One-time locking anchoring method, formation layer displacement monitoring method and formation structure plane stress change monitoring method

Abstract

The application discloses a one-time locking anchoring method, a stratum layer displacement monitoring method and a stratum structure surface stress change monitoring method. The anchoring method comprises the following steps: drilling and hole cleaning; a tensile hole and a grouting hole are preformed on a pressure bag, a tensile member is passed through the tensile hole, a grouting pipe is passed through the grouting hole, and the pressure bag is fixed at a predetermined position of the tensile member; the pressure bag is lowered with the tensile member to a preset position in the hole; grouting is performed into the pressure bag through the grouting pipe, the pressure bag is expanded to abut against the inner wall of the hole, and the friction between the pressure bag and the inner wall of the hole reaches a certain value; grouting is performed into the bottom end of the hole through the grouting pipe or into the hole between adjacent pressure bags. The application can provide the required tensile force without waiting for the grout between the anchoring segment of the tensile member and the stratum to solidify, can quickly provide the required tensile force, and can provide greater tensile force to meet the tensile force requirement after the grout solidifies.

Description

Technical Field

[0001] The present application relates to the field of geological disaster and engineering hazard rescue and monitoring technology, and in particular to a one-time locking anchoring method, a stratum layer displacement monitoring method, and a stratum structure surface stress change monitoring method. Background Art

[0002] Landslides are a significant global geological hazard, posing a significant threat to human life, property, and economic development. For example, they can bury factories, mines, and towns, disrupt transportation, block rivers, and damage engineering projects. Landslides are particularly frequent in my country, a country with a vast territory and a preponderance of mountainous terrain, causing significant losses. Slope stability has long been a key research topic and goal in geotechnical engineering.

[0003] Tension members are widely used in geological disaster control, mine support, engineering construction, landslide damage feature prediction (damage change monitoring) and other activities. Since the stratum is a semi-infinite body in space relative to engineering activities, the connection between the tension member and the stratum can only be established through friction. The failure of the tension member is often caused by factors such as the volume shrinkage of the grouting liquid in the anchoring section of the member, the grouting fullness, and the stress deformation of the stratum, resulting in various accidents. The best prevention and control time is also missed because of the need to wait for the grouting liquid in the anchoring section between the member and the stratum to solidify. Summary of the Invention

[0004] The present application provides a one-time locking anchoring method, a stratum layer displacement monitoring method and a stratum structural surface stress change monitoring method, which can provide the required tension required by the design without waiting for the slurry between the anchor section of the tension member and the stratum to solidify. After the slurry solidifies, it can provide greater tension to meet the tension requirement.

[0005] The present application provides a one-time locking and anchoring method using the following technical solutions:

[0006] A one-time locking anchoring method comprises the following steps:

[0007] S1, drilling and hole cleaning;

[0008] S2. Pre-opening a tensile through hole and a grouting through hole on the pressure bag, passing the tensile member through the tensile through hole, passing the grouting pipe through the grouting through hole, and fixing the pressure bag at a predetermined position on the tensile member;

[0009] S3, lowering the pressure bag along with the tensile member to the preset drilling position;

[0010] S4. The slurry guide pipe has unidirectional conductivity from the inlet to the slurry outlet. The unidirectional conductivity can be adjusted according to the slurry pressure in the pressure bladder. Grout is injected into the pressure bladder through the slurry guide pipe, so that the pressure bladder expands until it abuts against the inner wall of the borehole, and the friction between the pressure bladder and the inner wall of the borehole reaches a certain value.

[0011] S5. Grouting is performed into the bottom of the borehole or into the boreholes between adjacent pressure bags through the grouting pipe.

[0012] By adopting this technical solution, high-pressure grouting can be completed in a single step, eliminating the need to wait for the grouting fluid to solidify before performing a secondary grouting. Furthermore, the pressure bag's compression of the ground immediately provides a certain amount of tension to the tensile member, eliminating the need to wait for the grouting fluid to solidify and providing the required tension. Furthermore, after the pressure bag expands during grouting, the tensile member is positioned at the center of the borehole, allowing it to overcome gravity and effectively avoid contact with the surrounding ground, thereby preventing corrosion and failure of the tensile member caused by groundwater and ground forces. The locking structure formed by the pressure bag ensures that the locking between the tensile member and the ground is both effective and provides an effective release mechanism.

[0013] Optionally, step S4 further includes:

[0014] S41. Pre-install a first one-way pressure valve and a second one-way pressure valve in the slurry guiding pipe, and pre-open a slurry hole connecting the slurry guiding pipe and the pressure bag on the side wall of the slurry guiding pipe between the first one-way pressure valve and the second one-way pressure valve. The pressure conductance value of the second one-way pressure valve is greater than the pressure conductance value of the first one-way pressure valve, and the pressure conductance value of the second one-way pressure valve is less than a certain level of the maximum pressure to which the pressure bag is subjected.

