CN111676990A

CN111676990A - Assembled composite soil nailing wall supporting structure and construction process

Info

Publication number: CN111676990A
Application number: CN202010655886.9A
Authority: CN
Inventors: 陈涛; 巩建波; 丁文举; 刘宇; 曹忱; 王攀
Original assignee: CITIC Guoan Construction Group Co Ltd
Current assignee: CITIC Guoan Construction Group Co Ltd
Priority date: 2020-07-09
Filing date: 2020-07-09
Publication date: 2020-09-18

Abstract

The invention discloses an assembled composite soil nailing wall supporting structure and a construction process, which solve the problems that the existing soil nailing wall supporting structure has poor shockproof effect on the protection of a side slope with high stone content in an earthquake frequent occurrence area, the invention comprises a protective surface layer and a composite steel pipe, the composite steel pipe is inserted into a protective side slope, the composite steel pipe is detachably connected with the protective surface layer through a connecting piece, the composite steel pipe comprises a hollow core pipe, a pipe sleeve and a side pipe, the core pipe comprises a conical bottom and a cylinder body, the pipe sleeve is sleeved on the outer layer of the core pipe, a clearance is arranged between the pipe sleeve and the core pipe to form an interlayer cavity, the side pipe is arranged in the interlayer cavity, and the inner cavity of the core pipe is communicated with the outside of the sleeve, elastic concrete is filled in the interlayer cavity, concrete is filled in the inner cavity of the core pipe and the side pipe, and concrete is filled in the composite steel pipe and the surrounding protective slope soil. The invention has the advantages of stable structure, good shockproof effect and the like.

Description

Assembled composite soil nailing wall supporting structure and construction process

Technical Field

The invention relates to the technical field of slope protection, in particular to an assembled composite soil nailing wall supporting structure and a construction process.

Background

Soil nailing Wall (Soil Nail Wall) is an in-situ Soil body reinforcement technology. The slope of the foundation pit is reinforced by soil nails made of materials such as reinforcing steel bars, a reinforcing mesh is laid on the surface of the slope, and a layer of concrete surface layer is sprayed on the surface of the slope to combine with the soil slope. The construction is a complex formed by firmly bonding a reinforced rod piece (namely a soil nail or an anchor rod) arranged in a slope body with the surrounding soil body, and a supporting structure similar to a gravity retaining wall formed by surface layers.

The soil nail is divided into the following types: the method comprises the steps of drilling and grouting, direct driving and grouting, wherein the drilling and grouting comprises the steps of firstly drilling a hole in a soil body by using mechanical equipment such as a drilling machine, then arranging a rod body (generally made of HRB335 ribbed steel bars) after the hole is formed, and then injecting cement slurry along the whole length. The drilling and grouting nail is almost suitable for various soil layers, has high pulling resistance, reliable quality and low manufacturing cost, and is the most common soil nail type. The direct driving is to directly drive steel pipes, angle steels and other section steels, reinforcing steel bars, mao bamboos, round timbers and the like into soil without grouting. The driven-in soil nail has small diameter, low bonding friction resistance with soil body, low bearing capacity and limited nail length, so the driven-in soil nail is densely arranged and can be driven by machines such as manpower or vibration impact drills, hydraulic hammers and the like. The direct driving-in soil nail has the advantages that the direct driving-in soil nail does not need to be drilled in advance, the disturbance to in-situ soil is small, the construction speed is high, the direct driving-in soil nail is difficult to drive into hard cohesive soil, the direct driving-in soil nail is not suitable for permanent supporting projects with service life longer than 2 years, the construction cost is slightly high when the rod body is made of metal materials, and the direct driving-in soil nail is rarely applied in. The grouting type is that grouting holes are arranged in the middle and the tail of a steel pipe to form a steel flower pipe, and cement paste is directly grouted into soil and then pressed to form soil nails. The steel perforated pipe grouting soil nail has the advantages of direct nail driving, high pulling resistance, wide application, higher manufacturing cost than drilling grouting soil nail, poor corrosion resistance and inapplicability to permanent engineering, and is particularly suitable for soft soil layers such as silt, mucky soil and the like with difficult hole forming, various filling soils and sandy soils.

