A real-time monitoring method for dynamic change of stress of roadway surrounding rock

Abstract

A kind of real-time monitoring method of roadway surrounding rock stress dynamic change, comprising the following steps: (one), in the working face roadway area needing to carry out surrounding rock stress monitoring, drilling is carried out;(two), assemble surrounding rock stress monitoring equipment;(three), surrounding rock stress monitoring equipment is sent into borehole;(four), surrounding rock stress monitoring equipment is connected with data collector signal and is calibrated, start monitoring work;(five), the stress change trend and distribution range of roadway surrounding rock are monitored in real time by data collector, and impact ground pressure is early warned, and certain pressure relief measures are promptly taken to carry out dynamic treatment to roadway surrounding rock.This application can accurately monitor and real-time monitor the stress condition of roadway surrounding rock, maximize the monitoring strength, timely take certain pressure relief measures to carry out dynamic treatment to roadway surrounding rock, reduce the occurrence of impact ground pressure and other dynamic disasters, and the surrounding rock stress monitoring equipment can be reused, reducing the cost of monitoring equipment.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of mine disaster monitoring, in particular to a real-time monitoring method for dynamic change of roadway surrounding rock stress. BACKGROUND

[0002] With the continuous increase of coal mining depth and mining intensity in China, deep mine is prone to dynamic disaster accidents such as rock burst, causing serious equipment damage and personnel casualties. Because the deep coal rock mass is in the "three high and one disturbance" surrounding rock environment, the surrounding rock structure will be subjected to a large stress after the excavation of roadway and working face, and different degrees of stress abnormal increase area can occur in the stress range of its supporting pressure. These abnormal increase areas are the main areas of rock burst and other dynamic disasters, so it is necessary to strengthen the monitoring of these areas to understand the stress distribution range and peak value of the roadway surrounding rock, and to ensure the normal mining of the working face and roadway. Therefore, for deep mines, especially for roadways with impact risk, certain monitoring equipment and instruments must be used to monitor the roadway surrounding rock to ensure the accuracy and effectiveness of the monitoring results.

[0003] At present, the equipment for monitoring the roadway surrounding rock mainly drills holes in the roadway coal wall to monitor the changes of the surrounding rock coal mass. The monitoring method mainly includes two ways, one is the traditional method, i.e. the physical monitoring mainly based on the drilling method, which takes the coal powder amount obtained by drilling as the main standard for judging the stress size; the other is the modern method, i.e. the monitoring mainly based on force measuring devices, such as strain gauge type force measuring rod and hydraulic type force measuring rod. Although the above two types are still in use and have some irreplaceable advantages, they also have many defects, such as the drilling method monitoring needs to weigh the coal powder amount every 1 meter, which has many uncertain factors and large errors; the metal force measuring rod monitoring has discontinuous data and lagging results, and is greatly affected by humidity, temperature and other factors, so the monitoring results are not timely and accurate. Therefore, in order to maximize the real-time monitoring and accurate monitoring of the roadway surrounding rock stress, it is necessary to research a real-time monitoring method for dynamic change of roadway surrounding rock stress. SUMMARY

[0004] The purpose of the present application is to provide a real-time monitoring method for dynamic change of roadway surrounding rock stress, which can accurately and real-time monitor the stress condition of the roadway surrounding rock, maximize the monitoring intensity, timely take certain pressure relief measures to dynamically process the roadway surrounding rock, reduce the occurrence of dynamic disasters such as rock burst, and the surrounding rock stress monitoring equipment can be reused, reducing the cost of monitoring equipment.

[0005] To achieve the above purpose, the present application adopts the following technical scheme:

[0006] A kind of real-time monitoring method of roadway surrounding rock stress dynamic change, comprising the following steps:

[0007] (I), drilling hole is carried out in the roadway area of working face needing to carry out surrounding rock stress monitoring;

[0008] (II), according to the drilling depth, the surrounding rock stress monitoring device is assembled;

[0009] (III), the surrounding rock stress monitoring device is sent into the drilling hole;

[0010] (IV), the surrounding rock stress monitoring device is connected with data collector signal and is calibrated, and monitoring work is started;

[0011] (V), the stress change trend and distribution range of roadway surrounding rock are monitored in real time by data collector, and the data results are used to early warn rock burst, and timely take certain pressure relief measures to dynamically process roadway surrounding rock, ensure that roadway surrounding rock is stable, and reduce the occurrence of rock burst.

