JP6608272B2 - Tunnel excavation method and shield excavator - Google Patents

Description

  The present invention relates to a tunnel excavation method and a shield excavator.

  A shield machine is used for tunnel excavation. The shield machine includes a cylindrical shield, and a disc-shaped cutter head provided with a cutting blade for cutting the ground is provided on the front side of the shield. The shield machine advances while cutting the ground by rotating the cutter head.

  The shield machine described in Patent Document 1 below includes an exploration radar that searches the front of the shield machine, and removes detected obstacles by a boring machine. In this shield machine, excavation by the shield machine is performed after filling the inside of the cavity formed by the boring machine when removing the obstacle.

JP-A-6-336895

  When constructing the succeeding tunnel in the vicinity of the preceding tunnel, a relatively large gap (skin removal) may occur in the ground between the preceding tunnel and the succeeding tunnel. If such a gap is left unattended, the ground around the tunnel may sink. In addition, if there is a large gap between the preceding tunnel and the succeeding tunnel, the shield machine that excavates the succeeding tunnel may shift in the direction in which the gap is generated, and may not proceed as designed.

  It is an object of the present invention to provide a tunnel excavation method and a shield excavator that can detect a gap generated in the vicinity of a shield machine and prevent occurrence of a malfunction due to the detected gap.

  The present invention relates to a tunnel excavation method using a shield excavator, which includes a tunnel excavation process in which a tunnel is excavated by the shield excavator and a transmitter provided on the inside of the skin plate of the shield excavator. A transmission step of transmitting a detection wave to the ground of the surface, a reception step of receiving a reflected wave reflected at the boundary between the gap outside the skin plate and the ground by a receiving unit provided inside the skin plate, and reception A gap detecting step of detecting a gap based on the reflected wave received in the process.

  In this tunnel excavation method, a detection wave is transmitted from the inner side to the outer side of the skin plate of the shield machine, and a reflected wave reflected at the boundary between the gap and the ground is received to detect the gap. Thereby, the space | gap produced close to the shield machine can be detected. Further, by taking measures against the detected gap, it is possible to prevent the occurrence of a defect due to the gap. For example, the gap can be filled by injecting a filler into the detected gap. Problems caused by the gap generated in the vicinity of the shield machine include ground subsidence in the vicinity of the gap, a shift in the traveling direction of the shield machine, inflow of groundwater and sediment accumulated in the gap into the shield machine, and the like.

  Further, in the transmission step, detection waves are transmitted from a plurality of transmission units arranged in the circumferential direction of the skin plate, and in the reception step, reflected waves are received by a plurality of reception units arranged in the circumferential direction of the skin plate. The air gap detecting step may include a air gap calculating step for calculating the size of the air gap based on the reflected waves received by the plurality of receiving units. Thereby, the space | gap range can be pinpointed based on the reflected wave received by the several receiving part arrange | positioned in the position which differs in the circumferential direction of a skin plate.

  The tunnel excavation method may further include a filler injection step of injecting a filler into the void detected in the void detection step. By injecting the filler into the gap as described above, the gap can be filled and the occurrence of a defect due to the gap can be prevented.

  Further, the skin plate is provided with an injection hole behind the receiving unit in the direction in which the shield machine advances, and in the filler injection step, the filler may be injected from the injection hole behind the receiving unit. . Thereby, a receiving part can receive a reflected wave, pinpoint the position of a space | gap, and can inject a filler from the injection hole of the back of the receiving part. Therefore, it is possible to detect the gap while moving the shield machine, and immediately after the gap is detected, the filler can be injected from the injection hole behind the receiving unit in the shield machine.

  The injection hole is formed in the upper region of the skin plate, and in the filler injection step, the filler may be injected from the injection hole formed in the upper region of the skin plate. As a result, if the filler is injected from the injection hole formed in the upper region, if there is a gap below, the filler flows downward and fills the gap. Therefore, there is no need to provide an injection hole below.

  The transmitting unit transmits an electromagnetic wave as a detection wave, and the skin plate is provided with a non-magnetic part that allows the electromagnetic wave to pass therethrough. In the transmitting step, the electromagnetic wave is transmitted through the non-magnetic part, and a receiving step Then, you may receive a reflected wave through a non-magnetic-material part. Thereby, the electromagnetic wave transmitted from the transmission unit passes through the non-magnetic body unit and reaches the ground outside the skin plate. The reflected wave reflected at the boundary between the air gap and the ground passes through the non-magnetic body part and is received by the receiving part. Thereby, a space | gap can be detected using electromagnetic waves.

