JPS6217221A - Confirming method for residual drain material and its device - Google Patents

Abstract

PURPOSE:To improve economical property, by detecting the mandrel-side relative displacement generated on lifting up drain material at the same time, with mechanical means set on the mandrel side and continuously, when the mandrel is taken out to leave the drain material in ground. CONSTITUTION:When a mandrel 10 is lifted up leaving drain material 2, the roller 18b of a rotary body 18 is rotated along the drain material 12 because the drain material 12 is energized on the projection side of the rotary body 18 by the pressure of a plate spring 16. After that, the rotation of the roller 18b is converted to electric signal by a magnetic sensor 24, and the input to a comparison operation apparatus 26 is provided. In this case, if the drain material 12 is not lifted up at the same time, the lifting speed of the mandrel 10 which is measured by an encoder 30 is equal to the lifting speed of the mandrel 10 which is found out by the magnetic sensor 24. In the meantime, if the drain material 12 is lifted up at the same time, the lifting speed of the mandrel 10 which is determined by the sensor 24 is different from the speed measured by the encoder 30. The existence and degree of the lifting-up are indicated and recorded in an indicator 32 and in a storage unit 34.

Description

[Detailed Description of the Invention] (Industrial Application Field) This invention relates to a drain construction method for improving the properties of soft ground by drainage and consolidation, and in particular, a method for checking the remaining condition of drain material left in the ground. and an apparatus for carrying out this method.

(Prior Art) As is well known, in the drain construction method, which is constructed as a method for improving soft ground, for example, P, V, and C drain materials are left in the ground.

To leave the drain material, insert the drain material into the mandrel, attach and hold the cone to the tip, drive the mandrel to the required depth in the ground, and then insert the cone into the WA.
This is done by pulling out the mandrel.

The most important thing in this type of construction method is to leave the drain material at the required depth, and if the drain material rises together with the mandrel due to the influence of the surrounding soil and water pressure, the drainage and consolidation effects will not be sufficient. I can't get it.

Therefore, in order to deal with such problems, for example, JP-A-60-85114@publication or JP-A-60-102
A method of confirming the remaining position as seen in Japanese Patent No. 413 is provided.

(Problems to be Solved by the Invention) In all of the remaining position confirmation methods disclosed in the above-mentioned publications, a detection means, such as a metal body, is attached to the drain material.

A large number of magnetic members such as magnets are attached along the length of the drain material at predetermined intervals, and the structure is such that the magnetic members are detected by a detection means provided on the mandrel.

However, with this method, it is not only difficult to attach the detection means at an accurate pitch to the drain material extending over hundreds or thousands of meters, but also the drain material itself becomes expensive, and the installation of the detection means is a labor-intensive task. Therefore, there was a drawback that the economic disadvantage was extremely large.

The present invention has been made in view of these problems, and its purpose is to provide a method and a confirmation device that can confirm the remaining state of drain material without making any changes to the drain material. It's about doing.

(Another Means to Solve the Problems) In order to achieve the above object, the present invention provides a mechanical detection means that contacts the drain material on the mandrel side, and uses the drain material as an object to be detected. After driving the mandrel holding the material to the required depth in the ground, when the mandrel is pulled out and the drain material is left in the ground, the relative displacement on the mandrel side caused by the uplift of the drain material. A feature of the method invention is that the mandrel is continuously detected by the mechanical means, and the mandrel is placed on at least one side of the held drain material, and the drain material is not provided with an object to be detected and is detected by the same upward movement. A feature of the invention is that the apparatus includes mechanical means for detecting relative displacement of the mandrel in contact with the drain material.

(Embodiments and Effects) Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIGS. 1 to 3 show the rA of the drain material according to the present invention.
1 shows an embodiment of an I confirmation method and a confirmation device.

The confirmation device shown in the figure inserts a drain material 12, for example, a flat band-shaped P, V, C drain material mainly made of synthetic resin, into a mandrel 10 made of a hollow cylindrical body, and leaves it at the tip. After attaching and holding the cone 14, and driving the mandrel 10 into the soft ground to the required depth,
It is used when the mandrel 10 is pulled out while the cone 14 is attached and detached and the drain material 12 is left in the ground.

The confirmation device is placed near the tip of the mandrel 10,
A biasing means consisting of a plate spring 16 formed by bending the upper and lower ends of a flat plate provided on one side of the drain material 12 inserted and held along the central axis of the mandrel 10; a rotating body 18 provided on the other side;
A protrusion 20 is provided on the outer periphery of the rotating body 18 and comes into contact with the surface of the drain material 12.

The leaf spring 16 is supported by a rod 21 fixed to the inner peripheral surface of the mandrel 10, and presses the drain material 12 toward the protrusion 20.

The rotating body 18 rotates around the spacer 1 around the rod 21.
A pair of rollers 18b, 18b provided at a predetermined distance by a roller 8a, a rotating shaft 18c inserted into the spacer 18a and passing through the roller 18b, and a rotating shaft 18c.
a pair of support arms 18d rotatably supporting both ends of the
18d, and a support arm 18d on the cover 22 which closes the opening 10a formed in the side surface of the mandrel 10.

