Soft rock tunnel engineering deep hole micro-seismic monitoring device and installation and recovery method thereof

Abstract

The invention discloses a soft rock tunnel engineering deep hole micro-seismic monitoring device and an installation and recovery method thereof, a micro-seismic sensor is arranged in a monitoring surrounding rock drill hole, an iron sleeve is fixed in the drill hole, and an anchoring agent is compacted and laid on the surface of a bottom rock mass; the sensor is pressed and fixed on the anchoring agent, the outer end of the sensor is connected with a fixing rod, the other end of the fixing rod is connected with a telescopic rod of a threaded sleeve structure, and the outer end of the telescopic rod is located at a drill hole opening, provided with a spring and pressed and fixed at the hole opening through a hemispherical protective shell fixed at the drill hole opening; and the iron sleeve is filled with sealing polystyrene foam. The micro-seismic sensor of the device is simple and easy to install, is controlled by adopting a bolt mechanism, can be overhauled, checked, recycled and reutilized, is effectively protected in the monitoring process by installing the iron sleeve after drilling a drill hole, can adapt to unfavorable geologies such as rock mass breakage and wide joint distribution, and is high in reliability. And meanwhile, effective coupling of the micro-seismic sensor and the rock wall can be effectively realized during deep hole monitoring.

Description

Technical Field

[0001] The invention belongs to the technical field of microseismic monitoring in building construction technology, and in particular relates to a deep hole microseismic monitoring device for a soft rock tunnel project and an installation and recovery method thereof. Background Art

[0002] Microseismic monitoring technology can capture the elastic wave signals generated when rock mass breaks. As an important means of non-destructive monitoring of surrounding rock deformation and damage at an engineering scale, it is widely used in rock stability monitoring and dynamic disaster warning in the field of underground engineering.

[0003] When using microseismic monitoring technology in soft rock tunnel projects, it is an important technical prerequisite to ensure that the microseismic sensor can effectively receive the elastic wave signal generated when the rock mass breaks and reduce noise. Usually, it is necessary to drill the microseismic sensor into the deep part of the borehole, and use resin anchors, cement mortar, etc. to couple the microseismic sensor with the surrounding rock.

[0004] When installing microseismic sensors in deep holes, the existing technology cannot ensure that the microseismic sensors can be fully coupled with the rock mass, and it is easy to cause the coupling between the microseismic sensors and the surrounding rock to fail under interference such as blasting and surrounding rock movement. At the same time, microseismic sensors are expensive, and the violent surrounding rock movement of soft rock tunnels can easily cause the borehole to collapse, making the microseismic sensors unable to be recovered, increasing the economic cost of monitoring.

[0005] Microseismic monitoring of tunnel engineering requires frequent migration of microseismic sensors to the tunnel face. Therefore, a deep-hole microseismic sensor and its installation and recovery method are designed to effectively and conveniently install the microseismic sensor in the deep borehole and ensure effective coupling between the microseismic sensor and the surrounding rock. At the same time, the effective recovery of the microseismic sensor is still a difficulty in microseismic monitoring of soft rock tunnels. Summary of the invention

[0006] Aiming at the limitations of existing deep hole microseismic monitoring devices for soft rock tunnel engineering and installation and recovery methods thereof, the present invention proposes a deep hole microseismic monitoring device for soft rock tunnel engineering and an installation and recovery method thereof which is easy to install, accurate in monitoring and recyclable.

[0007] The present invention is achieved through the following technical solutions:

[0008] A deep-hole microseismic monitoring device for a soft rock tunnel project includes a microseismic sensor, which is characterized in that: the microseismic sensor is arranged in a borehole formed by drilling in the surrounding rock to be monitored; an iron sleeve matching the borehole diameter is fixed in the borehole, and an anchor is compacted and laid on the surface of the rock mass at the bottom of the borehole; the microseismic sensor is pressed and fixed on the anchor, and a fixing rod is connected to the outer end, and the other end of the fixing rod is connected to a telescopic rod of a threaded sleeve structure, the outer end of the telescopic rod is located at the borehole opening and a spring is arranged, and the spring is pressed and fixed to the borehole opening through a hemispherical protective shell fixed to the borehole opening; the iron sleeve is filled with sealing foam.

[0009] Furthermore, the contact end between the microseismic sensor and the anchoring agent is coated with a coupling agent.

[0010] Furthermore, the signal line of the microseismic sensor is in the iron sleeve and is led out through the hemispherical protective shell.

[0011] Furthermore, the hemispherical protective shell is fixed to the surrounding rock via expansion bolts on all sides.

[0012] Furthermore, a flat bottom plate is arranged at the outer end of the telescopic rod, one end of the spring is fixedly contacted with the bottom plate, and the other end is pressed and connected with the hemispherical protective shell.

[0013] The present invention also discloses an installation and recovery method using the above monitoring device, comprising the following steps:

[0014] The first step is to select a drill bit that is larger than the microseismic sensor to drill a hole. After the drilling is completed, put the iron sleeve into the hole as soon as possible.

