Recovery device for sensor embedded in drill hole

Abstract

The utility model discloses a recovery device of a drill hole embedded sensor, which comprises at least one drill hole embedded sensor, a cylindrical protective shell is arranged outside each drill hole embedded sensor, and the protective shell comprises an inner layer and an outer layer. A gap is formed between the protective shell inner layer and the protective shell outer layer, and the borehole embedded sensor is tightly attached to the protective shell inner layer; a gap between the inner layer and the outer layer of the protective shell is filled with fixing glue, and the fixing glue is sprayed and filled on the wall of the drill hole through a circular hole formed in the outer layer of the protective shell; and a resistance wire is arranged between the protective shell inner layer and the protective shell outer layer and is used for melting the fixed glue solidified between the borehole embedded sensor and the wall of the borehole through heating of the resistance wire, so that recovery of the borehole embedded sensor is realized. According to the utility model, effective contact coupling of the sensor and the monitoring hole is realized, and the sensor has the characteristics of being recyclable and convenient to install.

Description

Technical Field

[0001] The utility model relates to the field of engineering monitoring, and particularly relates to a recovery device for a reusable borehole-embedded sensor. The device can realize the effective coupling between the sensor and the monitoring hole while realizing the reuse of the borehole-embedded sensor, so as to reduce the monitoring cost. Background Technique

[0002] Borehole-embedded sensors in engineering mainly include pore pressure sensors, vibrating wire earth pressure gauges, surrounding rock stress and microseismic signal sensors, etc. The application of these borehole-embedded sensors is of great significance for improving the safety of civil engineering, monitoring geological changes, and optimizing engineering design.

[0003] In order to ensure the effective coupling between the sensor in the monitoring hole and the monitoring hole wall, the working environment of traditional borehole-embedded sensors needs to adopt the method of injecting cement slurry into the hole on site to form an integral body between the sensor and the rock wall. However, this method has the following disadvantages: First, the sensor after injecting cement cannot be recycled, resulting in high economic costs; Second, if it is found that the injected sensor has no signal or poor signal, it cannot be inspected. To ensure the monitoring effect, it is necessary to re-drill and reinstall the sensor, which is time-consuming and laborious; Third, due to the depth of the monitoring hole, it is difficult to ensure the grouting effect at the sensor installation site. There may be a situation where the sensor fails to be effectively coupled with the monitoring hole rock wall and there is no signal. In addition, as the depth of the monitoring hole increases, the total shrinkage deformation amount after the injected cement solidifies will also increase, and the signal transmission cable bonded to the cement will be subjected to tension due to the shrinkage deformation of the cement, thereby reducing the effectiveness of signal transmission; Fourth, the humidity in the monitoring hole is usually high, and it takes a long time for the injected cement to solidify, resulting in an extended construction period; Fifth, using explosives during the excavation process may cause the relaxation of the grouting surface and the rock wall surface, thereby reducing the transmission effect of the monitored signal; Sixth, the installation process is cumbersome, requiring professional grouting equipment and well-trained construction personnel, and the required human resources are large.

[0004] These sensors are often expensive. In order to retrieve the sensors after the monitoring is completed and reduce the project cost. Currently, there are reusable microseismic monitoring acoustic emission sensors on the market. Its main working principle is to extend a metal bracket on the microseismic monitoring acoustic emission sensor and fix it to the hole wall. However, in this device design, the contact area between the extended metal bracket and the hole wall is small, so there is a problem that it cannot be effectively coupled with the hole wall. Poor coupling results in low accuracy of the results measured by this kind of microseismic monitoring acoustic emission sensor, which brings difficulties to the earthquake source positioning work.

[0005] Therefore, in the field of on-site monitoring and research, it is still a challenging task to install borehole-embedded sensors in monitoring holes and ensure effective hole wall coupling to guarantee highly accurate measurement results. Especially in the design and use of reusable sensor devices, there are obvious deficiencies in the existing technologies, and a recovery device for borehole-embedded sensors needs to be designed to ensure the coupling effect and the accuracy of monitoring results. Summary of the Utility Model

[0006] Aiming at the current situation and deficiencies of the existing technologies, the purpose of the present utility model is to provide a recovery device for reusable borehole-embedded sensors, which can not only achieve effective contact and coupling between the sensor and the monitoring hole, but also has the characteristics of being recyclable and reusable and convenient for installation, improving the accuracy of monitoring and reducing the monitoring cost.

[0007] In order to achieve the above-mentioned utility model purpose, the present utility model provides the following technical solutions:

[0008] A recovery device for borehole-embedded sensors includes at least one borehole-embedded sensor. A cylindrical protective shell is arranged outside each of the borehole-embedded sensors. The protective shell includes two layers, namely an inner layer of the protective shell and an outer layer of the protective shell. There is a gap between the inner layer of the protective shell and the outer layer of the protective shell, and the borehole-embedded sensor is in close contact with the inner layer of the protective shell.

