JPH018582Y2 - - Google Patents

Description

[Detailed explanation of the invention] (a) Industrial application field This invention is particularly applicable to drain material driving devices for drain methods such as paper drain method and rope drain method, which are implemented to promote drainage and consolidation of soft ground. The present invention relates to a drain material driving device equipped with a function of detecting the remaining position of drain material.

(b) Prior Art Drain materials such as paper and rope in the drain construction method are engaged with the tip of a mandrel and driven into the ground, and are left in the ground when the mandrel is pulled out.

Leaving the drain material at a predetermined depth is essential in order to obtain the desired drain effect, but due to the influence of earth pressure, water pressure, etc., the drain material rises with the mandrel, a so-called co-existence phenomenon. A rising phenomenon may occur, and as a result, there is a problem in that the drainage and consolidation effects cannot be fully exerted.

In order to solve this problem, objects to be detected such as magnets are attached to the drain material at regular intervals, and a detection means such as a magnetic sensor that rises together with the mandrel is installed. By detecting and observing and recording the detection signal,
There is a method for confirming the remaining position of the drain material, and the applicant has already proposed this method.

(c) Problems to be solved by the invention The method for confirming the remaining position of the drain material described above has a remarkable effect in that the remaining position of the drain material can be confirmed by the detection signal, but there are still issues to be improved. There is a problem like this.

That is, in the above device, a drain material is placed along the outer surface of the mandrel, and the lower end of the drain material is bent to engage the lower end of the mandrel, and the detection means is attached to the lower end surface of the mandrel. It is worn so that it is exposed.

Generally, in order to reliably detect the object to be detected by a detection means, it is necessary that the distance between the two be closer than a certain level, and that there be no obstructions between the two. In the conventional case, the drain material is placed along the outer surface of the mandrel, so the position of the drain material may shift due to the influence of water pressure, earth pressure, etc., and soil may enter between the mandrel and the drain material. Sometimes. Therefore, there is a problem that the detection of the remaining position of the drain material becomes inaccurate.

Therefore, the object of this invention is to solve the above problems and provide a drain material driving device that can perform highly accurate detection.

(d) Means to solve the problem In order to solve the above problem, this invention
The mandrel is formed into a cylindrical shape, a hole is provided at the lower end of the mandrel for drawing out the lower end of the drain material to the outside, and the detection means is fixed to the inner peripheral surface of the lower end of the mandrel.

(e) Example Figures 1 and 2 are used for the paper drain method. This invention relates to a drain material driving device.

The mandrel 1 has a cylindrical shape with a tapered lower end and a hole 2 provided at its tip. The leg portion 4 of the tip shoe 3 is inserted into this hole 2, and the lower end of the drain member 5 and the leg portion 4 are connected. The tip shoe 3 is formed of a gently curved plate of metal, plastic, or the like.

A detector 6 is attached to the inner peripheral surface of the lower end of the mandrel 1. This detector 6 is housed and sealed in a case 8 together with a controller 7, and is attached via a pair of upper and lower attachment members 9, 9. An inspection window is formed in a portion of the mandrel 1 behind the case 8, and is closed by a palate 10.

Note that the cable 11 drawn out through the controller 7 is drawn out through the protection tube 12 to the outside.

The drain material 5 is inserted into the center of the mandrel 1, and objects 13 to be detected are mounted on the surface facing the detector 6 at regular intervals. Further, in order to position the drain material 5, the guide members 14, 14 are connected to the mandrel 1 so as to be in contact with the back surface of the drain material 5.
It spans in the diametrical direction.

The above device is supported by a well-known leader, and is penetrated into the ground by a well-known penetration device with the drain material 5 inserted, and then pulled out from the ground.

FIG. 3 shows this situation. When the mandrel 1 penetrates to a predetermined depth and then moves on to the drawing process, the tip of the drain material 5 engages with the ground, which usually causes it to rise. It is left in the ground without any damage. Therefore, when the detector 6 rises with the rise of the mandrel 1, pulse signals are generated one after another as it passes in front of the object to be detected 13. As a result, in the observation/recording device, when the extraction speed is constant, a detection signal a with constant pulse intervals is obtained, and when the extraction speed changes midway, a detection signal a with unequal pulse intervals is obtained.
a′ is obtained.

Therefore, by comparing and contrasting the reference signals b and b' corresponding to the length of the mandrel 1 to be pulled out, it is possible to determine whether the drain material 5 is co-raised based on whether the two signals a and b or a' and b' match or do not match. The presence or absence can be detected.

Note that the detected object 13 and the detector 6 can be based on a detection principle using magnetism, ultrasonic waves, or the like.

(f) Effect As mentioned above, this invention forms the mandrel into a cylindrical shape, inserts the drain material into the inside, and also provides the detection means on the inner peripheral surface of the mandrel. The position can be accurately maintained without being affected by water pressure or earth pressure.

Therefore, this invention has the effect of accurately detecting the remaining position of the drain material.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional front view of the embodiment, FIG. 2 is a cross-sectional plan view thereof, and FIG. 3 is an explanatory diagram of the remaining position detection method. 1...mandrel, 2...hole, 3...shew,
5...Drain material, 6...Detector, 13...Detected object.

Claims (1)

[Scope of utility model registration request] Objects to be detected are attached to the drain material at predetermined intervals, a detection means for the detected object is provided on the mandrel, the drain material is engaged with the lower end of the mandrel and penetrates into the ground, and the drain material is inserted into the ground. In a drain material driving device for a drain construction method in which only the mandrel is pulled out while remaining inside the mandrel, the mandrel is formed into a cylindrical shape, and a hole is provided at the lower end of the mandrel to draw out the lower end of the drain material to the outside, and the above-mentioned detection A drain material driving device for a drain construction method, characterized in that a means is fixed to the inner peripheral surface of the lower end of a mandrel.