JPH04128413A - Well point rod - Google Patents

Abstract

PURPOSE:To obtain a well point rod, which can be switched easily, by arranging a diaphragm body, which can be adhered and peeled with the positive and the negative pressure, inside of a pipe member, in which circumferential direction water collecting holes are provided, and providing a valve for opening and closing an injection water collecting passage freely in the tip of the pipe member. CONSTITUTION:An well point rod consists of a pipe member 1, in which circumferential direction water collecting holes 11 are provided, a diaphragm body 3 and a ball valve 23, and an injection bit 2 is installed to the pipe member 1 to form the structure that an injection water collecting passage 13 and injection ports 21 are communicated with each other. The diaphragm body 3 is made of the elastic material such as rubber, and at the time of injecting the high pressure water, the diaphragm body 3 is adhered to the inner surface of the pipe member 1 to close the water collecting holes 11, and at the time of collecting the ground-water, the film member 3 is peeled from the inside of the pipe member 1 by the negative pressure to open the water collecting holes 11. Switching of the high pressure water injection ports provided in the tip of the pipe member 1 and the ground-water collecting port can be thereby performed easily.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a well point rod used in the well point construction method.

<Conventional technology> In the construction of structure foundations, underground structures, underground objects, etc., when excavation below the groundwater table is required, the Well Point I construction method has been used to lower the groundwater level. .

This well point construction method involves driving a collection pipe below the groundwater table and using a vacuum pump to forcibly suck up and drain groundwater.

<Problems to be Solved by the Present Invention> The well point construction method described above uses a two-point rod, which performs excavation by injecting high-pressure water from its tip, and after driving it below the groundwater table. , has the function of collecting groundwater.

However, with conventional well point rods, the opening/closing device between the injection port at the tip of the rod and the underground water collection hole is activated during suction, and when the rod is driven into the ground, high-pressure water flows out from the injection port and water collection hole. , there is a problem that the pressure from the injection port at the tip decreases.

Therefore, before driving the Wellpoint rod, high-pressure water is injected using a lot equipped with only an injection port at the tip of the rod, and it is driven into the ground to loosen the consolidation of the ground in advance, which results in poor workability. Become.

<Objective of the present invention> The present invention has been made to solve the above-mentioned problems, and has a structure in which the opening/closing device between the high-pressure water injection port at the tip of the rod and the underground water collection hole has a simple structure. The purpose is to provide a well point rod that can be used in a variety of ways.

<Means for Solving the Problems> That is, the present invention involves driving a hollow tube into the ground while jetting high-pressure water from its tip, and then removing the tube by a vacuum pump connected to the base end of the tube. In the well point rod used in the well point construction method, which generates negative pressure inside the body and collects and drains groundwater in the pipe body, a predetermined flow of high pressure water is provided in the middle of the high pressure water injection path at the tip of the pipe body. It consists of a valve that is opened by injection pressure, a water collection hole opened in the pipe body slightly proximal to the valve, and a membrane placed on the inner peripheral surface of the water collection hole opening of the pipe body. When high-pressure water is injected, the membrane adheres closely to the inner circumferential surface of the pipe body to block the water collection hole, and when collecting groundwater, the membrane body closes to the inner circumferential surface of the pipe body due to negative pressure.
This is a well point rod characterized in that it is configured to open a water collection hole.

In addition, there is a water collection hole opened in the frame at the tip of the pipe, a partition wall provided in the axial direction with a gap from the inner circumferential surface of the pipe inside the water collection hole opening of the pipe body, and a partition wall opened in this partition wall. A water collection window, a slide tube that is slidably housed in the bulkhead in the axial direction, a water collection window opened at the proximal end of the slide tube, and a water collection window provided at the tip end of the slide tube to collect high-pressure water. The valve is opened by a predetermined injection pressure, and when collecting groundwater, the slide tube moves toward the proximal end due to negative pressure, and the water collection window on the bulkhead and the water collection window on the slide tube overlap, and high-pressure water is released. This well point rod is characterized in that, when the water is injected, the slide cylinder moves toward the distal end due to the injection pressure, and the water collection window of the partition wall is closed by the circumferential surface of the slide cylinder.

<Description of the present invention> The present invention will be explained in detail below.

<A> Strainer Pipe The strainer pipe 1 is attached to the tip of a riser pipe, which is a hollow main pipe (not shown), and a water collection hole 11 is provided in its body.