  The present invention is a shield machine for digging a tunnel, which is disposed inside a skin plate of the shield machine, and transmits a detection wave to the ground outside the skin plate, and the inside of the skin plate A receiving unit that receives the reflected wave reflected at the boundary between the gap outside the skin plate and the ground, and a gap detecting unit that detects the gap based on the reflected wave received by the receiving unit. Prepare.

  In this shield machine, a detection wave is transmitted from the inside of the skin plate of the shield machine to the outside ground, and a reflected wave reflected at the boundary between the gap and the ground is received to detect the gap. Thereby, the space | gap produced close to the shield machine can be detected. Further, by taking measures against the detected gap, it is possible to prevent the occurrence of a defect due to the gap.

  According to the present invention, it is an object to provide a tunnel excavation method and a shield excavator that can detect a gap generated in the vicinity of a shield excavator and prevent occurrence of a malfunction due to the detected gap. To do.

It is the schematic which shows the shield machine of one Embodiment of this invention. It is a longitudinal cross-sectional view of a preceding tunnel and a subsequent tunnel, and is a diagram showing an arrangement of sensors of the air gap detection device arranged inside the skin plate of the subsequent tunnel. It is the cross-sectional view which cut | disconnected the preceding tunnel and the succeeding tunnel in the horizontal direction, and is a figure which shows the space | gap detection apparatus and filler injection apparatus which are arrange | positioned inside the skin plate of a succeeding tunnel. It is sectional drawing which expands and shows the space | gap detection apparatus and the filler injection | pouring apparatus which are arrange | positioned inside the skin plate. It is a block block diagram of a space | gap detection apparatus. It is a figure which shows the waveform of the reflected wave received by the receiving part. It is a flowchart which shows the procedure in the tunnel excavation method.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In addition, in each figure, the same code | symbol is attached | subjected to the same part or an equivalent part, and the overlapping description is abbreviate | omitted.

  As shown in FIG. 1, the shield machine 1 includes a cylindrical metal skin plate 2. A cutter head 3 that is a cutter unit is provided in front of the front end opening of the skin plate 2. A cutter chamber 4 is formed behind the cutter head 3. On the back side of the cutter chamber 4, a disk-shaped partition wall 5 that partitions the inside and outside of the cutter chamber 4 is disposed.

  A number of cutter bits 6 are provided in front of the cutter head 3. A rotating shaft 7 extending rearward is connected to the back surface of the cutter head 3. The rotating shaft 7 rotates around the axis when a rotational driving force is transmitted by an electric motor serving as a driving source. As the rotary shaft 7 rotates, the cutter head 3 rotates and the face 101 is excavated by the cutter bit 6. The excavated soil is accommodated in the cutter chamber 4 through an opening provided in the cutter head 3.

  A screw conveyor 8 is connected to the lower side of the partition wall 5. The screw conveyor 8 discharges the mud filled in the cutter chamber 4. The mud discharged from the cutter chamber 4 by the screw conveyor 8 is conveyed to the rear of the skin plate 2 and discharged outside the tunnel 100B.

  Further, a plurality of shield jacks 9 are provided at the rear portion of the skin plate 2. The shield jack 9 is a drive unit for propelling the shield machine 1 and includes a shield jack cylinder 10 and a shield jack rod 11. The shield jack cylinder 10 is fixed to the inner peripheral surface 2 a of the skin plate 2, and the shield jack rod 11 extends rearward from the shield jack cylinder 10. The rear end portion of the shield jack rod 11 is pressed against the end surface of the segment 102 constructed on the inner peripheral surface 2a of the tunnel 100B, and the shield jack rod 11 extends, whereby the shield machine 1 is pushed forward.

  Further, the shield machine 1 is provided with an erector (not shown) that automatically assembles the plurality of segments 102. A backfilling material injection hole 102H is formed in a part of the plurality of segments 102. A backfilling material injection device 12 is connected to the backfilling material injection hole 102H. The backfilling material injection device 12 supplies the backfilling material through the backfilling material injection hole 102H, and the supplied backfilling material is filled in a gap between the segment 102 and the ground.

