JP6748918B2 - Tunnel face exploration method - Google Patents

Description

The present invention relates to a front tunnel face exploration method suitable for the construction of a mountain tunnel by the NATM method, and more particularly to a front tunnel face exploration method using vibration during construction of a tunnel excavating machine.

Conventionally, in construction of a mountain tunnel by the NATM method, a method described in Patent Document 1 proposed by the present inventors is known as a method for estimating the ground condition in front of a tunnel face. This method uses the vibration generated by the tunnel excavating machine as a vibration source for geophysical exploration to estimate the ground condition in front of the face. In addition, the method described in Patent Documents 2 and 3 proposed by the present inventors is known as a method using a rock bolt, which is one of the tunnel support works, as a probe for receiving vibration. By using the techniques described in Patent Documents 1 to 3, it is possible to carry out and continue exploration on a daily basis without stopping the tunnel excavation work.

Japanese Patent No. 5839271 JP, 2005-090032, A JP, 2014-181948, A

By the way, in the above-mentioned conventional patent document 1, as shown in FIG. 2, the timing of performing the exploration in a series of excavation work is as follows (step S7) and when drilling/charging the face ( It is set as step S9). This is because there is a timing at which vibration can be directly applied to the face face. Direct vibration to the face is more effective in exploring the situation in front of the face.

However, the timing at which the direct vibration is applied to the face face in the series of excavation work is not limited to the above, and the exploration cannot be executed unless it is the above timing. Regarding the timing of performing the exploration without stopping the work, it is preferable that the exploration can be performed more widely in a series of excavation work, because the practicality of the exploration ahead of the face improves. For this reason, there has been a demand for a method for exploring the face ahead of the face where the exploration timing can be set wider.

The present invention has been made in view of the above, and an object of the present invention is to provide a tunnel face forward search method capable of setting a wider search timing.

In order to solve the above problems and achieve the object, a tunnel face forward exploration method according to the present invention is a method for exploring the face forward of a face face by a reflected wave seismic survey method during tunnel construction by the NATM method. After installing a vibration sensor in at least one of the sensor installation hole or support provided in the tunnel pit wall behind by a predetermined distance from, hit the face with a construction machine installed near the face, It is characterized by having a hitting exploration step of measuring the vibration propagating through the ground with the vibration receiving sensor.

Further, another tunnel face forward exploration method according to the present invention, in the above-mentioned invention, the impact exploration step, during the scraping work or after the end until the concrete spraying work on the tunnel shaft wall A step of installing a vibration-receiving sensor in at least one of the sensor installation hole or the supporting structure, and during or after the leveling work as the construction machine placed near the face face during or after the spraying work. Later, a step of hitting a face face with this leveling machine is included.

Further, the other tunnel face forward exploration method according to the present invention, in the above-mentioned invention, after installing the vibration sensor and at least one of the sensor installation hole or the supporting work and the crushing machine, the vibration sensor is installed, The present invention is characterized by further comprising an exploration step for measuring the vibration during the work of scraping the face face with the crushing machine by the vibration receiving sensor.

Further, another tunnel face forward exploration method according to the present invention is the above-mentioned invention, in which the vibration receiving is installed in at least one of the sensor installation hole or the support work before the concrete is sprayed onto the tunnel pit wall. Once the sensor is removed, and during or after the concrete spraying work, a vibration sensor is installed again on at least one of the hole for sensor installation or the support work on the tunnel pit wall and the drilling machine, and blasting with the drilling machine. The present invention is characterized by further comprising an exploration step during boring, in which vibration during boring of the hole is measured by the vibration sensor.

Further, another tunnel face forward exploration method according to the present invention is characterized in that, in the above-mentioned invention, the face forward exploration is continuously performed during tunnel construction by repeating the exploration step.

According to the tunnel face forward exploration method of the present invention, a method for exploring the face ahead of the face face by the reflected wave seismic survey method during the construction of the tunnel by the NATM method is provided on the tunnel wall behind the face face by a predetermined distance. After installing a vibration sensor in at least one of the sensor installation hole or support, strike the face with a construction machine installed in the vicinity of the face, and measure the vibration propagating through the ground by this impact with the above-mentioned sensor. Since the impact exploration step is performed, it is possible to set the exploration timing wider than before.

