JPS6411774B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a muddy water supply and drainage system during construction of underground continuous walls, cast-in-place piles, etc.

When constructing underground continuous walls or cast-in-place piles, the excavated soil is filled with muddy water to prevent the ground from collapsing, and the excavated soil is discharged together with the muddy water.

For example, when constructing a circular underground structure such as a large-diameter underground tank or cast-in-place pile, it is common to construct an underground continuous wall around it.
When constructing such an underground continuous wall, excavation is usually performed from multiple locations in a clockwise or counterclockwise direction.

Generally, when constructing an underground continuous wall, the technique described above is to prevent the ground from collapsing by filling it with muddy water, and before concrete is poured, sediment is removed and treated muddy water is supplied. However, a technique for effectively performing this work is disclosed in, for example, Japanese Patent Laid-Open No. 54-24103.

However, with such known techniques, it is difficult to maintain a stable level of mud water in an excavation area that is gradually being excavated, and as the excavation work progresses, in some cases, mud water supply and discharge It required difficult work such as adding piping.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a mud water supply and drainage system for constructing underground continuous walls, etc., which allows easy management of mud water and simple piping work for supplying and discharging mud water.

According to the muddy water supply and drainage method in the construction of underground continuous walls, etc. according to the present invention, the ground excavation part is filled with muddy water to prevent the ground from collapsing, and the excavated soil is discharged together with the muddy water to form underground continuous walls and cast-in-place piles. In the mud water delivery and drainage system used when constructing mud water, the mud water stored in the mud water tank is sent to the pressure tank by a mud pump, and the pressure in the pressure tank is maintained at an arbitrary set pressure. A mud feeding pipe is routed around the ground excavation part and connected to the pressure tank, and mud water is supplied to the ground excavation part via a plurality of automatic valves from the nearest point of the mud feeding pipe routed around the ground excavation part. At the same time, the automatic valve is controlled by a liquid level gauge installed in the ground excavation part to maintain a constant mud water level in the ground excavation part, and the earth and sand excavated by the excavator is discharged together with mud water to the mud water treatment equipment by a mud pump. Then, the mud is collected by a muddy water treatment device, and the muddy water is returned to the muddy tank for circulation and use.

Here, the earth and sand excavated by the excavator is discharged together with muddy water to a muddy water treatment device. The sludge pump may be singular or plural. Further, the piping from the sludge pump to the mud hydraulic system may be combined into a relay tank and configured as one line.

Therefore, the muddy water stored in the muddy water tank is sent from the muddy pump to the pressure tank, and is supplied from the muddy pipe to the ground excavation section via an automatic valve. The muddy water filled in the ground excavation section is sent to the muddy water treatment device along with the excavated earth and sand through a series of pipes by a plurality of mud pumps, where the earth and sand are treated and returned to the muddy water tank for circulation.

At that time, since the mud water pipe is routed around the ground excavation part, no matter where the excavation work starts, it is only necessary to install an automatic valve at the position closest to that position. can be selected arbitrarily. The same is true when starting excavation work from multiple locations at the same time, so the work process can be shortened. Since the liquid level of the mud in each excavation section is controlled by each automatic valve, the liquid level in all the plurality of excavation sections is maintained at an appropriate level. Since the plurality of sludge pumps are connected to one line of piping, piping work is also easy.

As described above, according to the present invention, by circulating the mud feeding pipe around the ground excavation part, excavation work can be performed from any plurality of points, and work efficiency is improved. Therefore, it is extremely suitable for excavating the ground in a closed curve. Moreover, mud water can be supplied from automatic valves to each excavation section, making it easy to control the mud water level.

EMBODIMENT OF THE INVENTION Hereinafter, with reference to drawings, the Example which implemented the muddy water supply and discharge system of this invention is described.

FIG. 1 is a flow sheet showing the first embodiment,
Broadly divided, it consists of muddy water treatment equipment A, excavation site B, relay tank C, and piping that connects them.

The muddy water treatment facility A includes a muddy water tank 1, a mud pump 2, a pressure tank 3, an automatic valve 4, a muddy water treatment device 17, and the like. Mud water stored in a mud water tank 1 is sent to a pressure tank 3 by a mud pump 2. A pressure gauge 18 is installed in the pressure tank 3, and the pressure is arbitrarily set, and the mud pumps 2-1 to 2-4 are sequentially operated so as to reach the set pressure.
The automatic valves 4-1 to 4-4 are for preventing backflow, and are opened when the slurry pump 2 is in operation and closed when the slurry pump 2 is stopped.

A mud feeding pipe, that is, a ring-shaped circle pipe 6, is arranged around the ground excavation part, that is, the excavation groove 9, which is excavated to construct an underground continuous wall, etc. As shown in the figure, a sleeve valve 19 is provided and serves as a connection port for taking out muddy water. The circle pipe 6 is connected to the pressure tank 3 by a mud feeding pipe 5. The end of the circle pipe 6 is connected to a relay tank 12.