In addition, a screen 12 is provided around the outer circumference of the Lehner pipe 1 to prevent sand, gravel, etc. that are sucked in together with groundwater from entering.

Note that one end of the Riser Vibe is equipped with equipment used in normal well point construction methods, such as a separator tank to separate groundwater and air, a vacuum pump, or a Hugal pump.

<Mouth> Injection bit The injection bit 2 is an excavation bit with an injection port 21 for high-pressure water.

The injection bit 2 is attached to the tip of the strainer pipe 1, and communicates the injection collection channel 13 of the strainer pipe 1 with the injection port 21.

<C> A water passage gate 22 that projects inward in an annular shape is provided between the valve injection collection channel 13 and the injection port 21.

A known ball valve 23 is provided on the injection port 21 side of the water passage gate 22 so that the water passage gate 22 can be opened and closed.

The ball valve 23 is configured to be opened by a predetermined injection pressure of high-pressure water.

For example, a method may be used in which the spring 24 is used to bias the water passage gage I/22 side, or a method in which the ball valve 23 is formed of wood or the like in a float type.

<2> Membrane body The membrane body 3 is a cylindrical body arranged so as to cover the inner peripheral surface of the strainer pipe.

This membrane body 3 is formed of rubber or the like, and when high-pressure water is injected, it comes into close contact with the inner peripheral surface of the strainer pipe 1 to block the water collection hole 11. When collecting groundwater, the strainer pipe 1 is closed by negative pressure. It is configured to be peeled off from the inner circumferential surface to open the water collection hole 11.

<Action of the present invention> Next, the operation of the present invention will be explained.

<B> Injection of high-pressure water As shown in FIG. Can be injected underground.

At this time, the membrane body 3 is strained by the pressure of high pressure water.
It is in close contact with the inner circumferential surface of the pipe 1 and closes the water collection hole 11.

Therefore, high-pressure water does not escape from the water collection hole 11 to the outside.

<Port> Collecting groundwater When collecting groundwater, as shown in FIG. 2, the vacuum pump at the upper end of the riser vibe is operated to generate negative pressure within the strainer vibe 1.

Then, the membrane 3 deflates due to the negative pressure and peels off from the inner peripheral surface of the strainer pipe 1, opening the water collection hole 1.

On the other hand, the ball valve 23 closes the water passage gate 22.

Therefore, groundwater is injected through the water collection hole 11 into the water collection channel 13.
Water is collected inside.

The collected groundwater rises through the riser pipe and is drained into the ground.

〈Other aspects〉 The description in “U” shows the case where the membrane body 3 is housed inside the strainer pipe 1, but by housing the slide tube described later, it is possible to connect the high-pressure water injection port and the underground water collection hole. It is possible to switch between opening and closing.

<A> The bulkhead strainer pipe 1 has water collection holes 11 as described above.
is provided, and an injection bit 2 is attached to the tip.

Inside the strainer pipe 1, a tubular partition wall 4 is provided in the axial direction with a gap from the inner peripheral surface of the strainer pipe 1.

The inside of this partition wall 4 is used as a high-pressure water injection path 41, and the outside is used as an underground water collection channel 42.

Further, a water collection window 43 is provided in the partition wall 4 to communicate the injection path 41 and the collection channel 42.

The base end side of the water collection channel 42 is closed by a closing member 44 .

<Opening> Slide tube The slide tube 5 is a cylindrical body that is open at both ends and is housed in the partition wall 4 so as to be slidable in the axial direction.

A water collection window 51 is provided at the base end of the slide tube 5, and a known ball valve 52, which is opened by a predetermined injection pressure of high-pressure water, is housed at the distal end.

The ball valve 52 is configured to open and close a water passage gate 53 which is annularly protruded inside the slide cylinder 5.

For example, there may be a method in which the spring 54 is used to urge the water passage gate 53 side, or a method in which the ball valve 52 is made of wood or the like in a floating manner.

Further, on both sides of the slide tube 5 in the axial direction, stoppers 45 and 46 are attached to the inner peripheral surface of the partition wall 4, and the upper stopper 4-
A spring 55 is interposed between the upper end of the slide cylinder 5 and the upper end of the slide cylinder 5.

The positional relationship between the water collection window 43 of the partition wall 4 and the water collection window 51 of the slide cylinder 5 is such that the water collection window 51 and the water collection window 43 slide when the cylinder 5 is pushed down.
The water collection window 43 and the water collection window 51 are opened so that they overlap when the slide tube 5 rises due to negative pressure when collecting groundwater.

