of a box culvert foundation pit support structure that spans an underground structure during the initial construction of an embodiment of the utility model;

[0022] Figure 2 It is a schematic structural cross-sectional view of a box culvert structure of a box culvert foundation pit support structure that crosses an underground structure in an embodiment of the utility model when the box culvert structure is completed;

[0023] Figure 3 It is a schematic plan view of a box culvert foundation pit support structure that spans an underground structure according to an embodiment of the utility model;

[0024] Figure 4 The box culvert structure schematic diagram is a box culvert foundation pit support structure that spans over an underground structure according to an embodiment of the utility model.

[0025] In the accompanying drawings, the components represented by the reference numerals are listed as follows:

[0026] 0. Box culvert body, 1. Side wall, 2. Upper support beam, 3. Lower support beam, 4. Reserved steel bars for top plate, 5. Blade foot, 6. High-pressure rotary jet piles, 7. Horizontal connecting steel bars, 8. Longitudinal connecting steel bars, 9. Bottom structure, 10. Bottom plate, 11. Top plate. DETAILED DESCRIPTION

[0027] The principles and features of the present invention are described below in conjunction with the accompanying drawings. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0028] like Figures 1 to 4 As shown, it includes a box culvert body 0 arranged in a foundation pit, a gap is formed between the bottom of the box culvert body 0 and the bottom wall of the foundation pit, a bottom sealing structure 9 is arranged in the gap, and a plurality of high-pressure rotary jet piles 6 are arranged between the outer side walls on both sides of the box culvert body 0 and the inner side walls on both sides corresponding to the foundation pit, and the two adjacent high-pressure rotary jet piles 6 are interlocked.

[0029] The box culvert foundation pit support structure of the utility model that crosses the underground structure can isolate the soil by arranging high-pressure rotary jet piles 6 on the inner walls on both sides of the foundation pit, further reducing the deformation of the surrounding soil and the impact on the surrounding buildings, reducing the construction risk, and ensuring the safety of the surrounding buildings. The soil is excavated between the high-pressure rotary jet piles 6 on both sides so that the box culvert main body 0 sinks to the designed elevation, which can avoid the need to construct the foundation pit support structure first when constructing the box culvert structure, solves the construction problem in space-constrained areas, saves engineering costs and construction period, and the box culvert structure has high overall rigidity, and the deformation of the structure itself and the surrounding soil is small.

[0030] In one or more embodiments of the utility model, the box culvert body 0 includes side walls 1 adjacently arranged on the inner side walls of the left and right sides of the foundation pit, an upper support beam 2 is arranged between the upper ends of the inner side walls of the left and right sides of the side walls 1, a top plate 11 is arranged between the tops of the left and right sides of the side walls 1, multiple lower support beams 3 are arranged between the lower ends of the inner side walls of the left and right sides of the side walls 1, and a bottom plate 10 is arranged between two adjacent lower support beams 3, a bottom sealing structure 9 is arranged at the lower part of the bottom plate 10, a blade foot 5 is arranged on the inner side of the bottom of the side wall 1, the top of the left and right sides of the side walls 1 are respectively connected to the left and right ends of the top plate 11, and the bottom of the left and right sides of the side walls 1 are respectively connected to the left and right ends of the bottom plate 10. By arranging the side walls 1, the upper support beam 2, the lower support beam 3, the bottom plate 10 and the top plate 11, a box culvert body 0 with a stable structure is formed in this way, ensuring the safety of the entire box culvert body 0 when sinking.

[0031] In one or more embodiments of the present invention, the horizontal spacing between each upper support beam 2 and the lower support beam 3 is the same, which is 4.0-5.0 m, and the central axes of the upper support beam 2 and the corresponding lower support beam 3 overlap in the height direction.

[0032] In one or more embodiments of the utility model, main reinforcement is provided in the side wall 1, and the upper end of the main reinforcement extends out of the top of the side wall 1, and the upper end of the main reinforcement extends into the top plate 11 to form the top plate reserved reinforcement 4. By providing the main reinforcement, on the one hand, the structural strength of the side wall 1 can be enhanced, and on the other hand, the upper end of the main reinforcement can extend into the top plate 11 to form the top plate reserved reinforcement 4, which facilitates the connection and fixation of the side wall 1 and the top plate 11, and the structure can be connected as one.