However, in recent years, due to frequent earthquakes, the slope of the foundation pit in the highly earthquake-prone area is susceptible to landslide and serious personal and property loss, and particularly, the slope with high stone content has higher requirements for a supporting structure, so that a soil nailing wall supporting structure with better earthquake-proof effect needs to be developed.

Disclosure of Invention

The technical problem to be solved by the invention is as follows: the existing soil nailing wall supporting structure has poor shockproof effect on the protection of a side slope with high stone content in an earthquake frequent area, and can cause the problems of soil nailing loosening, falling, collapse and the like.

The invention is realized by the following technical scheme:

compound soil nail wall supporting construction of assembled, including protection surface course and compound steel pipe, compound steel pipe inserts in the protection side slope, compound steel pipe pass through the connecting piece with the connection can be dismantled to the protection surface course, compound steel pipe includes hollow core pipe, pipe box and side pipe, the core pipe is including awl end and cylinder, the pipe box suit is in the skin of core pipe, the pipe box with clearance formation intermediate layer cavity has between the core pipe, the side pipe sets up in the intermediate layer cavity, the one end of side pipe with the cylinder connect and with the inner chamber intercommunication of core pipe, the other end of side pipe with pipe box connection just communicates with the outside, it has elastic concrete to fill in the intermediate layer cavity, it has concrete to fill in the inner chamber of core pipe and the side pipe, it has the concrete to fill in compound steel pipe and the protection side slope soil on every side.

According to the invention, the side slope which is high in stone content and is positioned in an earthquake zone is fully considered, when the side slope is subjected to earthquake action, the loose slippage of rock soil is easily caused, and in the vibration process, the composite steel pipe in the protection side slope is easily loosened by the rock solids in the side slope, so that the good pinning effect is lost.

According to the invention, the protective side slope with high stone content is considered, the composite steel pipe is drilled and then driven, the interlayer cavity formed by the core pipe and the sleeve pipe is filled with the elastic concrete, the concrete is filled in the inner cavity of the core pipe, the sleeve pipe and the surrounding protective side slope soil, so that the composite steel pipe and the surrounding protective side slope have better combination, the composite steel pipe is connected with the protective surface layer through the connecting piece, the protective surface layer and the composite steel pipe play a role in protecting and reinforcing the protective side slope together, and the elastic concrete in the interlayer cavity can play a certain role in buffering the composite steel pipe when the earthquake occurs, so that the displacement caused by the earthquake is reduced, the shaking and even loosening of the composite steel pipe caused by the earthquake are weakened, the adaptability of the supporting structure to the earthquake is improved, the side slope is better protected, and the slippage is reduced.

Furthermore, the diameter of the sleeve is smaller than or equal to that of the conical bottom, so that the sleeve can enter the soil nail hole more smoothly in the process of driving the composite steel pipe.

According to the preferable assembly type composite soil nailing wall supporting structure, the side pipe is internally provided with the spring, one end of the spring is fixedly arranged at the joint of the side pipe and the core pipe, the other end of the spring naturally extends along the side pipe, and the natural length of the spring is smaller than or equal to that of the side pipe.

According to the invention, the naturally-elongated spring is arranged in the side pipe, when the concrete is injected into the inner cavity of the core pipe, the concrete flows into the side pipe, the spring can generate certain elongation deformation under the pushing action of the concrete, and when an earthquake occurs, the deformation of the spring can absorb energy to the transverse vibration, so that the shock absorption effect is realized, and a certain protection effect is realized on the composite steel pipe.

The core pipe with the junction of side pipe is provided with the flange, the spring with flange fixed connection, the flange setting makes the spring can fix better, prevents to take place to drop at the concrete propulsion in-process.

According to the preferable assembled composite soil nailing wall supporting structure, the core pipe is in threaded connection with the connecting piece, the threaded connection is detachable connection, so that the supporting structure is an assembled structure and is easy to mount and dismount, and on the other hand, the threaded connection is stable, so that the integrity of the protective surface layer and the composite steel pipe is good.

According to the preferable assembly type composite soil nailing wall supporting structure, the through holes are formed in the side wall of the conical bottom, so that concrete can enter the protective side slope soil body around the composite steel pipe during pressurized grouting, and the composite steel pipe and the protective side slope are connected more stably.