It is attached by fixing the other end of 18d, and the projection 2
0 is a predetermined flwA in the circumferential direction of each roller iaa, iaa.
The protrusion 20 is made of a material having appropriate elasticity, such as rubber, and has a semicircular shape, and the area of the part that contacts the drain material 12 is extremely small. It has become.

Further, a magnetic sensor 24 is attached to the upper surface of the spacer 18a, and detects the number of rotations of the roller 18b by sensing the magnetic material fixed to the rotating wheel 18C.

The detection output from the magnetic sensor 24 is input to a comparison calculation device 26 provided on the ground.

The comparison calculation device 26 is rotatably driven via a wire V-28 fixed to the outside of the mandrel 10.
Also input is an output from an encoder 30 which produces pulses corresponding to the length of the zero implant and the rate of rise of the mandrel 10.

The output of the comparison calculation device 26 is inputted to a display device 32 and a recording device 34, respectively.

In addition, the code 36 shown in FIG. 1 is an 8-mount FF26.32.3
This is a power source for driving 4.

Next, a method of checking whether the drain material 12 remains by using the above-mentioned checking device will be explained.

When the cone 14 is attached and detached from the mandrel 10 and the mandrel 10 begins to rise while leaving the drain material 12,
Since the roller 18b of the rotating body 18 is biased toward the protrusion 20 by the pressing force of the plate spring 16,
It rotates along the drain material 12.

Here, what should be noted is that the protrusion 20 and the drain material 12
The state of contact with the surface of roller 1 reduces the contact area and
When 8b and 18b rotate, the drain material 12 should not be pulled up in the upward direction of the mandrel 10, and for this purpose, the pressing force of the leaf spring 16 should not be too strong.

The rotation of the rollers 18b, 18b is converted into an electrical signal by the magnetic sensor 24, and is input to the comparison calculation device 26.

At this time, if the drain material 12 does not rise together, the rising speed of the mandrel 10 measured by the encoder 30 and the rising speed of the mandrel 10 determined by the magnetic sensor 24 will be the same.

On the other hand, if the drain material 12 is rising together, the roller 18
The rising speed of the mandrel 10 detected by the magnetic sensor 24 through the rotation b becomes different from the speed measured by the encoder 30.

Therefore, by comparing and calculating the output of the magnetic sensor 24 and the output of the encoder 30, the presence or absence of co-upward movement of the drain material 12 and the amount of co-upward movement can be detected.

The presence or absence of co-uplink and the amount of co-uplink detected in this way are displayed on the display device 32. The information is displayed and recorded in the storage device 34, and is used to issue warnings to workers and for construction management.

Note that the sensor used to detect the rotation of the rotating body 18 is as follows:
In addition to the magnetic sensor 24 described above, other sensors such as a rotary encoder may be used, and a coil spring or the like may be used instead of the leaf spring 16.

Furthermore, when pulling up the mandrel 10, for example, if a driving source such as a sink is controlled to have a constant speed, it is possible to check whether or not the drain material 12 is being pulled up by the rotating body 18 alone without using the encoder 30 described above. can be detected.

Further, the rotating body 18 may be provided so as to be in contact with both side surfaces of the drain material 12 so as to bias each other, and in this case, the biasing means such as the leaf spring 16 may not be provided.

(Effects of the Invention) As described above in detail in the examples, according to the method for confirming the remaining drain material according to the present invention, the remaining drain material can be confirmed without performing any special processing on the drain material. , the economic efficiency of construction is incomparably improved compared to conventional methods.

[Brief explanation of the drawing]

FIG. 1 is an overall explanatory diagram of the method and apparatus of the present invention, and FIG.
FIG. 3 is an enlarged cross-sectional view of the main part of the figure, and FIG. 3 is a perspective view showing the relationship between the drain material and the rotating body 111Q. 10... Mandrel 12... Drain material 14... Cone 16...
- Leaf spring 18...Rotating body 20...
...Protrusion 22...Cover 24. :・
... Magnetic sensor 26 ... Comparison calculation device 2
8...Wire 30...Encoder
32...Display device 34...Recording device 36...Power source Patent applicant
Osamu Obayashi Co., Ltd.
Patent Attorney - Kensuke Shiro Figure J Figure 2 R Figure 3

Claims (3)

[Claims] (1) A mechanical detection means that comes into contact with the drain material is provided on the mandrel side, the drain material is used as the object to be detected, and the mandrel holding the drain material is driven into the ground to a required depth. When the drain material is pulled out and left in the ground, the relative displacement of the mandrel side caused by the rising of the drain material is continuously detected by the mechanical means. How to check if it is left behind. (2) It is arranged on at least one side of the drain material held by the mandrel, and the relative displacement of the mandrel due to the upward movement of the drain material is detected by contacting the drain material without providing a detected object on the drain material. 3. The drain material remaining confirmation device according to claim 2, further comprising a mechanical means for detecting the presence of drain material. (3) a biasing means in which the mechanical means is provided on one side of the drain material; a rotating body facing the biasing means and provided on the other side of the drain material; What is claimed is: 1. A device for confirming the remaining status of a drain material, comprising a protrusion that protrudes from the outer periphery and comes into contact with the surface of the drain material.