JPH03244714A - Construction of base pile - Google Patents

Abstract

PURPOSE:To construct base piles at a low cost by surrounding piles placed in the ground with a protective wall so that horizontal forces exerted on the piles are reduced by the protective wall. CONSTITUTION:A plural number of piles 1 are placed in the ground so that their bottom ends are fixed to the supporting ground while their top ends support a base 2. A protective wall 3 is arranged in the upper outside area to surround the piles 1. The bottom of the protective wall 3 is preferably fixed to the ground layer which stand horizontal force. Concrete 4 or soil cement is placed inside the protective wall 3 to make the piles 1 and the wall 3 integral. With this constitution, vertical loads are supported by the piles 1 and horizontal forces exerted on the piles 1 are reduced as the external diameter of the piles 1 is partially enlarged.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for constructing foundation piles in construction work.

[Conventional technology]

In construction work, the functions required after foundation piles are installed include both vertical bearing capacity to support the structure and lateral horizontal bearing capacity to support horizontal forces.

Foundation pile constructors include ready-made piles and cast-in-place piles, and various construction methods have been proposed and put into use for installing these piles in the ground.

The horizontal bearing capacity of foundation piles is determined by the soil quality of the ground and the pile diameter, and since foundation piles directly support horizontal forces, the pile diameter and cross-sectional structure are set so that they can support both vertical and horizontal forces.

(Problem to be Solved by the Invention) By the way, the easiest way to increase the horizontal bearing capacity of foundation piles and safely cope with the bending and shearing forces generated by horizontal forces is to increase the diameter of the piles. However, when constructing foundation piles, there is a construction limit to increasing the pile diameter, and there is a problem that increasing the diameter of the pile increases manufacturing and construction costs, and increases the horizontal bearing capacity of the foundation pile. The current situation is that this is not possible.

Therefore, the object of this invention is to construct a foundation pile that can effectively reduce the horizontal force applied to the foundation pile, focus on increasing the vertical supporting capacity of the pile body function, and enable construction of the foundation pile at low cost. Our goal is to provide construction methods.

[Means for Solving the Problems] In order to solve the above problems, the first invention surrounds the pile body installed in the ground with a protective wall, and reduces the horizontal force applied to the pile body with the protective wall. This is a method of construction.

Similarly, the second invention is to surround the pile body installed in the ground with a protective wall, and to integrate the pile body and the protective wall by pouring concrete or soil cement inside the protective wall. This is a construction method that reinforces the strength.

In addition, the third invention surrounds the pile body installed in the ground with a protective wall, and the inside of the protective wall is either hollow or backfilled so that horizontal force is not transmitted to the pile body, and the horizontal reaction force is absorbed by the protective wall. This construction method reduces the horizontal force acting on the pile by increasing the load, thereby increasing the vertical force shared by the pile.

[Effect]

When a pile body installed in the ground is surrounded by a protective wall, the protective wall supports the horizontal force of the ground, and the horizontal force applied to the pile body can be reduced by the protective wall, increasing the vertical force sharing of the pile body. By reducing the horizontal force support function, it is possible to reduce the cost of the pile body.

Furthermore, by separating the foundation that supports the structure from the protection wall, the protection wall can bear the horizontal force and reduce the horizontal force acting on the pile body.

〔Example〕

Embodiments of the present invention will be described below with reference to the accompanying drawings.

In the first embodiment shown in Figs. 1 and 2, the plurality of pile bodies 1 installed on the ground A support the foundation 2 at their upper ends, and although their tips are not shown, they are anchored to the supporting ground. ,
A protective wall 3 is placed outside the upper part of the above pile group 1 so as to surround the pile group.
is provided.

The protective wall 3 may be made of steel pipes, humid pipes, etc., and may be buried by piling up, digging, pushing, etc., or may be a double inner pipe consisting of an outer pipe and an inner pipe set in an excavated hole in the ground. The protective wall 3 may be constructed on site by removing the excavated earth and sand by pulling it out and pouring concrete into the inside of the outer pipe. A composite pile is constructed by driving soil cement and integrating the pile body group 1 and the protection wall 3.