According to the preferable assembly type composite soil nailing wall supporting structure, the protective surface layer is a flexible protective layer, the flexible protective layer is provided with the reinforcing ribs, and the connecting pieces are detachably connected with the reinforcing ribs.

According to the preferable assembly type composite soil nailing wall supporting structure, the reinforcing ribs comprise the first reinforcing rib and the second reinforcing rib which are perpendicular to each other, the first reinforcing rib and the second reinforcing rib are crossed to form a connecting point, and the connecting piece is detachably connected with the connecting point.

The strengthening rib has improved the protecting effect of protection surface course on the one hand, and on the other hand also can carry out fixed connection better with compound steel pipe, keeps whole supporting construction's wholeness and steadiness.

The construction process of the assembled composite soil nailing wall supporting structure comprises the following steps:

step 1: drilling holes on the protective side slope to form soil nail holes, wherein the hole diameter is 1.05-1.1 times of the diameter of the composite steel pipe;

step 2: driving the composite steel pipe into the protective side slope along the soil nail hole;

and step 3: injecting elastic concrete into the interlayer cavity;

and 4, step 4: injecting concrete into the inner cavity of the core pipe, wherein the concrete flows into the adjacent slope along the side pipe;

and 5: and laying the protective surface layer on the protective side slope, and fixing the protective surface layer and the composite steel pipe through the connecting piece.

The invention considers the slope structure with high stone content and high earthquake occurrence frequency, the hardness is larger, and the composite steel pipe is not convenient to be directly driven, therefore, the hole is drilled firstly, the aperture is slightly larger than the diameter of the composite steel pipe, the composite steel pipe is convenient to be inserted, after the composite steel pipe is inserted, the grouting is carried out for two times, the elastic concrete is injected into the interlayer cavity between the sleeve pipe and the core pipe for the first time, the concrete is injected into the inner cavity of the core pipe for the second time, the concrete in the inner cavity flows to the slope soil layer outside the sleeve pipe along the side pipe, for the elastic concrete formed by the first grouting, the composite steel pipe can be buffered and damped when the slope vibrates, the second injection leads the composite steel pipe and the slope to form better connection, in the second grouting process, the side pipe is provided with a spring, and the spring can be promoted to be stretched and deformed in the process that the concrete flows from the inner cavity of, when an earthquake occurs and the inside of the side slope shakes, the deformation energy of the spring can absorb the energy generated by earthquake waves in the stratum to a certain extent, so that the displacement caused by the earthquake waves is reduced, and the composite steel pipe is effectively protected.

According to the construction process of the assembled composite soil nailing wall supporting structure, the connection point is aligned with the composite steel pipe and connected by the connecting piece when the protective surface layer is specifically paved in the step 4.

Compared with the prior art, the invention has the following advantages and beneficial effects:

1. the invention considers the side slope of the earthquake area with high stone content, combines the prior construction modes of punching grouting and driving grouting, adopts the mode of firstly punching small holes, then driving composite steel pipes and grouting, and obtains the soil nailing wall supporting structure with good integrity and good shockproof effect.

2. The invention improves the existing steel perforated pipe, adopts a composite steel pipe with a two-layer structure, injects elastic concrete into the interlayer cavity, and injects concrete into the inner cavity of the core pipe and the surrounding soil layer of the protective side slope, so as to obtain the composite steel pipe with buffering effect, and the composite steel pipe is firmly pinned in the protective side slope.

3. According to the invention, the side pipe is used as a channel for concrete to flow into the protective side slope soil layer, and the naturally-extending spring with one fixed end is arranged in the side pipe, so that the concrete can drive the spring to stretch and deform during pressurized grouting, and the deformed spring can reduce vibration slippage caused by earthquake waves to a certain extent during earthquake, thereby improving the stability of the combination of the composite steel pipe and the protective side slope soil layer.

4. The composite steel pipe is detachably connected with the protective surface layer through threads, and is convenient to disassemble and assemble and good in integrity.

Drawings

The accompanying drawings, which are included to provide a further understanding of the embodiments of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the principles of the invention. In the drawings:

FIG. 1 is a schematic structural diagram of the present invention.

Fig. 2 is a schematic front view of the composite steel pipe of the present invention.

FIG. 3 is a schematic cross-sectional top view of the composite steel pipe before grouting according to the present invention.

