JPH05222735A - Building method for deep foundation type well base - Google Patents

Abstract

PURPOSE:To curtail concrete placing and the like and build the deep foundation type well base in a short time even in a mountainous area or the like by performing a deep foundation execution by which drilled soil is filled in an earth retainer made from precast concrete as the foundation of a steel tower and the like. CONSTITUTION:At first, the ground is drilled up to a decided depth by the use of a drilling machine and the like, and earth retaining is executed by means of precast concrete 1 assembled into nearly circular form out of segments of decided shape. In this assembly, PC steel bars 4 are passed through PC steel bar fitting holes 3 so as to make assembly in order in the depth direction, the strength of the whole foundation is increased by vertical fastening, and mortar is filled around the PC steel bars 4. Next, for increasing foundation supporting force, bottom stuffing concrete 5 is placed. Next, mortar is filled by the use of a filling pipe 6, drilled soil is charged in the foundation as intermediate stuffing members 7, and hardening material is pressed in it. Finally, cover concrete 8 is placed on a cover concrete receiving member 1b and hence the deep foundation type well base is completed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of constructing a deep foundation type well foundation which is preliminarily provided on the ground when constructing a steel tower or the like.

[0002]

2. Description of the Related Art Conventionally, when constructing a foundation such as a steel tower by a deep foundation method, first, the ground is input into a circle or an oval type or excavated by a machine, and the divided liner plates are sequentially assembled and earth retaining. To do. The above procedure is sequentially repeated to lower the liner plate to a predetermined position. When the liner plate reached the specified position, the reinforcing bars were installed and concrete was placed to complete the foundation construction.

[0003]

However, steel towers and the like are sometimes built in mountainous areas. In this case, there are many roads in the mountainous areas where large ready-mixed concrete vehicles cannot pass, and they are far from the concrete plant. There are problems that it may be difficult to pour concrete, and that it may take time to pour concrete, which may adversely affect the quality. In addition, when placing concrete on a cableway, there is a problem that a large number of days are required because the amount of placing a day is small and the construction period is prolonged. Furthermore, the excavated earth and sand had a problem in that there were few places to dispose in the mountainous area, and it took time and cost to dispose of it.

The present invention has been proposed in view of the above circumstances, and an object thereof is to reduce the amount of concrete and concrete pouring, prevent adverse effects on quality, and shorten the construction period. , It is to provide an economical deep foundation type well foundation construction method that reduces the amount of waste excavated soil.

[0005]

According to the present invention, in a well foundation of a deep well type, earth retaining at the time of construction of a deep foundation is performed by precast concrete 1 made by assembling segments 1a into a predetermined shape, and excavated by sand or excavated inside. The above object is achieved by filling a mixture of earth and sand with a hardening material or the like as the filling material 7.

[0006]

As described above, since the soil retaining is performed by the precast concrete 1, the amount of concrete for retaining soil and the amount of placing work can be reduced, and the quality is improved even in a mountainous area where workability is poor. It was made possible to build a foundation with a predetermined strength in a short time without causing a decrease in Further, the excavated earth and sand is used as the filling material 7, so that the time and labor required for the disposal of the excavated earth and sand is reduced.

[0007]

EXAMPLE FIG. 1 is a vertical cross section of a deep foundation type well foundation constructed by the construction method of the present invention, which is characterized in that precast concrete 1 is used in place of concrete pouring. FIG. 2 is a sectional view taken along the line AA of the precast concrete 1 portion in FIG. 1, and FIG. 3 is another example of the embodiment. Hereinafter, the building method of the present invention will be described with reference to these drawings.

First, the ground is excavated to a predetermined depth by using a well-known excavator and the like, and earth retaining is performed with the precast concrete 1 assembled into a substantially circular shape. As shown in FIG. 2, the precast concrete 1 for earth retaining is multi-divided in the same manner as the concrete segments in the shield tunnel, and these several predetermined-shaped segments 1a are assembled in a circle, and As shown in FIG. 1, the segments 1a are joined together by bolts 2 or the like.
Further, the precast concrete 1 is provided with a PC steel rod mounting hole 3 so that assembling in the depth direction results in PC
The steel rod mounting holes 3 are arranged so as to be continuously connected in a straight line. The PC steel rod mounting holes 3 are passed through the PC steel rods 4 and vertically tightened to increase the strength of the entire foundation, and the PC steel rods are also connected. Fill around 4 with mortar.

Next, bottom-filled concrete 5 is poured in order to increase the supporting force of the foundation. After that, the mortar is filled with the mortar using the filling pipe 6, and the excavated earth and sand is put into the foundation as the filling material 7, and the hardening material or the like is press-fitted. Alternatively, although not shown, there is also a method in which the excavated soil and the hardened material are mixed on the ground in advance and the mixture is put into the foundation as the filling material 7.
Alternatively, there is also a method in which after the excavated earth and sand is put into the foundation, a hardening material is jetted at high pressure to mix and harden it.

After that, by placing the cover concrete 8 on the cover concrete receiving member 1b projecting inside the precast concrete 1 in the upper part, a deep foundation type well foundation can be completed. And this cover concrete 8
The steel tower foundation material 9 may be installed on the upper part of the above, and the concrete concrete 10 may be placed around it to construct the steel tower.

[0011]

As described above, in the present invention, the earth retaining is performed by assembling the precast concrete instead of the concrete pouring, so that the amount of concrete pouring and the work can be significantly reduced. Even with the above, a foundation having a predetermined strength can be built in a shorter time than the conventional method. Moreover, since the excavated soil is also used as the filling material 1, the amount of the excavated soil to be disposed can be reduced and the cost required for the disposal can be reduced.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view of a deep foundation type well foundation manufactured by a building method of the present invention.

FIG. 2 is a sectional view taken along the line AA in FIG.

FIG. 3 shows another embodiment of the precast concrete used in the present invention.

[Explanation of symbols]

 1 Precast concrete 1a Segment 1b Lid concrete receiving member 2 Segment mounting bolt 3 PC steel rod mounting hole 4 PC steel rod 5 Bottom filling concrete 6 Mortar filling pipe 7 Filling material 8 Lid concrete 9 Steel tower foundation material 10 Basic concrete

Claims (1)

[Claims] 1. In a deep foundation well foundation, earth retaining at the time of construction of a deep foundation is performed by precast concrete (1) in which segments (1a) are assembled in a predetermined shape, and excavated earth or hardened material for excavated earth. A method of constructing a deep foundation type well foundation, which comprises filling a mixture of the above materials as a filling material (7) to construct a foundation.