JP6761709B2 - Face ground exploration method and equipment - Google Patents

Description

The present invention relates to a face ground exploration method and an apparatus used in a muddy water shield tunneling method, and more particularly, a ground above the face in front of the cutter head of a shield machine and a ground around the top of the cutter head (collapse of the ground). It relates to the face tunnel exploration method and equipment for exploring the presence or absence of the tunnel, the state of the surplus digging artificially performed by the copy cutter, etc.

In the muddy water shield method, excavation is carried out while stabilizing the face by supplying muddy water from the shield machine side to the face surface to be excavated by the shield machine and pressurizing it. And muddy water are separated, excavated earth and sand are collected, and muddy water is reused.
Shield machines used in this method is generally cutter driving unit having a driving motor for rotating the cutter head and the cutter head comprising a face plate and a plurality of cutter Bitto rotatably supported by the front end of the machine body, the cutter head It is configured to include a cutter chamber (hereinafter referred to as a chamber) separated by a partition wall at the rear, a mud feeding pipe and a mud draining pipe inserted into the chamber from the machine body side.
Thus rotates the cutter head by a cutter driving unit in the stable of tunnel face by a mud plus viscous material is supplied filled into the chamber working face surface such as bentonite and clay from Okudoro tube pressurized with mud water The excavation is carried out while trying to carry out the excavation, and the earth and sand excavated by the cutter head is taken into the muddy water to make it muddy water, and this muddy water is transported to the ground through the muddy drain pipe.
In such a muddy water shield method, if excessive excavated soil is taken in or an imbalance between the soil water pressure and the face muddy water pressure occurs, there is a concern that the ground will collapse or a cavity will be generated around the tunnel. There is a high risk of collapse due to fluctuations in face water pressure and changes in muddy water , especially in the ground where a sand layer with a small uniformity coefficient exists on the face in front of the cutter head and the ground around the cutter head . When a collapse occurs in the ground and the state is left behind, fine particles in the ground move due to the flow of groundwater, etc., causing loosening of the ground and expansion of cavities, resulting in subsidence and depression on the ground surface. May cause. Therefore, strict construction management is required for excavation of the face.
However, since the muddy water type shield machine is a closed type, the state of the face on the front surface of the cutter head cannot be directly visually observed from inside the shield machine. Therefore, in the working face management of conventional mud type shield method, properties of transmission and distribution mud, earth removal amount, as well as constantly monitors the properties of the soil discharge, the working face mud pressure, cutters torque value or variation of such thrust The current situation is to monitor and make decisions based on the experience of the operator. In addition, when exploring the condition of the face inside the shield machine, boring must be performed from inside the shield machine toward the face, and in this case, the excavation of the shield machine must be stopped for a long time. However, the construction period may be delayed.

On the other hand, conventionally, various methods and devices for exploring the ground in front of the shield machine have been proposed in Patent Documents 1-5 and the like.
(1) Patent Document 1
Patent Document 1 relates to a forward exploration method. In this exploration method, first, sound waves are sent forward from a transmitter provided at the front of a shield excavator that excavates the ground, and in front of the shield excavator. The reflected wave from the obstacle existing in the ground is received by the receiver installed at the front of the shield excavator, and then the cross-correlation between the transmitted data and the received data is obtained, and at the same time, The noise of the received wave is removed by extracting the received signal with a large correlation function, and the shield excavation is performed from the difference between the time of sending the transmitted wave and the time of receiving the received wave and the underground propagation speed of the sound wave. Calculate the distance from the aircraft to the obstacle.
In this way, the noise of the received wave is removed and the distance to the obstacle is obtained. In addition, the size of obstacles is also measured by changing the frequency of sound waves.
(2) Patent Document 2
Patent Document 2 relates to soil survey device excavation proceeds machine, this locator is provided with a wave transmitter and a wave receiver to shield faceplate excavator, it is protruded shaft during forward ground shield faceplate other party By installing a transmitter, the sound wave from the transmitter is reflected by the obstacle in front of the excavation and received by the receiver, and the sound wave is directly received from the other transmitter to the receiver. ..
In this way, the accurate sound wave velocity and the degree of sound pressure attenuation required in the soil to know the sound wave characteristics of the soil are measured, and the influence of the direct wave propagating in the excavator body is removed.
(3) Patent Document 3
Patent Document 3 relates to soil survey device excavation proceeds machine, the locator is provided on the shield surface plate of the excavator, a wave transmitter for transmitting a sound wave is provided on the shield surface plate, originating acoustic waves ground A receiver that receives sound waves that are reflected by obstacles such as artificial structures and buried objects inside and sound waves that are transmitted from the transmitter on the shield face plate, and a shield that is installed in the receiver. It consists of a vibrometer that measures unnecessary waveforms such as sound waves transmitted from the face plate, and apart from the transmitter, the sound waves are sent directly to the receiver at the tip of the shaft that protrudes into the ground in front of the shield face plate. A destination transmitter will be provided to determine the soil quality to be excavated by the excavator based on the sound wave velocity to the receiver and the degree of sound wave attenuation.
In this way, the sound wave velocity and the sound wave attenuation between the two devices are measured by directly receiving the sound waves from the destination transmitter installed in the ground in front of the excavator to the same receiver separately from the transmitter. Determine the soil quality to be dug and grasp the distance to the obstacle.
(4) Patent Document 4
Patent Document 4 relates to a ground penetrating radar, in which a ground penetrating radar is attached to the front cutter face plate of an excavator, and an obstacle in the ground in front is searched inside by a sound wave reflection method. A hydrophone, which is a ground penetrating sensor, will be installed.
In this way, the obstacles in the ground in front of the excavator are explored.
(5) Patent Document 5
Patent Document 5 relates to a method for detecting a ground collapse and a device thereof.
In this detection method, a measuring bullet with one end of the wire attached is fired from the shield excavator side toward the ground, a part of the measuring bullet is penetrated into the ground, and then the length of the wire extended from the shield excavator. Detects the collapse of the ground by measuring.
In addition, this detection device includes a launch tube that launches a measurement bullet provided with a wire mounting groove, a measurement bullet supply device that loads the measurement bullet into the launch tube, and a wire reel that supplies the wire to be mounted on the measurement bullet. A wire cutter, which is arranged in order from the opening between the opening of the tube and the measuring bullet supply device, and a stopper mounting device that attaches a stopper that fixes this wire to the measuring bullet to the wire, according to the rotation of the wire reel. A rotation detection device that outputs a rotation signal, and a flight distance that inputs a rotation signal from this rotation detection device, measures the length of the wire extending from the shield excavator body, and determines whether collapse has occurred based on that length. It is equipped with a detection device.
When the measuring bullet with the wire attached is fired at high speed in this way, the measuring bullet penetrates the accumulated matter such as muddy water and reaches the uncollapsed hard face surface, so that the groundwater or muddy water is accumulated or loosely. Even if sediment is accumulated, it detects whether there is a true collapse without causing an error.