[0012] The surrounding rock stress monitoring device comprises a plurality of monitoring rods, the monitoring rods are arranged horizontally along the front-back direction, the monitoring rods are spaced apart in front and back and are detachably connected in sequence, an oil pressure circular bag is sleeved on the monitoring rod, the inner wall of the oil pressure circular bag is adhesively fixed to the outer circumference of the monitoring rod, the adjacent ends of the two adjacent oil pressure circular bags are fixedly provided with oil pipe quick connectors, the two adjacent oil pressure circular bags are connected through the corresponding oil pipe quick connectors, the front end of the frontmost monitoring rod is fixedly connected with a conical drill bit with a front sharp end and a rear thick end, the rear end face of the conical drill bit is adhesively fixed to the front end of the oil pressure circular bag on the frontmost monitoring rod, a plurality of stress sensors arranged in a circumferential array are fixedly attached to the outer circumference of the middle part of the monitoring rod, the stress sensors are in contact with the inner wall of the oil pressure circular bag, a pressure gauge and an oil supply port are arranged at the rear end of the last oil pressure circular bag, an oil supply valve is mounted at the outer end of the oil supply port, and the data collector is signal-connected with each stress sensor through a wire.

[0013] The monitoring rod is made of metal material, a plurality of grooves arranged in a circumferential array are formed in the outer circumference of the middle part of the monitoring rod, each stress sensor is adhesively embedded in the corresponding groove, and the height of the stress sensor is higher than the depth of the groove.

[0014] A circular wire slot for arranging wires is formed in the outer circumference of the monitoring rod near each groove along the length direction of the monitoring rod.

[0015] The length of the monitoring rod is 1-1.2 m, the diameter of the monitoring rod is 30 mm, the diameter of the oil pressure circular bag is 60 mm, and the maximum diameter of the conical drill bit is the same as the diameter of the oil pressure circular bag.

[0016] The step (1) is specifically: selecting a roadway region of a working face needing to be monitored for surrounding rock stress, and drilling a borehole at a proper position of a coal wall side of the roadway near the working face, with the borehole position being ahead of the working face by 40-200 m.

[0017] The borehole in the step (1) is specifically arranged: drilling the borehole at a position of the middle part of the roadway near the coal wall side and lower part, with the borehole depth being 3-5 times of the roadway width, i.e. reaching the lateral support pressure range of the surrounding rock of the roadway, specifically 6-15 m, which needs to be determined according to the geological conditions and mining conditions; the interval between two adjacent boreholes is 10-15 m, the borehole diameter is 90-100 mm, the borehole is drilled in the horizontal direction, and the borehole is ensured to have no more coal powder.

[0018] The step (2) is specifically: determining the length of the surrounding rock stress monitoring equipment according to the borehole depth, selecting a proper number of monitoring rods, and sequentially assembling and connecting the monitoring rods according to the design, connecting the two adjacent oil pressure circular bags through the corresponding oil pipe quick connector, and connecting the wires of the corresponding stress sensors of the two adjacent monitoring rods in series, thereby assembling the surrounding rock stress monitoring equipment.

[0019] The step (3) is specifically: aligning the front end of the conical drill bit with the borehole, slowly sending the surrounding rock stress monitoring equipment into the borehole, ensuring that the front end of the conical drill bit is in contact with the bottom of the borehole, then opening the oil supply valve, using the oil pump to inject hydraulic oil into the oil pressure circular bag through the oil supply port, so that the hydraulic oil completely fills all the oil pressure circular bags, ensuring that the outer walls of the oil pressure circular bags are in close contact with the inner walls of the borehole, and the inner walls of the oil pressure circular bags are in close contact with the corresponding monitoring rods, respectively, and the stress sensors on the monitoring rods are in close contact with the inner walls of the corresponding oil pressure circular bags, then closing the oil supply valve to stop the oil pump from injecting hydraulic oil.

[0020] The step (4) is specifically: connecting the wires of the stress sensors to the data collector, then the stress sensors transmit the monitored data to the data collector in real time, monitoring the oil pressure through the pressure gauge reading, adjusting the reading of the data collector, calibrating the stress sensor, ensuring accuracy, then clearing the data collector, and starting the monitoring work.