[0015] By adopting this technical solution, the grouting liquid can first flow into the pressure bag, expand the pressure bag, and achieve a certain friction between the pressure bag and the inner wall of the hole before grouting the hole. At this time, the pressure bag acts as a plugging end. When grouting the hole, the volume shrinkage rate of the grouting liquid and the grouting fullness can be achieved, thereby improving anchoring efficiency.

[0016] The magnitude of the tensile force provided by the tensile member during the locking process is:

[0017] In the first stage, the contact length between the pressure bag and the formation is l, the diameter of the pressure bag is d, the pressure inside the bag is p, and the friction coefficient between the bag and the formation is μ, then the tension F1=πdlpμ;

[0018] In the second stage, the length of the grouting section between the bottom hole and the pressure bag is L, the diameter of the slurry bonding section is D, and the bonding strength between the formation and the slurry is P. Then the tension F2=πDLP;

[0019] Through the pre-locking feature of the pressure bag, the tensile member overcomes the problem of direct shear contact with the stratum under the action of gravity, and a gap is formed between the tensile member and the stratum. The gap is filled and bonded by grouting liquid, isolating the groundwater and air, and solving the problem of rust often caused by contact with groundwater in the tensile member.

[0020] A method for monitoring stratum displacement comprises the following steps:

[0021] S1, drilling and hole cleaning;

[0022] S2. Pre-opening grouting holes on the pressure bladder and installing displacement sensors, inserting grouting pipes into the grouting holes, fixing multiple pressure bladders at predetermined positions on the grouting pipes, and connecting the displacement sensors to a data acquisition center;

[0023] S3, lowering multiple pressure bags along with the grouting pipe to preset positions in the borehole so that different pressure bags are located in different formations;

[0024] S4. The slurry guide pipe has unidirectional conductivity from the inlet to the slurry outlet. The unidirectional conductivity can be adjusted according to the slurry pressure in the pressure bladder. Grout is injected into the pressure bladder through the slurry guide pipe, so that the pressure bladder expands until it abuts against the inner wall of the borehole, and the friction between the pressure bladder and the inner wall of the borehole reaches a certain value.

[0025] S5. Collect, count and analyze the data of the displacement sensor at different times.

[0026] By adopting the above technical solution, a displacement sensor is installed at the displacement to be measured in the borehole using a pressure bag. The pressure bag is locked with the formation and moves with the movement of the formation. When the formation moves, the pressure bag moves and drives the displacement sensor to move, thereby solving the problem that the displacement sensor is difficult to couple with the formation.

[0027] Optionally, the step S2 of installing a displacement sensor on the pressure bladder bag specifically includes:

[0028] S21. Pre-opening a protective tube mounting hole and a sensor mounting hole in the pressure bag;

[0029] S22, installing the displacement sensor in the sensor installation hole;

[0030] S23. Provide a communication equipment protection tube that contains a line between the displacement sensor and the data acquisition center, and pass the communication equipment protection tube through the protection tube installation hole.

[0031] By adopting the above technical solution, the displacement sensor can be quickly installed in the pressure bag and the normal operation of the displacement sensor is guaranteed.

[0032] A method for monitoring the stress change between formation structural planes, comprising the following steps:

[0033] S1. Drill holes and clean the holes;

[0034] S2. Provide multiple pressure bladder bags with force sensors installed inside;

[0035] S3. Connect the force sensors between adjacent pressure bladder bags in advance, apply a certain prestress to the connected force sensors, and obtain the prestress value between the connected force sensors;

[0036] S4. Lock the pressure bladder bags at predetermined positions in the drill holes so that different pressure bladder bags are in different formations;

[0037] S5. Measure the change in prestress between the connected force sensors at different times, and determine the force change between the structural planes according to the change in prestress.

[0038] By adopting the above technical solution, force sensors are installed in the pressure bladder bags at the measured positions in the drill holes. The pressure bladder bags are locked with the formation and move with the movement of the formation. When the formation moves, the pressure bladder bags move and drive the force sensors to move. By monitoring the numerical change of the force sensors, the force change between the structural planes can be judged. The solution of this application uses the pressure bladder bag as the locking mechanism of the force sensor, locks the force sensor with the formation and can change accurately with the change of the formation, improving the accuracy of the monitoring result.

