Foundation pit supporting structure for staged construction of undercrossing road box culvert

Abstract

The utility model relates to a foundation pit supporting structure for staged construction of an underpass road box culvert, which comprises a row pile partition wall arranged in the middle of a road, and the left side of the row pile partition wall is vertically connected with early-stage row pile enclosure walls located on the two sides of an early-stage box culvert foundation pit. The right side of the row pile partition wall is perpendicularly connected with the later-stage row pile enclosure walls on the two sides of the later-stage box culvert foundation pit, the early-stage row pile enclosure walls on the two sides of the early-stage box culvert foundation pit are connected, inclined supporting beams are arranged at the right-angle positions formed by the row pile partition wall and the early-stage row pile enclosure walls, and a temporary retaining wall separated from the row pile partition wall is arranged at the top of the early-stage box culvert. The row pile partition wall and the temporary retaining wall are arranged in the middle of the road for staged construction of the box culvert, it can be guaranteed that half road traffic is not interrupted when the box culvert transversely penetrates through the road for excavation construction, and the temporary retaining wall can guarantee the road structure and traffic safety; local gaps are backfilled with plain concrete, so that backfilled soil between the box culvert structure and the enclosure wall cannot collapse, and the safety of the foundation pit and the road is ensured.

Description

Technical Field

[0001] The utility model relates to the technical field of box culvert construction, in particular to a foundation pit supporting structure for staged construction of a box culvert under a road. Background Art

[0002] When a new box culvert structure is built under an existing urban road in an underground project, in order to avoid the impact of the box culvert construction on the existing road traffic, a non-excavation construction method such as pipe jacking under the road can be adopted when the surrounding conditions, geological conditions and other conditions permit. However, pipe jacking construction has strict requirements on construction conditions, especially the high cost of rectangular pipe jacking. Therefore, in general, the box culvert structure is constructed by driving support piles on the existing road to excavate the foundation pit. At the same time, in order to ensure that road traffic continues to flow when the box culvert is under the road, it is necessary to adopt a phased construction method. The existing phased construction method of the foundation pit generally only considers the setting of partition walls along the horizontal direction of the foundation pit, without considering the temporary support of the backfill soil inside the foundation pit. After the partition wall is removed, the shallow backfill soil of the foundation pit is still at risk of collapse under the influence of road traffic. Summary of the invention

[0003] The technical problem to be solved by the utility model is to provide a foundation pit support structure for staged construction of a box culvert under a road in view of the deficiencies of the above-mentioned prior art.

[0004] The utility model solves the above-mentioned technical problems through the following technical solutions: a foundation pit support structure for staged construction of a box culvert under a road, comprising a pile row partition wall arranged in the middle of the road, the left side of the pile row partition wall being vertically connected to an early row of pile retaining walls located on both sides of an early box culvert foundation pit, the right side of the pile row partition wall being vertically connected to a later row of pile retaining walls located on both sides of a later box culvert foundation pit, the early row of pile retaining walls on both sides of the early box culvert foundation pit being connected by early top support beams, an oblique support beam being arranged at a right angle formed by the pile row partition wall and the early row of pile retaining walls, and a temporary retaining wall spaced apart from the pile row partition wall being arranged on the top of the early box culvert.

[0005] The beneficial effects of the utility model are as follows: the foundation pit support structure of the utility model for the staged construction of the box culvert under the road, by arranging a pile partition wall and a temporary retaining wall in the middle of the road for staged construction of the box culvert, can ensure that traffic on half of the road is continuously flowing when the box culvert crosses the road for excavation construction, the temporary retaining wall can ensure the road structure and driving safety, the local gaps are backfilled with plain concrete so that the backfill soil between the box culvert structure and the surrounding wall will not collapse, thereby ensuring the safety of the foundation pit and the road.

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

[0007] Further: the row of pile partition walls, early row of pile retaining walls and later row of pile retaining walls are bored cast-in-place piles, steel sheet piles or steel piles.