Further, according to another tunnel face forward exploration method according to the present invention, the impact exploration step is for installing the sensor during or after the scraping work and before the concrete spraying work on the tunnel wall. A step of installing a vibration receiving sensor in at least one of the hole or the supporting work, and during or after the leveling work by the leveling machine as the construction machine arranged near the face face during or after the spraying work, Since it has a step of striking the face face with a leveling machine, there is an effect that the face forward exploration can be performed by utilizing the timing of the leveling work by the leveling machine after the spraying work.

Further, according to another method for exploring a tunnel face according to the present invention, a vibration-receiving sensor is installed in at least one of the sensor installation hole or the supporting work and the crushing machine after the completion of blasting and slipping, and the crushing machine. Since there is further an exploration step for measuring the vibration during the work of scooping the face with the vibration-receiving sensor, there is an effect that the face forward exploration can be carried out by utilizing the timing of the scooping work. ..

Further, according to another tunnel face forward exploration method according to the present invention, once the vibration receiving sensor installed in at least one of the sensor installation hole or the support structure is sprayed before the concrete is sprayed onto the tunnel wall. During removal of concrete and after concrete spraying, or after completion, install a vibration sensor on at least one of the hole for sensor installation or support of the tunnel shaft and the drilling machine, and drill the blast hole with the drilling machine. Since the method further includes the hole drilling exploration step of measuring the vibration in the hole with the vibration receiving sensor, there is an effect that the face front exploration can be performed by utilizing the timing of the drilling operation before the charging.

Further, according to another tunnel face exploration method according to the present invention, the face face exploration is continuously performed during tunnel construction by repeating the exploration step, so the work is interrupted in a series of excavation work. The effect is that the front face exploration can be carried out without any trouble.

FIG. 1 is a schematic process diagram showing an embodiment of a tunnel face forward exploration method according to the present invention. FIG. 2 is a schematic process diagram showing an example of a conventional tunnel face forward exploration method.

Embodiments of a tunnel face forward exploration method according to the present invention will be described in detail below with reference to the drawings. The present invention is not limited to this embodiment.

The tunnel face exploration method according to the present invention is a method for exploring the face ahead of the face face by the reflected wave seismic exploration method using a tunnel excavating machine during the tunnel construction by the NATM method, and the timing of the exploration is the conventional method ( For example, it can be set wider than the method described in Patent Document 1).

In the present embodiment, an exploration time exploration process (hereinafter sometimes referred to as process A), a spraying/supporting work exploration process (striking exploration process; hereinafter sometimes referred to as process B), and a cutting process. A hole/charge exploration step (drilling exploration step; hereinafter sometimes referred to as step C). The process A and the process C correspond to the process 1 and the process 2 described in Patent Document 1, respectively.

In step A (exploration step during squirt), a vibration sensor is installed on the tunnel wall behind the face by a predetermined distance from the time when the blast hole is drilled until the hole is charged and blasted. A hole for sensor installation for the crushing machine, and then, after blasting and slipping out, install a vibration sensor in the hole for sensor installation and the crushing machine. It is something to measure.

Process B (blasting/supporting work exploration process: impact exploration process) is installed in the vicinity of the face of the face after installing the vibration sensor in the sensor installation hole in the tunnel wall behind the face of the face by a predetermined distance. The face of the face is struck by the construction machine, and the vibration that propagates through the ground due to the struck is measured by the vibration sensor. This step B is a step of installing a vibration-receiving sensor in the sensor installation hole during the scavenging work or after the completion of the concrete spraying work on the tunnel pit wall, and a face cutting process during or after the spraying work. And a step of hitting the face face with the leveling machine during or after the leveling work as a construction machine arranged near the surface.

In process C (drilling/exploration process during charging), the vibration-receiving sensor installed in the sensor installation hole is temporarily removed before the concrete is sprayed onto the tunnel shaft, and after the concrete spraying work is completed. The vibration receiving sensor is installed again in the hole for sensor installation in the tunnel pit wall and the drilling machine, and the vibration during the drilling of the blast hole is measured by the vibration receiving sensor by the drilling machine.

In the above-mentioned steps A to C, instead of installing the vibration receiving sensor in the sensor installation hole, or in addition to this, installing the vibration receiving sensor in support work such as a lock bolt provided in the tunnel pit wall. Vibration may be measured. As the vibration measuring method when the vibration receiving sensor is installed on the lock bolt, for example, the methods described in Patent Documents 2 and 3 can be used.

In the present embodiment, the above-mentioned steps A to C are repeatedly performed as necessary along with the tunnel excavation, so that the front face exploration can be continuously performed during the tunnel construction. Hereinafter, the tunnel face forward exploration method according to the present embodiment will be described more specifically with reference to the process diagram of the mountain tunnel construction by the NATM method in FIG. 1. In FIG. 1, step S7 corresponds to step A, step S8-1 corresponds to step B, and step S9 corresponds to step C.

