JP6396824B2 - Shield tunnel forward exploration device and method - Google Patents

Description

  The present invention relates to a shield tunnel forward exploration apparatus and method for conducting geological exploration in front of a shield machine by receiving elastic waves from an oscillation point in a shield machine for tunnel excavation.

  Patent Document 1 discloses at least a front gripper and a rear gripper for fixing and holding the front and rear trunks of the TBM on the inner wall surface of the tunnel for forward exploration mainly by a TBM (tunnel boring machine) for excavating a tunnel in the rock. On the other hand, it is disclosed that an oscillating part is arranged and a vibration receiving part is arranged on the inner wall of the tunnel behind the TBM.

  Patent Document 2 discloses disposing an oscillation part on the cutter face of the shield machine and a vibration receiving part on the cutter face or skin plate for forward exploration with a shield machine that mainly excavates a tunnel in soft ground. Has been.

JP 09-053390 A JP 2009-185511 A

In soft ground where a shield machine is used for tunnel excavation, the attenuation of the elastic wave from the oscillating unit is large, so the position setting of the receiving unit is important.
In Patent Document 1, a vibration receiving portion is arranged on the inner wall of the tunnel behind the TBM. When this is applied to a shield tunnel, vibration is received on the segment side. However, since the segment is a permanent structure and is not suitable for drilling, it is difficult to arrange the vibration receiving portion at a position where vibration is easily received.

  Moreover, in patent document 2, the vibration receiving part is arrange | positioned to the cutter face or skin plate of a shield machine, and it protrudes toward the natural ground from the cutter face or skin plate. However, the arrangement on the cutter face necessitates a significant design change of the cutter face. In this respect, the arrangement on the skin plate is relatively easy. However, the diameter of the skin plate is smaller than the diameter of the cutter face, and there is a gap between the skin plate and the natural ground. For this reason, depending on the arrangement of the vibration receiving portion, vibration may be difficult due to the gap.

  In view of such a conventional problem, the present invention includes a shield machine for tunnel excavation provided with a vibration receiving facility for receiving elastic waves from an oscillation point, and performs forward exploration of a shield tunnel that performs geological exploration in front of the shield machine. An object of the present invention is to improve the vibration receiving performance of the apparatus.

  In order to solve the above-described problems, a vibration receiving facility in a forward exploration device for a shield tunnel according to the present invention includes an opening provided in a skin plate of a shield machine, and an inner side of the skin plate connected to the opening. And a geophone that is inserted into the guide portion and arranged so as to be able to protrude into and out of the skin plate through the opening. Here, at the time of vibration receiving, at least a part of the geophone becomes a grounding portion that penetrates or is pressed against a natural ground outside the skin plate.

  Further, the forward exploration method of the shield tunnel according to the present invention is a shield machine for tunnel excavation, receiving an elastic wave from the oscillation point to perform geological exploration in front of the shield machine. Through the opening provided in the skin plate of the machine, the skin plate is protruded to the outside, and at least a part of the geophone is passed through the gap on the back of the skin plate to penetrate or press into the natural ground.

  According to the present invention, the geophone is protruded from the skin plate of the shield machine, and at least a part of the geophone is penetrated or pressed into the ground, thereby improving the vibration receiving performance and more accurately performing the forward exploration of the shield tunnel. Can be.

Schematic sectional view of a shield tunnel showing one embodiment of the present invention Front longitudinal sectional view of the receiving equipment when retracted Front longitudinal sectional view of receiving equipment Side view of receiving equipment Illustration of geological analysis method Front longitudinal sectional view of vibration receiving equipment when using a drill Explanatory drawing when installing vibration generator (oscillation point) on the ground Schematic cross section of shield tunnel when receiving vibration on the segment side

Hereinafter, embodiments of the present invention will be described in detail.
FIG. 1 is a schematic cross-sectional view of a shield tunnel showing an embodiment of the present invention.
The shield machine 1 for shield tunnel excavation is disposed on the skin plate 2 constituting the cylindrical main body, the cutter head 3 disposed on the front end side (face side) of the skin plate 2, and the rear of the cutter head 3. And a partition wall (bulkhead) 4.

