阅读说明：本技术 一种钻孔灌注桩及其施工方法 (Cast-in-situ bored pile and construction method thereof ) 是由 刘思谋 刘思广 于 2019-09-05 设计创作，主要内容包括：本发明公开了一种钻孔灌注桩及其施工方法,应用于具有淤泥层的地质环境中,通过在桩柱钢筋笼的外围设置薄壳混凝土圆管,从而避免钻孔灌注桩位于淤泥层的部位在灌注混凝土时发生扩径或缩颈的现象,提高施工质量,降低施工成本。(The invention discloses a cast-in-situ bored pile and a construction method thereof, which are applied to a geological environment with a sludge layer.)

1. The cast-in-situ bored pile is applied to geological environment with a silt layer and comprises a pile steel reinforcement cage and concrete poured in a pile hole.

2. A bored pile according to claim 1, wherein the tubular is a cement tubular.

3. The cast-in-situ bored pile according to claim 2, wherein the positioning block is a steel plate embedded part embedded in the cement round pipe, and the steel plate embedded part is welded to a positioning rib provided on the pile reinforcement cage.

4. The bored pile according to claim 3, wherein the distance from the inner wall of the cement round tube to the pile reinforcement cage plus the thickness of the wall of the cement round tube is equal to the thickness of the cement protective layer of the pile reinforcement cage.

5. A bored pile according to claim 2, wherein a steel wire mesh is arranged in the wall of the cement round pipe, the diameter of the steel wire mesh is 3mm, and the mesh size of the steel wire mesh is 5cm x 5 cm.

6. The cast-in-situ bored pile according to claims 1 to 5, wherein the circular tube has a tube wall thickness in a range of 3cm to 7 cm.

7. Cast-in-situ bored pile according to claims 1 to 5, wherein the length of the circular tube is in the range of 2m to 10 m.

8. Cast-in-situ bored pile according to claims 1 to 5, wherein the respective lengths of round tubes are connected together by tongue-and-groove joints.

9. A bored pile according to claims 1 to 5, wherein said circular tube is provided at a portion of the pile reinforcement cage located at the sludge layer.

10. A cast-in-situ bored pile construction method using the cast-in-situ bored pile according to any one of claims 1 to 9, comprising the steps of:

s1: carrying out construction lofting on the pile position to determine the center of the pile position and the circumferential line of the pile position;

s2: paving roadbed box plates around the pile position to form a construction platform around the pile position;

s3: installing a drilling machine on the construction platform, performing drilling operation to form a pile hole, and then cleaning sludge and residues in the pile hole;

s4: manufacturing a pile reinforcement cage, and installing a circular pipe on the part of the reinforcement cage, which is positioned on the sludge layer, according to a geological structure diagram;

s5: installing a pile reinforcement cage with a circular pipe into the pile hole;

s6: cleaning residual silt and residue in the pile hole;

s7: and continuously pouring concrete into the pile hole.

Technical Field

The invention relates to the technical field of pile foundation construction, in particular to a construction method of a cast-in-situ bored pile applied to a sludge layer environment.

Background

The cast-in-situ bored pile is an important pile foundation in building engineering and bridge engineering, and in the construction process, firstly, a pile hole is dug in a mechanical hole forming or manual hole forming mode, and then a reinforcement cage is installed, and finally concrete is poured. The cast-in-situ bored pile is subdivided into an end-bearing pile and a friction pile in a stressed manner. When the construction is carried out in a thick silt layer geological environment, if friction piles are adopted, deep pile holes are needed; if end-bearing piles are used, the length of the pile hole entering the bedrock should also be more than twice the diameter of the pile. In addition, the difficulty of pile construction operation in a coastal area or in a wet land and other environments with thick sludge layers is high, firstly, mechanical equipment is difficult to normally position, and when concrete is poured after hole forming, the phenomenon of necking and expanding is easily generated at the position of the sludge layer, so that the construction quality of the cast-in-situ bored pile is seriously influenced, meanwhile, the waste of concrete is also caused, and the construction cost is increased.

Disclosure of Invention

The present invention is made to solve the above-mentioned technical problems, and an object of the present invention is to provide a method for constructing a cast-in-situ bored pile, which can reduce construction cost and increase construction speed while ensuring construction quality.