[0039] Optionally, the readings of the connected force sensors are equal, and the step S5 includes:

[0040] S51. Obtain the values of the force sensors at the t0 moment, the t1 moment and the t2 moment respectively. The obtained values are:

[0041] At the t0 moment, it is measured that x1 = x2 = fAB0;

[0042] At the t1 moment, it is measured that x1 = x2 = fAB1;

[0043] At the t2 moment, it is measured that x1 = x2 = fAB2;

[0044] S52. Calculate the obtained values:

[0045] If fAB1 - fAB0 = fAB2 - fAB1, it means that the adjacent structural planes are relatively stable;

[0046] If fAB1 - fAB0 < fAB2 - fAB1, it means that the adjacent structural planes expand;

[0047] If fAB1 - fAB0 > fAB2 - fAB1, it means that the adjacent structural planes are compressed.

[0048] By adopting the above technical solution, the stress changes between the stratum structural surfaces can be accurately monitored and judged. By monitoring the force change trends at more times, the stratum movement trends and rates on both sides of the structural surfaces can be monitored and calculated.

[0049] Optionally, step S3 includes:

[0050] S31, pre-connecting adjacent force sensors using pre-tensioned steel wires and pre-stressed steel wires;

[0051] S32, pulling the pre-tensioned steel wire with a certain tension;

[0052] S33, obtaining the tension value between the connected force sensors;

[0053] After step S4, the following steps are also included:

[0054] S34. Eliminate the tension on the pre-tensioned steel wire.

[0055] By adopting the above technical solution, the accuracy of the force sensor detection results is guaranteed.

[0056] Optionally, the certain tensile force in step S52 refers to no more than 1 / 3 of the load of the prestressed steel wire.

[0057] By adopting the above technical solution, excessive force is avoided to prevent the prestressed steel wire from breaking and failing during subsequent stratum changes.

[0058] Optionally, step S4 includes:

[0059] S41, pre-opening a grouting hole on the pressure bag, inserting a grouting pipe into the grouting hole, and fixing multiple pressure bags at predetermined positions on the grouting pipe;

[0060] S42, lowering multiple pressure bags along with the grouting pipe to preset positions in the borehole so that different pressure bags are located in different formations;

[0061] S43. The slurry guide tube has unidirectional conductivity from the inlet to the slurry outlet. The unidirectional conductivity can be adjusted according to the slurry pressure in the pressure bag. Grouting is injected into the pressure bag through the slurry guide tube, so that the pressure bag expands to abut against the inner wall of the borehole, and the friction between the pressure bag and the inner wall of the borehole reaches a certain value.

[0062] By adopting the above technical solution, a method for quickly and easily locking the bladder at a predetermined position in the drill hole is provided.

[0063] Optionally, step S43 includes:

[0064] S431. Pre-install multiple groups of first one-way pressure valves and second one-way pressure valves in the slurry guide pipe, and pre-open a slurry hole connecting the slurry guide pipe and the pressure bag on the side wall of the slurry guide pipe between the first one-way pressure valve and the second one-way pressure valve. The pressure conductance value of the second one-way pressure valve is greater than the pressure conductance value of the first one-way pressure valve, and the pressure conductance value of the second one-way pressure valve is less than a certain level of the maximum pressure to which the pressure bag is subjected. The liquid outlet end of the second one-way pressure valve faces the pressure bag below.

[0065] By adopting the above technical solution, the position of the pressure bag is locked in sequence from top to bottom, reducing the possibility of position change of the pressure bag and improving the accuracy of subsequent monitoring results.

[0066] In summary, this application includes at least one of the following beneficial technical effects:

[0067] 1. High-pressure grouting can be completed in one go, eliminating the need to wait for the grouting fluid to solidify before performing a secondary grouting. The pressure bag's compression of the ground provides instant tension to the tensile member, eliminating the need to wait for the grouting fluid to solidify. Furthermore, after the pressure bag expands during grouting, the tensile member is positioned at the center of the borehole, overcoming gravity and effectively preventing contact with the surrounding ground. This prevents corrosion and failure of the tensile member due to groundwater and ground forces.

[0068] 2. A displacement sensor is installed at the displacement to be measured in the borehole using a pressure bag. The pressure bag is locked with the stratum and moves with the movement of the stratum. When the stratum moves, the pressure bag moves and drives the displacement sensor to move, thus solving the problem of the displacement sensor being difficult to couple with the stratum.

[0069] 3. The present application utilizes a pressure bag as a locking mechanism for the force sensor, so that the force sensor is locked to the stratum and can accurately change with changes in the stratum, thereby improving the accuracy of the monitoring results. This enables real-time monitoring of stress changes between stratum structural surfaces, providing an important basis for geological disaster risk assessment, so that effective measures can be taken in a timely manner to prevent and control the occurrence of geological disasters. BRIEF DESCRIPTION OF THE DRAWINGS

[0070] Figure 1 This is a schematic diagram of the disposable locking anchoring device of Example 1 of the present application.