The cutter head 3 has a disk shape slightly larger in diameter than the skin plate 2 and has a large number of cutter bits 3a on the front surface. The cutter head 3 is connected to the swivel ring 6 via a support arm 5. The swivel ring 6 is supported by the partition wall 4 so as to be pivotable while penetrating the partition wall 4. Then, behind the partition wall 4, a plurality of pinion gears 9 attached to the output shaft of a motor 8 arranged in the circumferential direction are meshed with a ring gear 7 attached integrally to the swivel ring 6. Therefore, the cutter head 3 turns using the motor 8 as a drive source to excavate natural ground.
The partition wall 4 is also provided with a rotary joint 10 for connecting the device on the cutter head 3 side and the device behind the partition wall 4 with hydraulic pressure or electric wires.

  A chamber 11 is defined between the cutter head 3 and the partition wall 4. Due to excavation of the natural ground by the cutter head 3, excavated earth and sand accumulate in the chamber 11, and earth pressure is generated. The earth removal mechanism 12 discharges the excavated earth and sand in the chamber 11 to the rear of the partition wall 4, and simultaneously controls the earth pressure in the chamber 11 to prevent the face from collapsing.

The shield machine 1 further advances along with the excavation of the segment assembly mechanism (electa 13) for assembling the segment SG and the main body of the shield machine 1 along the tunnel wall surface (wall surface of natural ground) 101 excavated by the cutter head 3. And a propulsion mechanism (shield jack 14).
The segment assembling mechanism mainly includes an erector 13 that grips and assembles the segment SG while moving in the tunnel radial direction and the front-rear direction at the rear portion in the skin plate 2.
The propulsion mechanism is mainly composed of a plurality of shield jacks 14 arranged at almost equal intervals along the inner surface of the skin plate 2, and generates thrust by pushing the end face of the constructed segment SG.

Here, the diameter of the skin plate 2 is smaller than the diameter of the cutter head 3, and there is a gap 102 between the tunnel wall surface (wall surface of natural ground) 101 excavated by the cutter head 3 and the outer peripheral surface of the skin plate 2. There is.
Further, a backfilling injection material (not shown) is provided between a tunnel wall surface (wall surface of natural ground) 101 excavated by the cutter head 3 and a cylindrical covering body 103 constructed by assembling the segments SG. Is filled.

  In the tunnel construction using the shield machine 1 as described above, the nature of the natural ground has a great influence on the tunnel excavation. For example, when it hits a gravel layer, it is difficult to excavate as it is. Therefore, it is important for safe and rational construction work to accurately predict and evaluate geological information ahead of the face so that such obstacles can be avoided in advance.

A forward exploration device that performs geological exploration in front of the shield machine 1 will be described.
The shield machine 1 has a natural ground with an oscillation point at the outside of the skin plate 2 (for example, the X1 point) or the outside of the cutter head 3 (for example, the X2 or X3 point) for forward exploration while the excavation is stopped. One to a plurality of vibration generators (oscillation equipment) 21 or 22 are installed so as to give vibration to the motor.

  For example, the vibration generator 21 on the skin plate 2 side is pierced or pressed into a natural mountain by piercing a window portion previously formed in the skin plate 2 in a radial direction by hitting a hammer or the like inside the skin plate 2. The ground is vibrated through the member (rod), and an elastic wave having an oscillation point X1 in the figure is generated.

For example, the vibration generator 22 on the cutter head 3 side is inserted through a member that is pierced or pressed into the ground by penetrating the partition wall 4 and the cutter head 3 in the horizontal direction by hitting a hammer or the like behind the partition wall 4. Then, vibration is applied to the natural ground, and an elastic wave having an oscillation point X2 in the figure is generated.
Furthermore, a boring hole of about 1 to 10 m in the horizontal direction is formed in the natural ground in front of the cutter head 3, and a member penetrating the partition wall 4 and the cutter head 3 in the horizontal direction is pierced to the innermost part of the boring hole, You may make it make the innermost part (X3 point in a figure) of this boring hole be an oscillation point.

  As a method for oscillating in the oscillating equipment 21 or 22, a method using a blasting, breaker, electromagnetic control type oscillating device or the like may be used in addition to hitting with a hammer or the like.