  A tail seal 30 that is continuous in the circumferential direction is provided at the rear end of the skin plate 2. The tail seal 30 stops water between the segment 102 and the shield machine 1 at the rear end portion of the shield machine 1, and prevents inflow of groundwater and earth and sand to the inside of the skin plate 2. By closing the rear-assembled segment 102 and the inside of the skin plate 2 with the tail seal 30, inflow of groundwater or the like into the skin plate 2 is prevented.

  As shown in FIGS. 2 and 3, the shield machine 1 is applied to, for example, excavation of the trailing tunnel 100B adjacent to the preceding tunnel 100A. FIG. 2 shows a cross section orthogonal to the direction in which the tunnels 100A and 100B extend. The preceding tunnel 100A is shown on the right side of the figure, and the trailing tunnel 100B is shown on the left side of the figure.

  During excavation of the succeeding tunnel 100B, there may be a case where a skin drop that forms a large gap 103 occurs in the ground between the succeeding tunnel 100B and the preceding tunnel 100A. Due to the excavation of the shield machine 1, a part of the ground 104 between the shield machine 1 and the preceding tunnel 100 </ b> A collapses, causing skin peeling and forming a large gap 103.

  Here, as shown in FIGS. 3 and 4, the shield machine 1 is detected with a gap detection device (gap detection unit) 13 that detects the gap 103 close to the skin plate 2 of the shield machine 1. And a filler injection device 14 for injecting the filler 105 into the gap 103. The gap close to the skin plate 2 is assumed to be, for example, a side or an upper side, and is mainly a side, and is a region outside the skin plate 2 in the horizontal radial direction of the cylindrical skin plate 2.

  The air gap detection device 13 transmits electromagnetic waves (detection waves) and receives reflected waves from the ground, and an operation for calculating the position and size of the air gap 103 based on the reflected waves received by the sensors 15. Unit (gap calculation unit) 16 and a display unit 17 for displaying the result calculated by the calculation unit 16. The detection wave refers to an electromagnetic wave, an ultrasonic wave, or the like that can detect a void formed in the ground.

  The plurality of sensors 15 are arranged, for example, at the same position in the axial direction of the subsequent tunnel 100B (the traveling direction of the shield machine 1). The plurality of sensors 15 are spaced apart from each other in the circumferential direction of the skin plate 2. The plurality of sensors 15 are arranged on the preceding tunnel 100A side in order to detect the air gap 103 between the preceding tunnel 100A and the succeeding tunnel 100B. When the highest position is set to 0 [deg] on the inner peripheral surface 2a of the skin plate 2, the plurality of sensors 15 are indicated by a clockwise rotation angle about the axis of the trailing tunnel 100B, for example, 63 [Deg], 76.5 [deg], 90 [deg], 103.5 [deg], and 117 [deg] are arranged. The arrangement interval between adjacent sensors 15 is, for example, 13.5 [deg].

A plurality of sensors _{15 (15 1,} 15 2, 15 _3, 15 4, 15 ₅₎ of, in order from the top, the sensor 15 ₁ is 63 [deg], the sensor 15 ₂ 76.5 [deg], the sensor 15 ₃ 90 [deg], the sensor 15 ₄ 103.5 [deg], the sensor 15 ₅ is disposed in the 117 [deg]. The plurality of sensors 15 may be arranged at other angular positions. Further, the plurality of sensors 15 may be disposed on the inner peripheral surface 2a opposite to the preceding tunnel 100A, or may be disposed at different positions in the axial direction of the subsequent tunnel 100B.

Sensor 15 includes a receiver 19 for receiving a transmission unit 18 and reflected wave _{L 2} transmits an electromagnetic wave _{L 1.} The transmission unit 18 and the reception unit 19 are, for example, arranged side by side in the axial direction of the subsequent tunnel 100B, the reception unit 19 is arranged on the front side, and the transmission unit 18 is arranged on the rear side in the traveling direction of the shield machine 1. Has been. The transmission unit 18 may be disposed on the front side of the reception unit 19, and the transmission unit 18 and the reception unit 19 may be disposed side by side in the circumferential direction of the skin plate 2.