[0009] The outer layer of the protective shell is provided with uniformly distributed circular holes. Fixing glue is filled into the gap between the inner and outer layers of the protective shell and is sprayed and filled on the borehole wall through the circular holes on the outer layer of the protective shell.

[0010] A resistance wire is arranged between the inner layer of the protective shell and the outer layer of the protective shell, which is used to heat the resistance wire to melt the solidified fixing glue between the borehole-embedded sensor and the borehole wall, so as to realize the recovery of the borehole-embedded sensor.

[0011] Optionally, each of the protective shells is connected to a glue storage and heating device through a glue delivery pipe. The glue storage and heating device includes fixing glue, a container for storing the fixing glue, an electro-hydraulic system and an internal power supply. The output end of the electro-hydraulic system extends into the container for storing the fixing glue. The internal power supply is connected to the electro-hydraulic system to supply power to the electro-hydraulic system, and the fixing glue stored inside the container is extruded into the glue delivery pipe through the electro-hydraulic system.

[0012] Furthermore, the resistance wire is connected to the internal power supply of the glue storage and heating device through a cable to supply power to the resistance wire and realize the heating of the resistance wire.

[0013] Preferably, the outer diameter of the protective housing is 10-20 mm smaller than the diameter of the drill hole, and the diameter of the circular hole is 5-10 mm.

[0014] Optionally, a temperature sensor is provided at the top of the protective housing near the borehole-embedded sensor for monitoring the melting temperature of the fixing glue.

[0015] Furthermore, each borehole-embedded sensor and the temperature sensor are connected to the corresponding monitoring data collector through a communication cable for collecting the data sensed by the borehole-embedded sensor and the temperature sensor.

[0016] Compared with the prior art, the present utility model has at least the following beneficial effects:

[0017] (1) Using the fixing glue to fill the space between the sensor and the hole wall can ensure a good coupling effect between the sensor and the hole wall, guaranteeing the accuracy of the monitoring data; the design principle of the recovery device is simple and the operation is convenient.

[0018] (2) Melting the fixing glue in the recovery device through the electric heating device can realize the recovery and reuse of the borehole-embedded sensor, reducing the use cost. Description of the Drawings

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present utility model. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0020] Figure 1 It is a schematic diagram of the recovery device for the borehole-embedded sensor provided by an embodiment of the present utility model.

[0021] Figure 2 It is a schematic diagram of the glue storage and heating device provided by an embodiment of the present utility model.

[0022] Reference numerals: 1-outer layer of the protective housing; 2-circular hole; 3-borehole-embedded sensor; 4-inner layer of the protective housing; 5-glue delivery pipe; 6-cable; 7-resistance wire; 8-temperature sensor; 9-glue storage and heating device; 10-communication cable; 11-monitoring data collector; 12-electric hydraulic system; 13-internal power supply. Detailed Embodiments

[0023] To facilitate the understanding of the present utility model, the present utility model will be described more comprehensively below with reference to the relevant drawings. The present utility model can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, these embodiments are provided to make the disclosure of the present utility model more thorough and comprehensive.

[0024] A recovery device for a borehole buried sensor, as Figure 1 , Figure 2 shown, includes at least one borehole buried sensor 3. A cylindrical protective housing is provided outside each borehole buried sensor 3. The protective housing includes two layers, namely an inner protective housing layer 4 and an outer protective housing layer 1. There is a gap between the inner protective housing layer 4 and the outer protective housing layer 1, and a fixing glue can be filled into the gap between the inner protective housing layer 4 and the outer protective housing layer 1. The materials and structural designs of the inner protective housing layer 4 and the outer protective housing layer 1 are different. Specifically, the diameter of the inner protective housing layer 4 is adapted to the diameter of the borehole buried sensor 3, so that the borehole buried sensor 3 can be in close contact with the inner protective housing layer 4. The material of the inner protective housing layer 4 is selected as a heat-insulating material. The material of the outer protective housing layer 1 is selected as a metal material. The diameter of the outer protective housing layer 1 is 10-20 mm smaller than the diameter of the borehole. The outer protective housing layer 1 is provided with uniformly distributed circular holes 2 with a hole diameter of 5-10 mm.

[0025] In the present utility model, the fixing glue can fill the gap between the inner and outer layers of the protective housing and can be sprayed and filled on the borehole wall through the circular holes 2 provided on the outer protective housing layer 1. This spraying and filling can simulate the effect of cement mortar perfusion of the traditional borehole buried sensor to achieve a good coupling effect between the borehole buried sensor and the borehole wall and ensure the accuracy of the monitoring data.