Fig. 4 is a schematic cross-sectional top view of the composite steel pipe after grouting according to the present invention.

FIG. 5 is a schematic front view of a protective layer according to the present invention.

Reference numbers and corresponding part names in the drawings:

1-protective surface layer, 100-first reinforcing rib, 101-second reinforcing rib, 2-composite steel pipe, 3-core pipe, 30-column body, 31-conical bottom, 310-through hole, 32-internal thread, 4-sleeve pipe, 5-side pipe, 6-interlayer cavity, 7-connecting piece, 70-external thread, 71-nut, 8-elastic concrete, 9-concrete, 10-spring, 11-flange and 12-protective side slope.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail below with reference to examples and accompanying drawings, and the exemplary embodiments and descriptions thereof are only used for explaining the present invention and are not meant to limit the present invention.

Example 1

As shown in fig. 1-5, an assembled composite soil nailing wall supporting structure includes a protective surface layer 1 and a composite steel pipe 2, the composite steel pipe 2 is inserted into a protective side slope 12, the composite steel pipe 2 is detachably connected with the protective surface layer 1 through a connecting member 7, the composite steel pipe 2 includes a hollow core pipe 3, a pipe sleeve and a side pipe 5, the core pipe 3 includes a conical bottom 31 and a cylinder 30, the pipe sleeve is sleeved on an outer layer of the core pipe 3, a diameter of the sleeve 4 is equal to a diameter of the conical bottom 31, a gap is formed between the pipe sleeve and the core pipe 3 to form an interlayer cavity 6, the side pipe 5 is disposed in the interlayer cavity 6, one end of the side pipe 5 is connected with the cylinder 30 and communicated with an inner cavity of the core pipe 3, the other end of the side pipe 5 is connected with the pipe sleeve and communicated with the outside, the interlayer cavity 6 is filled with elastic concrete 8, concrete 9 is filled in the inner cavity of the core pipe 3 and the side pipe 5, and concrete 9 is filled in the composite steel pipe 2 and the surrounding protective slope 12.

The elastic concrete 8 is polyurethane concrete.

The concrete 9 is high-strength concrete.

The side wall of the conical bottom 31 is provided with a through hole 310, so that when pressurized grouting is performed, the concrete 9 can enter the soil body of the protective side slope 12 around the composite steel pipe 2, and the connection between the composite steel pipe 2 and the protective side slope 12 is more stable.

The protective surface layer 1 comprises reinforcing ribs and a flexible surface, the reinforcing ribs comprise a first reinforcing rib 100 and a second reinforcing rib 101 which are perpendicular to each other, the first reinforcing rib 100 and the second reinforcing rib 101 are crossed to form a connecting point, and the connecting piece 7 is detachably connected with the connecting point.

The upper section of the inner cavity of the core tube 3 is provided with an internal thread 32, the connecting piece 7 is provided with an external thread 70, the core tube 3 is in threaded connection with the connecting piece 7, and the connecting piece 7 passes through the connecting point of the first reinforcing rib 100 and the second reinforcing rib 101 and is screwed up and fixed by the nut 71.

In the specific connection, the connector 7 sequentially passes through the second reinforcing rib 101, the first reinforcing rib 100 and the flexible face and then enters the core tube 3, and then is screwed and fixed by the nut 71.

Example 2

The present embodiment is different from embodiment 1 in that a spring 10 is disposed in the side tube 5, one end of the spring 10 is fixedly disposed at the connection position of the side tube 5 and the core tube 3, the other end of the spring 10 naturally extends along the side tube 5, and the natural length of the spring 10 is less than or equal to the length of the side tube 5.

The connection part of the core pipe 3 and the side pipe 5 is provided with a flange 11, the spring 10 is fixedly connected with the flange 11, and the flange 11 is arranged to enable the spring 10 to be better fixed and prevent falling off in the pushing process of the concrete 9.

Example 3

step 1: drilling holes on the protective side slope 12 to form soil nail holes, wherein the hole diameter is 1.05-1.1 times of the diameter of the composite steel pipe 2;

step 2: the composite steel pipe 2 is driven into the protective side slope 12 along the soil nail hole;

and step 3: injecting elastic concrete 8 into the interlayer cavity 6;

and 4, step 4: injecting concrete 9 into the inner cavity of the core pipe 3, wherein the concrete 9 flows into the adjacent slope soil along the side pipe 5;

and 5: the protective surface layer 1 is laid on the protective side slope 12, and the protective surface layer 1 and the composite steel pipe 2 are fixed through the connecting piece 7.