The shield machine 1 is also provided with one to a plurality of vibration receiving facilities 30 on the skin plate 2 in order to receive elastic waves from the oscillation point by the vibration generating facilities 21 or 22.
The details of the vibration receiving equipment 30 are shown in FIGS. 2 is a front longitudinal sectional view when the vibration receiving equipment is stored, FIG. 3 is a front longitudinal sectional view when the vibration receiving equipment is received, and FIG. 4 is a side view of the vibration receiving equipment.

  The vibration receiving equipment 30 includes an opening 31 provided in the skin plate 2 of the shield machine 1, a guide tube 32 that is connected to the opening 31 and extends inside the skin plate 2, and a guide And a geophone 33 which is inserted into the portion 32 and arranged so as to be able to appear and retract outside the skin plate 2 through the opening 31.

At the time of vibration receiving, at least a part of the vibration receiving device 33 serves as a grounding portion that penetrates or is pressed against a natural ground outside the skin plate 2.
In the illustrated embodiment, the geophone 33 includes a grounding portion 33a at the tip, a sensor portion 33b following this, and a pipe portion 33c extending rearward of the sensor portion 33b.
In the illustrated embodiment, in particular, the geophone 33 is formed in a bowl shape and is configured to penetrate into the natural ground, and the grounding portion 33a at the tip forms a piercing portion.
The sensor part 33b is cylindrical and has an acceleration sensor housed therein.
The grounding portion (piercing portion) 33a is provided in the form of a two-step conical diameter reduction in front of the sensor portion 33b so that it can be easily pierced into the natural ground. Further, the grounding portion (piercing portion) 33a has a function as a vibration input portion that receives an elastic wave and transmits the elastic wave to the sensor portion 33b.
The pipe portion 33c functions as a support portion and a sliding portion, and a signal line from the sensor portion 33b is passed through the pipe portion 33c to protect the signal line.

  The vibration receiving facility 30 further includes an opening / closing valve 34, a seal portion 35, and a drain valve 36.

  The opening / closing valve 34 is attached to the opening 31 of the skin plate 2, opens and closes the opening 31, and allows the vibration receiving device 33 (the grounding portion 33a and the sensor portion 33b) to pass when opened. Therefore, the guide tube 32 is attached to the opening 31 of the skin plate 2 via the open / close valve 34.

Specifically, the on-off valve 34 is configured by a ball valve.
The ball valve is formed by forming a circular through hole 34c in a direction orthogonal to the rotation shaft 34a in a sphere 34b that can be rotated by the rotation shaft 34a. Therefore, as shown in FIG. 2, the passage of the guide tube 32 can be closed by the spherical surface of the sphere 34b by making the through hole 34c horizontal and orthogonal to the guide tube 32. Further, as shown in FIG. 3, the passage of the guide tube 32 can be opened through the through hole 34c by making the through hole 34c vertical and in the same direction as the guide tube 32.
A lever 34d for rotation operation is attached to the outer end of the rotation shaft 34a.

The seal portion 35 is provided on the guide tube 32 and seals the vibration receiving device 33 (pipe portion 33c) in a slidable manner.
Specifically, the seal portion 35 includes a first seal cap 35a that is fitted and attached to the lower end of the guide tube 32, and a second seal cap 35b that is screwed and attached to the rear end portion of the first seal cap 35a. The pipe part 33c of the geophone 33 is slidably inserted into the center holes of the first and second seal caps 35a and 35b. Then, two O-rings 35c are mounted on the inner peripheral surface of the first seal cap 35a, and an O-ring 35d is mounted between the first seal cap 35a and the second seal cap 35b. These O-rings 35c, 35d Thus, the pipe portion 33c of the geophone 33 is sealed.

  In the seal portion 35, the water is basically stopped by two O-rings 35c attached to the first seal cap 35a, but an O-ring 35d is inserted between the first seal cap 35a and the second seal cap 35b, By tightening the two-seal cap 35b, it is structured to improve water stoppage.

The drain valve 36 is attached to a branch passage from the middle of the guide pipe 32, and can open the space in the guide pipe 32 to the outside between the opening / closing valve 34 and the seal portion 35.
The drain valve 36 is also composed of a ball valve similar to the open / close valve 34 and is normally closed, but can be opened by a lever 36d.