[0026] In this utility model, each protective housing can be connected to the glue storage and heating device 9 through a glue delivery pipe 5, and the material of the glue delivery pipe 5 is also selected as a metal material. The glue storage and heating device 9 includes a fixing glue, a container for storing the fixing glue, an electro-hydraulic system 12, and an internal power supply 13. The output end of the electro-hydraulic system 12 extends into the container for storing the fixing glue. The internal power supply 13 is connected to the electro-hydraulic system 12 to supply power to the electro-hydraulic system 12. Through the electro-hydraulic system 12, the fixing glue stored inside the container can be extruded into the glue delivery pipe 5 and transported through the glue delivery pipe 5 to the space between the inner and outer layers of the protective housing. A heating wire 7 is also provided between the inner layer 4 and the outer layer 1 of the protective housing. The heating wire 7 includes multiple strands, which are arranged side by side along the outer circumference of the inner layer 4 of the protective housing in the axial direction. The heating wire 7 is connected to the internal power supply 13 of the glue storage and heating device 9 through a cable 6 to supply power to the heating wire 7, realizing the heating of the heating wire 7, melting the fixing glue solidified between the borehole-embedded sensor 3 and the borehole wall, and thus realizing the smooth recovery of the borehole-embedded sensor 3.

[0027] In this utility model, to avoid damage to the borehole-embedded sensor 3 caused by heating, a temperature sensor 8 is provided near the top of the borehole-embedded sensor 3 inside the protective housing, which is used to monitor the melting temperature of the fixing glue, ensuring that the temperature is higher than the melting temperature of the fixing glue and once the temperature is higher than the high-temperature upper limit that the borehole-embedded sensor 3 can withstand, the internal power supply 13 can be timely turned off.

[0028] In this utility model, each borehole-embedded sensor 3 and temperature sensor 8 are connected to the corresponding monitoring data acquisition instrument 11 through a communication cable 10, and the data sensed by the borehole-embedded sensor 3 and temperature sensor 8 can be collected.

[0029] As a preferred embodiment of this utility model, the heat-insulating material of the inner layer of the protective housing is selected as rigid polyurethane foam plastic, which has a low thermal conductivity and can play an obvious heat-insulating effect, realizing the protection of the sensor in a high-temperature environment.

[0030] As a preferred embodiment of this utility model, the type of the fixing glue is selected as AB glue. AB glue has the advantages of reliable bonding performance, rapid curing, being unaffected by a humid environment, and bonding durability, and has a low cost and is suitable for various engineering environments.

[0031] As a preferred embodiment of this utility model, the borehole-embedded sensor can be selected as a borehole stress sensor of model YHZ-0820, the monitoring data acquisition instrument can be selected as a YHR-1103 monitoring data acquisition instrument; the internal power supply can be selected as a 12V power supply; the electro-hydraulic system can be selected as a SOV-RCD multi-stage hydraulic jack; the temperature sensor can be selected as a BD-NF temperature sensor of platinum electric-BDRTD.

[0032] The above are only the preferred embodiments of the present utility model. It should be noted that for those of ordinary skill in the art, without departing from the technical principle of the present utility model, several improvements and modifications can be made, and these improvements and modifications should also be regarded as the protection scope of the present utility model.

Claims

1. A recovery device for a drilling and embedding type sensor, characterized in that, It includes at least one borehole-embedded sensor, and a cylindrical protective housing is provided outside each of the borehole-embedded sensors. The protective housing includes two layers, namely an inner layer of the protective housing and an outer layer of the protective housing. There is a gap between the inner layer of the protective housing and the outer layer of the protective housing, and the borehole-embedded sensor is in close contact with the inner layer of the protective housing; The outer layer of the protective housing is provided with uniformly distributed circular holes. The fixing glue is filled into the gap between the inner and outer layers of the protective housing and is sprayed and filled on the borehole wall through the circular holes on the outer layer of the protective housing; A resistance wire is arranged between the inner layer of the protective housing and the outer layer of the protective housing, and is used to heat the resistance wire to melt the fixing glue solidified between the borehole-embedded sensor and the borehole wall, so as to realize the recovery of the borehole-embedded sensor.

2. The recovery device for the drilling and embedding type sensor according to claim 1, wherein, Each of the protective housings is connected to a glue storage and heating device through a glue delivery pipe. The glue storage and heating device includes fixing glue, a container for storing the fixing glue, an electro-hydraulic system and an internal power supply. The output end of the electro-hydraulic system extends into the container for storing the fixing glue, and the internal power supply is connected to the electro-hydraulic system for supplying power to the electro-hydraulic system to squeeze the fixing glue stored inside the container into the glue delivery pipe.

3. The recovery device for the drilling and embedding type sensor according to claim 2, characterized in that, The resistance wire is connected to the internal power supply of the glue storage and heating device through a cable for supplying power to the resistance wire to realize the heating of the resistance wire.

4. The recovery device for the borehole-embedded sensor according to claim 1, characterized in that, The diameter of the outer layer of the protective housing is 10 - 20 mm smaller than the diameter of the borehole, and the diameter of the circular hole is 5 - 10 mm.

5. The recovery device for the borehole-embedded sensor according to claim 1, characterized in that, A temperature sensor is arranged at the top of the protective housing near the borehole-embedded sensor for monitoring the melting temperature of the fixing glue.

6. The recovery device for the borehole-embedded sensor according to claim 5, wherein, Each of the borehole-embedded sensors and the temperature sensors is connected to a corresponding monitoring data acquisition instrument through a communication cable for collecting the data sensed by the borehole-embedded sensors and the temperature sensors.

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