Japanese Unexamined Patent Publication No. 3-85483 Japanese Patent No. 3081712 Japanese Patent No. 3136202 Jikkenhei 4-122795 Japanese Unexamined Patent Publication No. 6-58078

However, Patent Document 1-5 has the following problems.
(1) In the forward exploration method of Patent Document 1, in order to search for an obstacle existing in the ground in front of the shield excavator, sound waves are sent forward from a transmitter provided at the front of the shield excavator to perform an obstacle. The reflected wave from an object is received by a receiver installed at the front of the shield excavator, and the distance from the shield excavator to the obstacle is calculated, but the sound wave has a long wavelength and low directivity. Therefore, this exploration method cannot explore the boundary surface between the ground above the face in front of the cutter head or the ground around the top of the cutter head and muddy water.
(2) in soil survey device excavation proceeds machine of Patent Document 2, measure the degree of attenuation of the exact speed of sound and the sound pressure in soil need to know about acoustic characteristics of the soil, and propagate the shield machine main body In order to eliminate the influence of direct waves, a transmitter and a receiver are installed on the shield face plate of the excavator, and a shaft is projected into the ground in front of the shield face plate to install a forward transmitter. The sound wave from the wave device is reflected by the obstacle in front of the excavation and received by the receiver, and the sound wave is directly received from the destination transmitter to the receiver, but the sound wave has a long wavelength. Due to the low directivity, this exploration device cannot explore the boundary surface between the ground above the face in front of the cutter head or the ground around the top of the cutter head and muddy water.
Also, in this case, since the front is drilled from the cutter head and the shaft to which the destination transmitter is attached is projected for measurement, the excavator must be stopped during that time, and high-speed construction by the excavator is required. It is considered that the feasibility is low.
(3) in soil survey device excavation proceeds machine of Patent Document 3, it is determined the soil to now tunneling, to grasp the distance to the obstacle is provided in the shield faceplate excavator, transmitting that transmits sound waves A receiver and a receiver that receives the sound waves that are transmitted and reflected by obstacles such as artificial structures and buried objects in the ground and returned, and the sound waves that are transmitted from the transmitter on the shield face plate. , A vibration meter provided on the handset that measures unnecessary waveforms such as sound waves transmitted from the shield face plate to the receiver, and the tip of the shaft that protrudes into the ground in front of the shield face plate separately from the transmitter. It is equipped with a forward transmitter for transmitting sound waves directly to the receiver and determining the soil quality to be excavated by the excavator based on the sound wave velocity to the receiver and the degree of sound wave attenuation. However, since sound waves have a long wavelength and low directivity, this exploration device can be used to explore the boundary between the ground above the face in front of the cutter head or the ground around the top of the cutter head and muddy water. Can not.
(4) In the ground penetrating radar of Patent Document 4, in order to search for obstacles in the ground in front, a sound wave exploration device is attached to the front cutter face plate of the excavator, and a hydrophone is provided inside the ground penetrating radar. However, due to the long wavelength and low directivity of sound waves, this exploration device cannot explore the boundary surface between the ground above the face in front of the cutter head or the ground around the top of the cutter head and muddy water. .. In addition, the sound wave exploration device is installed on the cutter head toward the face, and is equipped with a means for injecting water in order to remove air bubbles and adhering earth and sand that may occur on the front surface of the sound wave exploration device. However, since the sound wave probe is attached to the cutter head and the front surface is almost the same surface as the cutter head face plate, if this front surface is washed with water, the water flow and water pressure will affect the face surface as well. In some cases, the mud film formed by the muddy water may be destroyed, making it impossible to hold the face, and it is considered that the muddy water shield is not suitable.
( 5 ) In the ground collapse detection method and device of Patent Document 5, in order to detect the ground collapse, a measuring bullet equipped with one end of a wire is fired from the shield excavator side toward the ground and measured on the ground. After a part of the bullet was penetrated, the length of the wire extending from the shield excavator was measured, but after the measurement, the wire was cut and this cut wire was left in the ground, so a small amount However, in some cases, this may get entangled with the cutter and cause the cutter to be unable to rotate or the chamber to be blocked.

