JPS5826449B2 - Well point construction method and water and sand separation tank used for this method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a well point construction method and a tank for separating water and sand used therein.

In the conventional well point construction method, which is used during civil engineering work on soft ground with high groundwater levels, the nottsuchi tank is usually placed close to the vacuum pump to supply make-up water to the vacuum pump from the nottsuchi tank. As a result, the groundwater pumped into Notsuchi Tank is drained only by the droplets in Notsuchi Tank, so it is often difficult to drain water to a place with drainage equipment, so it is difficult to drain water from Notsuchi Tank. There is a defect in which water collected near the well point device causes problems in various operations.

The present invention was completed with the object of the above-mentioned defect-free well point construction method and a tank for separating water and sand used therein.Hereinafter, the illustrated well point device will be described in detail as an example.

1 is a well point buried underground, and each riser pipe 2 has the well point 1 attached to its lower end.
are arranged at required intervals in the header pipe 3, and a drainage pump 5 is connected to the header pipe 3 via a separator tank 4 that separates air mixed with water and sucked up.

The suction pipe 6 attached to the separator tank 4 is connected to the suction port IC of the vacuum pump 7, and a branch pipe 9 is connected to the discharge pipe 8 connected to the drainage pump 5 at a position close to the vacuum pump 7. The branch pipe 9 is connected to a water inlet 13 of a tank 10 for separating water and sand.

In addition, if this tank 10 for separating water and sand is explained in detail, a water passage 20a is left below in the box-shaped tank main body 10a, and a partition plate 20 is stretched, and a chamber is connected by the water passage 20a. 10 b t 10 c are partitioned, and one of the chambers 10 b has a bent path for sand separation with a weir plate 19 on the inner surface of the bottom, and an overflow port 15 and a water inlet 13 are provided vertically on the side wall. Also, the other chamber 10c
A return water inlet 18 and a make-up water supply inlet 17 are disposed vertically on the side wall of the trough, and the overflow trough 24 is provided with a plurality of water inlets 22 on its upper surface as a float valve 14 at the overflow inlet 15. One end is connected to the overflow trough 24, and a valve plate 23 with a float 25 is pivotally attached to the upper surface of the overflow trough 24.

Further, the make-up water receiving lower a and the exhaust lower b of the vacuum pump 7 are connected to the make-up water supply port 17 and the return water inlet 18 of the water and sand separation tank 1o through connection pipes 11 and 11'. The vacuum pump 7 is supplied with sand-free water, and the water mixed with the exhaust gas and discharged from the exhaust lower b is returned to the water and sand separation tank 10. The tip of the pipe 8 is connected to a drainage notch tank 12 installed close to drainage equipment, and the water is drained after measuring the amount of water pumped up.

Note that 21 in the figure is a lid that is placed on the separation tank 1o.

In order to drain underground water using the well point device configured as described above, the drain pump 5 and the vacuum pump 7 are operated in the same way as when using a conventional well point device. When groundwater is forcibly sucked up from the well point 1 where the groundwater is, the air mixed with the water and sucked up is separated by the separator tank 4 and sucked into the vacuum pump 7 through the suction pipe 6, and the water in the separator tank 4 is It is similar to the conventional well point construction method that the water is sent to the seven-tube tank 12 through the discharge pipe 8 by the drainage pump 5 and discharged, but in the present invention, a part of the water passing through the discharge pipe 8 is transferred to the branch pipe. 9 to water and sand separation tank 1 via water inlet 13
The sand mixed in this water is dammed by the weir plate 19 and the partition plate 20 in one chamber 1ob, and only the water containing no sand passes through the water passage 20a to the other chamber I.
Qc and is supplied as makeup water from the makeup water supply port 17 to the makeup water receiving lower a of the vacuum pump 7 through one connecting pipe 11 to cool and seal the vacuum pump 7. A part of the water is circulated and collected from the exhaust lower b through the other connecting pipe 11' to the return water inlet 18 and stored in the water and sand separation tank 10. When the water level rises and the water comes to act on the float valve 14, the float 25 moves against the valve plate 2.
3 and floats to open the water flow population 22, so the overflow water that has come onto the float valve 14 flows through each water flow population 22.
The water enters the overflow trough 24 from the overflow port 15 and flows into the reflux pipe 16.
is returned to the header pipe 3, sucked again, and sent to the separator tank 4.

That is, in the first invention, the make-up water used for the vacuum pump is not sent from the seven tanks as in the conventional method, but is sent to the tank 1o for separating water and sand through a branch pipe branched from the discharge pipe at a position near the vacuum pump. Since a portion of the wastewater sent is used, the Nottsu tank can be installed close to the drainage equipment, and there is no possibility of any wastewater leaking into the vicinity of the Wellpoint device, which will not cause any problems during work. .

Furthermore, the second invention has an extremely simple structure that removes sand from a part of the wastewater that is branched in from the discharge pipe, thereby preventing sand from entering the vacuum pump and preventing water from overflowing. This has the advantage of being able to supply only clean water that does not contain sand, significantly increasing the durability of the vacuum pump 7, and also being able to accurately prevent damage caused by water overflow.

As is clear from the description of the above-mentioned embodiments, the present invention is directed to a well-point construction method that can eliminate the defects of the conventional well-point construction method in which water discharged from a notch tank accumulates near the well-point device and hinders work. It is of great value to the industry as a tank for separating water and sand.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway perspective view showing an example of an apparatus for carrying out the construction method of the present invention, and FIG. 2 is a partially cutaway perspective view of a tank for separating water and sand. 1: Well point, 2: Riser pipe, 3: Header pipe, 4: Separator tank, 5: Drain pump, 7
: Vacuum pump, 8: Discharge pipe, 9: Branch pipe, 10: Water and sand separation tank, 10a: Tank main body, 10b one chamber, 10c: other chamber, 13: water inlet, 14: float valve , 15: Overflow port, 17: Make-up water supply port, 18: Return water inlet, 19: Weir plate, 20a: Water passage.

Claims (1)

[Claims] 1. A drain pump 5 is connected to a header pipe 3 provided with a riser pipe 2 with a well point 1 via a separator tank 4 that separates air mixed with water and sucked up. The suction pipe 6 attached to the tank 4 is connected to the suction lower c of the vacuum pump 7 to drain groundwater from the well point 1 buried underground to the drainage pump 5.
In the well point construction method, water is drained through a discharge pipe 8 connected to the vacuum pump 7, and a part of the waste water is separated into water and sand using a branch pipe 9 branched from the discharge pipe 8 at a position near the vacuum pump 7. The water is introduced into the tank 10 to remove sand, and is then replenished to the vacuum pump 7. The water discharged from the vacuum pump 7 along with the exhaust is returned to the water and sand separation tank 10, and further, the water and sand are separated. A well point construction method characterized in that overflowing water from the separation tank 10 is returned to the header pipe 3. 2 Chambers 10 b t 10 c are provided in the box-shaped tank main body 10 a and communicated through a water passage 20 a, and one chamber 10 b is provided with a weir plate 19 for sand separation at its inner bottom, and a water inlet is provided on the side wall. 13 and an overflow port 15 with a float valve 14, and a make-up water supply port 17 and a return water inlet 18 are provided in the side wall of the other chamber 10C. and sand separation tank.