  The plurality of sensors 15 are attached to the inner peripheral surface 2 a so as to contact the inner peripheral surface 2 a of the skin plate 2. In the skin plate 2, for example, a non-magnetic body portion 20 (see FIG. 4) is provided at a portion where the sensor 15 contacts. The nonmagnetic part 20 can transmit electromagnetic waves and has a predetermined strength. The non-magnetic part is a part in which a part of the skin plate is not made of metal but is made of a non-magnetic substance such as an acrylic resin. For example, an opening is provided in the skin plate 2, and a disk-like nonmagnetic material is incorporated in the opening to constitute the nonmagnetic material portion 20.

The calculation unit 16 is electrically connected to the plurality of sensors 15, and analyzes and calculates the data of the reflected wave L ₂ received by the reception unit 19. As illustrated in FIG. 5, the calculation unit 16 includes a skin drop depth calculation unit 25, a skin drop area calculation unit 26, a skin drop volume calculation unit 27, and a storage unit 28. The arithmetic unit 16 includes a CPU that performs arithmetic processing, a ROM and a RAM that are storage units, an input signal circuit, an output signal circuit, a power supply circuit, and the like. The storage unit 28 stores calculation results in the calculation unit 16, data necessary for the calculation, and data regarding the positions of the plurality of sensors 15.

  The calculation unit 16 specifies the position of the sensor 15 in the axial direction of the succeeding tunnel 100B based on the position information of the shield machine 1.

Skin fall depth calculation unit 25 of the arithmetic unit 16 analyzes the data of the reflected wave L _2, calculates the skin drop depth l [m]. The skin drop depth l is the depth of the gap 103, and is the distance [m] from the outer peripheral surface 2b of the skin plate 2 to the boundary 106 between the gap 103 and the ground 104 in the radial direction of the skin plate 2.

ここで、ｃは光速（３×１０^８〔ｍ／ｓｅｃ〕）、ε_２は空隙１０３の比誘電率、ｔは反射波の時間差〔ｓｅｃ〕である。 The calculating part 16 calculates skin | peeling depth l [m] using following formula (1).

Here, c is the speed of light (3 × 10 ⁸ [m / sec]), ε ₂ is the relative dielectric constant of the gap 103, and t is the time difference [sec] of the reflected wave.

FIG. 6 is a diagram illustrating an example of a waveform of a reflected wave received by the receiving unit 19. In Figure 6, it shows the elapsed time on the vertical axis indicates the wavelength of the reflected wave L ₂ on the horizontal axis. The time ta shown in FIG. 6 is the time at which the direct reflection wave L ₃ (see FIG. 4) reflected by the outer peripheral surface 2 b of the skin plate 2 is received by the receiving unit 19. The time ta is the time from when the electromagnetic wave is transmitted by the transmitter 18 until the reflected wave L ₃ reflected by the outer peripheral surface 2 b of the skin plate 2 is received by the receiver 19. Time tb shown in FIG. 6 is a time that has received a reflected wave _{L 2} reflected by the boundary 106 between the air gap 103 and the ground 104 at the receiving unit 19. The time tb is the time from when the electromagnetic wave is transmitted by the transmitter 18 until the reflected wave L ₂ reflected by the boundary 106 is received by the receiver 19. Then, the time difference t of the reflected wave is the difference between _{t b} and _{t a.}

ここで、Ｓ_１は、センサ１５_１とセンサ１５_２との間の肌落ち面積〔ｍ^２〕、Ｓ_２はセンサ１５_２とセンサ１５_３との間の肌落ち面積、Ｓ_ｎは、センサ１５_ｎとセンサ１５_ｎ＋１との間の肌落ち面積である（ｎ＝自然数）。

ここで、Ｒは、スキンプレート２の外径〔ｍ〕、θは周方向に隣接するセンサ１５の配置角であり例えば１３．５度である。 Also, skin fall area calculating unit 26 of the arithmetic unit 16, the following equation (2) to calculate skin fall area _{S m} ^{[m 2]} with reference to (3). The skin removal area S _m is, for example, the area of the gap 103 in contact with the outer peripheral surface 2b of the skin plate 2.

Here, _{S 1} is the skin fall area between the sensor 15 ₁ and the skin fall area between the sensor 15 ₂ ^{[m 2],} _{S 2} sensor 15 ₂ and the sensor 15 _{3, S n,} the sensor 15 It is the skin drop area between _n and sensor 15 _{n + 1} (n = natural number).