A plurality of vibration receiving facilities 30 (a plurality of vibration receiving points) are provided for one vibration generating facility 21 or 22 (one oscillation point) and / or one vibration receiving facility 30 (one vibration receiving point). On the other hand, a plurality of vibration generators 21 or 22 (a plurality of oscillation points) are provided.
When providing a plurality of receiving facilities 30 (a plurality of receiving points), in order to set a plurality of receiving points in the circumferential direction and / or the front-rear direction of the skin plate 2, At least an opening 31 with an opening / closing valve 34 is provided so that a guide tube 32 or the like can be attached.

Next, forward exploration using the vibration receiving equipment 30 will be described.
When performing geological exploration in front of the shield machine 1, the vibration receiving equipment 30 is installed while the shield machine 1 is not excavated.
Specifically, after a guide tube 32 is set in a closed open / close valve 34 attached to the opening 31 of the skin plate 2, a seal cap in which a saddle-shaped geophone 33 is passed through the guide tube 32. 35a and 35b are set. Thereby, the state of FIG. 2 is obtained.

From this state, by operating the lever 34d, the open / close valve 34 is opened, and the saddle-shaped geophone 33 protrudes to the outside of the skin plate 2. As a result, the grounding portion (piercing portion) 33a and the sensor portion 33b of the geophone 33 are passed through the through-hole 34c of the spherical body 34b of the opening / closing valve 34, and further, the gap 102 on the back of the skin plate 2 is allowed to pass through. The wall of the natural mountain) 101 is penetrated into the natural mountain. Thereby, the state shown in FIG. 3 is obtained.
At this time, at least a part of the geophone 33, that is, the grounding part 33a and the sensor part 33b, or from the grounding part 33a to a part of the sensor part 33b, or a part of the grounding part 33a is penetrated into the ground. Thus, the substantial grounding portion (penetrating portion) 300 is obtained.

  In this state, an elastic wave is generated from the skin plate 2 or the cutter head 3 toward the front of the shield machine 1 using the vibration generator 21 or 22. The vibration receiving facility 30 receives a direct wave from the oscillation point and a reflected wave from a geological boundary such as a gravel layer in front of the shield machine 1.

The diameter of the cutter head 3 is larger than the diameter of the skin plate 2 and therefore has a gap 102 behind the skin plate 2 in the excavated tunnel. Therefore, even if the geophone 33 protrudes outside the skin plate 2, if it is only protruded into the gap 102 and is not penetrated into the natural ground (or not pressed), it is transmitted through the natural ground. It is difficult to receive the elastic wave that can be analyzed.
In this regard, in the present invention, at least a part of the geophone 33 is the grounding portion 300 that penetrates (or is pressed) into the ground on the outside of the skin plate 2, thereby improving the vibration receiving performance. Can do.

After receiving the vibration, based on the received vibration information, etc., it is analyzed by a computer for analysis to know the presence and location of geological boundaries such as gravel layers.
The analysis method in this case will be briefly described below.

  Referring to FIG. 5, the receiving facility 30 (receiving point R <b> 1) is directly transmitted from the oscillation point X <b> 1, and is oscillated from the oscillation point X <b> 1 and reflected by a geological boundary such as a gravel layer and transmitted. Receive vibration (reflected wave). Thus, specifically, the reception time of the direct wave and the reception time of the reflected wave are known, and the difference between the oscillation time measured separately and the time Td from the oscillation until the direct wave is input, from the oscillation The time Tr until the reflected wave is input is measured.

Since the linear distance from the oscillation point X1 to the receiving point R1 is known, if this is Sd, the propagation velocity V of vibration from the oscillation point X1 to the receiving point R1 is expressed by the following equation.
V = Sd / Td (1)
Assuming that the geology from around the shield machine to the front of the geological boundary is the same, the propagation speed of vibration can be assumed to be equal to V for the reflected wave.
Therefore, for the reflected wave, the reflection path distance Sr can be expressed by the following equation.
Sr = V · Tr = Sd · (Tr / Td) (2)

  Therefore, it can be estimated that the reflected wave is reflected from a point where the sum of the distance from the oscillation point X1 and the distance from the receiving point R1 is Sr = Sd · (Tr / Td). Therefore, it can be seen that the reflection point is on the ellipse EL1 with the oscillation point X1 and the receiving point R1 as focal points and the sum of the distances from these focal points being Sr = Sd · (Tr / Td).