The present invention solves such a conventional problem, and can be used in a simple and short-time exploration process directly above the face where there is a concern about the collapse of the ground or the formation of cavities around the tunnel. Without affecting the holding of the face and without affecting the holding of the face, the situation and the presence or absence of cavities can be grasped at an early stage, and countermeasures can be taken at an early stage to prevent the influence of the surroundings and delays in the process. The purpose is to provide a method and device for exploring the ground face to prevent it.

In order to achieve the above object, the ground face exploration method of the present invention
A cutter head composed of a face plate at the tip of a muddy water shield machine and a cutter is rotated, and muddy water is supplied and filled into a chamber separated by a bulkhead behind the cutter head by a mud pipe to fill the face surface in front of the cutter head. This is a face ground exploration method for grasping the state of the ground in front of the cutter head and around the top of the cutter head, which was excavated while pressurizing with muddy water.
While the shield machine is stopped, a search rod having an ultrasonic transmitter / receiver connected to the control device by a cable or radio at the tip is passed through a hole formed in the bulkhead from the inside of the main body of the shield machine into the chamber. While inserting it into the muddy water, the ultrasonic wave receiver and transmitter are directed toward the ground above the face in front of the cutter head or the ground around the top of the cutter head, and the interface between the ground and the muddy water is directed to the muddy water. It moves to a searchable point according to the specific gravity of, emits ultrasonic waves from the ultrasonic receiver / transmitter in the muddy water, and transmits / receives the reflected wave at the interface between the ground and the muddy water. By detecting with a device and measuring the distance from the ultrasonic transmitter / receiver to the ground, the state of the face and the ground can be grasped.
The gist is that.
In this case, a general-purpose machine including an ultrasonic measuring device for measuring the side wall of a continuous underground wall is used for the ultrasonic receiving transmitter and the control device.
In this case, the ultrasonic receiver / transmitter to be used can search the boundary surface between the simulated muddy water and the simulated earth and sand in a water tank containing the simulated muddy water and the simulated earth and sand having the same specific gravity as the muddy water supplied into the chamber in advance. The distance from the boundary surface is measured, and based on the distance, the exploration rod is inserted into the muddy water in the chamber through the hole formed in the bulkhead from the ultrasonic transmitter / receiver, and the ultrasonic wave is inserted into the muddy water. A point where the boundary surface between the ground and the muddy water can be explored according to the specific gravity of the muddy water toward the ground above the face in front of the cutter head or the ground around the top of the cutter head. Move to.
In this case, the ultrasonic receiver / transmitter to be used can search the boundary surface between the simulated muddy water and the simulated earth and sand in advance in a water tank containing the simulated muddy water and the simulated earth and sand having the same specific gravity as the muddy water supplied into the chamber. The distance from the boundary surface is measured, and the length required for the exploration rod is calculated based on the distance.
In this case, the ultrasonic waves transmitted and received from the ultrasonic receiver and transmitter are transmitted through the face plate of the cutter head through a slit formed for taking in earth and sand.

In order to achieve the above object, the ground face exploration device of the present invention
A cutter head composed of a face plate at the tip of a muddy water shield machine and a cutter is rotated, and muddy water is supplied and filled into a chamber separated by a bulkhead behind the cutter head by a mud pipe to fill the face surface in front of the cutter head. It is a face ground exploration device that grasps the state of the ground in front of the cutter head and around the top of the cutter head excavated while pressurizing with muddy water.
An ultrasonic receiver / transmitter that receives and transmits ultrasonic waves,
A control device that controls the ultrasonic transmitter / receiver and
The ultrasonic wave receiver / transmitter is attached to the tip, and is provided with an exploration rod having a predetermined length for moving the ultrasonic wave receiver / transmitter in muddy water.
The probe rod having the ultrasonic wave receiver / transmitter at the tip is passed through a hole formed in the bulkhead from the inside of the main body of the shield machine, and the muddy water in the chamber is passed through the ground above the face in front of the cutter head or the cutter head. The boundary surface between the ground and the muddy water is extended to the exploration point that can be explored according to the specific gravity of the muddy water toward the ground around the crown, and ultrasonic waves are transmitted from the ultrasonic receiver / transmitter at the exploration point. The ultrasonic wave receiver / transmitter detects the reflected wave at the interface between the ground and muddy water, and measures the distance from the ultrasonic receiver / transmitter to the ground.
The gist is that.

