CN218117852U

CN218117852U - Device suitable for microstrain method test bottom plate destruction degree of depth

Info

Publication number: CN218117852U
Application number: CN202222667454.7U
Authority: CN
Inventors: 李昂; 周永根
Original assignee: Xian University of Science and Technology
Current assignee: Xian University of Science and Technology
Priority date: 2022-10-11
Filing date: 2022-10-11
Publication date: 2022-12-23
Anticipated expiration: 2032-10-11

Abstract

The utility model relates to a device suitable for microstrain method test bottom plate destruction depth, data acquisition station (6) pass through signal transmission cable (5) and connect two or more waterproof type microstrain sensor (1), waterproof type microstrain sensor (1) is tied up outside extension pipe (2) by fastening band (15); the traditional micro-strain sensor (1.1) is wrapped by the waterproof protective shell (1.2); a plurality of hollow straight pipes (2.4) are connected in series through a straight-through connector (2.5) or a three-way connector (2.3), a slurry inlet (2.1) is positioned at the upper part of an extension conduit (2), a side port of the three-way connector (2.3) at the lower part of the extension conduit (2) is a slurry outlet (2.2), the working face can be continuously monitored, the slurry can be ensured to be coupled with the rock mass around a drill hole, meanwhile, damage to a vulnerable sensor and a signal transmission cable can be prevented, and monitoring efficiency and continuity of the working face can be effectively improved.

Description

Device suitable for microstrain method test bottom plate destruction degree of depth

Technical Field

The utility model relates to a detection device specifically is a device suitable for microstrain method test bottom plate destroys degree of depth.

Background

The water disaster is one of five disasters of a mine, and is always the key direction of mine disaster prevention and control, the threat of a limestone confined aquifer under a substrate is increasingly prominent in the coal seam stoping process of the North China coal field, and in order to ensure that coal resources can be safely and efficiently stoped, the danger of water inrush from a bottom plate must be evaluated, and then corresponding prevention and control measures are taken. The bottom plate rock mass is damaged to a certain depth under the strong mining disturbance, so that the thickness of an effective water-resisting layer is reduced, when the damage depth generated by the bottom plate is too large, the bottom plate rock mass even can penetrate into the water-bearing layer, the water inrush accident of the bottom plate is caused, and the accurate and effective exploration of the damage depth of the bottom plate is the key for evaluating the water inrush danger.

In order to ensure safe and efficient coal resource recovery, related personnel carry out a large amount of field test work, and the current main test methods comprise micro-seismic monitoring, pressurized-water experiments and the like. The microseism monitoring mainly is through burying the microseism sensor underground in the drilling, through the weak signal that breaks of response bottom plate rock mass, tests bottom plate destruction depth, and the environmental requirement of microseism monitoring to whole test is higher, and when the background noise of test environment was too big, the weak signal that the bottom plate rock mass broke can not better be sensed to the microseism sensor, and the accuracy of test result is difficult to guarantee. The water-pressing experiment mainly comprises the steps of carrying out high-pressure water injection in a drill hole by using a drilling machine in cooperation with a hole packer, judging the crack development degree of a rock body according to the water injection loss amount to test the damage depth of a bottom plate rock body, wherein the water-pressing experiment needs the cooperation of the drilling machine and has a complex process; the rock mass around the drilled hole is disturbed, so that hole collapse is easily caused to cause experiment failure; the pressurized water test can only test the rock destruction before the working face is mined through the test drill hole, and can not continuously monitor the rock destruction of the bottom plate directly above the drill hole mined from the working face or the drill hole mined from the working face (the drill hole enters the goaf).

In the past, a solid rod is adopted as an extension guide rod of the sensor when the micro-strain sensor is installed in a drill hole, and after the micro-strain sensor is installed, hole sealing is carried out by methods such as grouting at a drill hole opening, so that injected slurry cannot be effectively coupled with rock mass around the drill hole, the accuracy of a monitoring result is affected, the sensor and a signal transmission cable are easily damaged, and the failure of a testing system is caused. Traditional little strain sensor does not possess waterproof or high strength's characteristics, does not carry out the processing of protective housing such as waterproof to it mostly when using, leads to little strain sensor to appear malfunctioning phenomenon even damaged when receiving the invasion of factors such as water easily, influences the test result.