  Therefore, by performing measurement at a plurality of receiving points for one oscillation point X1, or by setting a plurality of oscillation points for one receiving point R1 and performing measurement, a plurality of reflection points can be obtained. Ellipses can be created. For example, in the example of FIG. 5, another ellipse EL2 can be created by measuring at the oscillation point X1 and the receiving point R2. Then, it is possible to know that there is a reflection point near the intersection of the plurality of ellipses EL1 and EL2, and it is possible to know that there is a geological boundary such as a gravel layer in the tangential direction.

After completion of the forward exploration, the saddle-shaped geophone 33 is removed from the ground, and the grounding portion 33a and the sensor portion 33b are passed through the opening / closing valve 34 and pulled back into the guide tube 32.
Next, the open / close valve 34 is closed. In this state, it is assumed that the space between the opening / closing valve 34 and the seal portion 35 is filled with groundwater. Therefore, after closing the open / close valve 34, the drain valve 36 may be temporarily opened at an appropriate timing to discharge the water in the guide tube 32.

  According to this embodiment, the vibration receiving equipment 30 for forward exploration includes an opening 31 provided in the skin plate 2 of the shield machine 1 and a guide tube that is connected to the opening 31 and extends inside the skin plate 2. 32 and a vibration receiving device 33 inserted into the guide tube 32 and arranged to be able to protrude and retract outside the skin plate 2 through the opening 31, and the vibration receiving device 33 is at least at the time of vibration reception. A part of the grounding portion 300 penetrates or is pressed against the natural ground outside the skin plate 2, so that the vibration receiving performance can be improved and the forward exploration of the shield tunnel can be made more accurate.

  In other words, the geophone 33 is projected to the outside of the skin plate 2 through the opening 31 provided in the skin plate 2 of the shield machine 1, and at least a part of the geophone 33 is placed behind the skin plate 2. By passing through the gap 102 and penetrating or pressing into the natural ground, the vibration receiving performance can be improved, and the forward exploration of the shield tunnel can be made more accurate.

  Further, according to the present embodiment, the geophone 33 includes the grounding portion 33a at the tip, the sensor portion 33b that follows the ground portion 33a, and the pipe portion 33c that extends to the rear of the sensor portion 33b. Penetration into the mountain or pressing operation becomes easy. Further, in particular, by being formed into a bowl shape, penetration into a natural mountain, that is, piercing, becomes easy.

  Further, according to the present embodiment, the vibration receiving device 30 is provided on the guide tube 32 and the opening / closing valve 34 that opens and closes the opening 31 and allows the vibration receiving device 33 to pass through when the opening 31 is opened. Since it is configured to further include a seal portion 35 that seals movably, it can be used without being affected by sudden spring water or the like.

  Further, according to the present embodiment, the vibration receiving equipment 30 further includes the drain valve 36 that can open the space in the guide pipe 32 between the opening / closing valve 34 and the seal portion 35 to the outside. Effluent treatment after vibration is also easy.

Next, a description will be given of measures for preventing the geophone 33 from being pushed back by the back surface water pressure due to groundwater when the geophone 33 is penetrated or pressed into a natural ground.
This measure is shown in FIG.
A bracket 37 is fixed to the rear end of the pipe portion 33 c of the geophone 33, and an airfoil bracket 38 is fixed to the outer periphery of the guide tube 32. The wire 39 hooked to the bracket 37 at the rear end of the pipe portion 33c is passed through the hole of the airfoil bracket 38 so that the wire 39 can be pulled by a machine (not shown). Thereby, pulling and holding the wire 39 can prevent the geophone 33 from being pushed back.

  Next, when the ground pile that pierces the saddle-shaped geophone 33 is hard, or the backfilling injection material on the side of the covering body 103 flows into the gap between the skin plate 2 and the natural ground, the geophone 33 Measures to be taken when it is necessary to penetrate a backfilling injection material to pierce or press a natural ground.