According to the face ground exploration method and device of the present invention, while the shield machine is stopped, an exploration rod having an ultrasonic receiver / transmitter connected to the control device by a cable or radio is attached to the tip from inside the main body of the shield machine. While inserting it into the muddy water in the chamber through the hole formed in the bulkhead, point the ultrasonic transmitter / receiver toward the ground above the face in front of the cutter head or the ground around the top of the cutter head with the ground and muddy water. Moves to a distance that can be explored according to the specific gravity of the muddy water, emits ultrasonic waves from the ultrasonic receiver / transmitter in the muddy water, and receives the reflected waves at the boundary surface between the ground and the muddy water. By detecting with a transmitter and measuring the distance from the ultrasonic receiver / transmitter to the ground, the condition of the face and the ground can be grasped, so that the ground collapses and cavities occur around the tunnel. By exploring directly above the face, which is a concern, in a simple and short time, the situation and the presence or absence of cavities can be detected early without affecting the excavation process and without affecting the retention of the face. This book says that in the event of a collapse of the ground or the occurrence of a cavity, it is possible to take early measures and prevent the influence of the surroundings and delays in the process. It has a special effect unique to the invention.

A view showing a face ground exploration method and an apparatus according to an embodiment of the present invention ((a) is a vertical cross-sectional view (b) near a chamber is a cross-sectional view (c) of a bulkhead (bulkhead), and (c) is a cross section of a face plate slit. View) The figure which shows the state which pushed out the exploration rod which attached the ultrasonic wave receiver and transmitter to the tip from the bulkhead toward the exploration point in the same method and device, and pulled back in the installed state. The figure which shows the confirmation experiment of the ultrasonic exploration of the muddy water (in the case of the muddy water specific gravity 1.220) by the ultrasonic transmitter / receiver in the same method and the apparatus ((1) is a figure (2) which shows the experimental method schematically, is FIG. Figure showing experimental results) The figure which shows the confirmation experiment including the directivity of the ultrasonic exploration of the muddy water (in the case of the muddy water specific gravity 1.220) by the ultrasonic transmitter / receiver in the same method and apparatus ((1) is a figure which shows typically the method of the experiment. (2) is a diagram showing the experimental results) The figure which shows the confirmation experiment of the slit transmission of the ultrasonic exploration of the muddy water (in the case of the muddy water specific gravity 1.220) by the ultrasonic transmitter / receiver in the same method and device ((1) is a figure which shows typically the method of the experiment ((1) 2) is a diagram showing the experimental results) The figure which shows the confirmation experiment of the ultrasonic exploration of the muddy water (in the case of the muddy water specific gravity 1.250) by the ultrasonic transmitter / receiver in the same method and the apparatus ((1) is a figure (2) which shows the experimental method schematically, is FIG. Figure showing experimental results) The figure which shows the confirmation experiment including the directivity of the ultrasonic exploration of the muddy water (in the case of the muddy water specific gravity 1.250) by the ultrasonic transmitter / receiver in the same method and apparatus ((1) is a figure which shows typically the method of the experiment. (2) is a diagram showing the experimental results) The figure which shows the confirmation experiment of the slit transmission of the ultrasonic exploration of the muddy water (in the case of the muddy water specific gravity 1.250) by the ultrasonic transmitter / receiver in the same method and apparatus ((1) is a figure which shows typically the method of the experiment ((1) 2) is a diagram showing the experimental results)

Next, a mode for carrying out the present invention will be described with reference to the drawings.
Fig. 1 shows the face mountain exploration method.
As shown in FIG. 1, in this face ground exploration method, a chamber formed by rotating a cutter head 1 composed of a face plate 10 and a cutter 11 at the tip of a muddy water type shield machine S and separated by a bulkhead 2 behind the cutter head 1. Muddy water M is supplied and filled into 3 by a mud pipe, and the face P1 in front of the cutter head 1 is excavated while pressurizing the face P in front of the cutter head 1 with muddy water. (Sometimes referred to as P1) and the state of the ground P2 around the top of the cutter head 1 (hereinafter, sometimes referred to as the ground P2). In this method, the number of laps is higher than that of sound waves. , Adopt ultrasonic exploration using highly directional ultrasonic waves.
In this method, in particular, while the shield machine S is stopped, a search rod B having an ultrasonic receiver U connected to the control device (not shown) of the ultrasonic measuring device by a cable or radio is attached to the tip of the shield machine. The ultrasonic receiver U is inserted into the muddy water M in the chamber 3 through the hole 20 formed in the bulkhead 2 from the inside of the main body of S, and the ultrasonic receiver U is inserted into the ground P1 above the face in front of the cutter head 1 or the top end of the cutter head 1. Move toward the surrounding ground P2 to the exploration point where the boundary surface between the ground P1 or P2 and the muddy water M can be explored according to the specific gravity of the muddy water M, and super-from the ultrasonic transmitter / receiver U in the muddy water M. A sound wave is transmitted, the reflected wave at the interface between the ground P1 or P2 and the muddy water M is detected by the ultrasonic receiver U, and the distance from the ultrasonic receiver U to the ground P1 or P2. By measuring the condition of the face and the ground, the condition of the face and the ground can be grasped.