Here, R is the outer diameter [m] of the skin plate 2, and θ is an arrangement angle of the sensors 15 adjacent in the circumferential direction, for example, 13.5 degrees.

ここで、Bは、１リング掘進距離〔ｍ〕であり、セグメント１０２の幅〔ｍ〕である。ｖは、シールド掘進機１の掘進速度〔ｍ／ｓ〕である。 Moreover, the skin removal volume calculation part 27 of the calculating part 16 calculates skin removal volume V [m < ³ >] using following formula (4). The skin removal volume V is the volume of the gap 103.

Here, B is a 1-ring excavation distance [m] and a width [m] of the segment 102. v is the digging speed [m / s] of the shield machine 1.

As shown in FIGS. 3 and 4, the filler injection device 14 includes a filler transfer pump 21 and a filler injection tube 22. The skin plate 2 is provided with a filler injection hole 23 penetrating in the thickness direction of the skin plate 2. The filler injection hole 23 is disposed at a position behind the sensor 15 in the traveling direction of the shield machine 1, for example. A plurality of filler injection holes 23 are provided in the circumferential direction of the skin plate 2. In the circumferential direction of the skin plate 2, the position of the filler injection hole 23 may be the same as the position of the sensor 15 (sensors 15 ₁ to 15 ₅ ), or may be provided at a position higher than the position of the sensor 15. The position of the filler injection hole 23 may be provided at a position lower than the position of the sensor 15.

  The filler transfer pump 21 pumps the filler 105. The filler injection pipe 22 connects the filler transfer pump 21 and the filler injection hole 23. The filler pumped by the filler transfer pump 21 flows through the filler injection tube 22, passes through the filler injection hole 23, and is injected into the gap 103 outside the skin plate 2.

  The filler injection device 14 includes a pressure gauge (pressure detector) that detects the internal pressure of the filler injection pipe 22 (or the discharge pressure of the filler transfer pump 21), for example. The filler injection device 14 can manage the injection amount of the filler based on the pressure detected by the pressure gauge. For example, when a predetermined determination threshold value is reached, the filling material injection is stopped.

  The filler injection hole 23 is provided on the side of the skin plate 2, for example. Accordingly, the filler can be injected from the filler injection hole 23 provided at a position close to the gap 103 corresponding to the side of the skin plate 2 where the gap 103 is relatively likely to occur.

  The filler injection hole 23 may be provided, for example, above the skin plate 2. Accordingly, the filler that has flowed out of the skin plate 2 through the filler injection hole 23 flows along the outer peripheral surface of the skin plate 2 and is filled in the gap 103.

  As a filler, what contains hardeners, such as cement, cement-type solidification material, slaked lime, can be used, for example. Further, the filler may be mixed with a polymer in order to improve the stability of the material contained in the filler. Moreover, shear resistance can be improved by making a filler contain a fiber. The filler is a self-hardening material, and solidifies to the strength of the surrounding natural ground over several weeks after injection, for example. As a result, the ground 104 can be prevented from collapsing.

  Next, a tunnel excavation method using the shield machine 1 will be described with reference to FIG.

  In this tunnel excavation method, the subsequent tunnel 100B is excavated adjacent to the preceding tunnel 100A. The leading tunnel 100A and the trailing tunnel 100B are provided side by side in the horizontal direction, for example. In this tunnel excavation method, after the preceding tunnel 100A is excavated, the subsequent tunnel 100B is excavated using the shield excavator 1 (step S1: tunnel excavation process). The shield machine 1 advances by driving the shield jack 9 while digging the face 101 by rotating the cutter head 3.

  Further, the shield machine 1 searches the ground 104 in order to detect a skin fall on the side of the skin plate 2 while performing the drilling process S1 (skin drop searching process). Specifically, a transmission process (step S2), a reception process (step S3), and a gap calculation process (step S4) are executed.

In the transmission step S2, while excavation by the shield machine 1 transmits the electromagnetic wave L ₁ from the transmitter 18. The electromagnetic wave L ₁ transmitted from the transmission unit 18 passes through the nonmagnetic body unit 20 and reaches the ground 104 outside the skin plate 2. Skin fall has not occurred to the outside of the ground 104 of the skin plate 2, when there is no air gap 103, or the electromagnetic wave L ₁ proceeds as it is reflected by the back-filling material and the segment of the adjacent preceding tunnels 100A. When the skin 104 is peeled off and the gap 103 is formed on the ground 104 outside the skin plate 2, the electromagnetic wave L ₁ travels inside the gap 103 and the boundary 106 between the gap 103 and the ground 104. Reflect on.