[0015] The second step is to apply coupling agent to the end of the resin anchor compactor, connect the fixing rod and the resin anchor compactor through a stainless steel clamp, send the resin anchor to the bottom of the borehole and press it tightly and compact it; then take out the resin anchor compactor;

[0016] The third step is to separate the fixing rod from the resin anchor compactor; apply coupling agent to the end of the microseismic sensor and send it to the bottom of the borehole after connecting it to the fixing rod;

[0017] Step 4: After adjusting the telescopic rod to a suitable position, fix the length of the telescopic rod and spray the sealing foam inside the iron sleeve;

[0018] The fifth step is to fix the hemispherical protective shell to the tunnel surrounding rock through expansion bolts, connect the signal line out of the borehole, and carry out microseismic monitoring;

[0019] Step 6. After the microseismic monitoring is completed, loosen the expansion bolts to remove the hemispherical protective shell, and completely remove the microseismic sensor through the fixing rod.

[0020] The benefits of the present invention:

[0021] The microseismic sensor of the deep hole microseismic monitoring device for soft rock tunnel engineering of the present invention is simple and easy to install, saving a lot of manpower, and can be installed in the deep hole, overcoming the influence of construction noise in the tunnel on microseismic signal collection.

[0022] The deep hole microseismic monitoring device for soft rock tunnel engineering of the present invention is controlled by a bolt mechanism, and can realize the maintenance and inspection of microseismic sensors during the microseismic monitoring process, and realize the recovery and re-reading of microseismic sensors, which facilitates construction and reduces engineering costs.

[0023] The deep hole microseismic monitoring device for soft rock tunnel engineering of the present invention installs an iron sleeve after drilling the borehole to achieve effective protection of the microseismic sensor during the monitoring process. It can adapt to unfavorable geological conditions such as rock fragmentation and widespread joint distribution, and at the same time ensure effective coupling between the microseismic sensor and the rock wall during deep hole monitoring. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a schematic diagram of the drilling construction state of the deep hole microseismic sensor for soft rock tunnel engineering of the present invention;

[0025] Figure 2 This is a schematic diagram of the installation state of the deep hole microseismic sensor for soft rock tunnel engineering of the present invention;

[0026] Figure 3 Flowchart of installation and recovery method of deep hole microseismic sensors for soft rock tunnel engineering

[0027] In the figure: 1 is an anchoring agent, 2 is a coupling agent, 3 is surrounding rock, 4 is an iron sleeve, 5 is a microseismic sensor, 6 is a stainless steel clamp, 7 is a signal line, 8 is a fixing rod, 9 is a drill hole, 10 is a telescopic rod, 11 is an expansion bolt, 12 is a spring, 13 is a resin anchoring agent compactor, 14 is a hemispherical protective shell, and 15 is a sealing foam. DETAILED DESCRIPTION

[0028] The present invention is further described below in conjunction with specific implementation methods. The specific implementation methods are further descriptions of the principles of the present invention and do not limit the present invention in any way. Technologies that are the same or similar to the present invention do not exceed the scope of protection of the present invention.

[0029] Combined with the attached pictures.

[0030] As shown in the figure, the installation of the microseismic sensor in this embodiment involves the following structures or materials: resin anchor 1, coupling agent 2, iron sleeve 4, microseismic sensor 5, signal line 7, fixing rod 8, telescopic rod 10, spring mechanism 12, hemispherical protective shell 14, resin anchor compactor 13, and sealing foam 15.

[0031] The resin anchor 1 is a common slow anchor on the market, which is located at the bottom of the borehole 9 and is used to correct the bottom of the borehole 9 to a plane, so that the microseismic sensor 5 can be in close contact with the bottom of the borehole 9 and effectively receive rock fracture signals.

[0032] The coupling agent 2 is located between the resin anchoring agent 1 at the bottom of the borehole 9 and the microseismic sensor 5 . Generally, industrial vaseline can be selected to better couple the microseismic sensor 5 with the bottom of the borehole 9 .

[0033] The iron sleeve 4 is located inside the borehole 9, with an outer diameter slightly smaller than the inner diameter of the borehole 9 and an inner diameter slightly larger than the outer diameter of the microseismic sensor 5. The iron sleeve 4 is placed in the borehole 9 as soon as the borehole 9 is formed, and is used to support the borehole 9 to prevent collapse during the detection of the microseismic sensor 5, thereby ensuring that the microseismic sensor 5 can be recovered smoothly.

[0034] The bottom of the microseismic sensor 5 is connected to a signal line 7 for transmitting the signal received by the microseismic sensor 5 out of the borehole 9 .

[0035] The fixing rod 8 is composed of two rigid rods having a depth approximately equal to that of the drilled hole 9 .

[0036] The telescopic rod 10 is composed of an inner rod section, an outer rod section and screws. The inner rod and the fixed rod 8 are connected as a whole by welding. The length can be dynamically adjusted by the cooperation of the inner rod section, the outer rod section and the screws.

