JPH0146653B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cleaning method for horizontally installed collection and drainage boreholes constructed as a landslide prevention measure.

Generally speaking, landslide prevention methods for landslides, etc., include drilling horizontal holes from side walls for collection and drainage, and inserting water collection pipes into these holes to receive groundwater flow and drain water outside the wall. It is being

However, when this water collection pipe is inserted, earth and sand may enter the water collection hole and accumulate inside the pipe, or the hole may become clogged, resulting in the underground water not draining as expected even after the hole storage pipe is inserted. This results in accidents such as landslides.

The present invention cleans the inside of the water collection pipe by jetting jet water immediately after inserting the water collection pipe, which is such a hole storage pipe, or several days after installation, to remove the sediment that has accumulated inside the pipe. While flushing toward the outlet, a jet stream is ejected from the water collection hole to temporarily suspend and flow the sediment around the water collection hole, and when the sediment is suspended and flowed, the water is collected from the gravel with the highest gravity first. The water falls around the outer periphery of the hole, and the mouth of the water collection hole is covered with these sand and gravel to prevent clogging of the hole with clay, etc. Silt, clay, etc. with low specific gravity are piled up on the outside of this sand and gravel and are trapped in this area. A filter layer of sand and gravel is formed, and after cleaning with jet water, the water collection hole of the hole storage pipe will not be clogged, and the inside of the pipe will always be clean, so underground water will not be discharged. In addition, since the area around the water collection hole is covered with relatively large grains of gravel, groundwater collects well, making the drainage effect even better.

The construction method of the present invention will be explained step by step with reference to the accompanying drawings. Figure 1 shows an example of construction, in which a hole storage pipe 1 is inserted laterally into a cliff G where landslides are likely to occur. do. This storage pipe 1 has a large number of water collection holes 2 drilled therein, and groundwater flows through these water collection holes 2.
The water is collected from the cliff, passes through the pipe 1, and is drained outside the cliff.

Figure 2 is a detailed diagram showing the state of clogging in the pipe and the sediment deposited in the pipe immediately after the hole storage pipe 1 is inserted. It is clear that the water collection hole 2 is clogged with a complicated geological formation with few voids, and the soil 4 that fell from the water collection hole 2 when the storage pipe 1 was inserted is deposited inside the pipe. If it is as shown in the figure, groundwater will not enter through the collection hole 2, and even if it does flow into the pipe 1, there is a risk that it will not be able to be discharged, leading to accidents such as landslides. This is something that is more likely to occur.

FIG. 3 shows an embodiment in which the cleaning method of the present invention is implemented, and as shown in FIG. 3 is inserted. In the figure, a water stream rotates from the injection nozzle 3 as shown by the arrow below, washing away the inside of the pipe, and when this jet stream reaches the water collection hole 2, the surrounding earth and sand G is blown away by the water stream. At this time, the soil outside the water collection hole 2 is separated into gravel 5, which has a heavy specific gravity, and soil 6, which has a light specific gravity, and after the water flow passes through it, the accumulated soil is cleaned inside the pipe, as shown in Figure 4. Not only that, only coarse particles of gravel 5 gather around the water collection hole 2, and fine earth and sand 6, which can cause clogging or accumulation inside the pipe, gather around it and cause the gravel 5 to accumulate.
By this, a good filter layer with voids is formed.

In addition, in the method of the present invention, when inserting the rotary nozzle 3 that spouts jet water into the pipe 1, the nozzle 3 can be repeatedly inserted back and forth, thereby cleaning the inside of the pipe 1 and cleaning the filter. It is also possible to make the layer formation more effective.

The cleaning method of the present invention is particularly effective when performed immediately after inserting the hole storage tube 1 or several days after the tube is installed, and the hole storage tube 1 is always clean after performing the pipe interior cleaning of the present invention. Since there is a filter layer around the water collection hole 2, there is no intrusion of earth and sand, making the collection and drainage of groundwater extremely smooth, and accidents such as landslides caused by the flow of groundwater are completely eliminated, something that has not been seen in the past. It has an unprecedented effect.

[Brief explanation of drawings]

FIG. 1 shows a state diagram in which the hole storage pipe 1 is inserted into a cliff face, and FIGS. 2, 3, and 4 show embodiment diagrams showing the construction state. 1... Hole storage pipe, 2... Water collection hole, 3... Jet water spout nozzle.

Claims (1)

[Claims] 1 Immediately after inserting the hole storage pipe 1 having the water collection hole 2 into the soil laterally or after several days, the inside of the pipe 1 is removed by inserting a rotary nozzle 3 that spouts jet water into the pipe 1. The horizontal type is characterized in that the sediment 4 accumulated in the drain is discharged toward the outlet, and jet water is jetted out from the water collection hole 2 to form a filter layer of coarse particles 5 on the outer periphery of the hole 2. A cleaning method for collecting and draining boreholes installed in