[0071] Figure 2 This is a schematic diagram of calculating the tension of the pressure bag of the disposable locking anchoring device in Example 1 of the present application.

[0072] Figure 3 This is a schematic diagram of calculating the tensile force of the high-pressure slurry solidified body using the disposable locking anchoring device in Example 1 of the present application.

[0073] Figure 4 It is a schematic diagram of the layer structure of the pressure bladder bag of this application.

[0074] Figure 5 This is a schematic diagram of the stratum displacement monitoring device according to Example 2 of the present application.

[0075] Figure 6 This is a schematic diagram of the equipment for monitoring stress changes between formation structural surfaces in Example 2 of the present application.

[0076] Figure 7 This is a schematic diagram of the connection relationship of the force sensors in Example 2 of the present application.

[0077] Description of reference numerals:

[0078] 10. Tensile member; 11. Tension rod (rope); 12. Tension rod (rope) retaining spring; 20. Pressure bladder; 21. Bladder tension net; 22. Bladder anti-seepage membrane; 201. Tensile through hole; 202. Grouting through hole; 203. Protection tube mounting hole; 204. Sensor mounting hole; 30. Slurry guide pipe; 301. Slurry hole; 31. First one-way pressure valve; 32. Second one-way pressure valve; 33. High-pressure pump; 40. Displacement sensor; 50. Data acquisition center; 51. Communication equipment protection tube; 60. Force sensor; 601. Waterproof shell; 602. Force sensor body; 603. Force sensor fixed end; 70. Pre-tensioned steel wire; 71. Prestressed steel wire. DETAILED DESCRIPTION

[0079] The following is combined with Figure 1-7 This application is described in further detail.

[0080] Example 1

[0081] Reference Figure 1 , the embodiment of the present application discloses a one-time locking anchoring method, comprising the following steps:

[0082] S1. Drilling and hole cleaning.

[0083] Specifically, a hole is drilled at a location where the tensile member 10 needs to be installed, and after the drilling is completed, all mud and sediment in the hole are cleaned out.

[0084] S2. Pre-open a tensile through hole 201 and a grouting through hole 202 on the pressure bag 20, pass the tensile member 10 through the tensile through hole 201, pass the grouting pipe 30 through the grouting through hole 202, and fix the pressure bag 20 at a predetermined position on the tensile member 10.

[0085] Optionally, one or more pressure bags 20 may be passed through the tensile member 10 and temporarily fixed in relative positions. The pressure bags 20 are connected by a slurry guide tube 30 , the head end of which extends out of the ground and is connected to a high-pressure pump 33 .

[0086] S3. Lower the pressure bag 20 along with the tensile member 10 to the preset drilling position.

[0087] Specifically, since grouting is not performed in the pressure bag 20 , the pressure bag 20 is in a relaxed state and can be placed at a predetermined position in the drill hole along with the tensile member 10 .

[0088] S4. The slurry guide tube 30 has unidirectional conductivity from the inlet to the slurry outlet. The unidirectional conductivity can be adjusted according to the slurry pressure in the pressure bag 20. Grout is injected into the pressure bag 20 through the slurry guide tube 30, so that the pressure bag 20 expands to abut against the inner wall of the borehole, and the friction between the pressure bag 20 and the inner wall of the borehole reaches a certain value.

[0089] Preferably, step S4 includes:

[0090] S41. A first one-way pressure valve 31 and a second one-way pressure valve 32 are pre-installed in the slurry guiding pipe 30, and a slurry hole 301 connecting the slurry guiding pipe 30 and the pressure bag 20 is pre-opened on the side wall of the slurry guiding pipe 30 located between the first one-way pressure valve 31 and the second one-way pressure valve 32. The pressure conductance value of the second one-way pressure valve 32 is greater than the pressure conductance value of the first one-way pressure valve 31, and the pressure conductance value of the second one-way pressure valve 32 is less than a certain level of the maximum pressure to which the pressure bag 20 is subjected, so as to prevent the pressure bag 20 from being damaged due to excessive pressure in the pressure bag 20, so that the slurry guiding pipe 30 has unidirectional conductivity from the inlet to the slurry outlet.

[0091] Specifically, the certain level of the maximum pressure to which the pressure bag 20 is subjected refers to 0.5-0.8 times of the maximum pressure to which the pressure bag 20 is subjected.

[0092] Specifically, a high-pressure pump 33 is used to inject grout into the pressure bag 20 through the grouting pipe 30. The injected high-pressure slurry expands the pressure bag 20, and the pressure bag 20 compacts the hole wall formation under the pressure conditions provided by the pressure bag 20.

[0093] S5. Grouting is performed into the bottom of the borehole or into the boreholes between adjacent pressure bags 20 through the grouting pipe 30 .