[0021] The present application has outstanding substantial features and significant progress compared with the prior art, specifically, the present application utilizes the surrounding rock stress monitoring equipment to monitor, the coal rock mass exerts pressure on the outer wall of the oil pressure toroidal bag, and the inner wall of the oil pressure toroidal bag exerts pressure on the monitoring rod through hydraulic oil, the stress sensor on the monitoring rod is subjected to pressure, and the purpose of monitoring the surrounding rock stress is achieved. The monitoring steps are specifically as follows: the surrounding rock stress monitoring equipment is assembled by sequentially splicing and combining each monitoring rod of the surrounding rock stress monitoring equipment, meanwhile, two adjacent oil pressure toroidal bags are connected through corresponding oil pipe quick connectors, and the wires of the corresponding stress sensors on the two adjacent monitoring rods are respectively connected in series, then the surrounding rock stress monitoring equipment is assembled, the assembled surrounding rock stress monitoring equipment is sent into the drill hole, then the hydraulic oil is injected into each oil pressure toroidal bag through the oil pump, when the hydraulic oil completely fills each oil pressure toroidal bag and ensures that the inner wall and the outer wall of each oil pressure toroidal bag are in close contact with the monitoring rod and the drill hole wall respectively, the oil injection is stopped, the data collector reading is adjusted according to the pressure gauge, and after calibration and zeroing, the monitoring work can be normally carried out.

[0022] The present application has the advantages that, through the soft characteristics of the oil pressure toroidal bag shell, the oil pressure toroidal bag can be in close and seamless contact with the drill hole wall and the stress sensor, the stress size is monitored through physical change, the anti-interference performance is high, the accuracy of the monitoring data is improved, the direct contact between the stress sensor and the surrounding rock of the roadway is avoided, the damage rate of the stress sensor is reduced, the service life of the stress sensor is increased, the hydraulic oil in the oil pressure toroidal bag is discharged after the monitoring is completed, the monitoring rod can be reused after being taken out, and the cost of the monitoring equipment is reduced.

[0023] In the process of sending the surrounding rock stress monitoring equipment into the drill hole, the conical drill bit can protect the oil pressure toroidal bag from being damaged, and the surrounding rock stress monitoring equipment is easy to be sent into the drill hole and safe and reliable; the height of the stress sensor is higher than the depth of the groove, so that the stress sensor protrudes from the groove, the stress sensor is better in contact with the inner wall of the oil pressure toroidal bag, and the measurement is more accurate; the setting of the circular wire slot can avoid damage to the wire and affect signal transmission. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 is a schematic view of the working of the surrounding rock stress monitoring equipment of the present application.

[0025] Figure 2 is a schematic view of the surrounding rock stress monitoring equipment of the present application when not assembled.

[0026] Figure 3 is a schematic view of the surrounding rock stress monitoring equipment of the present application after being assembled and connected with the data collector.

[0027] Figure 4 is a schematic view of the cross section of the middle part of the monitoring rod of the present application. DETAILED DESCRIPTION

[0028] The embodiments of the present application are further illustrated below with reference to the drawings.

[0029] As Figures 1-4 shown in the drawings, a real-time monitoring method for dynamic changes of roadway surrounding rock stress comprises the following steps:

[0030] (1) Drilling holes 2 in the area of the working face roadway 1 where surrounding rock stress monitoring is required;

[0031] (2) Assembling surrounding rock stress monitoring equipment 3 according to the depth of the drilling holes 2;

[0032] (3) Sending the surrounding rock stress monitoring equipment 3 into the drilling holes 2;

[0033] (4) Signal connecting the surrounding rock stress monitoring equipment 3 with the data collector 4 and calibrating, starting the monitoring work;

[0034] (5) Real-time monitoring the stress change trend and distribution range of the roadway 1 surrounding rock through the data collector 4, and pre-warning through the data results, and timely taking certain pressure relief measures (conventional technology in the art, including drilling hole pressure relief, water injection pressure relief, etc.) to dynamically process the roadway 1 surrounding rock, ensuring the stability of the roadway 1 surrounding rock and reducing the occurrence of rock burst.

