JPS6117973B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a construction method for underground walls constituting earth retaining walls, water-stop walls, etc.

Conventionally, earth retaining walls and the like are generally constructed using sheet piles, but this may not be possible due to pollution problems. In-ground walls made of cast-in-place concrete require advanced technology to construct, and the use of precast members has the advantage of being able to control strength more reliably.

By the way, when building with precast materials, it is necessary to remove the soil from drilling holes. Also, backfilling is required between the drilled hole and the precast member, but simply earth cannot be used as an underground wall.

This invention is a construction method developed in view of the above circumstances, and will be explained below with reference to the illustrated embodiments.

During construction, first the stand pipe 1 is sunk. Next, a reversing machine 2 is inserted into the standpipe 1, and a hole 3 is drilled to a required depth using the muddy water method. Next, for example, an H-beam 4 as a precast member is inserted into the hole 3. Next, improved soil 5 is filled between the hole 3 and the H-shaped steel 4, and then the stand pipe 1 is pulled out, and these are constructed in succession. (See Figures 1 to 10) When performing continuous construction, drill every other hole 3 and fill with H-beam 4 and improved soil 5, and then perform construction in the same way in the middle. .

The improved soil is made by separating excess moisture from the muddy soil discharged by drilling holes with a screen, then putting it into a slurry mixer to form a slurry, mixing it with a predetermined amount of hardening material such as cement, and making it into a secondary slurry. It is mixed in a mixing plant and then forced into the hole using a concrete pump.

The H-beams may be inserted into the holes 3 in two rows, three rows, or every other row. (See FIGS. 1 to 12) Furthermore, a steel pipe 6 may be inserted instead of the H-shaped steel. In this case, the steel pipe 6 is also filled with improved soil 5. (See Figure 12) Other precast members that may be used include steel sheet piles, steel pipe sheet piles, reinforced concrete sheet piles 7, or sheet piles 8. In addition, in FIG. 13, the female joint 9 provided on the side edge of the sheet pile 8 inserted into the hole 3 first is guided by the male joint provided on the side edge of the sheet pile 8 to be inserted next into the adjacent hole 3. These are inserted to connect adjacent sheet piles.

Furthermore, the hole is not limited to a circular shape, but may be rectangular.

This invention has the above-mentioned configuration, and in addition to building a precast material into a hole that has been drilled to a large size, a continuous underground wall is built between the hole and the precast material by using improved soil mixed with a hardening material, etc. This allows for reliable underground walls, combined with the stable strength of the precast members. In particular, in this invention, since a reverse machine is used for drilling holes, the earth and sand becomes muddy water on the ground and is discharged containing water.The water is successively separated from this earth and sand by a screen, and then it is turned into a slurry by a slurry mixer. The earth and sand to be filled can be easily prepared through the integrated process of mixing hardening materials such as cement, mixing the mixture to a predetermined composition in a secondary mixing plant, and blending to obtain the required strength and unit volume weight. Since this improved soil is press-filled using a concrete pump, the discharged soil can be used effectively, the amount of discharged soil that must be disposed of is reduced, and construction costs can be reduced, and the soil mixed with hardened materials can be press-filled. The ground reinforcement is remarkable.

[Brief explanation of the drawing]

Figures 1 and 2, Figures 3 and 4, Figures 5 and 6, Figures 7 and 8, and Figures 9 and 10 are cross sections shown in the order of the construction process. Figures and longitudinal sections,
FIGS. 11, 12, and 13 are cross-sectional views showing modified examples. 1...stand pipe, 2...reverse machine, 3
... Hole, 4 ... H-shaped steel, 5 ... Improved soil, 6 ...
Steel pipe, 7... Concrete sheet pile, 8... Sheet pile, 9
...Joint.

Claims (1)

[Claims] 1. Precast material is built into a hole drilled to a larger size by a reverse machine, and then excess water is separated from the muddy soil discharged to the ground by the drilling with a screen, and the material is put into a slurry mixer to form a slurry. This is mixed with a predetermined amount of hardening material such as cement, and mixed in a mixing plant to provide the required strength.The improved soil is then injected into the space between the hole and the precast material using a concrete pump, and A construction method for underground walls that is characterized by constructing them in succession.