Disclosure of Invention

To the problem that above-mentioned prior art exists, the utility model provides a device suitable for microstrain method test bottom plate destroys degree of depth can carry out continuous monitoring to the working face to can ensure to prevent that vulnerable sensor and signal transmission cable from damaging when thick liquid and the rock mass coupling around the drilling, can improve working face monitoring efficiency and continuity effectively.

In order to realize the purpose, the utility model discloses a following technical scheme realizes: a device suitable for testing the damage depth of a bottom plate by a microstrain method comprises waterproof microstrain sensors, an extension guide pipe, a test drill hole, a test drill site, a signal transmission cable, a data acquisition station, a bottom plate, a coal seam to be mined, a stoping roadway, a coal pillar, a top plate, a working surface, a goaf, cement slurry and a fastening belt, wherein the data acquisition station is connected with more than two waterproof microstrain sensors through the signal transmission cable, and the waterproof microstrain sensors are bound outside the extension guide pipe through the fastening belt; the waterproof micro-strain sensor comprises a traditional micro-strain sensor and a waterproof protective shell, and the traditional micro-strain sensor is wrapped by the waterproof protective shell; coating a layer of waterproof flexible glue on the outer surfaces of all traditional micro-strain sensors to be used, and pouring waterproof mortar on the traditional micro-strain sensors to form a waterproof protective shell to form the waterproof micro-strain sensors; the extension guide pipe comprises a pulp inlet, a pulp outlet, a three-way connector, a plurality of hollow straight pipes and a straight-through connector, wherein the hollow straight pipes are connected in series through the straight-through connector or the three-way connector, the pulp inlet is positioned at the upper part of the extension guide pipe, and a side port of the three-way connector at the lower part of the extension guide pipe is the pulp outlet; the extension pipe is located the junction of test drilling lower part and adopts the tee bend connector as the grout outlet, can adopt the tee bend connector in one or more junctions according to actual conditions, but the position that adopts the tee bend connector should be in test drilling lower part as far as possible, and the extension pipe junction that is located upper and middle part in the test drilling should adopt the through connection head, otherwise probably influences the slip casting effect.

Firstly, arranging a bottom plate test drill hole on a side excavation drill site of a coal seam to be mined in a stoping roadway in front of a working face, wherein the size of the test drill site meets the construction space required for drilling the test drill hole and installing a waterproof micro-strain sensor, and the bottom surface elevation of the test drill site is positioned in a certain depth of a bottom plate rock mass, so that the test system is prevented from being damaged when the stoping of the working face is right above the test drill hole; after the excavation of the test drill site is finished, the test drill hole is drilled, the test drill hole is provided with a casing pipe in a certain depth from the hole opening, and the hole opening of the drill hole is prevented from collapsing before grouting hole sealing is finished. And then fastening the waterproof micro-strain sensor on an extension conduit and installing the waterproof micro-strain sensor in a test drill hole, injecting cement slurry into the test drill hole by using the extension conduit to seal the hole, finally embedding all waterproof micro-strain sensor signal transmission cables outside a coal pillar lateral stoping roadway, monitoring and analyzing the change conditions of micro-strain before, during and after stoping disturbance of a bottom plate rock mass, and determining the damage depth of the bottom plate. The distance between the test borehole and the working surface is determined according to the designed monitoring time, and parameters such as the borehole depth, the inclination angle, the azimuth angle and the like are also designed according to the actual condition of the bottom plate rock mass; the number of waterproof micro-strain sensors to be installed in the test drill hole is determined according to the actual condition of the bottom plate rock mass.

A plurality of waterproof type micro strain sensors should be installed according to the designed interval distance, the installation order of a plurality of waterproof type micro strain sensors is recorded simultaneously to mark on respective signal transmission cable, prepare for follow-up monitoring to the floor rock mass micro strain variation situation of the different degree of depth.

And after the waterproof micro-strain sensor is completely installed, injecting cement slurry into the extension guide pipe, enabling the cement slurry to reach the bottom of the hole of the test drill hole from a slurry outlet at the bottom of the extension guide pipe, continuously injecting the cement slurry into the extension guide pipe until the cement slurry in the test drill hole rises to the hole opening from the bottom of the hole, and finishing the grouting and hole sealing process.