The pile bodies 1 may be ready-made piles such as rope piles or concrete piles, or cast-in-place piles constructed on site, and the number and diameter of each pile will depend on the vertical load of the structure to be supported and the properties of the ground. In addition, the diameter and thickness of the protective wall 3 should be set so that it can support horizontal force (passive earth pressure), and the lower part of the protective wall 3 should be set in a stratum that can resist horizontal force. It is desirable to set it to .

In this first embodiment, first, a required number of pile bodies 1 are installed on the ground A so that their tips are fixed to the support layer.

The upper outer side of a group of pile bodies installed on the ground A is surrounded by a protective wall 3, the internal space of the protective wall 3 is filled with concrete 4 or soil cement, and the first group of pile bodies and the protective wall 3 are integrated. This results in a composite pile consisting of one group of pile bodies and the protection wall 3, and the vertical load of the structure is supported by the first group of pile bodies.

In addition, the protective wall 3 is integrated with the pile body 1 group, so that the pile body 1
The outer diameter of the protective wall 3 can be partially enlarged.
The reaction force against the horizontal force on the ground is large, and the horizontal force applied to the pile body 1 can be reduced.

Next, in the second embodiment shown in FIGS. 3 and 4, the protective wall 3 surrounding the pile body 1 is formed of concrete and integrated with the foundation 2.

In this second embodiment, by supporting the horizontal force of the ground A by the protective wall 3 integrated with the foundation 2, the horizontal force acting on the pile body 1 can be reduced.

In the third embodiment shown in FIG. 5, a protective wall 3 is provided to surround the pile body 1 installed on the ground A. This protective wall 3 is made of corrugated pipes, raw potato boards, humid pipes, etc., and is provided over a range of strata that can resist horizontal forces from the ground surface.

A base fj12 is constructed inside and at the upper part of the protective wall 3 so as to be supported by the pile body 1, and the lower space within the protective wall 3 is backfilled or concrete 4 or soil cement is poured.

In this third embodiment, the pile body 1, the foundation 2, and the protection wall 3 are integrated, and the horizontal force acting on the pile body 1 can be reduced by the protection wall 3.

In each of the embodiments described above, the outside of the pile body 1 group is covered with a protective wall 3.
By enclosing the pile body 1 with the protection wall 3 and reducing the horizontal force acting on the pile body 1 with the protective wall 3, it is possible to increase the share of the vertical force of the pile body 1.

[Effect] As described above, according to the present invention, the pile body installed in the ground is surrounded by a protective wall, and the horizontal force applied to the pile body is reduced by the protective wall, so that the pile body only supports vertical force. It is only necessary to take this into consideration, and the diameter of the pile body can be reduced accordingly, and the construction cost of the pile body can be significantly reduced.

[Brief explanation of drawings]

Fig. 1 is a longitudinal cross-sectional view showing the first embodiment of the construction method according to the present invention, Fig. 2 is a cross-sectional plan view taken along arrows ■-■ in Fig. 1, and Fig. 3 is a longitudinal cross-sectional view showing the second embodiment. Front view, Figure 4 is the 3rd
FIG. 5 is a cross-sectional plan view taken along the arrow IV--IV in the figure, and a vertical cross-sectional front view showing the third embodiment. 1...Pile body, 2...Foundation, 3
...Protection wall, 4...Concrete, A...Ground.

Claims (3)

[Claims] (1) A construction method for foundation piles in which the pile body installed in the ground is surrounded by a protective wall, and the horizontal force applied to the pile body is reduced by the protective wall. (2) Surround the pile installed in the ground with a protective wall, and pour concrete or soil cement inside the protective wall to integrate the pile and the protective wall, reinforcing the pile against horizontal forces. A construction method for synthetic foundation piles. (3) By surrounding the pile body installed in the ground with a protective wall, leaving the inside of the protective wall hollow or backfilling it so that horizontal force is not transmitted to the pile body, and having the horizontal reaction force be borne by the protective wall. A foundation pile construction method that reduces the horizontal force acting on the pile body, thereby increasing the vertical force shared by the pile body.