Fig. 1 also shows the face ground exploration device.
As shown in FIG. 1, this face ground exploration device rotates a cutter head 1 composed of a face plate 10 and a cutter 11 at the tip of a muddy water type shield machine S, and a chamber separated by a bulkhead 2 behind the cutter head 1. Muddy water M is supplied and filled into 3 by a mud pipe, and the face P1 in front of the cutter head 1 is excavated while pressurizing the face P in front of the cutter head 1 with muddy water M. ) And the state of the ground around the top of the cutter head 1 (the ground P2). This device receives ultrasonic waves that have a higher frequency than sound waves and have strong directivity. An ultrasonic measuring device including a transmitter U and a control device (not shown) for controlling the ultrasonic wave receiving / transmitting device U is adopted.
In this device, in particular, an ultrasonic measuring device, that is, an ultrasonic receiving / transmitting device U that transmits / receives ultrasonic waves, a control device that controls the ultrasonic receiving / transmitting device U, and an ultrasonic receiving / transmitting device U are at the tip. The inside of the main body of the shield machine S is provided with a search rod B having a predetermined length for moving the ultrasonic receiver U in muddy water, and the search rod B having the ultrasonic receiver U at the tip. Through the hole 20 formed in the bulkhead 2, the muddy water M in the chamber 3 is directed toward the ground P1 above the face in front of the cutter head 1 or the ground P2 around the top of the cutter head, and the ground P1 or P2 and muddy water. The boundary surface with M is extended to an exploration point that can be explored according to the specific gravity of muddy water M, ultrasonic waves are transmitted from the ultrasonic receiver U at the exploration point, and at the boundary surface between the ground P1 or P2 and muddy water. The reflected wave of the above is detected by the ultrasonic receiver U, and the distance from the ultrasonic receiver U to the ground P1 or P2 is measured.

Hereinafter, this exploration method and device will be described in detail.
In this exploration method and device, a general-purpose machine such as an ultrasonic measuring device for measuring the side wall of a continuous underground wall is diverted to the ultrasonic measuring device. In this case, the ultrasonic measuring device is for measuring the side wall of the continuous underground wall, and is a control device that can be connected to a personal computer including a transmitting unit, a receiving unit, a control unit, a recording unit, and a cable or a cable to this control device. It is configured to include an ultrasonic transmitter / receiver U connected wirelessly.
Further, the exploration rod B is formed of a rigid metal rod material having a predetermined length. In this exploration method, as will be described later, the ultrasonic receiver used in a water tank containing simulated muddy water and simulated earth and sand having the same specific gravity as the muddy water M supplied into the chamber 3 in advance before the actual exploration of the face ground. Since the transmitter U measures the distance from the boundary surface where the boundary surface between the simulated muddy water and the simulated earth and sand can be explored, that is, the distance from the boundary surface to the exploration point where the boundary surface can be explored, the distance is set to the distance. Based on this, the length required for the exploration rod B is calculated. In this case, the total length of the exploration rod B is the length from the bulkhead 2 to the exploration point, which is left inside the main body of the shield machine S, and the length required for supporting and operating the exploration rod B is added. Further, in this case, the peripheral surface of the exploration rod B may be graduated from the tip so that the protrusion length of the exploration rod B from the hole 20 of the bulkhead 2 can be seen at a glance.
As shown in FIG. 2, the exploration rod B to which the ultrasonic wave transmitter / receiver U is attached to the tip is inserted into the hole 20 formed in the bulkhead 2 through a seal member such as a ball valve 21 to form a shield machine S. It is attached so that it can be pushed out from the inside of the main body through the chamber 3 toward a predetermined exploration point, and vice versa. Further, in this case, in order to improve the operability of the exploration rod B, a gantry for supporting the exploration rod B and a guide for moving and guiding the exploration rod B toward the exploration point are also installed. May be good.