As a further improvement of the utility model, the extension conduit is a hollow tube made of seamless galvanized steel tube or PVC tube and other materials.

As a further improvement of the utility model, the length of the hollow straight pipe is thirty centimeters.

As a further improvement of the utility model, the signal transmission cable is packaged by a galvanized steel pipe or a wear-resistant rubber hard pipe.

As the utility model discloses a further improvement scheme, signal transmission cable bury the bottom plate, the signal transmission cable should use the fastening area to fix together on extending the pipe along with every waterproof type micro strain transducer, after all waterproof type micro strain transducer installations are accomplished, should cross the stoping tunnel from the test drilling drill way with whole signal transmission cable in unison and bury underground to the coal pillar side, later along the coal pillar side direction stoping tunnel bury underground outward.

As a further improvement of the utility model, the signal transmission cable buried depth is higher than three centimeters.

As a further improvement of the utility model, the waterproof protective housing be cylindrical or cuboid and the like.

Borrow by above-mentioned scheme, the utility model discloses at least, have following advantage: compared with a conventional monitoring device, the grout injection mode adjusted by the extension guide pipe and the waterproof micro-strain sensor with waterproof capability can continuously monitor the working face, can ensure that the grout is coupled with the rock mass around the drill hole, simultaneously prevents the damage of the easily damaged sensor and the signal transmission cable, and can effectively improve the monitoring efficiency and the continuity of the working face.

Drawings

FIG. 1 is a perspective view of an apparatus suitable for microstrain-based testing of depth of failure of a substrate;

FIG. 2 is a perspective view of an extension duct of an apparatus suitable for microstrain-based testing of the depth of failure of a substrate;

FIG. 3 is a view showing the structure of a waterproof type micro-strain sensor for a device for testing the depth of damage of a base plate by a micro-strain method;

FIG. 4 is a schematic top plan sectional layout view of an apparatus for microstrain-based failure depth testing of a substrate;

FIG. 5 is a front cross-sectional layout of a working surface of an apparatus suitable for microstrain-based testing of failure depth of a substrate;

in the figure: 1. waterproof type micro strain sensor, 1.1, traditional type micro strain sensor, 1.2, waterproof protective housing, 2, extension pipe, 2.1, advance thick liquid mouth, 2.2, go out thick liquid mouth, 2.3, tee junction head, 2.4, hollow straight tube, 2.5, through connector, 3, test drilling, 4, test drill site, 5, signal transmission cable, 6, data acquisition station, 7, bottom plate, 8, wait to adopt the coal seam, 9, stope tunnel, 10, coal pillar, 11, roof, 12, working face, 13, collecting space area, 14, cement thick liquid, 15, fastening area.

Detailed Description

The present invention will be further explained with reference to the accompanying drawings.

As shown in fig. 1 to 3, the device suitable for testing the damage depth of the bottom plate by the microstrain method comprises a waterproof microstrain sensor 1, an extension conduit 2, a test drill hole 3, a test drill site 4, a signal transmission cable 5, a data acquisition station 6, a bottom plate 7, a coal seam to be mined 8, a stoping roadway 9, a coal pillar 10, a top plate 11, a working surface 12, a goaf 13, cement slurry 14 and a fastening belt 15, wherein the data acquisition station 6 is connected with more than two waterproof microstrain sensors 1 through the signal transmission cable 5, and the waterproof microstrain sensors 1 are bound outside the extension conduit 2 by the fastening belt 15; the waterproof micro-strain sensor 1 comprises a traditional micro-strain sensor 1.1 and a waterproof protective shell 1.2, and the traditional micro-strain sensor 1.1 is wrapped by the waterproof protective shell 1.2; coating a layer of waterproof flexible glue on the outer surfaces of all traditional microstrain sensors 1.1 required to be used, and pouring waterproof mortar on the traditional microstrain sensors to form a waterproof protective shell 1.2 to form a waterproof microstrain sensor 1; the extension conduit 2 comprises a pulp inlet 2.1, a pulp outlet 2.2, a three-way connector 2.3, a plurality of hollow straight pipes 2.4 and a straight-through connector 2.5, wherein the plurality of hollow straight pipes 2.4 are connected in series through the straight-through connector 2.5 or the three-way connector 2.3, the pulp inlet 2.1 is positioned at the upper part of the extension conduit 2, and a side port of the three-way connector 2.3 at the lower part of the extension conduit 2 is the pulp outlet 2.2; the extension pipe is located the junction of test drilling 3 lower part and adopts tee bend connector 2.3 as play thick liquid mouth 2.2, can adopt tee bend connector 2.3 at one or more junctions according to actual conditions, but the position of adopting tee bend connector 2.3 should be in test drilling 3 lower part as far as possible, and the extension pipe 2 junction of upper and middle portion in test drilling 3 should adopt through connector 2.5, otherwise probably influences the slip casting effect.