[0094] In this embodiment, grouting is performed through the grouting tube 30 toward the bottom of the borehole. At this point, the high-pressure grouting inflates the pressure bag 20, causing the friction between the pressure bag 20 and the inner wall of the borehole to reach a certain value. The second one-way pressure valve 32 is then opened, allowing the grouting liquid to flow to the bottom of the grouting tube 30 and into the borehole from there. Due to the blocking effect of the pressure bag 20, the grouting liquid can penetrate deeply into the stratum drilled out of the borehole under a certain pressure. This allows high-pressure grouting to be completed in one go, eliminating the need to wait for the grouting liquid to solidify before performing a secondary grouting operation. Furthermore, the compression of the pressure bag 20 against the stratum instantly provides a certain amount of tension to the tensile member 10, eliminating the need to wait for the grouting liquid to solidify and providing the required tension.

[0095] Specifically, the tension value provided by the pressure bladder 20 and the tensile member 10 is calculated as follows:

[0096] Reference Figure 2 The initial tension F1 provided by the pressure bag 20: the pressure inside the pressure bag 20 is p, the length of the pressure bag 20 is ι, the maximum diameter of the pressure bag 20 is d, and the friction coefficient between the formation and the pressure bag 20 is μ, then F1=πdLpμ.

[0097] Reference Figure 3 The tensile force F2 provided by the tensile member 10 after the tail end high-pressure slurry solidifies is: the bonding strength between the high-pressure slurry solidified body and the formation is P, the length is L, and the diameter is D, then F2=πDLP.

[0098] In another embodiment, grouting is performed through the grouting pipe 30 into the borehole between adjacent pressure bags 20. Specifically, the pressure bags 20 on the tensile member 10 form two blocked ends. After the pressure bags 20 at both ends are grout-locked, the grout flows into the borehole between the two pressure bags 20 to achieve grouting anchoring.

[0099] In addition, a large-diameter high-pressure bag can be used to perform radial compression on the hole wall of the soft soil layer, thereby providing a larger anchor head of the tensile member 10 in the soft soil layer, providing greater tension and reliable stability.

[0100] In this application, the pressure bag 20 is expanded by grouting, and the tensile member 10 is located at the center of the drill hole, so that the tensile member 10 overcomes the effect of gravity and effectively avoids its contact with the strata around the hole wall, thereby preventing the tensile member 10 from rusting and failing due to the action of groundwater and strata.

[0101] Reference Figure 1The embodiment of the present application also discloses a disposable locking anchoring device. The anchoring device includes a pressure bag 20 and a tensile member 10. The pressure bag 20 is provided with a tensile through hole 201 and a grouting through hole 202. The tensile member 10 passes through the tensile through hole 201. The grouting through hole 202 is connected to a grouting pipe 30. A first one-way pressure valve 31 and a second one-way pressure valve 32 are pre-installed in the grouting pipe 30. A grouting hole 301 is pre-opened on the side wall of the grouting pipe 30 between the first one-way pressure valve 31 and the second one-way pressure valve 32 to connect the grouting pipe 30 and the pressure bag 20. The pressure conductance value of the second one-way pressure valve 32 is greater than the pressure conductance value of the first one-way pressure valve 31, and the pressure conductance value of the second one-way pressure valve 32 is less than a certain level of the maximum pressure to which the pressure bag 20 is subjected.

[0102] Optionally, the tensile member 10 may include a tension rod (rope) 11 and a tension rod (rope) spring 12. The tension rod (rope) spring 12 is fixed to the outer wall of the tension rod (rope) 11 and is located outside the pressure bag 20. After the slurry in the borehole solidifies, the tension rod (rope) spring 12 can provide additional tensile stress.

[0103] Reference Figure 4 Preferably, the pressure bladder 20 in the present application includes a bladder tension net 21 and a bladder anti-seepage membrane 22 that are bonded to each other. The bladder anti-seepage membrane 22 is arranged on the inner wall of the pressure bladder 20, and the bladder tension net 21 is arranged on the outer wall of the pressure bladder 20. This structure can improve the anti-seepage performance and high-pressure resistance of the pressure bladder 20.

[0104] The disposable locking anchoring device of the embodiment of the present application can complete the high-pressure grouting work in one time, and the secondary grouting can be carried out without waiting for the grouting liquid to solidify. The pressure bag 20 squeezes the formation to provide a certain tension to the tensile member 10 in real time, and the required tension can be provided without waiting for the grouting liquid to solidify.

[0105] Example 2

[0106] Reference Figure 5 The present application discloses a method for monitoring stratum displacement, comprising the following steps:

[0107] S1. Drilling and hole cleaning.

[0108] Specifically, a hole is drilled at a location where stratum changes need to be monitored, and all mud and sediment in the hole are cleaned out after the drilling is completed.

