JPH03194023A - Pumping well capable of adjusting pressure reduction - Google Patents

Abstract

PURPOSE:To automatically adjust to reduce water pressure of an aquiferous layer by dividing the well main body of a pumping well used at a construction site and the like into an upper chamber and a lower chamber, providing a communicating pipe between both chambers, and draining ground water flowing in the upper chamber. CONSTITUTION:The well main body 1 of a pumping well used for an underground drainage work at a construction site and the like is divided into an upper chamber 1a and a lower chamber 1b with a partition 2, and the main body 1 is built into the ground so that the lower end is positioned in an aquiferous layer 13 between upper and lower non-permeable layers 11, 12. A pipe 3 having adjustable length is standingly provided on the partition 2, to communicate the upper chamber 1a and the lower chamber 1b with each other. A drainage pump 4 arranged on the lower part of the upper chamber 1a is driven for draining ground water flowing in the upper chamber 1a. Hereby, water pressure in the aquiferous layer 13 is automatically adjusted to reduce pressure, and minify the drain water quantity to a minimum necessary quantity for saving consuming power.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a pumping well used for underground drainage work at construction sites and the like.

[Prior Art] Generally, pumping wells are used to drain groundwater when excavating at construction sites and the like. This type of pumping well is always used when there is an impermeable water retention layer underground, especially when the overburden is small, even when a water stop method is used.

[Problems to be Solved by the Invention] Conventional pumping wells discharge water from the water reservoir, but when the water pressure in the water reservoir is greater than the pressure in the overburden, the water reservoir must be depressurized.

For this reason, a drainage pump is installed at the bottom to drain water from the aqueous layer and reduce the pressure, but this has the drawbacks of requiring a large amount of power consumption and increasing the cost of draining more water than necessary.

In order to avoid such drawbacks, it is possible to control the amount of drainage using a valve, but in that case, the water in the water reservoir layer would flow to the bottom of the root cut, making it impossible to perform dry work. There is.

The present invention was made in order to solve these conventional problems, and its technical object is to provide a pumping well that can automatically reduce the pressure of the aqueous layer and can adjust the pressure reduction. be.

[Means for Solving the Problem] As a means for solving this technical problem, the present invention provides a well body that is divided into an upper chamber and a lower chamber by providing a partition wall inside.
It is built into the ground so that its lower end is located in the water retention layer between the upper and lower impermeable layers, and a length-adjustable pipe is erected upward on the partition wall to connect the upper and lower chambers. The gist is that a drainage pump is provided in the lower part of the upper chamber.

[Function] When the water is drained by the drainage pump, the pressure in the upper chamber becomes negative, and the stagnant water in the lower chamber flows into the upper chamber through the pipe, thereby reducing the water pressure in the water stagnant layer. I can do it. Further, since the water that has flowed into the upper chamber is discharged, the amount of water discharged by the drainage pump is smaller than that of the conventional method, and power consumption can be reduced.

[Example] Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

In FIG. 1, reference numeral 1 denotes a well body made of metal and formed into a cylindrical shape, and a partition wall 2 is provided near the bottom of the well body to divide it into an upper chamber 1a and a lower chamber 1b. A length-adjustable pipe 3 is attached upward, and the upper chamber 1a and the lower chamber 1b are communicated with each other. The well body 1
is built into the ground at a construction site etc., and its lower end penetrates the upper impermeable layer 11 underground and forms the lower impermeable layer 12.
In other words, it is located in the water retaining layer 13. At this time, grout 14 is filled between the holes in the upper impermeable layer 11 and the well body 1 to shut off water. For example, as shown in FIG. 2(A), the pipe 3 is constructed by fitting an upper pipe 32 into a lower pipe 31 fixed to the partition wall 2, so that the entire length of the pipe 3 can be adjusted by moving the upper pipe 32. Alternatively, as shown in Figure (0), the lower pipe 33 and the upper pipe 34 are screwed together so that the total length of the pipe 3 can be adjusted by attaching and detaching upper pipes of different lengths. It can be configured.

A filter 5 is provided below inside the upper chamber 1a and the lower chamber 1b.
and 6, respectively, and the drain pipe 4 is connected via a connecting pipe 7 to a valve 8 installed on the ground surface. 9 is a drain pipe connected to the valve 8. still,
Reference numeral 15 is a water-stop wall for stopping the well, and reference numeral 1B is a cover material placed over the upper end of the well body 1.

The water pumping well according to the present invention is configured as described above, and the water accumulated in the upper chamber 1a of the well body 1 can be pumped up by driving the drainage pump 4, and can be drained to the outside through the drainage pipe 9. The area surrounded by the water stop wall 15 for stopping the mountain is excavated, and the pressure W caused by overburdening is the water pressure P of the water retaining layer 13.
If the water pressure P in the water retention layer 13 becomes smaller (W<P), it is necessary to reduce the water pressure P in the water retaining layer 13, but if the water pressure in the upper chamber 1a decreases due to drainage from the drainage pump 4 as described above, Since the retained water in the chamber 1b flows into the royal palace 1a through the pipe 3, the water pressure P in the retained water layer 13 can be automatically reduced. This reduced pressure ΔP is the difference between the water pressure P of the water retaining layer 13 and the pressure W of the overlay (ΔP = P−W)
If it is set so that the water pressure in the water retaining layer 13 is
P), and when the water pressure becomes higher than this water pressure, it flows into the upper chamber 1a as described above, and the amount that flows in is drained by the drainage pump 4. Therefore, the falling water level of the aqueous layer 3 becomes smaller, and the amount of water discharged by the drainage pump is drastically reduced compared to the conventional method, thereby making it possible to reduce power consumption.

The length of the pipe 3 can be adjusted to bring the pressure closer to the target, and the diameter of the pipe is preferably set according to the amount of water in the water retaining layer 13.

[Effects of the Invention] As explained above, according to the present invention, a well main body, which is divided into an upper chamber and a lower chamber by providing a partition wall inside, has its lower end connected to the water retention layer accumulated between the upper and lower impermeable layers. A pipe with an adjustable length is erected upward on the partition wall to communicate the upper chamber and the lower chamber, and a drainage pump is provided at the lower part of the upper chamber. Therefore, when the upper chamber becomes negative pressure due to drainage from the drainage pump, the retained water in the lower chamber flows into the upper chamber through the pipe, thereby automatically reducing and adjusting the water pressure in the water retaining layer. I can do it. Also,
Since the drain pump drains the water that has flowed into the upper chamber, the amount of water drained is smaller than before, which has the effect of reducing power consumption.

[Brief explanation of drawings]

Fig. 1 is a schematic sectional view for explaining the present invention in detail, and Fig. 2 (() and (0) are perspective views showing examples of pipes provided in the well body. 1... Well body 1a...Upper chamber 1b...
Lower chamber 2...Partition wall 3...Pipe
4...Drain pump 5.6...Filter 7
... Connection pipe 8 ... Valve 9 ... Drain pipe lO ... Ground 11 ... Upper impermeable layer 12 ... Lower impermeable layer 13 - Water retention layer 14 ...
・Grout 15...Water stop wall for mountain stop! B...Lid material C

Claims (1)

[Claims] The main body of the well is divided into an upper chamber and a lower chamber by a partition wall inside, and is built into the ground so that its lower end is located in the water retention layer between the upper and lower impermeable layers. An adjustable pipe is erected upward to communicate the upper chamber and the lower chamber,
A pumping well capable of adjusting pressure reduction, further comprising a drainage pump provided at a lower part of the upper chamber.