As shown in FIG. 1, first, a tunnel face is blasted (step S1), and a slipping out is performed (step S2). Subsequently, a support work is built in the tunnel 10 and concrete is sprayed on the pit wall (step S3). Next, the blast hole is drilled and the hole is charged (step S4). Here, from the time when the blast hole is drilled until the time when the hole is charged and blasted, a predetermined distance from the face face 12 (for example, about 10 to 15 m. That is, the length of the hole making machine to be placed in front of the face face) The sensor installation hole 14 for installing the vibration-receiving sensor is drilled in the tunnel pit wall at the rear only. Note that FIG. 1 illustrates the case where three sensor installation holes 14 are installed at intervals of 5 m.

Next, blasting is performed on the face (step S5), and slipping is performed (step S6). After the completion of the blasting and the slipping out, the face of the face is scooped by the hydraulic breaker 16 (crushing machine) (step S7), but before the scooping work is started, the sensor installation hole 14 and the hydraulic breaker 16 (crushing machine) are used. Machines) and the vibration receiving sensors 28 and 18 are installed, respectively, and the recording and analysis device 20 is wired.

Then, in step S7, the face of the cutting face is scraped by the hydraulic breaker 16, and the vibration during the scooping work is measured by the vibration receiving sensors 28, 18 (process A: exploration process during scraping). The measured vibration data is recorded in the recording and analysis device 20 through the wiring cable. By analyzing this data by the exploration method shown in Patent Document 1 or Patent Document 2 described above, for example, the condition of the ground in front of the cutting face is searched.

Subsequently, a support work is built in the tunnel 10 and concrete is sprayed on the pit wall (step S8). Here, it is assumed that the vibration receiving sensor 28 and the wiring cables installed in the sensor installation hole 14 are temporarily removed and retracted rearward before the concrete is sprayed onto the tunnel pit wall.

After the spraying work is completed, the concrete excessively attached to the support work such as the ground and rock bolts is smoothed using a trowel-shaped tool (step S8-1). This leveling work is performed using a trowel 32 attached to a hydraulic breaker 16 (leveling machine, construction machine) arranged near the facet 12. The trowel 32 is temporarily attached to the chisel 30 (a metal rod having a pointed tip in the shape of a chisel for hitting and crushing rock) of the bending arm 16a of the hydraulic breaker 16, and the arm 16a is attached. Perform leveling work by moving. As described above, in the present embodiment, the front face of the cutting face is searched using the timing when the hydraulic breaker 16 approaches the face 12 during the leveling work after the spraying/supporting process (process B: blowing/supporting work). Time exploration process). The specific procedure is as follows.

(1) From the time of the scooping work of step S7 to the time of the spraying/supporting work of step S8, the vibration-receiving sensor 28 is installed on the ground and wiring with the recording and analysis device 20 is performed. The method of installing the vibration receiving sensor 28 may be a method of installing it in the sensor installation hole 14 provided in the tunnel pit wall, or, for example, as in the above-mentioned Patent Documents 2 and 3, supporting of existing lock bolts or the like. The vibration sensor 28 may be attached to the work, or both may be used together.

(2) After the completion of the spraying work and the construction work of the support work, the hydraulic breaker 16 equipped with the trowel 32 is put in the vicinity of the face face 12 for the leveling work. During or after this leveling work, the trowel 32 is temporarily removed from the chisel 30 and the facet 12 is struck by the chisel 30 for a short time. Generally, the trowel 32 is simply inserted into the chisel 30 to be attached, and the trowel 32 is very easily attached and detached. The vibration propagating through the ground due to this impact is measured by the vibration-receiving sensor 28, and the measurement data is analyzed by the exploration method shown in Patent Document 1 or Patent Document 2, for example. To explore.

Subsequently, if necessary, measurement/exploration can be performed even during drilling/charging work (step S9). In this case, the vibration receiving sensors 28 and 24 are respectively installed in the sensor installation hole 14 of the tunnel pit wall and the drill jumbo 22 (drilling machine) arranged in the vicinity of the facet 12, and wiring with the recording and analysis device 20 is performed. I'll go. Then, the blast hole is drilled by the drill jumbo 22, and the vibration during the drilling is measured by the vibration receiving sensors 28 and 24 (process B: drilling/exposure step during charging). The measured vibration data is recorded in the recording and analysis device 20 through the wiring cable. By analyzing this data by the exploration method shown in Patent Document 1 or Patent Document 2 described above, for example, the condition of the ground in front of the cutting face is searched. In addition, as described above, instead of installing the vibration receiving sensor 28 in the sensor installation hole 14, or in addition to this, installing the vibration receiving sensor 28 in a support work such as a rock bolt constructed on a tunnel pit wall and vibrating. You may measure.