[0035] The surrounding rock stress monitoring equipment 3 comprises a plurality of monitoring rods 5, the monitoring rods 5 are arranged horizontally along the front-back direction, the monitoring rods 5 are spaced apart in front and back and are detachably connected in sequence, an oil pressure circular bag 6 is sleeved on the monitoring rod 5, the inner wall of the oil pressure circular bag 6 is adhesively fixed with the outer circumference of the monitoring rod 5, the adjacent ends of the two adjacent oil pressure circular bags 6 are fixedly provided with an oil pipe quick connector 7, the two adjacent oil pressure circular bags 6 are connected through the corresponding oil pipe quick connector 7, the front end of the frontmost monitoring rod 5 is fixedly connected with a front-thin-rear-thick conical drill bit 8, the rear end face of the conical drill bit 8 is adhesively fixed with the front end of the oil pressure circular bag 6 on the frontmost monitoring rod 5, four circumferential array arranged stress sensors 9 are fixedly pasted on the outer circumference of the middle part of the monitoring rod 5, the stress sensors 9 are in contact with the inner wall of the oil pressure circular bag 6, a pressure gauge 10 and an oil supply port are arranged at the rear end of the last oil pressure circular bag 6, an oil supply valve 11 is installed at the outer end of the oil supply port, the data collector 4 is signal connected with each stress sensor 9 through a wire 12.

[0036] The monitoring rod 5 is made of metal material, four circumferential array arranged grooves are arranged on the outer circumference of the middle part of the monitoring rod 5, each stress sensor 9 is adhesively embedded in the corresponding groove, and the height of the stress sensor 9 is higher than the depth of the groove.

[0037] The outer circumference of the monitoring rod 5 is provided with a circular wire slot 13 for arranging the wire 12 near each groove along the length direction.

[0038] The length of the monitoring rod 5 is 1-1.2 m, the diameter of the monitoring rod 5 is 30 mm, the diameter of the oil pressure circular bag 6 is 60 mm, and the maximum diameter of the conical drill bit 8 is the same as the diameter of the oil pressure circular bag 6.

[0039] Step (one) is specifically: selecting the area of the working face roadway 1 that needs to be monitored, and selecting a suitable position on the coal wall side of the roadway 1 near the working face to drill a hole 2, and the position of the hole 2 is ahead of the working face by 40-200 m.

[0040] In step (one), the hole 2 is specifically arranged: drilling the hole 2 at the lower middle position of the roadway 1 near the coal wall, the depth of the hole 2 is 3-5 times the width of the roadway 1, that is, reaching the lateral support pressure range of the surrounding rock of the roadway 1, specifically 6-15 m, which needs to be considered according to the geological conditions and mining conditions; the distance between adjacent two holes 2 is 10-15 m, the diameter of the hole 2 is 90-100 mm, and the hole 2 is drilled in the horizontal direction, and it is ensured that there is no more coal powder in the hole 2.

[0041] Step (two) is specifically: according to the depth of the hole 2, the length of the surrounding rock stress monitoring equipment 3 is determined, an appropriate number of monitoring rods 5 are selected, and each section of the monitoring rod 5 is sequentially connected end to end according to the design, and the adjacent two oil pressure circular bags 6 are connected through the corresponding oil pipe quick connector 7, and the wires 12 of the corresponding stress sensors 9 on the adjacent two monitoring rods 5 are respectively connected in series, and then the surrounding rock stress monitoring equipment 3 is assembled.

[0042] Step (three) is specifically: aligning the front end of the conical drill bit 8 with the hole 2, slowly sending the surrounding rock stress monitoring equipment 3 into the hole 2, ensuring that the front end of the conical drill bit 8 is in contact with the bottom of the hole 2, then opening the oil supply valve 11, using the oil pump to inject hydraulic oil into the oil pressure circular bag 6 through the oil inlet, so that the hydraulic oil completely fills all the oil pressure circular bags 6, ensuring that the outer walls of each oil pressure circular bag 6 are in close contact with the inner wall of the hole 2, and the inner walls of each oil pressure circular bag 6 are in close contact with the corresponding each section of the monitoring rod 5, and each stress sensor 9 on each section of the monitoring rod 5 is in close contact with the inner wall of the corresponding each oil pressure circular bag 6, then closing the oil supply valve 11, and stopping the oil pump from injecting hydraulic oil.