[0109] S2. Pre-open a grouting hole 202 on the pressure bag 20 and install a displacement sensor 40. Insert the grouting tube 30 into the grouting hole 202 and fix multiple pressure bags 20 at predetermined positions on the grouting tube 30. Connect the displacement sensor 40 to the data acquisition center 50.

[0110] Specifically, multiple pressure bags 20 are passed through the slurry guide tube 30 and temporarily fixed in relative positions. The pressure bags 20 are connected by the slurry guide tube 30 , and the head end of the slurry guide tube 30 extends out of the ground and is connected to the high-pressure pump 33 .

[0111] The step S2 of installing the displacement sensor 40 on the pressure bladder 20 specifically includes:

[0112] S21 , pre-opening a protection tube mounting hole 203 and a sensor mounting hole 204 in the pressure bag 20 .

[0113] S22 , installing the displacement sensor 40 in the sensor installation hole 204 .

[0114] S23 , providing a communication equipment protection tube 51 that contains a line between the displacement sensor 40 and the data acquisition center 50 , and passing the communication equipment protection tube 51 through the protection tube installation hole 203 .

[0115] Preferably, step S2 also includes S24, pre-installing a first one-way pressure valve 31 and a second one-way pressure valve 32 in the slurry guide pipe 30, and pre-opening a slurry hole 301 connecting the slurry guide pipe 30 and the pressure bag 20 on the side wall of the slurry guide pipe 30 located between the first one-way pressure valve 31 and the second one-way pressure valve 32. The pressure conductance value of the second one-way pressure valve 32 is greater than the pressure conductance value of the first one-way pressure valve 31, and the pressure conductance value of the second one-way pressure valve 32 is less than a certain level of the maximum pressure to which the pressure bag 20 is subjected. The liquid outlet end of the second one-way pressure valve 32 faces the pressure bag 20 below, so that the slurry guide pipe 30 has unidirectional conductivity from the inlet to the slurry outlet.

[0116] S3. Lowering multiple pressure bags 20 along with the grouting pipe 30 to preset positions in the borehole so that different pressure bags 20 are located in different strata.

[0117] Specifically, since grouting is not performed in the pressure bag 20 , the pressure bag 20 is in a relaxed state and can be placed at a predetermined position in the borehole along with the grouting tube 30 .

[0118] In this embodiment, the ground layers are divided into ground layer A, ground layer B and ground layer C, and the pressure bladder 20 is locked in the ground layer A, ground layer B and ground layer C respectively.

[0119] S4. Grouting is injected into the pressure bag 20 through the grouting pipe 30 to expand the pressure bag 20 until it contacts the inner wall of the borehole, and the friction between the pressure bag 20 and the inner wall of the borehole reaches a certain value.

[0120] Specifically, a high-pressure pump 33 is used to inject grout into the pressure bag 20 through the grouting pipe 30. The injected high-pressure slurry expands the pressure bag 20. Under the pressure conditions provided by the pressure bag 20, the pressure bag 20 compacts the hole wall formation. Multiple pressure bags 20 can be expanded from top to bottom in sequence and locked in position.

[0121] S5. Collect, count and analyze the data of the displacement sensors 40 at different positions at different times.

[0122] Specifically, the data A of the displacement sensor A 40 and the displacement sensor B 40 at time T0 is recorded, and the distance LA between the displacement sensor A 40 and the displacement sensor B 40 at time T0 is calculated based on the data A. The data B of the displacement sensor A 40 and the displacement sensor B 40 at time T1 is recorded, and the distance LB between the displacement sensor A 40 and the displacement sensor B 40 at time T1 is calculated based on the data B. Based on the distances LA and LB, the displacement change of the stratum is determined.

[0123] The present application can solve the problem that the displacement sensor 40 is difficult to couple with the formation.

[0124] The present application also discloses a stratum displacement monitoring device. Figure 5 The monitoring equipment includes a pressure bag 20, a displacement sensor 40, a communication equipment protection tube 51, and a data acquisition center 50. A grouting hole 202 is provided on the pressure bag 20, and a grouting pipe 30 is connected to the grouting hole 202. A first one-way pressure valve 31 and a second one-way pressure valve 32 are pre-installed in the grouting pipe 30. A grouting hole 301 is pre-opened on the side wall of the grouting pipe 30 between the first one-way pressure valve 31 and the second one-way pressure valve 32 to connect the grouting pipe 30 and the pressure bag 20. The pressure conductance value of the second one-way pressure valve 32 is greater than the pressure conductance value of the first one-way pressure valve 31, and the pressure conductance value of the second one-way pressure valve 32 is less than a certain level of the maximum pressure to which the pressure bag 20 is subjected. The liquid outlet of the second one-way pressure valve 32 faces the pressure bag 20 below.