[0008] The beneficial effect of the above further scheme is: according to the depth of the box culvert foundation pit, a suitable type of retaining wall is selected to facilitate construction and reduce the impact on road traffic.

[0009] Further: the early top support beams, the oblique support beams and the later top support beams are reinforced concrete beams or steel pipes.

[0010] The beneficial effect of the above further scheme is: selecting the appropriate type of support beam according to the depth of the box culvert foundation pit and the type of the retaining wall, thereby saving construction time and cost while ensuring the safety of the foundation pit.

[0011] Furthermore: the angles between the oblique support beams and the pile row partition wall and the early pile row retaining wall are both 45 degrees.

[0012] The beneficial effect of the above further solution is that by arranging the oblique support beams symmetrically on both sides of the foundation pit, the force is more stable, thereby ensuring the safety of the foundation pit in the early construction area.

[0013] Further: the temporary retaining wall is a reinforced concrete structure, and the length of the main reinforcement of the temporary retaining wall anchored in the previous box culvert top plate is not less than 35 times the diameter of the main reinforcement.

[0014] The beneficial effect of the above further scheme is: by setting up a temporary reinforced concrete retaining wall, the road structure formed after the backfilling of the preliminary box culvert foundation pit is ensured to be more stable, thereby ensuring driving safety.

[0015] Furthermore: the temporary retaining wall and the preliminary box culvert top plate are cast in one piece, and the distance between the temporary retaining wall and the pile partition wall is not less than 1m.

[0016] The beneficial effect of the above further scheme is: by casting the temporary retaining wall and the preliminary box culvert top plate as an integral part, the connection between the temporary retaining wall and the preliminary box culvert can be made more stable, and the distance between the temporary retaining wall and the pile partition wall is not less than 1m to ensure that the safety of the temporary retaining wall is not affected when the pile partition wall is removed.

[0017] Further: the gap between the preliminary box culvert and the preliminary pile retaining wall on the left side of the temporary retaining wall is backfilled with plain concrete.

[0018] The beneficial effect of the above further scheme is that the local voids in the foundation pit are backfilled with plain concrete so that when the box culvert foundation pit is constructed in the later stage, the backfill soil between the voids of the early box culvert and the early pile retaining wall will not collapse, ensuring the safety of the foundation pit and the road.

[0019] Furthermore: the strength of the plain concrete is not less than C20, and the backfill height of the plain concrete is equal to the height of the temporary retaining wall. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic plan view of a foundation pit support structure for staged construction of a box culvert under a road according to an embodiment of the utility model;

[0021] Figure 2 It is a longitudinal cross-sectional schematic diagram of a foundation pit support structure for staged construction of a box culvert under a road according to an embodiment of the utility model;

[0022] Figure 3 It is a schematic transverse section diagram of a foundation pit support structure for staged construction of a box culvert under a road according to an embodiment of the utility model.

[0023] In the accompanying drawings, the components represented by the reference numerals are listed as follows:

[0024] 0. Pile partition wall, 11. Early box culvert, 12. Early pile retaining wall, 13. Early top support beam, 14. Diagonal support beam, 15. Temporary retaining wall, 16. Plain concrete, 21. Later box culvert, 22. Later pile retaining wall, 23. Later top support beam. DETAILED DESCRIPTION

[0025] 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.

[0026] like Figures 1 to 3 As shown, a foundation pit support structure for staged construction of a box culvert under a road comprises a pile partition wall 0 arranged in the middle of the road, the left side of the pile partition wall 0 is vertically connected to the early pile retaining walls 12 located on both sides of the foundation pit of the early box culvert 11, the right side of the pile partition wall 0 is vertically connected to the later pile retaining walls 22 on both sides of the foundation pit of the later box culvert 21, the early pile retaining walls 12 on both sides of the foundation pit of the early box culvert 11 are connected by early top support beams 13, the later pile retaining walls 22 on both sides of the foundation pit of the later box culvert 21 are connected by late top support beams 23, an oblique support beam 14 is arranged at the right angle formed by the pile partition wall 0 and the early pile retaining walls 12, and a temporary retaining wall 15 is arranged on the top of the early box culvert 11.

[0027] The utility model discloses a foundation pit support structure for staged construction of a box culvert under a road. The utility model carries out staged construction of the box culvert by arranging a pile partition wall and a temporary retaining wall at the center line of the road. When the box culvert crosses the road for excavation construction, it can ensure that traffic on half of the road continues to flow. The temporary retaining wall can ensure the road structure and driving safety. The local gap is backfilled with plain concrete so that the backfill soil between the box culvert structure and the surrounding wall will not collapse, thereby ensuring the safety of the foundation pit and the road.

[0028] In one or more embodiments of the present invention, the row pile partition wall 0, the early row pile retaining wall 12 and the later row pile retaining wall 22 are bored piles, steel sheet piles or steel piles. According to the depth of the box culvert foundation pit, a suitable retaining wall type is selected to facilitate construction and reduce the impact on road traffic.

[0029] In practice, the pile row partition wall 0 and the early pile row retaining wall 12 should be constructed first, and the later pile row retaining wall 22 should be constructed after the road traffic in the early construction area is restored. The pile row partition wall 0 and the early pile row retaining wall 12, i.e., the left side of the road, should be constructed first, and the area of ​​the later pile row retaining wall 22, i.e., the right side of the road, should be reserved for traffic. After the road traffic in the early construction area, i.e., the left side of the road is restored, the area of ​​the later pile row retaining wall 22, i.e., the right side of the road, should be constructed, ensuring that half of the road is reserved for traffic during the entire construction process.

[0030] In one or more embodiments of the utility model, the early top support beam 13, the oblique support beam 14 and the later top support beam 23 are reinforced concrete beams or steel pipes. According to the depth of the box culvert foundation pit and the type of the retaining wall, the appropriate type of support beam is selected to save construction time and cost while ensuring the safety of the foundation pit.

[0031] Optionally, in one or more embodiments of the utility model, the angles between the oblique support beams 14 and the pile partition wall 0 and the early pile enclosure wall 12 are 45 degrees. By arranging the oblique support beams 14 symmetrically on both sides of the foundation pit, the force is more stable, ensuring the safety of the foundation pit in the early construction area.

[0032] In one or more embodiments of the present invention, the temporary retaining wall 15 is a reinforced concrete structure, and the length of the main reinforcement of the temporary retaining wall 15 anchored in the top plate of the previous box culvert 11 is not less than 35 times the diameter of the main reinforcement. By setting up the reinforced concrete temporary retaining wall 15, the road structure formed after the foundation pit of the previous box culvert 11 is backfilled is ensured to be more stable, ensuring driving safety.

[0033] Optionally, in one or more embodiments of the utility model, the temporary retaining wall 15 is integrally cast with the top plate of the preliminary box culvert 11, and the distance between the temporary retaining wall 15 and the row of pile partition walls 0 is not less than 1m. By integrally casting the temporary retaining wall 15 with the top plate of the preliminary box culvert 11, the connection between the temporary retaining wall 15 and the preliminary box culvert 11 can be made more stable, and the distance between the temporary retaining wall 15 and the row of pile partition walls 0 is not less than 1m, which can ensure that the safety of the temporary retaining wall 15 is not affected when the row of pile partition walls 0 are removed.

[0034] In one or more embodiments of the present invention, the gap between the preliminary box culvert 11 and the preliminary row of pile retaining wall 12 on the left side of the temporary retaining wall 15 is backfilled with plain concrete 16. The local gap of the foundation pit is backfilled with plain concrete 16 so that when the box culvert 21 foundation pit is constructed later, the backfill soil between the gap between the preliminary box culvert 11 and the preliminary row of pile retaining wall 12 will not collapse, ensuring the safety of the foundation pit and the road.

[0035] Optionally, in one or more embodiments of the present invention, the strength of the plain concrete 16 is not less than C20, and the backfill height of the plain concrete 16 is equal to the height of the temporary retaining wall 15 .

[0036] Optionally, in one or more embodiments of the present invention, the row of pile partition walls 0 should be chiseled out during the construction of the box culvert 21 in the later stage.

[0037] Optionally, in one or more embodiments of the present invention,

[0038] The temporary retaining wall 15 should be removed as needed when the foundation pit of the box culvert 21 is backfilled at a later stage.

[0039] The foundation pit support structure of the utility model for the staged construction of the underpass road box culvert comprises the following specific construction steps:

[0040] ① After the site is leveled, the preliminary pile retaining wall 12 and the pile partition wall 0 are constructed in sequence;

[0041] ② Construction of the top support beam 13 and the diagonal support beam 14 in the early stage;

[0042] ③ Excavate earthwork to the bottom elevation of the preliminary box culvert 11;

[0043] ④Construction of preliminary box culvert 11 and temporary retaining wall 15;

[0044] ⑤ Backfilling of foundation pit earthwork and plain concrete 16 in the early construction area;

[0045] ⑥ Road traffic in the early construction area is restored;

[0046] ⑦ Pile retaining wall 22 and later top support beam 23 in the later stage of construction;

[0047] ⑧ Excavate earthwork to the bottom elevation of the later box culvert 21;

[0048] ⑨ Remove the pile partition wall 0 and construct the later box culvert 21 to connect with the earlier box culvert 11.

[0049] ⑩ Backfill the foundation pit in the later construction area and remove the temporary retaining wall 15 as needed.

[0050] Roads and traffic restored.

[0051] 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 foundation pit support structure constructed in stages under a road box culvert, characterized by: The invention comprises a pile row partition wall (0) arranged in the middle of a road, the left side of the pile row partition wall (0) is vertically connected to the early pile row retaining wall (12) located on both sides of the foundation pit of an early box culvert (11), the right side of the pile row partition wall (0) is vertically connected to the later pile row retaining wall (22) located on both sides of the foundation pit of a later box culvert (21), the early pile row retaining walls (12) on both sides of the foundation pit of the early box culvert (11) are connected by early top support beams (13), an oblique support beam (14) is arranged at a right angle formed by the pile row partition wall (0) and the early pile row retaining wall (12), and a temporary retaining wall (15) spaced apart from the pile row partition wall (0) is arranged on the top of the early box culvert (11).

2. The foundation pit support structure for staged construction of a box culvert under a road according to claim 1 is characterized by: The row of pile partition walls (0), the early row of pile enclosure walls (12) and the later row of pile enclosure walls (22) are bored cast-in-place piles, steel sheet piles or profiled steel piles.

3. The foundation pit support structure for staged construction of a box culvert under a road according to claim 1 is characterized by: The early top support beam (13), the oblique support beam (14) and the late top support beam (23) are reinforced concrete beams or steel pipes.

4. The foundation pit support structure for staged construction of a box culvert under a road according to claim 3 is characterized by: The angles between the oblique support beam (14) and the row of pile partition wall (0) and the early row of pile enclosure wall (12) are both 45 degrees.

5. The foundation pit support structure for staged construction of a box culvert under a road according to claim 1 is characterized by: The temporary retaining wall (15) is a reinforced concrete structure, and the length of the main reinforcement of the temporary retaining wall (15) anchored in the top plate of the previous box culvert (11) is not less than 35 times the diameter of the main reinforcement.

6. The foundation pit support structure for staged construction of a box culvert under a road according to claim 5 is characterized by: The temporary retaining wall (15) and the top plate of the preliminary box culvert (11) are cast in one piece, and the distance between the temporary retaining wall (15) and the pile partition wall (0) is not less than 1 m.

7. The foundation pit support structure for staged construction of a box culvert under a road according to claim 6 is characterized by: The gap between the preliminary box culvert (11) and the preliminary pile enclosure wall (12) on the left side of the temporary retaining wall (15) is backfilled with plain concrete (16).

8. The foundation pit support structure for staged construction of a box culvert under a road according to claim 7 is characterized by: The strength of the plain concrete (16) is not less than C20, and the backfill height of the plain concrete (16) is equal to the height of the temporary retaining wall (15).

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