[0037] The spring mechanism 12 is composed of a spring and a bottom plate. One end of the spring is connected to the hemispherical protective shell 14 , and the other end is connected to the bottom plate and in contact with the telescopic rod 10 .

[0038] The hemispherical protective shell 14 is a stainless steel shell with bolt holes distributed around the edge. The hemispherical protective shell 14 is fixed to the rock mass by expansion bolts 11, and there is a wiring opening to transmit the signal line 7 from the borehole 9.

[0039] The resin anchor compactor 13 is a truncated cone structure, which can be connected to the fixing rod 8 and is used to compact the resin anchor 1 at the bottom of the hole.

[0040] The sealing foam glue is a common foam glue available on the market, and is used to spray the sealing foam glue 15 to seal the borehole 9 after the microseismic sensor 5 is installed, so as to isolate the microseismic sensor 5 from the influence of noise outside the borehole 9.

[0041] The method for installing and recovering the deep hole microseismic sensor for soft rock tunnel engineering of the present invention adopts the following method:

[0042] The first step is to select a drill bit larger than the microseismic sensor 5 to drill the borehole 9, and after the drilling 9 is completed, the iron sleeve 4 is immediately placed inside the borehole 9;

[0043] The second step is to apply lubricant 2, such as industrial vaseline, to the end of the resin anchor compactor 13, connect the fixing rod 8 to the resin anchor compactor 13 through the stainless steel clamp 6, and send the resin anchor to the bottom of the borehole 9 to compress and compact it. Then take out the resin anchor compactor 13;

[0044] The third step is to separate the fixing rod 8 from the resin anchor compactor 13; apply coupling agent 2, such as industrial vaseline, to the end of the microseismic sensor 5, and send it to the bottom of the borehole 9 after the fixing rod 8 is connected;

[0045] Step 4: After adjusting the telescopic rod 10 to a suitable position, fix the length of the telescopic rod 10 and spray the sealing foam 15 in the iron sleeve 4;

[0046] Step 5: Fix the hemispherical protective shell 14 to the tunnel surrounding rock through the expansion bolts 11, connect the signal line 7 out of the borehole, and carry out microseismic monitoring;

[0047] Step 6: After the microseismic monitoring is completed, loosen the expansion bolts 11 to remove the hemispherical protective shell 14 , and completely take out the microseismic sensor 5 through the fixing rod 8 .

Claims

1. A deep hole microseismic monitoring device for soft rock tunnel engineering, including a microseismic sensor, characterized in that: The microseismic sensor is set in the surrounding rock to be monitored and in the borehole formed by drilling; an iron sleeve matching the borehole diameter is fixed in the borehole, and an anchor is compacted and laid on the surface of the rock at the bottom of the borehole; the microseismic sensor is pressed and fixed on the anchor, and a fixing rod is connected to the outer end, and the other end of the fixing rod is connected to a telescopic rod of a threaded sleeve structure, the outer end of the telescopic rod is located at the borehole opening and a spring is arranged, and the spring is pressed and fixed to the borehole opening through a hemispherical protective shell fixed to the borehole opening; the iron sleeve is filled with sealing foam.

2. The deep hole microseismic monitoring device for soft rock tunnel engineering according to claim 1 is characterized by: The contact end between the microseismic sensor and the anchoring agent is coated with a coupling agent.

3. The deep hole microseismic monitoring device for soft rock tunnel engineering according to claim 1 is characterized by: The signal line of the microseismic sensor is in the iron sleeve and is led out through the hemispherical protective shell.

4. The deep hole microseismic monitoring device for soft rock tunnel engineering according to claim 1 is characterized by: The hemispherical protective shell is fixed to the surrounding rock via expansion bolts on all sides.

5. The deep hole microseismic monitoring device for soft rock tunnel engineering according to claim 1 is characterized by: A plane bottom plate is arranged at the outer end of the telescopic rod, one end of the spring is in contact with and fixed to the bottom plate, and the other end is pressed and connected to and fixed to the hemispherical protective shell.

6. A method for installing and recovering a deep hole microseismic monitoring device for a soft rock tunnel project, characterized in that The following steps are involved: The first step is to select a drill bit that is larger than the microseismic sensor to drill a hole. After the drilling is completed, put the iron sleeve into the hole as soon as possible. The second step is to apply coupling agent to the end of the resin anchor compactor, connect the fixing rod and the resin anchor compactor through a stainless steel clamp, send the resin anchor to the bottom of the borehole and press it tightly and compact it; then take out the resin anchor compactor; The third step is to separate the fixing rod from the resin anchor compactor; apply coupling agent to the end of the microseismic sensor and send it to the bottom of the borehole after connecting it to the fixing rod; Step 4: After adjusting the telescopic rod to a suitable position, fix the length of the telescopic rod and spray the sealing foam inside the iron sleeve; The fifth step is to fix the hemispherical protective shell to the tunnel surrounding rock through expansion bolts, connect the signal line out of the borehole, and carry out microseismic monitoring; Step 6. After the microseismic monitoring is completed, loosen the expansion bolts to remove the hemispherical protective shell, and completely remove the microseismic sensor through the fixing rod.

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