The excavator 7 shown in FIG. 1 excavates excavated earth and sand by mixing it with mud water, sucks up the excavated mud water with a mud drain pump 8, and discharges the mud into a relay tank 12 through a mud drain pipe 11. In the example shown in Figure 1, the ground is excavated from four locations, so the number of sludge pumps is eight.
-1 to 8-4 are provided, and discharge the excavated mud water to the relay tank 12 through the mud discharge pipes 11-1 to 11-4.

As shown in Figure 1, a liquid level gauge 2 is installed in the excavation hole 21.
0 is provided, and when the mud water level drops, the automatic valve 10 opens and mud water is supplied from the circle pipe 6 to maintain the mud water level in the excavation hole 21 constant. When the pressure in the pressure tank 3 decreases by supplying muddy water, the muddy pump 2 replenishes the pressure tank 3 with muddy water to maintain the pressure in the pressure tank at an arbitrary set pressure.

The relay tank 12 collects the waste water sent from the plurality of excavators 7-1 to 7-4, and the slurry pump 13 passes the waste water through the waste pipe 16 to the mud water treatment device 1.
Send to 7. The sludge pump 13 is designed to continuously remove a certain amount of sludge so that the flow rate of the sludge pipe 16 is constant.
-1 to 13-4 are controlled. The automatic valves 14-1 to 14-4 are for preventing backflow, and are opened when the sludge pump 13 is in operation, and closed when the sludge pump 13 is stopped.

As shown in FIG. 1, the relay tank 12 is provided with a liquid level gauge 22, and the liquid level control valve 15 is adjusted so that the water level is constantly kept constant to replenish muddy water.

The muddy water treatment device 17 collects earth and sand, and the muddy water is returned to the muddy water tank 1 for circulation and use.

By stopping the excavation work and closing the sleeve valve 19, the internal pressure of the pressure tank 3 increases, and the mud pump 2 automatically stops.

FIG. 2 shows a second embodiment of the present invention. In the first embodiment, a relay tank is provided, and mud feeding water is mixed with excavation waste water to lower the concentration of the waste water and improve the sediment separation performance of the mud water treatment equipment. In this example, excavation waste water is directly discharged to the mud water treatment equipment without providing a relay tank.

According to the present invention, the following excellent effects can be obtained.

If the drilling hole and mud water treatment equipment are far apart,
A booster pump is required in the middle of the sludge drainage line, and if there are multiple excavators, individual sludge drainage pipes and operation management are required, but according to the present invention, only one sludge pipe system is required for piping work and operation. Management becomes easier.

Since mud feeding and mud removal are done separately from excavation, excavation can be done unconditionally, increasing the excavation speed.

By placing mud pipes around the excavation hole, piping can be installed over the shortest possible distance, reducing piping setup and piping time and increasing excavation speed.

Mud water is automatically supplied to the borehole and the mud water level can be kept constant.

Because there is one line each of sludge feed pipes and sludge discharge pipes, the site is organized and each work is safe.

Everything is automatically operated, saving labor and leading to cost reductions.

[Brief explanation of drawings]

The drawings show an embodiment of the mud water supply and drainage system of the present invention,
FIG. 1 is a flow sheet showing the entire structure of the first embodiment, FIG. 1 is a detailed view of an excavation hole, and FIG. 1 is a detailed view of a relay tank. FIG. 2 is a flow sheet showing the entire process of the second embodiment. 1...Mud water tank, 2-1 to 2-4...Sludge pump, 3...Pressure tank, 4-1 to 4-4...Automatic valve, 5...Sludge pipe, 6...Drilling hole Surrounding mud pipes, 7... Excavator, 8-1 to 8
-4...Sludge pump, 9...Drilling groove, 10-1~
10-4... Automatic valve, 11-1 to 11-4...
... Sludge pipe, 12 ... Relay tank, 13-1 to 13
-4...Sludge pump, 14-1 to 14-4...Automatic valve, 15...Liquid level control valve, 1
6...Sludge drainage pipe, 17...Mud water treatment device, 18...
Pressure gauge, 19...Sleeve valve, 20...Liquid level gauge, 21...Drilling hole, 22...Liquid level gauge.

Claims (1)

[Claims] 1. In addition to filling muddy water in the ground excavation area to prevent the ground from collapsing, the excavated soil is also discharged together with muddy water and stored in a muddy water tank in the muddy water system used when constructing underground continuous walls, cast-in-place piles, etc. The muddy water is sent to the pressure tank by the mud pump, and
The pressure inside the pressure tank is maintained at an arbitrary set pressure, and on the other hand, a mud pipe is routed around the ground excavation part and connected to the pressure tank, and the mud pipe routed around the ground excavation part is connected to the pressure tank. Supplying mud water to the ground excavation part from the nearest point via a plurality of automatic valves, and controlling the automatic valves with a liquid level gauge installed in the ground excavation part to maintain a constant mud water level in the ground excavation part, An underground continuous system characterized in that earth and sand excavated by an excavator is discharged together with muddy water to a muddy water treatment device by a mud pump, the earth and sand is recovered by the muddy water treatment system, and the muddy water is returned to the muddy water tank for circulation and use. A mud water pumping and draining method for constructing walls, etc.