In the receiving step S3, a reflected wave is received by the receiving unit 19 while performing excavation by the shield machine 1. When the skin 104 is peeled off, the reflected wave reflected by the boundary 106 between the gap 103 and the ground 104 is received by the receiving unit 19. Further, a part of the electromagnetic wave L ₁ transmitted from the transmitter 18 is reflected at the boundary between the non-magnetic member 20 and the gap 103 (a position corresponding to the outer peripheral surface 2b of the skin plate 2), and this reflected wave is received. Received by the unit 19.

ここで、ｃは光速（３×１０^８〔ｍ／ｓｅｃ〕）、ε_２は空隙１０３の比誘電率、ｔは反射波の時間差〔ｓｅｃ〕である。 In the gap calculation step (gap detection step) S4, the position and size of the gap 103 are calculated based on the reflected wave received in the reception step S3. Specifically, the skin drop depth calculation unit 25 of the calculation unit 16 calculates the skin drop depth l [m] using the following formula (1) (skin drop depth calculation step).

Here, c is the speed of light (3 × 10 ⁸ [m / sec]), ε ₂ is the relative dielectric constant of the gap 103, and t is the time difference [sec] of the reflected wave.

ここで、Ｓ_１は、センサ１５_１とセンサ１５_２との間の肌落ち面積〔ｍ^２〕、Ｓ_２はセンサ１５_２とセンサ１５_３との間の肌落ち面積、Ｓ_ｎは、センサ１５_ｎとセンサ１５_ｎ＋１との間の肌落ち面積である（ｎ＝自然数）。

ここで、Ｒは、スキンプレート２の外径〔ｍ〕、θは周方向に隣接するセンサ１５の配置角であり例えば１３．５度である。 Furthermore, the skin fall area calculation unit 26 of the calculation unit 16 calculates the skin fall area S _m [m ² ] using the following formulas (2) and (3) (skin fall area calculation step).

Here, _{S 1} is the skin fall area between the sensor 15 ₁ and the skin fall area between the sensor 15 ₂ ^{[m 2],} _{S 2} sensor 15 ₂ and the sensor 15 _{3, S n,} the sensor 15 It is the skin drop area between _n and sensor 15 _{n + 1} (n = natural number).

Here, R is the outer diameter [m] of the skin plate 2, and θ is an arrangement angle of the sensors 15 adjacent in the circumferential direction, for example, 13.5 degrees.

ここで、Bは、１リング掘進距離〔ｍ〕であり、セグメント１０２の幅〔ｍ〕である。ｖは、シールド掘進機１の掘進速度〔ｍ／ｓ〕である。 Furthermore, the skin removal volume calculation unit 27 of the calculation unit 16 calculates the skin removal volume V [m ³ ] using the following formula (4) (skin removal volume calculation step).

Here, B is a 1-ring excavation distance [m] and a width [m] of the segment 102. v is the digging speed [m / s] of the shield machine 1.

  Further, in the gap calculation step S <b> 4, the calculation result by the calculation unit 16 is displayed using the display unit 17. For example, a sectional view of the tunnel is displayed, and the position and size (shape) of the gap 103 in the ground outside the skin plate 2 are displayed. Further, as the size of the gap 103, the depth, area, and volume of the gap 103 may be displayed numerically. Further, the position and length of the gap 103 in the axial direction of the tunnel 100B may be displayed. The display unit may display data such as the waveform of the received reflected wave.

  Next, it is determined whether or not a filler is injected into the detected gap 103 (step S5). For example, when the skin drop volume V is greater than or equal to the determination threshold, it is determined that the filler is injected. If it is determined that the filler is to be injected, the process proceeds to step S6. If the skin removal volume V is not greater than or equal to the determination threshold, the processing of steps S1 to S4 is repeated without injecting the filler. For example, when skin peeling is not detected, tunnel excavation and skin peeling search are continued.

  In step S6, the tunnel excavation by the shield machine 1 is stopped. In subsequent step S7, a filler injection step of injecting the filler 105 into the gap 103 is performed. The filler injection device 14 uses the filler transfer pump 21 to transfer the filler. The filler discharged from the filler transfer pump 21 flows through the filler injection pipe 22, passes through the filler injection hole 23 provided behind the sensor 15, and is injected into the gap 103 outside the skin plate 2. The In the gap calculation step S4, since the volume of the gap 103 is calculated in advance, an amount of filler corresponding to the volume of the gap 103 is injected. This ensures that an appropriate amount of filler is injected and the gap 103 can be filled with the filler.

  After injecting the filler, the excavation by the shield machine 1 is resumed, and the segment 102 is constructed and the backfill material is injected in accordance with the progress of the shield machine 1. In addition, when the size of the gap 103 is small, it is possible to inject the filler while digging without stopping the digging by the shield machine 1. For example, the determination threshold is used to determine the size of the gap 103 and determine whether the filler is injected with the shield machine 1 stopped or whether the filler is injected without stopping the shield machine 1. May be.

  According to such a tunnel excavation method, an electromagnetic wave is transmitted from the inside of the skin plate 2 of the shield machine 1 to the outer ground 104 and a reflected wave reflected by the boundary 106 between the gap 103 and the ground 104 is received. Thus, the position, depth, area and volume of the gap 103 can be detected. Further, filling the gap 103 by injecting a filler into the detected gap 103 prevents the occurrence of defects due to the gap 103.

  In addition, problems due to the gap 103 generated in the vicinity of the shield machine 1 include ground subsidence in the vicinity of the gap 103, a shift in the progress of the shield machine 1, and the inside of the skin plate 2 of groundwater or earth and sand accumulated in the gap 103. Infiltration. In the tunnel excavation method according to the present embodiment, the filler 103 can be injected into the detected gap 103 to fill the gap 103, so that the occurrence of ground subsidence due to the gap 103 can be prevented. Further, by filling the gap 103, the deviation of the shield machine 1 toward the gap 103 is suppressed. Further, by filling the gap 103, there is no possibility that groundwater or earth and sand will accumulate, and it is possible to prevent entry of groundwater or earth and sand to the inside of the skin plate 2.

  In the tunnel excavation direction, the gap 103 is detected using a plurality of sensors 15 arranged at different positions in the circumferential direction, so that the gap range can be easily and accurately specified.

  The present invention is not limited to the above-described embodiments, and various modifications as described below are possible without departing from the gist of the present invention.

  In the above embodiment, the following tunnel is described in the horizontal direction, which is adjacent to the preceding tunnel. However, the direction in which the preceding tunnel and the subsequent tunnel are close to each other is not limited to the horizontal direction. The tunnel excavation method of the present invention may be applied to a case where it is arranged at a position higher than that of the tunnel, a case where it is arranged close to the other direction, and a case where it is arranged so as to cross the other direction. . Further, the tunnel excavation method of the present invention may be applied to a single tunnel in which there is no other tunnel near the tunnel to be excavated.

  When the preceding tunnel and the following tunnel are constructed close to each other in the vertical direction, the preceding tunnel is usually constructed on the lower side, and the rear tunnel is constructed above the preceding tunnel. In this case, when excavating the succeeding tunnel, there is no possibility that a void is formed in a region below the succeeding tunnel and between the succeeding tunnel and the preceding tunnel.

  In the above embodiment, the gap 103 is detected by transmitting an electromagnetic wave from the transmission unit 18. However, the gap 103 may be detected by transmitting another detection wave such as an ultrasonic wave.

  In the above embodiment, the filler 105 is injected from the filler injection hole 23 provided behind the receiving unit 19. However, the filler injection hole 23 is provided in front of the receiving unit 19 to inject this filler. The filler 105 may be injected from the hole 23. Further, the filler injection hole 23 may be provided at a position higher than the receiving unit 19 in the vertical direction, or may be provided at a position lower than the receiving unit 19. If the filler injection hole 23 is provided at a high position, the filler 105 flows downward, so that it is not necessary to provide the filler injection hole 23 at a low position.

  In the above embodiment, the filling material is injected after the excavation by the shield machine 1 is stopped. However, the filling material may be injected while the shield machine 1 is excavating.

  Moreover, in the said embodiment, although the several receiving part 19 was provided and the reflected wave was received, you may move the one receiving part 19 and receive a reflected wave, for example.