As shown in fig. 4 and 5, firstly, a bottom plate 7 test drill hole 3 is arranged on a to-be-mined coal seam side 8 excavation drill site 4 in a stoping roadway 9 in front of a working face 12, the size of the test drill site 4 is required to meet the construction space required for setting the test drill hole 3 and installing a waterproof micro-strain sensor 1, the bottom elevation of the test drill site 4 is required to be positioned in a certain depth of a rock body of the bottom plate 7, and the test system is prevented from being damaged when the working face 12 is stoped to be right above the test drill hole 3; after the excavation of the test drill site 4 is finished, the test drill hole 3 is drilled, the test drill hole 3 is provided with a sleeve in a certain depth from the hole opening, and the hole opening of the test drill hole 3 is prevented from collapsing before the grouting hole sealing is finished. And then fastening the waterproof micro-strain sensor 1 on an extension conduit 2 and installing the waterproof micro-strain sensor in a test borehole 3, injecting cement slurry 14 into the test borehole 3 by using the extension conduit 2 for hole sealing, finally embedding all the waterproof micro-strain sensor 1 signal transmission cables 5 outside a mining roadway 9 along a coal pillar side 10, and monitoring and analyzing the change conditions of micro-strain quantities before, during and after mining disturbance of a bottom plate 7 rock mass so as to determine the damage depth of the bottom plate 7. The distance between the test borehole 3 and the working face 12 is determined according to the designed monitoring time, and parameters such as the borehole depth, the inclination angle, the azimuth angle and the like are also designed according to the actual situation of the bottom plate rock mass; the number of waterproof micro-strain sensors 1 to be installed in the test borehole 3 is determined according to the actual condition of the rock mass of the bottom plate 7.

A plurality of waterproof type micro strain sensor 1 should install according to the spacing distance of design, and the installation order of a plurality of waterproof type micro strain sensor 1 of record simultaneously to mark on respective signal transmission cable 5, prepare for the follow-up monitoring to the bottom plate 7 rock mass micro strain variation situation of the different degree of depth.

And after the waterproof micro-strain sensor 1 is completely installed, injecting cement slurry 14 into the extension pipe 2, enabling the cement slurry 14 to reach the bottom of the test drill hole 4 from the slurry outlet 2.2 at the bottom of the extension pipe 2, and continuously injecting the cement slurry 14 into the extension pipe 2 until the cement slurry 14 in the test drill hole 3 rises to the hole opening from the bottom of the hole, so that the grouting and hole sealing process can be finished.

In order to make the better completion design objective of extension pipe 2 compromise the economic nature simultaneously, as the utility model discloses a further improvement scheme, extension pipe 2 adopt the hollow tube of other materials such as seamless galvanized steel pipe or PVC pipe.

In order to splice the extension pipe 2 according to the requirement, as a further improvement of the utility model, the length of the hollow straight pipe 2.4 is thirty centimeters.

In order to prevent the signal transmission cable 5 from being damaged by accident, as the utility model discloses a further improvement scheme, signal transmission cable 5 encapsulate with galvanized steel pipe or wear-resisting rubber hard tube.