[0043] Step (four) is specifically: connecting the wires 12 of each stress sensor 9 to the data collector 4, then each stress sensor 9 transmits the monitored data to the data collector 4 in real time, the oil pressure is monitored through the reading of the pressure gauge 10, the reading of the data collector 4 is adjusted, the stress sensor 9 is calibrated, and after ensuring accuracy, the data collector 4 is cleared, and the monitoring work begins.

[0044] The data collector 4 and the stress sensor 9 are both conventional technologies, and the specific structure and working principle will not be described here.

[0045] When the surrounding rock stress monitoring device 3 is monitored by the present application, the coal rock mass exerts pressure on the outer wall of the oil pressure circular bag 6, and the inner wall of the oil pressure circular bag 6 exerts pressure on the monitoring rod 5 through hydraulic oil, so that the stress sensor 9 on the monitoring rod 5 is subjected to pressure, thereby achieving the purpose of monitoring the surrounding rock stress. The monitoring steps are as follows: the surrounding rock stress monitoring device 3 is assembled by sequentially splicing and combining each section of the monitoring rod 5, connecting the adjacent two oil pressure circular bags 6 through the corresponding oil pipe quick connector 7, and respectively connecting the wires 12 of the corresponding stress sensors 9 on the adjacent two sections of the monitoring rod 5 in series, and then assembling the surrounding rock stress monitoring device 3, and then sending the assembled surrounding rock stress monitoring device 3 into the drill hole 2, and then injecting hydraulic oil into each oil pressure circular bag 6 by using an oil pump, and when the hydraulic oil completely fills each oil pressure circular bag 6 and ensures that the inner wall and the outer wall of each oil pressure circular bag 6 are in close contact with the monitoring rod 5 and the hole wall of the drill hole 2 respectively, the oil injection is stopped, the reading of the data collector 4 is adjusted according to the pressure gauge 10, and after calibration and zeroing, the monitoring work can be normally carried out.

[0046] The present application has the advantages that: through the soft characteristics of the outer shell of the oil pressure circular bag 6, the oil pressure circular bag 6 can be in close and seamless contact with the hole wall of the drill hole 2 and the stress sensor 9, the stress size is monitored through physical change, the anti-interference performance is high, and the accuracy of the monitoring data is improved; the direct contact between the stress sensor 9 and the surrounding rock of the roadway 1 is avoided, the damage rate of the stress sensor 9 is reduced, and the service life of the stress sensor 9 is increased; after the monitoring is completed, the hydraulic oil in the oil pressure circular bag 6 is discharged, and the monitoring rod 5 can be reused after being taken out, thereby reducing the cost of the monitoring equipment.

[0047] During the process of sending the surrounding rock stress monitoring device 3 into the drill hole 2, the conical drill bit 8 can protect the oil pressure circular bag 6 from being damaged, and the surrounding rock stress monitoring device 3 is easy to be sent into the drill hole 2, safe and reliable; the height of the stress sensor 9 is higher than the depth of the groove, so that the stress sensor 9 protrudes from the groove, and the stress sensor 9 is better in contact with the inner wall of the oil pressure circular bag 6, and the measurement is more accurate; the setting of the circular wire slot 13 can avoid the damage of the wire 12 and affect the signal transmission.

[0048] The above examples are only used to illustrate but not to limit the technical solutions of the present application, although the present application has been described in detail with reference to the above examples, those skilled in the art should understand that; the present application can still be modified or replaced equivalently without departing from the spirit and scope of the present application, any modification or partial replacement should be covered in the scope of the claims of the present application.