As shown in FIG. 6, a drill 40 can be set in place of the geophone 33 on the guide tube 32 attached to the opening 31 of the skin plate 2 via an opening / closing valve 34. In this case, a seal cap 41 for the drill 40 is used.
Therefore, before setting the geophone 33, the drill 40 is set, and the drill 40 is pierced and drilled in the ground or backfilling injection material, so that the geophone 33 is stabbed or pressed into the ground. Can be made easier.
After drilling with the drill 40, the drill 40 is removed, and then the geophone 33 is set on the guide tube 32 and inserted into a hole previously drilled in the ground or backfill injection material by the drill 40.

Next, a modified example of the vibration generating equipment will be described.
In the above embodiment, the vibration generator 21 or 22 is provided in the shield machine 1, but the vibration generator may be provided outside the shield machine 1, for example, on the ground.
FIG. 7 is an explanatory diagram in the case where a vibration generating facility (oscillation point) is provided on the ground.
In the example of FIG. 7, one to a plurality of excitation facilities (oscillation points) 23 are provided on the ground GL, and elastic waves from these oscillation points are received by one to a plurality of vibration receiving facilities 30 of the shield machine 1. In this case, the geology is analyzed using the distribution of the elastic wave propagation velocity between the oscillation point and the receiving point.

Next, a case where vibration is received on the constructed segment side will be described.
In the present invention, the shield machine 1 is provided with a vibration receiving device 30 and receives vibration through the opening 31 provided in the skin plate 2 of the shield machine 1. The reason for not receiving vibration on the segment side (the lining body 103 side) is that the segment is a permanent structure and is not suitable for drilling.
However, if there is an injection port for injecting backfilling injection material on the segment side, and this can be used as an opening for vibration reception, vibration can be received on the segment side.

  In this case, as shown in FIG. 8, in the shield tunnel forward exploration device, which includes a receiving facility 30 for receiving the elastic wave from the oscillation point in the shield tunnel and performs geological exploration in front of the face of the shield tunnel, The vibration receiving facility 30 includes an opening 31 provided in the shield tunnel segment (covering body 103), and a cylindrical guide portion (guide tube) connected to the opening 31 and extending inside the segment. ) 32 and a geophone 33 inserted into the guide portion 32 and arranged so as to be able to protrude and retract outside the segment through the opening portion 31. And the said geophone 33 becomes a grounding part by which at least one part penetrates or is pressed into a natural ground outside the said segment at the time of vibration receiving.

Even if it is a structure like FIG. 8, the effect similar to the case where it receives on the skin plate 2 side like FIG. 1 can be acquired. In addition, when receiving elastic waves on the segment side, the distance from the oscillation point to the receiving point can be increased, so the distribution of the elastic waves on the ground due to the propagation velocity can be measured accurately, and the accuracy of geological analysis is improved. improves.
In the case of a structure for receiving vibration on the segment side, since the backfilling injection material is injected between the segment (covering body 103) and the natural ground (wall surface 101 of natural ground), the drill as described in FIG. Using 40 is extremely effective.

  Incidentally, in the method of exploring forward by projecting the geophone 33 through the opening 31 provided in the skin plate 2 (when the geophone is installed in the shield machine), the propulsion of the shield jack 14 as the propulsion mechanism is performed. That is, it is necessary to stop excavation of the shield machine and receive the elastic wave from the oscillation point. In the method of searching forward by projecting the geophone 33 through the opening 31 provided in the segment, it is not necessary to stop the shield machine.

  A shield machine advances a shield machine to a natural ground by a propulsion mechanism. By the rear segment assembly mechanism, the segments are assembled at the rear part in the skin plate 2 to construct a tunnel lining body (segment lining body). In the method of exploring forward by projecting the receiving point from the segment lining body (when installing the receiving equipment on the segment lining body), the preparation of installing the geophone 33 and measuring the elastic wave is the work of the shield machine. Can be implemented without being affected. Therefore, it is not necessary to stop the shield machine from being dug. Moreover, even when the vibration generator is installed in the shield machine, the time for stopping the shield excavation can be shortened.