Preferably, as the utility model discloses a further improvement scheme, signal transmission cable 5 bury bottom plate 7, signal transmission cable 5 should use fastening area 15 to fix together on extension pipe 2 along with every waterproof type micro strain sensor 1, after all waterproof type micro strain sensors 1 installation is accomplished, should cross the extraction tunnel 9 from test drilling 3 drill holes in unison with whole signal transmission cable 5 and bury underground to coal column side 10, later along coal column side 10 to the extraction tunnel 9 outside bury underground.

In order to further prevent the signal transmission cable 5 from being damaged accidentally, as the utility model discloses a further improvement scheme, signal transmission cable 5 buried depth be higher than three centimetres.

In order to satisfy installation requirements such as ligature fastening, as the utility model discloses a further improvement scheme, waterproof protective housing 1.2 be shapes such as cylindrical or cuboid.

When the device is used, the device suitable for testing the damage depth of the bottom plate by the micro-strain method is installed, and the equipment can be put into use.

The utility model discloses when using, concrete work is as follows:

a. determining the distance between the test borehole 3 and the working face 12 according to the designed monitoring time, wherein the test borehole 3 is still positioned at a certain distance in front of the working face 12 after the waterproof micro-strain sensor 1 is installed and has the test conditions at the arrangement position of the test borehole 3, so that the micro-strain of the rock mass before the working face 12 adopts the test borehole 3 can be effectively monitored, and the parameters such as the depth, the inclination angle, the azimuth angle and the like of the test borehole 3 are designed according to the actual rock mass condition of the bottom plate 7; excavating a test drill site on the side of a coal seam to be mined in a stoping roadway, specifically excavating according to the determined design position of a test drill hole 3, wherein the size of the test drill site 4 meets the construction space required for constructing the test drill hole 3 and installing a waterproof micro-strain sensor 1, and the bottom surface elevation of the test drill site 4 is positioned in a certain depth of a rock mass of a bottom plate 7, so that the test system is prevented from being damaged when a working surface 12 is stoped to be right above the test drill hole 3; after the excavation of the test drill site 4 is finished, the test drill hole 3 is drilled, the test drill hole 3 is provided with a sleeve in a certain depth from the hole opening, and the hole opening of the test drill hole 3 is prevented from collapsing before the grouting hole sealing is finished.

b. Before a test system is installed, a layer of waterproof flexible glue is coated on the outer surface of a traditional micro-strain sensor; and then, pouring waterproof mortar on the traditional micro-strain sensor to form a waterproof protective shell 1.2, so as to form the waterproof micro-strain sensor 1. The waterproof protective shell 1.2 can be made into shapes such as a cylinder or a cuboid to meet installation requirements such as binding and fastening.

c. Installing a plurality of waterproof micro-strain sensors 1 to be embedded into a test borehole 3 along with an extension conduit 2 one by one according to a certain spacing distance, simultaneously recording the installation sequence of the plurality of waterproof micro-strain sensors 1, marking on respective signal transmission cables 5, and preparing for subsequent monitoring of the change condition of the micro-strain of the bottom plate 7 rock mass at different depths; each waterproof micro-strain sensor 1 is fixed on the extension conduit 2 by using a fastening belt 15, so that the phenomena of looseness, displacement and the like of the waterproof micro-strain sensor in a test drill hole are avoided, the fastening belt 15 can be a waterproof adhesive tape with high bonding degree according to actual use requirements, and any other objects with fastening effects such as a high-strength binding tape can be used, but the waterproof micro-strain sensor 1 or the extension conduit 2 is prevented from being damaged; the extension pipe 2 can adopt hollow pipes made of seamless galvanized steel pipes or PVC pipes and other materials, but the material of the extension pipe 2 needs to meet the use requirements of pressure resistance, high strength and the like according to actual conditions, the connection position of the extension pipe at the lower part of the test drill hole 3 can adopt a three-way connector 2.3 as a slurry outlet 2.2, the three-way connector 2.3 can be adopted at one or more connection positions according to actual conditions, but the position of the three-way connector 2.3 is required to be positioned at the lower part of the test drill hole 3 as far as possible, the connection position of the extension pipe 2 at the middle upper part of the test drill hole 3 is required to be directly communicated with a connector 2.5, otherwise, the grouting effect is possibly influenced.