In order to achieve the purpose, the invention provides a cast-in-situ bored pile, which is applied to a geological environment with a sludge layer and comprises a pile reinforcement cage and concrete poured in a pile hole, wherein a plurality of sections of round pipes are sleeved on the pile reinforcement cage, a plurality of positioning blocks are arranged on the inner wall of each round pipe along the length direction, and the round pipes are connected with the pile reinforcement cage through the positioning blocks.

Furthermore, the round pipe is a cement round pipe.

Furthermore, the positioning block is a steel plate embedded part embedded in the cement round pipe, and the steel plate embedded part is welded with a positioning rib arranged on the pile steel reinforcement cage.

Furthermore, the inner wall of the cement round pipe reaches the distance of the pile steel reinforcement cage plus the thickness of the pipe wall of the cement round pipe is equal to the thickness of the cement protective layer of the pile steel reinforcement cage.

Furthermore, a steel wire mesh is arranged in the pipe wall of the cement round pipe, the diameter of a steel wire of the steel wire mesh is 3mm, and the size of a grid of the steel wire mesh is 5cm multiplied by 5 cm.

Furthermore, the thickness of the pipe wall of the round pipe is within the range of 3 cm-7 cm.

Further, the length of the circular tube is within the range of 2m to 10 m.

Furthermore, all the sections of round pipes are connected together through tongue-and-groove joints.

Furthermore, the round pipe is arranged at the position of the pile reinforcement cage on the sludge layer.

On the other hand, the invention also provides a construction method of the cast-in-situ bored pile, which adopts the cast-in-situ bored pile and comprises the following steps:

s1: carrying out construction lofting on the pile position to determine the center of the pile position and the circumferential line of the pile position;

s2: paving roadbed box plates around the pile position to form a construction platform around the pile position;

s3: installing a drilling machine on the construction platform, performing drilling operation to form a pile hole, and then cleaning sludge and residues in the pile hole;

s4: manufacturing a pile reinforcement cage, and installing a circular pipe on the part of the reinforcement cage, which is positioned on the sludge layer, according to a geological structure diagram;

s5: installing a pile reinforcement cage with a circular pipe into the pile hole;

s6: cleaning residual silt and residue in the pile hole;

s7: and continuously pouring concrete into the pile hole.

According to the above description and practice, the cast-in-situ bored pile of the present invention has the advantages that the pile reinforcement cage is sleeved with the plurality of sections of the circular pipes which are butted together at the position of the sludge layer, and the pile hole is separated from the sludge layer by the circular pipes, so that the sludge cannot flow into the pile hole, and the necking phenomenon is avoided; meanwhile, concrete in the pile hole can not flow into the sludge layer, so that the expanding phenomenon is avoided, and the quality of the cast-in-situ bored pile is improved. By utilizing the circular tube and the construction method of the cast-in-situ bored pile, the construction of the pile in the geological environment of the sludge layer can be quickly completed, the construction cost is reduced, and the construction quality is improved.

Drawings

Fig. 1 is a schematic diagram of a cast-in-situ bored pile according to an embodiment of the present invention.

Fig. 2 is a schematic view of a bored pile according to an embodiment of the present invention, partially in section.

Fig. 3 is a schematic plan view of a construction platform involved in an embodiment of the invention.

Fig. 4 is a schematic flow chart of a method of constructing a cast-in-situ bored pile according to an embodiment of the present invention.

In the figure: 1. the construction method comprises the following steps of (1) filling a mixed soil layer, 2) a silt layer, 3, a strongly weathered rock stratum, 4, an intermediate weathered rock stratum, 5, a slightly weathered rock stratum, 6, a pile reinforcement cage, 7, a cement circular tube, 8, a steel plate embedded part, 9, a construction platform, 10 and a positioning rib;

71. concave part, 72, convex part.

Detailed Description

Embodiments of a cast-in-situ bored pile and a construction method thereof according to the present invention will be described below with reference to the accompanying drawings. Those of ordinary skill in the art will recognize that the described embodiments can be modified in various different ways, without departing from the spirit and scope of the present invention. Accordingly, the drawings and description are illustrative in nature and not intended to limit the scope of the claims. Furthermore, in the present description, the drawings are not to scale and like reference numerals refer to like parts.