[0033] In one or more embodiments of the utility model, the side wall 1 is provided with transverse connecting steel bars 7 along the longitudinal direction of the box culvert body 0, the lower support beam 3 and the box culvert body 0 are provided with longitudinal connecting steel bars 8 in the transverse direction, and the transverse connecting steel bars 7 are connected and fixed to the side wall 1, and the longitudinal connecting steel bars 8 are respectively connected and fixed to the lower support beam 3 and the bottom plate 10. By providing the transverse connecting steel bars 7 and the longitudinal connecting steel bars 8, it can be ensured that the main bars of the bottom plate 10 made later are connected to the main bars of the side wall 1 and the lower support beam 3, and the structure can be connected as one.

[0034] In practice, the transverse connecting steel bars 7 and the longitudinal connecting steel bars 8 are arranged in two rows, one above the other, using the construction technology of pre-reserved steel bars or later embedded steel bars, with a horizontal spacing of 0.3-0.4m and a vertical spacing the same as the main reinforcement spacing of the bottom plate 10.

[0035] Optionally, in one or more embodiments of the utility model, the cross-sectional dimensions of the upper support beam 2 and the lower support beam 3 are the same, both are square, the lower support beam 3 and the bottom plate 10 are arranged at the same height, and the thickness of the two is the same. By making the cross-sectional dimensions of the upper support beam 2 and the lower support beam 3 the same, both are square, the upper support beam 2 and the lower support beam 3 can ensure the safety of the foundation pit when the box culvert sinks, and the lower support beam 3 and the bottom plate 10 are arranged at the same height, which is convenient for construction on the one hand, and can make the lower support beam 3 and the bottom plate 10 synchronously and evenly stressed on the other hand.

[0036] In one or more embodiments of the present invention, the bottom plate 10 is a reinforced concrete plate arranged in the area surrounded by the side wall 1 and each of the lower support beams 3, and the bottom plate 10 is connected to the side wall 1 through the transverse connecting steel bar 7, and the bottom plate 10 is connected to the lower support beam 3 through the longitudinal connecting steel bar 8. The reinforced concrete plate has a high structural strength and is convenient for construction, and it is convenient for the transverse connecting steel bars 7 and the longitudinal connecting steel bars 8 to be reserved in advance or to be rebar-planted later.

[0037] In one or more embodiments of the utility model, the engagement between the pile bodies of two adjacent high-pressure jet grouting piles 6 is 0.1-0.2m, the distance between the pile body of the high-pressure jet grouting pile 6 and the side wall 1 is 0.2m, the top of the high-pressure jet grouting pile 6 is at the same height as the ground, and the bottom elevation of the high-pressure jet grouting pile 6 is the same as the bottom elevation of the blade foot 5. By setting the engagement between the pile bodies of two adjacent high-pressure jet grouting piles 6, all the high-pressure jet grouting piles 6 on each side can be formed into a whole, ensuring the overall support strength, thereby ensuring construction safety.

[0038] Specifically, in one or more embodiments of the present invention, the lower portion of the bottom cover structure 9 is a sand and gravel mixture with a thickness of 0.3 m, and the upper portion is a C20 plain concrete with a thickness of 0.3 m.

[0039] Optionally, in one or more embodiments of the present invention, the side wall 1, the upper support beam 2, the lower support beam 3, the blade foot 5, the bottom plate 10 and the top plate 11 are all reinforced concrete structures, and the overall length is 10-30m.

[0040] The box culvert foundation pit support structure of the utility model that crosses the underground structure specifically comprises the following steps:

[0041] ① Site leveling, positioning, and construction of high-pressure jet grouting piles 6;

[0042] ② Construct the main structure of the box culvert body 0 on the ground, including the side wall 1, the blade foot 5, the upper support beam 2, the lower support beam 3, the top plate reserved steel bars 4, the transverse connecting steel bars 7 and the longitudinal connecting steel bars 8;

[0043] ③ After the main structural strength of the box culvert body 0 reaches the design strength, dig the soil at the lower blade foot 5 of the box culvert body 0 and along the inner side of the high-pressure jet grouting pile 6;

[0044] ④ Sink the box culvert body 0 while digging the soil until the box culvert body 0 sinks to the designed elevation;

[0045] ⑤ Construction of bottom cover structure 9;

[0046] ⑥Construct the bottom plate 10, and connect it tightly with the side wall 1 through the transverse connecting steel bars 7, and connect it tightly with the lower support beam 3 through the bottom longitudinal connecting steel bars 8;

[0047] ⑦Construct the top plate 11 and connect it tightly with the side wall 1 through the reserved steel bars 4 on the top plate;

[0048] ⑧ After the main structure of the box culvert body 0 reaches the designed strength, complete the foundation pit backfilling and ground restoration.