<C> Effects By configuring as described above, the following effects can be obtained.

That is, when high-pressure water is injected, the injection pressure acts on the pressure receiving surface 56 of the water passage gate 53 to push down the slide tube 5, and at the same time push down the ball valve 52 to open the water passage gate 53.

Thereby, high-pressure water can be injected from the injection port 21 via the injection path 4-1.

At this time, since the slide tube 5 is pushed down, the water collection window 51 and the water collection window 43 are separated, and the water collection window 43 is pushed down by the slide tube 5.
It is occluded by the circumferential surface of the

Therefore, high-pressure water does not escape to the outside from the water collection hole 1 through the water collection window 43.

Further, when collecting groundwater, the ball valve 52 closes the water passage gate 53, so that the slide tube 5 rises due to negative pressure.

Then, the water collection window 43 and the water collection window 51 overlap, and the water collection hole 1
1 can be collected into the strainer pipe 1 through the water collection windows 43 and 51 via the collection channel 42.

<Effects of the Present Invention> Since the present invention has been described above, the following effects can be expected.

<A> When driving into the ground while spraying high-pressure water,
Water collection holes are blocked.

Therefore, high-pressure water is injected only from the injection port.

Therefore, the entire amount of high-pressure water is injected from the injection port, increasing the driving efficiency.

If a membrane body is used, when high-pressure water is injected, it adheres closely to the inner circumferential surface of the strainer pipe and blocks the water collection hole, and when collecting groundwater, the negative pressure causes the strainer →−− A hole is formed that is peeled off from the inner peripheral surface of the pipe to open the water collection hole.

In addition, when using a slide tube, when collecting underground water, the water collection window of the bulkhead and the water collection window of the slide tube overlap due to negative pressure, and when high-pressure water is injected, the circumference of the slide tube collects the water on the bulkhead. The water window will be blocked.

Therefore, the switching device between the high-pressure water injection port at the tip of the strainer pipe and the underground water collection hole can be configured with a simple structure, which is economical.

[Brief explanation of the drawing]

FIG. 1: An explanatory diagram showing the state of high-pressure water jetting from a rod having a membrane body. FIG. 2: An explanatory diagram showing the groundwater collection state of a rod having a membrane body. FIG. 3 is an explanatory diagram showing the state of high-pressure water jetting from a rod having a varnished slide cylinder. An explanatory diagram showing a groundwater collection state of a rod having a slide tube. Figure 4

Claims (2)

[Claims] (1) After driving a hollow tube into the ground while injecting high-pressure water from its tip, a vacuum pump connected to the base end of the tube generates negative pressure inside the tube, causing underground water to flow inside the tube. In the well point rod used in the well point construction method to collect and drain water, a valve is provided in the middle of the high pressure water injection path at the tip of the pipe body and is opened by a predetermined injection pressure of high pressure water; It consists of a water collection hole opened in the tube body slightly on the proximal end side, and a membrane body placed on the inner peripheral surface of the water collection hole opening of the tube body, and this membrane body protects the tube body when high-pressure water is injected. A well point is characterized by a structure in which it adheres closely to the inner circumferential surface of the pipe body to block the water collection hole, and when collecting groundwater, it peels off from the inner circumferential surface of the pipe body due to negative pressure and opens the water collection hole. rod. (2) After driving the hollow tube into the ground while injecting high-pressure water from its tip, a vacuum pump connected to the base end of the tube generates negative pressure inside the tube, causing underground water to flow inside the tube. In the well point rod used in the well point construction method to collect and drain water, a gap is formed from the inner circumferential surface of the tube between the water collection hole opened in the body at the tip of the tube and the inside of the opening of the water collection hole of the tube. A bulkhead installed in the axial direction at a distance, a water collection window opened in this bulkhead, a slide tube housed in the bulkhead so as to be slidable in the axial direction, and a water collection hole opened at the proximal end of the tube body of this slide tube. It consists of a window and a valve that is installed on the tip side of the tube body of the slide tube and is opened by a predetermined injection pressure of high-pressure water.When collecting groundwater, the slide tube moves toward the proximal end due to negative pressure, and the partition wall is The water collection window and the water collection window of the slide tube overlap, and when high-pressure water is injected, the slide tube moves toward the tip due to the injection pressure, and the water collection window of the bulkhead is closed by the circumferential surface of the slide tube. A well point rod characterized by: