CN214460477U

CN214460477U - Combined foundation pit support

Info

Publication number: CN214460477U
Application number: CN202120411152.6U
Authority: CN
Inventors: 雷立; 张学锋; 任超平; 付效铎; 全有维
Original assignee: Third Construction Co Ltd of China Construction Eighth Engineering Divison Co Ltd
Current assignee: Third Construction Co Ltd of China Construction Eighth Engineering Divison Co Ltd
Priority date: 2021-02-24
Filing date: 2021-02-24
Publication date: 2021-10-22
Anticipated expiration: 2031-02-24

Abstract

The utility model provides a combined foundation pit support, which comprises a collapse range backfill layer, wherein the outer side end of the collapse range backfill layer is provided with a retaining wall, the bottom end of the retaining wall is provided with a plurality of fixed components, and the outer side end of each fixed component is provided with a soil surface layer; the fixing component comprises a crown beam and a plurality of steel pipe piles, and the steel pipe piles are fixed at the bottom of the foundation pit; the retaining wall and the soil surface layer are fixed on the side portion of the foundation pit through a plurality of soil nails. The utility model discloses only can strut effectively foundation ditch side slope collapse position with simple method.

Description

Combined foundation pit support

Technical Field

The utility model relates to a foundation ditch support, concretely relates to modular foundation ditch support.

Background

In the earth excavation construction of the construction site, the slope excavation is often adopted by projects as an excavation method with simple construction and low manufacturing cost under the condition of permission of site conditions.

In the slope-laying excavation process, if the soil body at the position of the side slope of the foundation pit is found to be disturbed or backfilled with garbage soil, if the problem soil body is not completely excavated, the local collapse phenomenon of the foundation pit can occur in the process of earth excavation or foundation pit use of the side slope of the foundation pit, and the potential safety hazard is large. If the problem soil body is completely excavated, the area of the temporary site available at the edge of the foundation pit is reduced after the upper opening of the foundation pit is expanded outwards, or the arrangement of roads in the site is influenced. Aiming at the situation, under the condition of ensuring safety, the key for solving the problem is to select a supporting form which has small influence on the area of the site, is convenient to construct and is economic and reasonable as far as possible.

Disclosure of Invention

Technical problem to prior art exists, the utility model provides a modular excavation supporting to reach and only can carry out the purpose of effectively strutting with simple method to the foundation ditch side slope position of collapsing.

The utility model provides a combined foundation pit support, which comprises a collapse range backfill layer, wherein the outer side end of the collapse range backfill layer is provided with a retaining wall, the bottom end of the retaining wall is provided with a plurality of fixed components, and the outer side end of each fixed component is provided with a soil surface layer; the fixing component comprises a crown beam and a plurality of steel pipe piles, and the steel pipe piles are fixed at the bottom of the foundation pit; the retaining wall and the soil surface layer are fixed on the side portion of the foundation pit through a plurality of soil nails.

Preferably, the bottom of the steel pipe pile is provided with a conical pile tip.

Preferably, cement paste is filled in the steel pipe pile and the soil nail.

Preferably, the steel pipe pile is a phi 60 hot-dip galvanized steel pipe with a wall thickness of 4mm, and the top of the steel pipe pile is inserted into the crown beam by 300 mm.

Preferably, the soil nails are three-level phi 22 or phi 25 steel bars, the inclination angle is 15 degrees, and the aperture is 120 mm.

Preferably, the soil surface layer is a sprayed concrete surface layer, the vertical and horizontal reinforcing mesh piece phi 6@200, the sprayed concrete thickness is 80mm, and the concrete strength grade is C20.

Preferably, the crown beam is a reinforced concrete rectangular beam with the section size of 800 × 600 and the strength grade of C30.

Preferably, the retaining wall is a reinforced concrete structure, the wall thickness is 300mm, and the strength grade is C30.

Compared with the prior art, the utility model discloses following beneficial effect has: the utility model discloses can effectively solve and put the slope excavation in-process, because of the problem that local soil body is weak, collapses and cause, need not be under construction concrete piling and strut, only can carry out effectual strut to the foundation ditch side slope position of collapsing with simple method, improve the factor of safety of foundation ditch, reduce the influence that closes on the place to the foundation ditch, simple and practical, the cost is lower.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the embodiments or the technical solutions in the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

Fig. 1 is a schematic structural diagram of an embodiment of the present invention.

Fig. 2 is a schematic structural diagram of a fixing assembly in an embodiment of the present invention.

Wherein, 1, soil nailing; 2. steel pipe piles; 3. a crown beam; 4. a retaining wall; 5. a soil surface layer; 6. and (5) backfilling the soil layer in the collapse range.

Detailed Description

The following examples are provided for better understanding of the present invention, and are not limited to the best mode, and do not limit the scope and content of the present invention, and any product that is the same or similar to the present invention, which is obtained by combining the features of the present invention with other prior art or the present invention, falls within the scope of the present invention.

Examples

Referring to fig. 1-2, a combined foundation pit support comprises a collapse range backfill soil layer 6, wherein a retaining wall 4 is arranged at the outer side end of the collapse range backfill soil layer 6, a fixing component is arranged at the bottom end of the retaining wall 4, and a soil surface layer 5 is arranged at the outer side end of the fixing component; the fixing assembly comprises a crown beam 3 and two steel pipe piles 2, the crown beam 3 is arranged at the bottom end of the retaining wall 4, the bottom of each steel pipe pile 2 is provided with a conical pile tip, and the crown beam 3 is fixed at the bottom of the foundation pit through the steel pipe piles 2; retaining wall 4 and soil surface 5 are all fixed in the lateral part of foundation ditch through several soil nail 1, and soil nail 1 is tertiary phi 25 reinforcing bar, and the inclination 15 degrees, aperture 120 mm.