And in the step 4, when the protective surface layer 1 is specifically paved, the connecting point is aligned with the composite steel pipe 2 and is connected by the connecting piece 7.

The above-mentioned embodiments are intended to illustrate the objects, technical solutions and advantages of the present invention in further detail, and it should be understood that the above-mentioned embodiments are merely exemplary embodiments of the present invention, and are not intended to limit the scope of the present invention, and any modifications, equivalent substitutions, improvements and the like made within the spirit and principle of the present invention should be included in the scope of the present invention.

Claims

1. An assembled composite soil nailing wall supporting structure is characterized by comprising a protective surface layer (1) and a composite steel pipe (2), wherein the composite steel pipe (2) is inserted into a protective side slope (12), the composite steel pipe (2) is detachably connected with the protective surface layer (1) through a connecting piece (7), the composite steel pipe (2) comprises a hollow core pipe (3), a pipe sleeve and a side pipe (5), the core pipe (3) comprises a conical bottom (31) and a cylinder body (30), the pipe sleeve is sleeved on the outer layer of the core pipe (3), a gap is formed between the pipe sleeve and the core pipe (3) to form an interlayer cavity (6), the side pipe (5) is arranged in the interlayer cavity (6), one end of the side pipe (5) is connected with the cylinder body (30) and communicated with the inner cavity of the core pipe (3), the other end of the side pipe (5) is connected with the pipe sleeve and communicated with the outside, elastic concrete (8) is filled in the interlayer cavity (6), concrete (9) is filled in the inner cavity of the core pipe (3) and the side pipe (5), and concrete (9) is filled in the composite steel pipe (2) and the surrounding protective slope (12) concrete.

2. The fabricated composite soil nailing wall supporting structure according to claim 1, wherein a spring (10) is arranged in the side pipe (5), one end of the spring (10) is fixedly arranged at the joint of the side pipe (5) and the core pipe (3), the other end of the spring (10) naturally extends along the side pipe (5), and the natural length of the spring (10) is less than or equal to the length of the side pipe (5).

3. The fabricated composite soil nailing wall supporting structure of claim 1 or 2,

the core tube (3) is in threaded connection with the connecting piece (7).

4. The fabricated composite soil nailing wall supporting structure according to claim 1 or 2, wherein the side wall of the conical bottom (31) is provided with a through hole (310).

5. The fabricated composite soil nailing wall supporting structure according to claim 1 or 2, wherein the protective surface layer (1) is a flexible protective layer provided with reinforcing ribs, and the connecting pieces (7) are detachably connected with the reinforcing ribs.

6. The fabricated composite type soil nailing wall supporting structure according to claim 5, wherein the reinforcing bars comprise a first reinforcing bar (100) and a second reinforcing bar (101) which are perpendicular to each other, the first reinforcing bar (100) and the second reinforcing bar (101) cross to form a connection point, and the connecting member (7) is detachably connected with the connection point.

7. A construction process of an assembled composite soil nailing wall supporting structure, characterized in that the construction of the soil nailing wall supporting structure according to any one of claims 1-6 comprises the following steps:

step 1: drilling holes on the protective side slope (12) to form soil nail holes, wherein the hole diameter is 1.05-1.1 times of that of the composite steel pipe (2);

step 2: the composite steel pipe (2) is driven into the protective side slope (12) along the soil nail hole;

and step 3: injecting elastic concrete (8) into the interlayer cavity (6);

and 4, step 4: pouring concrete (9) into the inner cavity of the core pipe (3), wherein the concrete (9) flows into the adjacent slope along the side pipe (5);

and 5: the protective surface layer (1) is laid on the protective side slope (12), and the protective surface layer (1) and the composite steel pipe (2) are fixed through the connecting piece (7).

8. The construction process of an assembled composite soil nailing wall supporting structure according to claim 7, wherein in the step 4, when the protective surface layer (1) is specifically laid, the connecting point is aligned with the composite steel pipe (2) and connected by the connecting piece (7).