JPS62273480A - Soil inspection in shield construction - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] 3. Revised explanation of the invention Industrial applications The present invention relates to a soil exploration method included in the shield construction method.

When excavating a tunnel using a conventional shield tunneling machine, unless the soil quality of the ground is known in advance, there is a risk of collapse of the face, collapse of the ground, etc.

For this reason, there has conventionally been a method of digging a number of vertical shafts at appropriate intervals along the planned tunnel excavation route and analyzing soil samples to determine the soil conditions. In addition, a soil inspection hole is dug, and receivers for receiving vibrations are placed at appropriate intervals in the vertical direction within the shaft, and vibrations are applied from the ground surface to the ground to collect the vibration waveforms received by each of the receivers. There was also a method of observing and determining the soil quality.

Problems to be Solved by the Invention According to the above-mentioned conventional method, soil quality data can only be obtained at fixed intervals, and if the soil quality changes significantly during that time, there is a problem that it is difficult to predict. More shafts! There was also the problem of having to excavate.

Furthermore, when the shield promoting machine is a closed type such as one that pressurizes muddy water, there is a problem because excavation is carried out in a closed state.

Therefore, the purpose of the present invention is to incorporate the J3G soil exploration method into the shield construction method that can solve the above-mentioned problems. [
The soil exploration method is provided at the front to promote shielding.
Shake! A 7J generator generates vibrations toward the ground, and this vibrational elastic wave propagating through the ground is detected by a delivery device installed in the shield excavation fighting part, and the speed of this elastic wave is calculated. This is a method of determining the soil properties of the ground based on this result.

Function: In the above-mentioned soil exploration method of the present invention, vibration is generated from the front part of the shield body, and the vibration VJ elastic wave passing through and covering the ground is detected, and the velocity of the vibration is expressed to determine the soil properties of the ground. As a result, the soil properties of the ground can be continuously investigated, which can prevent unexpected accidents, as well as eliminate the need to excavate vertical shafts like in the past. Even if there is, there will be no anxiety.

EXAMPLE Hereinafter, an example of the present invention will be described based on FIGS. 1 and 2.

Reference numeral 1 denotes a shield main body of the shield excavation n2, and a cutter head 4 is rotatably supported at the front part of the shield via a swing bearing 3. Further, this cutter head 4 is connected to a rotary piece e via a ring gear 5 attached to its rear cylindrical portion 4a.
Rotated by device 6. Then, the cutter head 4
is equipped with a soil exploration device 11 used in the soil exploration method according to the present invention. That is, a vibration generator 12 is provided at a predetermined position on the outer periphery of the cutter head 4, and the vibration generator 12 generates a vibrating elastic wave by striking the face and imparting motion to the ground.
A protective tube 13 is inserted through the center of the cutter head 4, and a wave receiver 14 for detecting the above-mentioned elastic waves is provided inside the protective tube 13 so as to be able to move in and out from its tip. 1
5 connects the Fi dynamic generator 12J3 and receiver 14 to i! I
The control panel is connected to each other by a first electric wire 16 and a second electric wire 17. Then, an amplifier 18 is installed in the middle of this second electric wire 17, and
Connected to this amplifier 18 is a lightning rdlA schirograph 19 and an Illustrator 920. In addition, 21 is a protection bit for protecting the receiver 14 provided in the front center of the cutter head 4, 22 is a slip ring provided in the middle of the first and second electric wires 16 and 17 and at the rear of the protection tube 13. This is to cope with the rotation of the cutter head 4. Also,
Reference numeral 23 denotes a receiving and receiving rod for moving the wave receiver 14 in and out from the tip of the protection tube 13, and is connected to the rear end of the wave receiver 14.

Next, the soil exploration method will be explained.

First, the control panel 15 sends low tempo to the vibration vJ generator 12 via the first lightning 1i116 to strike the face and generate vibration elastic waves in the ground. When covered, this vibrating elastic wave passes through the ground and enters the delivery device 14. The vibrational elastic wave that entered the receiver 14 is converted into electricity (ji) and is sent to the amplifier 1.
8 and sent to an electromagnetic oscilloscope 19 for recording. At the same time, an electric signal is also sent to the performance device 20, where the rotational direction and rotational speed of the cutter head 4 are taken into consideration, and the transverse wave 3 of the elastic wave is generated! ! The degree is calculated. Incidentally, the transverse wave velocity of elastic waves is affected by the size, shape, and compaction state of soil particles in the ground. Therefore, if you investigate the correspondence between shear wave velocity and soil quality, you can determine the soil properties by simply looking at the shear wave velocity, that is, the compaction state of the ground (standard negative), the soil grain size (clay, sand, etc.). PLI), alluvial layer, and Hong V1 layer can be distinguished. For example, the shear wave velocity is 2
50771/sac, it can be seen that Nl is 20 or more and the unconfined compressive strength of the ground is ijKg/ci'F1 degree or more. Therefore, if the transverse wave velocity of the elastic wave of the rock face is known, the soil condition (composition) of the rock can be determined by Xt.

J3, the X-Y axis of the electromagnetic oscilloscope 19 corresponds to the X-Y axis at 43 in FIG. Further, the vibration VJ light generator 12 may be a mechanical one or one using gunpowder, and the method thereof is not limited.

Incidentally, in the above embodiment, the vibration generator 12 is provided in the cutter head 4, but as shown in FIG. 3, it may be made to project into the ground from within the shield body 1 by means of a cylinder device 31. Note that the wave receiver 14 may also be projected into the ground by a cylinder device, and the position of the wave receiver 14 is not limited to the center of the cutter head 4, but the vibration vJ generator 12 It is better to separate the wave receiver 14 and the wave receiver 14 as much as possible so that the soil properties can be seen throughout the surrounding area of the mansion.

Effects of the Invention According to the soil exploration method of the present invention described above, vibration is generated from the shield wooden body part #, and the vibration elastic waves passing through the ground are detected, and the speed of the waves is manipulated to determine the soil properties of the ground. In order to make a judgment, the soil properties of the ground can be continuously investigated, which can prevent unexpected accidents, as well as eliminate the need to excavate a vertical shaft like in the past. Even if it is a ceremony, there is no need to worry. Particularly in the case of large-diameter shields, the excavation area is large and the geological strata change rapidly, so knowing the ground conditions before excavation makes construction management easier.

[Brief explanation of the drawing]

FIG. 1 is an overall vertical cross-sectional view of one embodiment of the present invention, FIG. 2 is a front view of the same, and FIG. 3 (J is a cutaway side view of another embodiment of the present invention. ...Soil exploration equipment, 12
...Vibration IP1 generator, 13...Protection tube, 14...
Receiver, 15... Control WJ board, 19... Electromagnetic oscillograph, 20... Computing unit representative Yoshi Morimoto
Hirodai 7 Fig. 12-・MI stimulant count 2ρ −−1＠＄1,

Claims (1)

[Claims] 1. A vibration generator installed at the front of the shield excavator generates vibrations toward the ground, and this vibrational elastic wave propagating within the earth is transmitted by a receiver installed at the front of the shield excavator. A soil exploration method in the shield construction method that is characterized by detecting and calculating the speed of these elastic waves, and determining the soil properties of the ground based on the results.