Further, in this exploration method, in the actual face ground exploration, the ultrasonic receiver U is directed toward the ground P1 above the face in front of the cutter head 1 or the ground P2 around the top of the cutter head 1. In order to move the interface between P1 or P2 and the muddy water M to a searchable exploration point according to the specific gravity of the muddy water M, the same specific gravity as the muddy water M supplied into the chamber 3 in advance before the actual face ground exploration. In the water tank containing the simulated muddy water and the simulated earth and sand, the ultrasonic transmitter / transmitter U used measures the distance from the boundary surface where the boundary surface between the simulated muddy water and the simulated earth and sand can be explored.
This measurement method is illustrated in FIGS. 3 to 8.
The ultrasonic wave receiver / transmitter U used here originally directs ultrasonic waves toward the side wall of the vertical hole while moving up and down in the vertical hole in which muddy water (stabilizing liquid) is stored in the construction management of the underground continuous wall method. It radiates, receives the reflected wave, and measures the distance to the wall surface of the vertical hole. In this case, the specific gravity of muddy water is 1.04 to 1.10, whereas the muddy water shield The specific gravity of muddy water used in the construction method is as large as 1.1 to 1.25.
Therefore, it is necessary to grasp whether or not the boundary surface between the ground and the muddy water can be explored and the exploration distance by this ultrasonic receiver / transmitter U in the actual muddy water M used in the muddy water type shield method. A confirmation experiment of ultrasonic exploration by the ultrasonic transmitter / receiver U in simulated muddy water will be conducted using earth and sand. In this experiment, as shown in FIGS. 3 to 8, a predetermined amount of earth and sand E1 (simulated earth and sand E1) is placed diagonally from one end of the bottom to the vicinity of the center of the water tank A, and a predetermined amount of muddy water M1 (simulated muddy water M1) is placed. ), And the ultrasonic transmitter / receiver U is inserted into the simulated muddy water M1 via the exploration rod B, and the diagonal distance to the simulated earth and sand E1 (the interface between the simulated earth and sand E1 and the simulated muddy water M1) is determined. While changing, the distance was measured by ultrasonic waves.
FIG. 3 shows a case where the specific gravity of the simulated muddy water M1 is 1.220, the ultrasonic frequency of the ultrasonic transmitter / receiver U is f = 80 kHz, and the earth and sand angle is 60 °. The results are shown in the test result list. From this list, when the specific gravity is 1.220, the ultrasonic wave of 80 kHz captures the reflection from the earth and sand from 260 mm to 760 mm, but for the reflection from the earth and sand to 760 mm, the specific gravity at the time of the experiment depends on the passage of time. It is expected to be lower than 1.220, and in this case, the applicable distance of earth and sand is estimated to be about 700 mm.
FIG. 4 shows a case where the specific gravity of the simulated muddy water M1 is 1.220 and the ultrasonic frequency of the ultrasonic transmitter / receiver U is f = 80 kHz, and the earth and sand angles are variously changed. The results are shown in the test result list. From this list, when the specific gravity is 1.220, the ultrasonic wave of 80 kHz can detect the reflection of the earth and sand E1 up to the earth and sand angle of 70 ° to 90 °. In this case, the applicable limit of the earth and sand angle is 68 ° to. It is estimated to be 70 ° or more.
Further (see FIG. 1), in the muddy water type shield machine S, the cutter head 1 is generally a face plate type, and the earth and sand cut by the cutter 11 is passed through the slit (opening) 12 for taking in the earth and sand of the face plate 10 into the chamber 3. When the ultrasonic wave transmitter / receiver U is inserted into the chamber 3 by the exploration rod B, it is necessary to be able to explore the ultrasonic waves through the slit 12 by utilizing the directivity of the ultrasonic waves. Therefore, an experiment was conducted in which two iron plates were placed on the earth and sand E1 in the water tank A and the space between the two iron plates was regarded as a slit (simulated slit).
FIG. 5 shows a case where the specific gravity of the simulated muddy water M1 is 1.220 and the ultrasonic frequency of the ultrasonic transmitter / receiver U is f = 80 kHz. Two iron plates C are placed on the earth and sand E1 and two ultrasonic waves are applied. This is a case where the slit W between the iron plates C is passed through. The results are shown in the test result list. From this list, when the specific gravity is 1.220, the ultrasonic wave of 80 kHz is not affected by the slit W until the distance to the slit W is 440 mm. In this case, it is estimated that the distance to the slit W is 440 mm to 540 or less in the range not affected by the slit W. The directivity of the ultrasonic wave in this case is estimated to be within 19 ° to 23 °.
FIG. 6 shows a case where the specific gravity of the simulated muddy water M1 is 1.250, the ultrasonic frequency of the ultrasonic transmitter / receiver U is f = 80 kHz, and the earth and sand angle is 60 °. The results are shown in the test result list. From this list, when the specific gravity is 1.250, the ultrasonic wave of 80 kHz captures the reflection from the earth and sand E1 to 300 mm to 600 mm, and in this case, the applicable distance of the earth and sand is estimated to be 600 mm to 700 mm or less.
FIG. 7 shows a case where the specific gravity of the simulated muddy water M1 is 1.250 and the ultrasonic frequency of the ultrasonic transmitter / receiver U is f = 80 kHz, and the earth and sand angles are variously changed. The results are shown in the test result list. From this list, when the specific gravity is 1.250, ultrasonic waves of 80 kHz can detect the reflection of earth and sand E1 up to an earth and sand angle of 83 ° to 90 °, and in this case, the applicable limit of the earth and sand angle is 80 ° to 80 °. It is estimated to be 83 ° or higher.
FIG. 8 shows a case where the specific gravity of the simulated muddy water is 1.250 and the ultrasonic frequency of the ultrasonic transmitter / receiver U is f = 80 kHz. Two iron plates C are placed on the earth and sand E1 and ultrasonic waves are applied to the two iron plates. This is a case where the slit W between C is passed through. The results are shown in the test result list. From this list, when the specific gravity is 1.250, the ultrasonic wave of 80 kHz is not affected by the slit W until the distance to the slit W is 380 mm. In this case, it is estimated that the distance to the slit W is 380 mm to 490 mm or less in the range not affected by the slit W. The directivity of the ultrasonic wave in this case is estimated to be within 21 ° to 27 °.
From the above experiments, the ultrasonic wave transmitter / receiver U has a shorter ultrasonic wave exploration distance as the specific gravity of muddy water increases, and if the specific gravity of muddy water exceeds 1.25, it is impossible to search, but the specific gravity of muddy water. If is 1.25 or less, it was confirmed that the exploration distance can be explored within the range of 300 mm to 500 mm. Further, it was confirmed that the ultrasonic waves transmitted and received from the ultrasonic wave receiver / transmitter U can be searched through the simulated slit W between the two iron plates C due to its directivity, and the slit W has no effect.
In the water tank A containing the simulated muddy water M1 having the same specific gravity as the muddy water M supplied into the chamber 3 and the simulated earth and sand E1, the ultrasonic receiver U used is the boundary between the simulated muddy water M1 and the simulated earth and sand E1. By measuring the distance from the boundary surface where the surface can be explored, the feasibility and exploration of the boundary surface between the ground P1 or P2 and the muddy water M in the actual muddy water M used in the muddy water shield method You can grasp the distance.