  The illustrated embodiments are merely examples of the present invention, and the present invention is not limited to those directly described by the described embodiments, and various improvements and modifications made by those skilled in the art within the scope of the claims. Needless to say, it encompasses changes.

1 Shield machine 2 Skin plate 3 Cutter head 3a Cutter bit 4 Bulkhead
DESCRIPTION OF SYMBOLS 5 Support arm 6 Rotating ring 7 Ring gear 8 Motor 9 Pinion gear 10 Rotary joint 11 Chamber 12 Earth removal mechanism 13 Electa 14 Shield jack 21, 22, 23 Shaking equipment 30 Vibration receiving equipment 31 Opening part 32 Guide pipe (guide part)
33 Geophone 33a Grounding part (piercing part)
33b Sensor portion 33c Pipe portion 34 Open / close valve 34a Rotating shaft 34b Sphere 34c Through hole 34d Lever 35 Seal portion 35a, 35b Seal cap 35c, 35d O-ring 36 Drain valve 36d Lever 37 Bracket 38 Wing type bracket 39 Wire 40 Drill 41 Seal Cap 101 Tunnel wall surface
102 Gap 103 Lining body 300 by segment SG Ground contact part (penetration part) to natural ground

Claims (7)

A shield tunnel forward exploration device that includes a receiving device for receiving elastic waves from an oscillation point in a shield machine for tunnel excavation and performs geological exploration in front of the shield machine,
The vibration receiving equipment is
An opening provided in a skin plate of the shield machine;
A cylindrical guide connected to the opening and extending inside the skin plate;
A geophone that is inserted into the guide portion and arranged so as to be able to appear and retract outside the skin plate through the opening,
Comprising
The geophone is formed in a bowl shape, and at the time of vibration receiving, at least a part of the geophone is configured to penetrate the natural mountain, beyond the wall surface of the natural mountain, outside the skin plate , A forward exploration device for a shield tunnel, characterized in that the grounding portion at the tip forms a piercing portion .   2. The shield tunnel forward exploration device according to claim 1, wherein the geophone includes a grounding portion at a tip, a sensor portion following the ground portion, and a pipe portion extending rearward of the sensor portion. .   The vibration receiving device further includes an opening / closing valve that opens and closes the opening and allows the vibration receiving device to pass through the opening, and a seal portion that is provided in the guide portion and seals the vibration receiving device slidably. The forward exploration device for a shield tunnel according to claim 1, wherein the forward exploration device includes a shield tunnel.   4. The shield tunnel according to claim 3, wherein the vibration receiving device further includes a drain valve that can open a space in the guide portion between the opening and closing valve and the seal portion to the outside. Forward exploration device. When conducting geological exploration in front of the shield machine by receiving elastic waves from the oscillation point in the shield machine for tunnel excavation,
The geophone is formed in a bowl shape so that the grounding portion at the tip forms a piercing portion, and this geophone is projected to the outside of the skin plate through the opening provided in the skin plate of the shield machine,
A method for exploring a shield tunnel forward, wherein at least a part of the geophone is passed through a gap behind the skin plate and penetrates into a natural ground. A shield tunnel forward exploration device that includes a receiving facility for receiving an elastic wave from an oscillation point in a shield tunnel and performs geological exploration in front of the face of the shield tunnel,
An opening provided in a segment of the shield tunnel;
A cylindrical guide connected to the opening and extending inside the segment;
A geophone that is inserted into the guide portion and arranged so as to be able to appear and retract outside the segment through the opening,
Comprising
The geophone is formed in a bowl shape, and at the time of receiving vibration, at least a part of the geophone is configured to penetrate the natural ground outside the segment and beyond the wall surface of the natural ground. A forward exploration device for a shield tunnel, characterized in that a grounding portion of the shield forms a piercing portion . When conducting geological exploration in front of the face of the shield tunnel by receiving elastic waves from the oscillation point in the shield tunnel,
The geophone is formed in a bowl shape so that the grounding portion at the tip forms a piercing portion, and the geophone is projected to the outside of the segment through the opening provided in the segment of the shield tunnel,
A forward exploration method for a shield tunnel, characterized in that at least a part of the geophone is penetrated into a ground outside the segment.