  In the above embodiment, the volume of the gap 103 is calculated. However, only the depth of the gap 103 may be calculated, or only the area of the gap 103 may be calculated. Further, the length of the gap 103 in the axial direction of the tunnel 100B may be calculated based on the reflected wave received by the receiving unit and the moving speed of the shield machine 1. Moreover, in the said embodiment, although the magnitude | size of the space | gap 103 is detected, you may only determine the presence or absence of the space | gap 103 based on a reflected wave.

DESCRIPTION OF SYMBOLS 1 ... Shield machine 2 ... Skin plate, 2a ... Inner peripheral surface, 2b ... Outer peripheral surface 3 ... Cutter head 4 ... Cutter chamber 5 ... Bulkhead 6 ... Cutter bit 7 ... Rotating shaft 8 ... Screw conveyor 9 ... Shield jack 10 ... Shield Jack cylinder 11 ... Shield jack rod 12 ... Backfill material injection device 13 ... Air gap detection device 14 ... Filling material injection device 15 ... Sensor 16 ... Calculation unit 17 ... Display unit 18 ... Transmission unit 19 ... Reception unit 20 ... Non-magnetic body unit DESCRIPTION OF SYMBOLS 21 ... Filler transfer pump 22 ... Filler injection pipe 23 ... Filler injection hole 25 ... Skin fall depth calculation part 26 ... Skin fall area calculation part 27 ... Skin fall volume calculation part 28 ... Memory | storage part 30 ... Tail seal 100A ... Prior Tunnel 100B ... Follow-up tunnel 101 ... Face 102 ... Segment 102H ... Backfill material injection hole 103 ... Air gap 104 ... Ground 105 ... Filler 106 ... Boundary (Boundary between gap and ground)
L ₁ ... Electromagnetic wave (detection wave)
L ₂ ... Reflected wave R ... Outer diameter of skin plate B ... 1 ring excavation distance

Claims (5)

A tunnel excavation method using a shield excavator,
A tunnel excavation process of excavating a tunnel with the shield machine,
A transmission step of transmitting a detection wave to the ground outside the skin plate from the transmission unit provided inside the skin plate of the shield machine,
A receiving step of receiving a reflected wave reflected at the boundary between the gap outside the skin plate and the ground by a receiving unit provided inside the skin plate;
A gap detecting step of detecting the gap based on the reflected wave received in the receiving step;
Only including,
A filler injection step of injecting a filler into the gap detected in the gap detection step;
The skin plate is provided with an injection hole behind the receiving unit in the direction in which the shield machine advances.
The filler injection step injects the filler from the injection hole behind the receiving unit,
Tunneling method. In the transmission step, the detection waves are transmitted from the plurality of transmission units arranged in the circumferential direction of the skin plate,
In the receiving step, the reflected waves are received by the plurality of receiving units arranged in the circumferential direction of the skin plate,
2. The tunnel excavation method according to claim 1, wherein the air gap detecting step includes a air gap calculating step of calculating a size of the air gap based on the reflected waves received by a plurality of the receiving units. The injection hole is formed in a region on the upper side of the skin plate,
3. The tunnel excavation method according to claim 1, wherein, in the filler injection step, the filler is injected from the injection hole formed in an upper region of the skin plate. The transmission unit transmits electromagnetic waves as the detection wave,
The skin plate is provided with a non-magnetic part that allows the electromagnetic wave to pass through.
In the transmitting step, the electromagnetic wave is transmitted through the non-magnetic part,
The tunnel excavation method according to any one of claims 1 to 3 , wherein, in the reception step, the reflected wave is received through the non-magnetic body part. A shield machine that digs through a tunnel,
A transmitting unit that is arranged inside the skin plate of the shield machine, and transmits a detection wave to the ground outside the skin plate;
A receiving unit that is disposed inside the skin plate and receives a reflected wave reflected at a boundary between the gap outside the skin plate and the ground; and
A gap detecting unit that detects the gap based on the reflected wave received by the receiving unit, and
A filler injection device for injecting a filler into the gap detected by the gap detector;
The skin plate is provided with an injection hole behind the receiving unit in the direction in which the shield machine advances.
The filler injection device injects the filler from the injection hole behind the receiving unit;
Shield machine.

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