In addition, when the measurement is performed in the next shift, the sensor installation hole 26 for the next measurement is drilled at the same distance from the face face as in the previous shift measurement during this time, and this work is repeated thereafter. To do so. For example, when the measurement is performed for each shift in the tunnel excavation process, the process returns to step S5 and steps S5 to S9 are repeated (step S10). When the measurement is performed every two shifts in the tunnel excavation process, the process returns to step S1 and steps S1 to S9 are repeated (step S11).

As described above, according to the present embodiment, the timing at which the face forward exploration is performed without stopping the work by using the vibration generated by the tunnel excavating machine is the process A (step S7) in the series of excavating work, The process B (step S8-1) and the process C (step S9) can be set. That is, in the above-mentioned conventional patent document 1, the exploration timing is limited to be performed in steps A and C, but in the present embodiment, the exploration timing can be set in step B. Therefore, it is possible to set the exploration timing wider than in the conventional case. The practicality of face exploration is improved because it is possible to flexibly select the timing with less trouble according to the work situation at the site.

In the above embodiment, the case where the hitting exploration step is set to the step B (step S8-1) which is the exploration step during the blowing/supporting work has been described as an example, but the present invention is not limited to this. Absent. That is, in a series of excavation work, if there is an opportunity to install a construction machine capable of imparting vibrations by impact in the vicinity of the face face 12, it is possible to use this opportunity to perform face exploration. In this case, after the vibration-receiving sensor 28 is installed in advance in at least one of the sensor installation hole 14 provided in the tunnel pit wall behind the facet 12 by a predetermined distance or the support work such as the lock bolt, it is installed in the vicinity of the facet 12. If the face of the face in front of the face is searched by hitting the face 12 with the construction machine, measuring the vibration propagating through the ground by the impact with the vibration receiving sensor 28, and performing the analysis processing by the above-described search method. Good.

In addition, as the equipment used for generating vibration, vibration by excavating machines such as a hydraulic breaker (crushing machine) used for removing floating stones from the pit wall in tunnel construction by the NATM method and a drill jumbo (drilling machine) for blast hole drilling Since it is used as a vibration source, it does not require special equipment for front face exploration and can be performed in a short time only by moving the position of the vibration sensor along with the excavation. Can be fully integrated into the normal construction cycle.

Further, since no special time is required for exploring the front of the face, it is not necessary to stop the progress of the face, and the measurement can be continuously performed according to the progress of the face. Therefore, it is possible to estimate the position of the reflection surface such as the ground defect portion in front of the face without disturbing the normal construction cycle.

In addition, if a highly accurate reflective surface is found as a result of measurement, it is possible to select a position where a more detailed survey such as advanced boring should be performed. It is possible to grasp the position and shape of the reflecting surface.

In addition, since it can be measured as the excavation progresses, a large number of data with different distances between the face and the reflecting surface are used to compare the exploration results that are continuously measured, so that reflected waves are always generated during construction. The position can be specified, and the estimation accuracy of the position of the reflecting surface can be improved.

As the exploration method disclosed in Patent Document 1 above, there are a method of measuring a primary reflected wave from the front face of the face and a method of measuring multiple reflections between the face and the front face of the face. Although the measurement principles of these methods are all existing, since the measurement data can be continuously obtained by the method according to the present invention, it is possible to always identify the position where the reflective surface is generated by comparing a plurality of measurement data. It is possible to reduce erroneous determination due to noise or human error when measuring by emitting a single vibration.

Further, for example, it is possible to acquire data as monitoring accompanying construction without requiring special measuring equipment in the method of using explosive as a vibration source. If the position where the reflective surface occurs can always be identified from such monitoring data, it is possible to actually check the ground condition in front of the cutting face by separately performing short cutting advanced boring at the stage as close as possible to it. It will be easy.