Claims

1. A method for real-time monitoring of dynamic changes in the surrounding rock stress of a roadway, characterized in that: The method comprises the following steps: (1) drilling a hole in the roadway area of the working face where the surrounding rock stress needs to be monitored; (2) assembling the surrounding rock stress monitoring device according to the drilling depth; (3) sending the surrounding rock stress monitoring device into the hole; (4) connecting the surrounding rock stress monitoring device with the data collector and calibrating it to start the monitoring work; (5) monitoring the stress change trend and distribution range of the roadway surrounding rock in real time through the data collector, and warning the rock burst through the data results, and timely taking certain pressure relief measures to dynamically process the roadway surrounding rock to ensure the stability of the roadway surrounding rock and reduce the occurrence of rock burst; The surrounding rock stress monitoring device comprises a plurality of monitoring rods arranged horizontally along the front and back directions, the monitoring rods are spaced apart and connected in sequence, an oil pressure circular bag is arranged on the monitoring rod, the inner wall of the oil pressure circular bag is fixedly connected with the outer circumference of the monitoring rod, the adjacent ends of the two adjacent oil pressure circular bags are fixedly provided with oil pipe quick connectors, the two adjacent oil pressure circular bags are connected through the corresponding oil pipe quick connectors, the front end of the frontmost monitoring rod is fixedly connected with a conical drill bit with a front sharp end and a rear thick end, the rear end surface of the conical drill bit is fixedly connected with the front end of the oil pressure circular bag on the frontmost monitoring rod, a plurality of stress sensors arranged in a circular array are fixedly attached to the outer circumference of the middle part of the monitoring rod, the stress sensors are in contact with the inner wall of the oil pressure circular bag, a pressure gauge and an oil inlet are arranged at the rear end of the rearmost oil pressure circular bag, an oil valve is arranged at the outer end of the oil inlet, and the data collector is signal connected with each stress sensor through a wire; The monitoring rod is made of metal material, a plurality of grooves arranged in a circular array are arranged on the outer circumference of the middle part of the monitoring rod, each stress sensor is correspondingly fixedly arranged in the corresponding groove, and the height of the stress sensor is higher than the depth of the groove; A circular wire slot is arranged on the outer circumference of the monitoring rod near each groove along the length direction of the monitoring rod; Step (2) is specifically: determining the length of the surrounding rock stress monitoring device according to the drilling depth, selecting a proper number of monitoring rods, and sequentially connecting the monitoring rods in sequence according to the design, connecting the two adjacent oil pressure circular bags through the corresponding oil pipe quick connectors, and connecting the wires of the corresponding stress sensors of the two adjacent monitoring rods in series, thereby assembling the surrounding rock stress monitoring device; Step (3) is specifically: aligning the front end of the conical drill bit with the hole, slowly sending the surrounding rock stress monitoring device into the hole, ensuring that the front end of the conical drill bit is in contact with the hole bottom, then opening the oil valve, injecting hydraulic oil into the oil pressure circular bag through the oil inlet by using the oil pump, making the hydraulic oil completely fill all the oil pressure circular bags, ensuring that the outer walls of the oil pressure circular bags are in close contact with the inner wall of the hole, and the inner walls of the oil pressure circular bags are in close contact with the corresponding monitoring rods, the stress sensors on the monitoring rods are in close contact with the inner walls of the corresponding oil pressure circular bags, then closing the oil valve to stop the oil pump from injecting hydraulic oil. Step (four) is: the lead of each stress sensor is connected to the data collector, then each stress sensor transmits the monitored data to the data collector in real time, the oil pressure is monitored by the pressure gauge reading, the reading of the data collector is adjusted, the stress sensor is calibrated, and after ensuring accuracy, the data collector is cleared and the monitoring work is started.

2. The method of claim 1, wherein the method further comprises: The length of the monitoring rod is 1-1.2 m, the diameter of the monitoring rod is 30 mm, the diameter of the oil pressure circular ring bag is 60 mm, and the maximum diameter of the conical drill bit is the same as the diameter of the oil pressure circular ring bag.

3. The method of claim 1, wherein the method further comprises: Step (one) is: selecting the working face roadway area that needs to be monitored, selecting the appropriate position near the working face coal wall side of the roadway to drill a hole, and the drilling position is 40-200 m ahead of the working face.

4. The method of claim 3, wherein the method further comprises: In step (one), the drilling is specifically arranged: drilling at the lower position in the middle of the roadway near the coal wall side, the drilling depth is 3-5 times the width of the roadway, that is, reaching the lateral support pressure range of the surrounding rock of the roadway, specifically 6-15 m, which needs to consider the geological conditions and mining conditions; the spacing between adjacent two drillings is 10-15 m, the drilling diameter is 90-100 mm, the drilling is drilled in the horizontal direction, and it is ensured that there is no more coal powder in the drilling.

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