The specific implementation method of this embodiment is as follows:

1) and excavating earthwork layer by layer, namely excavating to the bottom of the collapse range of the foundation pit in the first step, and excavating soil in the collapse range.

2) And (4) carrying out soil nail construction within the first-step excavation height range, enabling the first soil nail to be 1m away from the ground, enabling the soil nail to be vertically, horizontally and longitudinally spaced by 1.5m from top to bottom, and throwing away the reinforcing steel bars at the ends of the soil nails.

3) After the upper field of the earth excavation surface at the bottom of the collapse range is leveled, a hot-dip galvanized steel pipe with the wall thickness of 4mm and the diameter of 60 mm is slowly pressed into the earth by an excavator, and the bottom of the steel pipe pile is ensured to be 3m lower than the bottom of the foundation pit; the longitudinal and transverse spacing of the steel pipe piles is 400mm, the top of each steel pipe pile extends into a crown beam by 300mm, the steel pipes are lengthened in a welding mode, PO42.5 cement paste is injected into the steel pipes after pile pressing is completed, the water cement ratio is 0.5, and holes are required to be led until the steel pipes are full, if the steel pipes are difficult to press in.

4) And excavating a crown beam foundation groove, constructing a C15 plain concrete cushion layer with the thickness of 100mm and a reinforced concrete crown beam with the thickness of 800 multiplied by 600mm respectively, determining the main reinforcement of the crown beam according to calculation, and inserting the vertical reinforcement of the retaining wall before pouring the concrete of the crown beam, wherein the concrete strength is C30.

5) Ligature retaining wall reinforcing bar to with the first step earthwork excavation within range soil nail whipping head reinforcing bar and retaining wall steel bar welding, the retaining wall is according to the thick formwork of 300mm, pours C30 concrete, and the retaining wall top is unanimous with the foundation ditch top surface.

6) And after the retaining wall template is removed, backfilling 3:7 lime soil in a soil mass collapse range on the back surface of the retaining wall layer by layer, compacting by tamping, backfilling to the top of a foundation pit, and hardening the surface of the foundation pit to form a 100mm thick C15 plain concrete surface layer.

7) And after extending 2m from the exposed side of the soil retaining wall to one side of the foundation pit, starting a second step of layered slope excavation, wherein the slope of the slope excavation is 1:0.4 or 1:0.33, and selecting according to the soil body.

8) In the second step of earthwork excavation, soil nails are inserted in time for construction, the distance between the soil nails is 1.5m from top to bottom and from left to right, and when each earthwork is excavated by 4m, the slope protection surface single-layer reinforcing mesh pieces are bound in time, and concrete is sprayed and maintained; the single-layer longitudinal and transverse reinforcing mesh phi 6@200 is characterized in that the concrete spraying thickness is 80mm, and the concrete strength grade is C20; the slope protection surface is provided with drain holes at an interval of 2 m.

The embodiment can effectively solve the problem that the excavation process of putting the slope, because of local soil body is weak, collapse and cause, need not construct concrete piling and strut, only can carry out effectual strut to the foundation ditch side slope position of collapsing with simple method, has improved the factor of safety of foundation ditch, has reduced the influence that closes on the place to the foundation ditch, simple and practical, and the cost is lower.

It should be understood that the above examples are only for clarity of illustration and are not intended to limit the embodiments. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. And obvious variations or modifications can be made without departing from the scope of the invention.

Claims

1. A combined foundation pit support is characterized by comprising a collapse range backfill layer, wherein a retaining wall is arranged at the outer side end of the collapse range backfill layer, a plurality of fixing assemblies are arranged at the bottom end of the retaining wall, and soil surface layers are arranged at the outer side ends of the fixing assemblies; the fixing component comprises a crown beam and a plurality of steel pipe piles, and the steel pipe piles are fixed at the bottom of the foundation pit; the retaining wall and the soil surface layer are fixed on the side portion of the foundation pit through a plurality of soil nails.

2. The modular foundation pit support of claim 1, wherein the bottom of the steel pipe pile is provided with a conical pile tip.

3. The modular foundation pit support of claim 1, wherein cement slurry is filled in both the steel pipe piles and the soil nails.

4. The modular foundation pit support of claim 1, wherein the steel pipe pile is a hot-dip galvanized steel pipe of phi 60 with a wall thickness of 4mm and a top inserted 300mm into the crown beam.

5. The modular foundation pit support of claim 1, wherein the soil nails are three-level 22 or 25 steel bars with an inclination angle of 15 degrees and a hole diameter of 120 mm.

6. The modular foundation pit support of claim 1, wherein the soil facing is a shotcrete facing, the longitudinal and transverse reinforcing mesh phi 6@200, the shotcrete thickness is 80mm, and the concrete strength rating is C20.

7. The modular foundation pit support of claim 1, wherein the crown beam is a reinforced concrete rectangular beam having a cross-sectional dimension of 800 x 600 and a strength rating of C30.

8. The modular foundation pit support of claim 1, wherein the retaining wall is a reinforced concrete structure with a wall thickness of 300mm and a strength grade of C30.