As described above, the tunnel face forward exploration method according to the present invention is a method for exploring the face forward of the face face by the reflected wave seismic exploration method during tunnel construction by the NATM method, which is a predetermined distance behind the face face. After installing a vibration sensor in at least one of the sensor installation hole or support provided in the tunnel wall, hit the face with a construction machine installed near the face, and the vibration that propagates through the ground by this impact Since there is a hitting exploration step of measuring the vibration with the vibration sensor, it is possible to set the exploration timing wider than before.

Further, according to another tunnel face forward exploration method according to the present invention, the impact exploration step is for installing the sensor during or after the scraping work and before the concrete spraying work on the tunnel wall. A step of installing a vibration receiving sensor in at least one of the hole or the supporting work, and during or after the leveling work by the leveling machine as the construction machine arranged near the face face during or after the spraying work, Since the step of hitting the face face with the leveling machine is included, the front face exploration can be performed by utilizing the timing of the leveling work by the leveling machine after the spraying work.

Further, according to another method for exploring a tunnel face according to the present invention, a vibration-receiving sensor is installed in at least one of the sensor installation hole or the supporting work and the crushing machine after the completion of blasting and slipping, and the crushing machine. Since the method further includes a scooping exploration step of measuring the vibration during the scooping work on the face by the vibration-receiving sensor, it is possible to carry out the exploration ahead of the cut face by utilizing the timing of the scooping work.

Further, according to another tunnel face forward exploration method according to the present invention, once the vibration receiving sensor installed in at least one of the sensor installation hole or the support structure is sprayed before the concrete is sprayed onto the tunnel wall. During removal of concrete and after concrete spraying, or after completion, install a vibration sensor on at least one of the hole for sensor installation or support of the tunnel shaft and the drilling machine, and drill the blast hole with the drilling machine. Since the method further includes a hole drilling exploration step in which vibrations in the hole are measured by the vibration receiving sensor, the face forward exploration can be performed using the timing of the drilling operation before charging.

Further, according to another tunnel face exploration method according to the present invention, the face face exploration is continuously performed during tunnel construction by repeating the exploration step, so the work is interrupted in a series of excavation work. It is possible to carry out exploration ahead of the working face without any need.

INDUSTRIAL APPLICABILITY As described above, the tunnel face exploration method according to the present invention is useful as a face exploration method in mountain tunnel construction by the NATM method, and in particular, does not require special equipment dedicated to exploration and requires a construction cycle. It is suitable for continuous measurement without disturbance.

10 tunnel 12 face face 14, 26 sensor installation hole 16 hydraulic breaker (crushing machine, leveling machine, construction machine)
16a Arm 18, 24, 28 Vibration sensor 20 Recording and analysis device 22 Drill jumbo (drilling machine)
30 chisel 32 trowel process A exploration process during sneak process B exploration process during spraying/supporting work (impact exploration process)
Process C Drilling and charging exploration process (drilling exploration process)

Claims (4)

A method for exploring the front of the face by the reflected wave seismic survey method during tunnel construction by the NATM method,
After installing a vibration sensor in at least one of the sensor installation hole or support provided in the tunnel wall behind the face by a predetermined distance, hit the face with a construction machine installed near the face, the vibrations propagating natural ground by striking have a striking exploration step of measuring by the geophone sensor,
The impact exploration step, a step of installing a vibration-receiving sensor in at least one of the sensor installation hole or the supporting work between the end of the scavenging work or after the end of the operation of spraying concrete onto the tunnel pit wall,
Spraying work during or after completion during or after completion of the leveling leveling by mechanical working as the construction machine which is arranged in the vicinity of the working face surface, a Rukoto which have a a step of striking the working face surface in this leveling machine Characteristic tunnel front face exploration method. After the completion of blasting and slipping, a vibration sensor is installed in at least one of the sensor installation hole or the supporting structure and the crushing machine, and the vibration is measured by the vibration sensor during the work of scraping the face face with the crushing machine. The tunnel face forward exploration method according to claim 1, further comprising an exploration step at the time of waking. Before the concrete is sprayed onto the tunnel wall, the vibration sensor installed in at least one of the sensor installation hole or the supporting structure is once removed, and the tunnel wall of the tunnel wall is again removed during or after the concrete spraying operation. At least one of the sensor installation hole or the support work and a vibration sensor is installed in the drilling machine, and a drilling exploration step of measuring vibration during drilling a blast hole by the drilling machine by the vibration receiving sensor is performed. The tunnel face forward exploration method according to claim 1 or 2 , further comprising: The front face exploration method for a tunnel face according to any one of claims 1 to 4 , wherein the front face exploration is performed continuously during tunnel construction by repeating the exploration step.

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