JPS6311484B2 - - Google Patents

Description

[Detailed description of the invention] This invention involves excavating a trench underground while filling it with muddy water such as bentonite muddy water, mixing a solidifying agent into the muddy water in the trench, and solidifying the muddy water by mixing and stirring in the trench. This invention relates to a method of stirring muddy water when constructing a muddy water solidification waterstop wall.

When constructing a mud water solidification water stop wall, an air blowing pipe is inserted into the stable liquid in the excavation trench, and air is blown through the blowing pipe to generate many bubbles in the stable liquid, and the upward flow of the bubbles stabilizes the liquid. Conventionally, a turbulent flow and a circulating flow of the liquid are generated, and a solidifying agent such as sodium silicate and cement is sequentially added thereto to stir the mixed liquid.

However, in this conventional method, it is necessary to arrange a large number of air blowing pipes at intervals in the longitudinal direction of the excavated trench in order to agitate the entire excavated trench, and even with this consideration, the length is generally too long. It is difficult to completely stir muddy water in excavated trenches that are over 3,700 mm long.

This invention solves the problems of the above-mentioned prior art by arranging a partition wall in an excavated trench.

Hereinafter, the stirring method of the present invention will be specifically explained based on the drawings. Reference numeral 1 denotes an excavated groove excavated underground, and a partition wall 2 is disposed approximately in the center of this excavated groove. As the partition wall 2, a steel pipe 3 as shown in FIG.
or H-beam 4 etc. are used. Since the partition wall 2 does not need to be completely watertight, the end of the wall may be made of a flexible material 5 such as sponge or rubber tube, as shown. If using a rubber tube, blow air into it when using it. If the end of the partition wall in contact with the ground is configured in this way, it can be conveniently adapted even if the groove width is increased or decreased to some extent.

The partition wall 2 is arranged so as to leave enough space in the upper and lower parts of the partition wall for muddy water to flow therethrough. Normally, the partition wall 2 is erected using supporting members such as pillars 6.

Next, muddy water is circulated from one side of the groove divided into two by the partition wall 2 to the other through the communication portions at the upper and lower portions of the partition wall 2. Circulation of the mud water is advantageously carried out by means of an air lift method using air blowing or a pump method using a pump.

FIG. 2 shows a method of stirring muddy water using an air lift method, in which the air blowing pipe 7 is arranged close to the bottom of one of the partition grooves 1a of the grooves partitioned by the partition wall 2. When air blowing is started, the muddy water in the partition groove 1a flows into the partition groove 1b through the upper part of the partition wall 2, and the muddy water in the partition groove 1b flows through the lower part of the partition wall 2 into the partition groove 1a. The water flows into the water, creating a muddy flow as shown by the arrow. When a solidifying agent, such as cement milk, is injected from the injection stirrer 8 before or after the generation of this muddy water flow, the milk is instantaneously dispersed in the muddy water flow, and a uniform solidifying muddy water is obtained. Therefore, a simple device as shown in FIG. 4 can be used as the injection stirrer 8. The closer the air blowing pipe 7 is placed to the bottom of the excavation trench 1, the more uniformly the muddy water will be stirred.
If there is a risk of dead space forming at the bottom of the excavation groove, air blowing grooves can also be placed in other partition grooves, and by switching to this blowing pipe, the rotation of the mud flow can be reversed to achieve full-scale agitation.

When this air lift method is used, it is possible to save resources because the power source is extremely small, but if air remains in the solidified mud, there is a possibility that a problem will arise in the future with respect to the strength of the solidified mud. Therefore, when the solidified mud water cutoff wall particularly requires strength, the pump system shown in FIG. 5 is preferable. pump 12
are arranged at the upper and lower parts of the bulkhead 2, although a lower pump is not necessarily required. As in the case of the air lift method, it is also possible to stir the entire surface by rotating the muddy flow in the opposite direction to the initial rotation. If a dead space occurs at the bottom of the groove even after doing this, perform the first stirring by disposing the partition wall 2 off the center of the excavated groove 1 (a dead space will occur at the bottom of the wider partition groove), Next, by shifting the position of the partition wall to a symmetrical position and reversing the rotation of the muddy water flow, complete agitation becomes possible.

As is clear from the above description, the method of the present invention uses a partition wall, so the stirring efficiency is high, and since it uses the theory of air lift, the power source for rotating the muddy water is extremely small, and the mud generated Since the solidifying agent is injected and stirred using a water stream, it has the advantage that a simple device is sufficient as the injection stirrer. Therefore, the stirring method of the present invention is an extremely useful method for on-site stirring of solidified muddy water, which is difficult to uniformly stir due to its high viscosity, in an excavated trench.

[Brief explanation of the drawing]

Figure 1 is a top plan view of the excavated trench in which the bulkhead is placed, Figures 2 and 5 are longitudinal sectional views of the same, and Figure 3
Figures a and b are cross-sectional views of the partition wall, and Figures a and b are schematic diagrams of the milk injection stirrer. 1... Excavation groove, 1a, 1b... Partition groove, 2...
Partition wall, 3... steel pipe, 4... H-shaped steel, 5... flexible material, 6... pedestal, 7... air blowing pipe, 8... injection stirrer, 9... milk injection machine, 10... ... Stirring plate, 11... Propeller stirrer, 12... Pump.

Claims (1)

[Claims] 1. When constructing a water stop wall for solidifying muddy water by excavating a trench in the ground using muddy water excavation, mixing a solidifying material into the muddy water in the trench, and mixing and agitating it in the trench, the edge of the wall is After arranging a partition wall made of a shaped steel made of flexible material with a space left above and below for muddy water circulation, muddy water is circulated from one side of the excavated trench partitioned by the partition wall to the other through this communication section. A method for stirring muddy water in an excavated trench, characterized by: