JPS6349006B2 - - Google Patents

Description

[Detailed description of the invention] (a) Industrial application field This invention is based on the paper drain method, which is implemented to promote drainage and consolidation of soft ground, in which the drain material in drain methods such as rope drain method is buried in the ground. The present invention relates to a method for confirming whether or not the device has been correctly placed on the computer, and an apparatus for implementing the method.

(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 the desired 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. There is a method of confirming the remaining position of the drain material by detecting the drain material and observing and recording the detection signal, which the applicants have already proposed.

(c) Problems to be solved by the invention Although 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, there are still problems to be improved. There is a problem like this.

In other words, the detection signal obtained by the above method is a pulse with an interval proportional to the length of the mandrel pulled out from the drain material, so if the drain material does not rise together (the time axis of the observation/recording device (assuming that the drawing speed of the mandrel is constant), this results in a signal with a constant reference interval.

However, if the pulses appear shifted, it is impossible to determine whether the cause is due to the co-rising phenomenon of the drain material or a change in the drawing speed of the mandrel.

Therefore, it is an object of the present invention to solve the above-mentioned problems and to provide an apparatus that can accurately detect the co-rising phenomenon of drain material, and that can be used directly to carry out the method. .

(d) Means for solving the problems In order to solve the above problems, this invention
In addition to the above detection signal, a reference signal is separately obtained for each predetermined pull-out length of the mandrel.The reference signal is obtained by a reference signal generator that works with the mandrel, and is sent to the observation and recording device. is input.

The above detection signal is related to the length of the mandrel pulled out relative to the drain material, and the reference signal is related to the length of the mandrel pulled out relative to the ground, so if the objects to be detected of the drain material are provided at predetermined intervals, A detection signal is generated every time the relative movement distance between the mandrel and the drain material passes a predetermined interval, and a reference signal is generated when the length of the mandrel pulled out from the ground is equal to the predetermined interval of the object to be detected bonded to the drain material. If it is set to occur when the drain material has fallen, by comparing and comparing both signals, it is possible to detect whether or not the drain material is rising relative to the ground, that is, whether or not the drain material is rising together.

(E) Example Figure 1 is a schematic diagram of the paper drain construction method.

The mandrel 1 in this case is a hollow tube, and although not shown, it is slidably supported by a well-known leader, and is penetrated into and pulled out of the ground by a well-known penetration device. It's starting to become easier.

A paper drain material 2 is inserted into the inside of the mandrel 1, and the lower end of the paper drain material 2 is connected to a shoe 3 inserted into the tip of the mandrel 1 at the lower end thereof.

Objects to be detected such as magnets are attached to the drain material 2 at regular intervals, and the mandrel 1
A detector 5 such as a magnetic sensor is installed on the inner wall near the bottom end of the
is fixed. The detection signal from the detector 5 is pulled out from the upper end of the mandrel 1 through the cable 6, and is input to the observation device 8 and the recording device 9 via the controller 7. , or displayed using a display device such as an oscilloscope. Further, the recording device 9 records the detection signal a using a pen graph or the like.

In addition to the above-mentioned observation and recording devices 8 and 9, a depth detection/reference signal generation device 10 is installed on the ground portion. This device 10 is rotated forward and backward by an endless band 11 connected to a part of the mandrel 1, detects the depth of the mandrel 1 based on the number of rotations and the direction of rotation, and observes the depth signal via a converter 12. device 8
and is input to the recording device 9.
In addition, the device 10 is provided with a reference signal generator in its rotating part, and generates a reference signal b corresponding to the length of the mandrel 1 when it is pulled out. It is input to the observation device 8 and the recording device 9 via the converter 12.

It goes without saying that the recording of the depth signal is necessary in order to preserve the record as a construction history of the drain construction together with the recording of the detection signal and the reference signal. Also,
By setting the lower end of the mandrel 1 at the required depth in the ground as the origin (starting point) and comparing and comparing the detection signal and the reference signal, it is possible to ensure that the drain material 2 is correctly left in the ground during the process of pulling out the mandrel 1. You can check if it is.

However, the comparison between the detection signal and the reference signal
If only comparison is required, depth recording is not necessarily necessary. In that case, the depth detection/signal generator 10 described above may be a mere detection signal generator, and this may be linked with the endless band 11.

FIG. 2 shows the relationship between the mandrel 1, the drain material 2, the detection signals a, a', and the reference signals b, b' when the drain material 2 is cast by the above system. When the drawing speed of the mandrel 1 is constant, the detection signal a and the reference signal b are the same as a',
b' is a case where the drawing speed becomes faster midway through (the position of the mandrel 1 in this case is shown by a constant chain line).

Hereinafter, the method for confirming the remaining position of drain material according to the present invention will be explained with reference to FIG. 2.