[0049] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A box culvert foundation pit support structure that spans an underground structure, characterized in that: The invention comprises a box culvert body (0) arranged in a foundation pit, a gap is formed between the bottom of the box culvert body (0) and the bottom wall of the foundation pit, a bottom sealing structure (9) is arranged in the gap, and a plurality of high-pressure rotary jet piles (6) are arranged between the outer side walls on both sides of the box culvert body (0) and the inner side walls on both sides corresponding to the foundation pit, and two adjacent high-pressure rotary jet piles (6) are arranged to be interlocked.

2. The box culvert foundation pit support structure for crossing an underground structure according to claim 1 is characterized in that: The box culvert body (0) comprises side walls (1) arranged adjacent to the inner walls on the left and right sides of the foundation pit, an upper support beam (2) is arranged between the upper ends of the inner walls of the side walls (1) on the left and right sides, a top plate (11) is arranged between the tops of the side walls (1) on the left and right sides, a plurality of lower support beams (3) are arranged at intervals between the lower ends of the inner walls of the side walls (1) on the left and right sides, and a bottom plate (10) is arranged between two adjacent lower support beams (3), the bottom of the bottom plate (10) is provided with the bottom sealing structure (9), a blade foot (5) is arranged on the inner side of the bottom of the side wall (1), the top of the side walls (1) on the left and right sides are respectively connected to the left and right ends of the top plate (11), and the bottom of the side walls (1) on the left and right sides are respectively connected to the left and right ends of the bottom plate (10).

3. The box culvert foundation pit support structure for crossing an underground structure according to claim 2 is characterized in that: Main reinforcement is arranged in the side wall (1), and the upper end of the main reinforcement extends out of the top of the side wall (1), and the upper end of the main reinforcement extends into the top plate (11) to form a reserved reinforcement (4) for the top plate.

4. The box culvert foundation pit support structure for crossing an underground structure according to claim 2 is characterized in that: The side wall (1) is provided with transverse connecting steel bars (7) along the longitudinal direction of the box culvert body (0), the lower support beam (3) is provided with longitudinal connecting steel bars (8) along the transverse direction of the box culvert body (0), and the transverse connecting steel bars (7) are connected and fixed to the side wall (1), and the longitudinal connecting steel bars (8) are respectively connected and fixed to the lower support beam (3) and the bottom plate (10).

5. The box culvert foundation pit support structure for crossing an underground structure according to claim 2 is characterized in that: The cross-sectional dimensions of the upper support beam (2) and the lower support beam (3) are the same, both are square, and the lower support beam (3) and the bottom plate (10) are arranged at the same height and have the same thickness.

6. The box culvert foundation pit support structure for crossing an underground structure according to claim 5 is characterized in that: The bottom plate (10) is a reinforced concrete plate arranged in an area surrounded by the side wall (1) and each of the lower support beams (3), and the bottom plate (10) is connected to the side wall (1) via a transverse connecting steel bar (7), and the bottom plate (10) is connected to the lower support beam (3) via a longitudinal connecting steel bar (8).

7. The box culvert foundation pit support structure for an upper span of an underground structure according to any one of claims 2 to 6, characterized in that: The engagement distance between the pile bodies of two adjacent high-pressure jet grouting piles (6) is 0.1-0.2 m, the distance between the pile body of the high-pressure jet grouting pile (6) and the side wall (1) is 0.2 m, the top of the high-pressure jet grouting pile (6) is at the same height as the ground, and the bottom elevation of the high-pressure jet grouting pile (6) is the same as the bottom elevation of the blade foot (5).

8. The box culvert foundation pit support structure for an upper span of an underground structure according to any one of claims 1 to 6, characterized in that: The bottom cover structure (9) has a lower portion made of a sand-gravel mixture with a thickness of 0.3 m, and an upper portion made of C20 plain concrete with a thickness of 0.3 m.

9. The box culvert foundation pit support structure for an upper span of an underground structure according to any one of claims 2 to 6, characterized in that: The side wall (1), upper support beam (2), lower support beam (3), blade foot (5), bottom plate (10) and top plate (11) are all reinforced concrete structures, and the overall length is 10-30m.

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