Then, in the actual operation of this exploration method, the cutter head 1 is rotated to a predetermined position (the slit 12 of the face plate 10 is a cutter) while the shield machine S is stopped digging during segment assembly or day / night change. After stopping at the ground P1 on the upper part of the face in front of the head 1 or the ground P2 around the top of the cutter head 1, the ultrasonic transmitter / receiver U was attached to the tip as shown in FIG. The exploration rod B is inserted into the muddy water M in the chamber 3 from the inside of the main body of the shield machine S through the hole 20 formed in the bulkhead 2, and the ultrasonic transmitter / receiver U at the tip is inserted into the ground above the face in front of the cutter head 1. Mountain P1 or cutter head 1 To the exploration point where the boundary surface between the ground P1 or P2 and muddy water M can be explored according to the specific gravity of muddy water M toward the ground P2 around the top, in this case, the cutter head 1 The ultrasonic exploration is carried out by moving the face plate 10 to a position separated from the slit 12 for taking in earth and sand by a predetermined distance or into the slit 12. That is, ultrasonic waves are transmitted from the ultrasonic receiver U at the exploration point in the muddy water M, the face plate 10 is transmitted through the slit 12 of the face plate 10 of the cutter head 1, and the boundary between the ground P1 or P2 and the muddy water M. The state of the face and the ground is grasped by detecting the reflected wave on the surface with the ultrasonic receiver U and measuring the distance from the ultrasonic receiver U to the ground P1 or P2. This exploration time is about a few minutes. After this exploration, the exploration rod B is pulled back from the chamber 2 side into the shield machine S main body.

As described above, according to this exploration method and device, the exploration in which the ultrasonic wave receiver U connected to the control device of the ultrasonic wave measuring device by a cable or wirelessly is attached to the tip while the shield machine S is stopped. The rod B is inserted into the muddy water M in the chamber 3 from the inside of the main body of the shield machine S through the hole 20 formed in the bulkhead 2, and the ultrasonic receiver U at the tip is inserted into the ground above the face in front of the cutter head 1. Move the boundary surface between the ground P1 or P2 and the muddy water M toward the ground P1 or the ground P2 around the top of the cutter head to a distance that can be explored according to the specific gravity of the muddy water M, and receive and transmit ultrasonic waves in the muddy water. Ultrasonic waves are transmitted from the device U, the reflected wave at the interface between the ground P1 or P2 and muddy water is detected by the ultrasonic receiver U, and the ultrasonic receiver U detects the ground P1 or P2. By measuring the distance to the face, the condition of the face and the ground is grasped, so it is possible to directly and easily search above the face where there is a concern that the ground may collapse or a cavity may occur around the tunnel. It is possible to grasp the situation and the presence or absence of cavities at an early stage. Then, when the ground collapses or a cavity occurs, early measures can be taken, and the influence of the surroundings and the delay of the process can be prevented.
Further, in this case, since the mud film formed on the face ground, which is a feature of the muddy water shield method, is not destroyed by ultrasonic waves, it does not affect the holding of the face.
Further, in this case, since the exploration work is short, the excavation process by the muddy water shield method is not affected.
Further, according to this exploration method and apparatus, it is also possible to explore the state of over-digging artificially excavated by a copy cutter in the same manner.