During penetration, the drain material 2 is driven into the ground together with the mandrel 1. At this time, the position of the drain material 2 is set so that the detector 5 faces the detected object 4 at the lowest end. Therefore, when the detector 5 is activated at an appropriate time, a detection signal a or a' appears.

When the mandrel 1 reaches a predetermined depth, the drawing process begins. At this time, the distal end shoe 3 of the drain material 2 engages with the ground, so that the drain material 2 is normally left in the ground without rising. Therefore, when the detector 5 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 4. As a result, in the observation/recording devices 8 and 9, when the extraction speed is constant, a detection signal a with a constant pulse interval is obtained, and when the extraction speed changes midway, a detection signal with an unequal pulse interval is obtained. A signal a′ is obtained.

On the other hand, the depth detection and reference signal generation device 10 generates a depth signal c in conjunction with the endless band 11, and also generates a reference signal b when the extraction speed is constant. Further, if the drawing speed changes midway, a reference signal b' is generated.

Furthermore, in order to more easily compare and contrast both signals a and b, it is desirable to display them with their generation start points coincident and their time axes parallel, as shown in FIG. Then, it is possible to confirm whether or not the drain material 2 is rising together based on whether the timings of generation of both signals a and b match or do not match. moreover,
Further, by providing a logical product (AND) circuit for both signals a and b, it is possible to display a matching signal or a mismatching signal on the observation device 8.

In addition, even if the drawing speed of the mandrel 1 changes midway, as long as the drain material 2 does not rise together, the pulse intervals of each signal a' and b' will change, but both change in the same way. In this case, the presence or absence of a co-increase can be confirmed in the same way as above by checking whether the two signals a' and b' match or do not match.

Note that FIGS. 3 and 4 show details of the inside of the mandrel 1, and guides are provided in the diametrical direction to maintain the distance between the detected object 4 of the drain material 2 and the detector 5 within a certain range. Members 13, 13 are spanned.

In the embodiment described above, the drain material 2 is inserted into the inside of the mandrel 1, but the drain material 2 is placed along the outer peripheral surface of the mandrel 1, and its lower end is engaged with the tip of the mandrel 1. In some cases, it may penetrate. The detector 5 in this case is mounted so as to be exposed on the outer peripheral surface of the lower end of the mandrel 1.

In addition to the above-mentioned magnetism, the object to be detected 4 and its detector 5 may be configured by using a piece of iron as the object to be detected 4 and using an electromagnetic coil through which a high frequency current is passed as the detector 5. Some devices detect changes in the level of the output signal due to changes in impedance when approaching.

Additionally, ultrasound can also be used. That is, a sound wave reflector is used as the object to be detected 4, a set of an ultrasonic projector and a receiver is used as the detector 5, and the output of the receiver is converted into an electrical signal and output. .

(F) Effects As described above, according to the present invention, in drain construction methods such as paper drain construction method and rope drain construction method, in addition to the detection signal related to the length of drain material pulled out from the mandrel, Since the reference signal related to the pulling length can also be observed and recorded, even if the mandrel pulling speed changes, both signals can be compared and recorded.
The comparison has the effect of reliably detecting whether or not the drain material is rising relative to the ground, that is, whether there is co-rising.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram of a system implementing the method of the present invention, Fig. 2 is an explanatory diagram of the method for confirming the remaining position, Fig. 3 is a longitudinal sectional front view of the mandrel, and Fig. 4 is a cross-sectional plan view of Fig. 3. be. DESCRIPTION OF SYMBOLS 1...Mandrel, 2...Drain material, 3...Shu, 4...Detected object, 5...Detector, 8...Observation device,
9... Recording device, 10... Depth detection/reference signal generator, 11... Endless band, a, a'... Detection signal, b, b'...
Reference signal.

Claims (1)

[Claims] 1. Objects to be detected are attached to drain material at predetermined intervals, a means for detecting the object to be detected is provided on a mandrel, the drain material is driven into the ground to a required depth by the mandrel, and then the mandrel is installed. In a method for confirming the remaining position of a drain material in a drain construction method, in which the drain material is pulled out and left in the ground, and a position detection signal of a detected object is obtained by the detection means, together with the detection signal, a length equivalent to the predetermined interval is used. A method for confirming the remaining position of drain material in a drain construction method, characterized in that a reference signal is obtained separately each time a mandrel is pulled out, and the two are compared. 2. An observation or recording device or an observation and recording device in which objects to be detected are attached to the drain material at predetermined intervals, a means for detecting the object to be detected is provided on the mandrel, and a detection signal from the detecting means is input to the above-ground part. In a device for confirming the remaining position of drain material in the drain construction method, which is equipped with a recording device, a reference signal generator is provided which works in conjunction with the mandrel to generate a signal corresponding to the length of the mandrel pulled out at the predetermined interval, and the reference signal is transmitted to the A device for confirming the remaining position of drain material in a drain construction method, characterized in that the information is input to an observation/recording device.