[0125] At the same time, a protective tube mounting hole 203 and a sensor mounting hole 204 that are interconnected are pre-opened in the pressure bag 20. The communication equipment protective tube 51 passes through the protective tube mounting hole 203, and the displacement sensor 40 is installed in the sensor mounting hole 204. A line is connected between the displacement sensor 40 and the data acquisition center 50, and the line is arranged in the communication equipment protective tube 51.

[0126] Reference Figure 4Preferably, the pressure bladder 20 in the present application includes a bladder tension net 21 and a bladder anti-seepage membrane 22 that are bonded to each other. The bladder anti-seepage membrane 22 is arranged on the inner wall of the pressure bladder 20, and the bladder tension net 21 is arranged on the outer wall of the pressure bladder 20. This structure can improve the anti-seepage performance and high-pressure resistance of the pressure bladder 20.

[0127] The implementation principle of a stratum displacement monitoring device in an embodiment of the present application is: a displacement sensor 40 is installed at the displacement to be measured in the borehole using a pressure bag 20. The pressure bag 20 is locked with the stratum and moves with the movement of the stratum. When the stratum moves, the pressure bag 20 moves and drives the displacement sensor 40 to move, thereby solving the problem that the displacement sensor 40 is difficult to couple with the stratum.

[0128] Example 3

[0129] Reference Figure 6 The present application discloses a method for monitoring stress changes between formation structural planes, comprising the following steps:

[0130] S1. Drilling and hole cleaning.

[0131] Specifically, a hole is drilled at a location where stratum changes need to be monitored, and all mud and sediment in the hole are cleaned out after the drilling is completed.

[0132] S2. Provide a plurality of pressure bladders 20 with force sensors 60 mounted therein.

[0133] Specifically, a protective tube mounting hole 203 and a sensor mounting hole 204 are pre-opened in the pressure bag 20; the force sensor 60 is installed in the sensor mounting hole 204; a communication equipment protective tube 51 is provided which accommodates the transmission line of the force sensor 60 inside, and the communication equipment protective tube 51 is passed through the protective tube mounting hole 203.

[0134] S3 . Pre-connect the force sensors 60 between adjacent pressure bladders 20 , apply a certain prestress to the connected force sensors 60 , and obtain the prestress values ​​between the connected force sensors 60 .

[0135] For details, refer to 6 and Figure 7 , step S3 includes:

[0136] S31 . Pre-connect adjacent force sensors 60 using pre-tensioned steel wires 70 and pre-stressed steel wires 71 , so that the readings of the connected force sensors 60 are equal.

[0137] S32. Pull the pre-tensioning steel wire 70 with a certain tension.

[0138] S33 , obtaining the tension value between the connected force sensors 60 .

[0139] Specifically, when the force sensor 60 is installed, the force sensor 60 is installed in the pressure bag 20. After the pressure bag 20 reaches the predetermined position, low-pressure slurry is injected into the pressure bag 20, and then the pre-tensioned steel wire 70 is pulled so that each force sensor 60 can read a certain value of tension, maintain the tension level of the pre-tensioned steel wire 70, and inject high-pressure slurry into the pressure bag 20 to lock the position of the force sensor 60. After completion, further tension is applied to the pre-tensioned steel wire 70 to further increase the tension of each force sensor 60 by a certain value, which cannot exceed 1 / 3 of the load of the prestressed steel wire 71.

[0140] S4. Lock the pressure bladders 20 at predetermined positions in the borehole so that different pressure bladders 20 are located in different strata.

[0141] Specifically, step S4 includes:

[0142] S41 , pre-opening a grouting hole 202 on the pressure bag 20 , inserting a grouting tube 30 into the grouting hole 202 , and fixing a plurality of pressure bags 20 at predetermined positions on the grouting tube 30 .

[0143] S42, lowering multiple pressure bags 20 along with the grouting pipe 30 to preset positions in the borehole so that different pressure bags 20 are located in different strata.

[0144] Specifically, since grouting is not performed in the pressure bag 20 , the pressure bag 20 is in a relaxed state and can be placed at a predetermined position in the borehole along with the grouting tube 30 .

[0145] S43. The slurry guide tube 30 has unidirectional conductivity from the inlet to the slurry outlet. The unidirectional conductivity can be adjusted according to the slurry pressure in the pressure bag 20. Grouting is injected into the pressure bag 20 through the slurry guide tube 30, so that the pressure bag 20 expands to abut against the inner wall of the borehole, and the friction between the pressure bag 20 and the inner wall of the borehole reaches a certain value.