It should be noted that the present invention uses an exploration rod with an ultrasonic transmitter / receiver attached to the tip to grasp the state of the ground above the face in front of the cutter head and around the top of the cutter head. Using an exploration rod with an ultrasonic transmitter / receiver attached to the tip in the same way, which position in the circumferential direction of the cutter head (for example, lower part, left and right side parts, between upper part and left and right side parts, lower part and left and right side parts) At any position in the ground around the cutter head (for example, around the bottom, around the left and right sides, between the top and the left and right sides, between the bottom and the left and right sides) ) But of course, the state can be grasped in the same way.

S Muddy water type shield machine M Muddy water P Face (face)
P1 Ground above the face in front of the cutter head P2 Ground around the top of the cutter head U Ultrasonic receiver B Exploration rod 1 Cutter head 10 Face plate 11 Cutter 12 Slit 2 Bulkhead (bulkhead)
20 holes 21 ball valve 3 chamber A water tank E1 earth and sand (simulated earth and sand)
M1 muddy water (simulated muddy water)
C iron plate W slit (simulated slit)

Claims (6)

A cutter head composed of a face plate at the tip of a muddy water shield machine and a cutter is rotated, and muddy water is supplied and filled into a chamber separated by a bulkhead behind the cutter head by a mud pipe to fill the face surface in front of the cutter head. This is a face ground exploration method for grasping the state of the ground in front of the cutter head and around the top of the cutter head, which was excavated while pressurizing with muddy water.
While the shield machine is stopped, a search rod having an ultrasonic transmitter / receiver connected to the control device by a cable or radio at the tip is passed through a hole formed in the bulkhead from the inside of the main body of the shield machine into the chamber. While inserting it into the muddy water, the ultrasonic wave receiver and transmitter are directed toward the ground above the face in front of the cutter head or the ground around the top of the cutter head, and the interface between the ground and the muddy water is directed to the muddy water. It moves to a searchable point according to the specific gravity of, emits ultrasonic waves from the ultrasonic receiver / transmitter in the muddy water, and transmits / receives the reflected wave at the interface between the ground and the muddy water. By detecting with a device and measuring the distance from the ultrasonic transmitter / receiver to the ground, the state of the face and the ground can be grasped.
This is a method for exploring the face mountain. The face ground exploration method according to claim 1, wherein a general-purpose machine including an ultrasonic measuring device for measuring the side wall of a continuous underground wall is used as an ultrasonic transmitting transmitter and a control device. In a water tank containing simulated muddy water and simulated earth and sand having the same specific gravity as the muddy water supplied into the chamber in advance, the boundary surface on which the ultrasonic receiver / transmitter to be used can explore the boundary surface between the simulated muddy water and the simulated earth and sand. The distance from the surface is measured, and based on the distance, the exploration rod is inserted into the muddy water in the chamber through the hole formed in the bulkhead from the ultrasonic receiver and transmitter, and the ultrasonic receiver and transmitter are inserted. Move the vessel toward the ground above the face in front of the cutter head or the ground around the top of the cutter head to a point where the interface between the ground and the muddy water can be explored according to the specific gravity of the muddy water. The face ground exploration method according to claim 1 or 2. In a water tank containing simulated muddy water and simulated earth and sand having the same specific gravity as the muddy water supplied into the chamber in advance, the boundary surface to which the ultrasonic receiver / transmitter to be used can explore the boundary surface between the simulated muddy water and the simulated earth and sand. The face ground exploration method according to any one of claims 1 to 3, wherein the distance from the surface is measured, and the length required for the exploration rod is calculated based on the distance. The face ground exploration method according to any one of claims 1 to 4, wherein the ultrasonic waves transmitted and received from the ultrasonic receiver and transmitter are transmitted through the face plate through a slit formed in the face plate of the cutter head for taking in earth and sand. A cutter head composed of a face plate at the tip of a muddy water shield machine and a cutter is rotated, and muddy water is supplied and filled into a chamber separated by a bulkhead behind the cutter head by a mud pipe to fill the face surface in front of the cutter head. It is a face ground exploration device that grasps the state of the ground in front of the cutter head and around the top of the cutter head excavated while pressurizing with muddy water.
An ultrasonic receiver / transmitter that receives and transmits ultrasonic waves,
A control device that controls the ultrasonic transmitter / receiver and
The ultrasonic wave receiver / transmitter is attached to the tip, and is provided with an exploration rod having a predetermined length for moving the ultrasonic wave receiver / transmitter in muddy water.
The probe rod having the ultrasonic wave receiver / transmitter at the tip is passed through a hole formed in the bulkhead from the inside of the main body of the shield machine, and the muddy water in the chamber is passed through the ground above the face in front of the cutter head or the cutter head. The boundary surface between the ground and the muddy water is extended to the exploration point that can be explored according to the specific gravity of the muddy water toward the ground around the crown, and ultrasonic waves are transmitted from the ultrasonic receiver / transmitter at the exploration point. The ultrasonic wave receiver / transmitter detects the reflected wave at the interface between the ground and muddy water, and measures the distance from the ultrasonic receiver / transmitter to the ground.
A faceted mountain exploration device that is characterized by this.