d. After the waterproof micro-strain sensor 1 is completely installed, cement grout 14 can be injected into the extension pipe 2 by using grouting equipment such as a manual grouting pump and a pneumatic grouting machine, and a small amount of accelerating agent is added into the injected cement grout 14, so that the test borehole 3 can be rapidly and compactly plugged; the cement grout 14 reaches the bottom of the test drill hole 14 from the grout outlet 2.2 at the bottom of the extension conduit 2, and the cement grout is continuously injected into the extension conduit until the cement grout in the test drill hole rises from the bottom of the test drill hole to the hole opening, so that the grouting and hole sealing process can be finished.

e. The signal transmission cables 5 are fixed on the extension guide pipe 2 together with each waterproof micro-strain sensor 1 by using a fastening belt 15, after all the waterproof micro-strain sensors 1 are installed, all the signal transmission cables 5 are uniformly buried from the test drill hole 3 to the coal pillar side 10 in a manner of crossing the stoping roadway 9, and then buried outside the stoping roadway 9 along the coal pillar side 10; before being buried, the signal transmission cable 5 can be firstly led into a galvanized steel pipe or a wear-resistant rubber hard pipe or other pipes made of other materials, and then buried at a certain depth, so that the signal transmission cable 5 is protected from being damaged to the greatest extent.

f. The arrangement position of the data acquisition monitoring station 6 is determined according to the design time length which needs to be monitored after the working face 12 adopts the test borehole 3, the signal transmission cable 5 is buried at the design position of the data acquisition monitoring station 6 and is pulled into the data acquisition station 6, and the acquisition and analysis of the rock deformation data of the bottom plate 7 in the whole stages before, during and after the working face adopts the test borehole 3 are carried out; the signal acquisition station 6 can be set into a manual acquisition type according to actual use requirements, and can also be designed into a more convenient and faster automatic acquisition type.

Claims

1. The device suitable for testing the damage depth of the bottom plate by the microstrain method comprises a signal transmission cable (5), a data acquisition station (6), the bottom plate (7), a coal seam to be mined (8), a stoping roadway (9), a coal pillar (10), a top plate (11), a working surface (12), a goaf (13), cement slurry (14) and a fastening belt (15), and is characterized in that the data acquisition station (6) is connected with more than two waterproof microstrain sensors (1) through the signal transmission cable (5), and the waterproof microstrain sensors (1) are bound outside an extension guide pipe (2) through the fastening belt (15); the waterproof micro-strain sensor (1) comprises a traditional micro-strain sensor (1.1) and a waterproof protective shell (1.2), wherein the traditional micro-strain sensor (1.1) is wrapped by the waterproof protective shell (1.2); extend pipe (2) including advancing thick liquid mouth (2.1), go out thick liquid mouth (2.2), tee junction head (2.3), hollow straight tube (2.4) and through connector (2.5), a plurality of hollow straight tubes (2.4) are established ties through connector (2.5) or tee junction head (2.3), advance thick liquid mouth (2.1) and are located extension pipe (2) upper portion, extend the side mouth of tee junction head (2.3) of pipe (2) lower part and be out thick liquid mouth (2.2).

2. The device for testing the damage depth of the soleplate by the microstrain method according to the claim 1, characterized in that the extension conduit (2) adopts a hollow pipe made of seamless galvanized steel pipe or PVC pipe.

3. A device suitable for microstrain depth testing of floors according to claim 1 or 2, characterized in that said hollow straight tube (2.4) has a length of thirty centimeters.

4. The device for testing the damage depth of the bottom plate by the microstrain method according to claim 1, wherein the signal transmission cable (5) is packaged by a galvanized steel pipe or an abrasion-resistant rubber hard pipe.

5. A device suitable for microstrain-based testing of the depth of failure of a floor according to claim 4, characterized in that said signal transmission cable (5) is embedded in the floor (7).

6. A device suitable for microstrain-based testing of the depth of failure of floors according to claim 5, characterized in that said signal transmission cable (5) is embedded to a depth higher than three centimeters.

7. The device for testing the damage depth of the bottom plate by the microstrain method according to claim 1, wherein the waterproof protective shell (1.2) is cylindrical or cuboid.