[0146] The step S43 further includes:

[0147] S431. Pre-install multiple groups of first one-way pressure valves 31 and second one-way pressure valves 32 in the slurry guiding pipe 30, and pre-open a slurry hole 301 connecting the slurry guiding pipe 30 and the pressure bag 20 on the side wall between the first one-way pressure valve 31 and the second one-way pressure valve 32. The pressure conductance value of the second one-way pressure valve 32 is greater than the pressure conductance value of the first one-way pressure valve 31, and the pressure conductance value of the second one-way pressure valve 32 is less than a certain level of the maximum pressure to which the pressure bag 20 is subjected. The liquid outlet end of the second one-way pressure valve 32 faces the pressure bag 20 below.

[0148] Specifically, a high-pressure pump 33 is used to grout into the pressure bladder 20 through a slurry guide pipe 30. The injected high-pressure slurry expands the pressure bladder 20. Under the pressure condition provided by the pressure bladder 20, the pressure bladder 20 compacts the hole wall formation. Multiple pressure bladders 20 can expand successively from top to bottom and lock their positions. After fixing the pressure bladder 20, the installation steel wire bracket is removed, and the tension on the pre-tensioned steel wire 70 is eliminated, so that each pressure bladder 20 can move freely with the formation.

[0149] S5. Measure the change in prestress between the connected force sensors 60 at different times, and determine the change in force between the structural surfaces according to the change in prestress.

[0150] In this embodiment, the formation is divided into formation A, formation B, and formation C, and the pressure bladders 20 are respectively locked in formation A, formation B, and formation C. There are upper and lower readings in the same force sensor 60. The upper reading is equal to the lower reading at the front end connected to it, and the lower reading is equal to the upper reading at the rear end connected to it.

[0151] Set: A, B, and C are three connected force sensors 60, and the prestressed steel wire 71 straddles two structural surfaces AB and BC. The readings of the force sensors 60 are: A lower = x1, B upper = X2, B lower = y1, C upper = y2. When installed properly, x1 = x2 and y1 = y2.

[0152] The step S5 includes:

[0153] S51. Obtain the values of the force sensors 60 at time t0, time t1, and time t2 respectively. The obtained values are:

[0154] At time t0, it is measured that x1 = x2 = fAB0; y1 = y2 = fBC0;

[0155] At time t1, it is measured that x1 = x2 = fAB1; y1 = y2 = fBC1;

[0156] At time t2, it is measured that x1 = x2 = fAB2; y1 = y2 = fBC2.

[0157] S52. Calculate the obtained values:

[0158] If fAB1 - fAB0 = fAB2 - fAB1, it means that the AB structural surface is relatively stable.

[0159] If fAB1 - fAB0 < fAB2 - fAB1, it means that the AB structural surface expands.

[0160] If fAB1 - fAB0 > fAB2 - fAB1, it means that the AB structural surface compresses.

[0161] Similarly,

[0162] If fBC - fBC0 = fBC2 - fBC1, it indicates that the BC structural plane is relatively stable.

[0163] If fBC1 - fBC0 < fBC2 - fBC1, it indicates that there is relative expansion between the BC structural planes.

[0164] If fBC1 - fBC0 > fBC2 - fBC1, it indicates that there is relative compression between the BC structural planes.

[0165] The solution of this application uses the pressure bladder 20 as the locking mechanism of the force sensor 60, enabling the force sensor 60 to be locked with the formation and accurately change with the change of the formation, improving the accuracy of the monitoring results, thus being able to monitor the stress change between the formation structural planes in real time, providing an important basis for geological disaster risk assessment, so as to take effective measures in a timely manner to prevent and control the occurrence of geological disasters.

[0166] This application embodiment also discloses a monitoring device for the stress change between formation structural planes. Refer to Figure 6 and Figure 7 , the monitoring device includes a pressure bladder 20, a force sensor 60, a communication device protection tube 51, and a data acquisition center 50. A grouting through-hole 202 is provided on the pressure bladder 20, and a grouting conduit 30 is connected in the grouting through-hole 202. A plurality of groups of first one-way pressure valves 31 and second one-way pressure valves 32 are pre-installed in the grouting conduit 30. A slurry permeation hole 301 connecting the grouting conduit 30 and the pressure bladder 20 is pre-opened on the side wall of the grouting conduit 30 between the first one-way pressure valve 31 and the second one-way pressure valve 32. The pressure conduction value of the second one-way pressure valve 32 is greater than the pressure conduction value of the first one-way pressure valve 31, the pressure conduction value of the second one-way pressure valve 32 is less than a certain level of the maximum pressure received by the pressure bladder 20, and the liquid outlet end of the second one-way pressure valve 32 faces the lower pressure bladder 20.

[0167] Refer to Figure 4 , preferably, the pressure bladder 20 in this application includes a bladder tensile mesh 21 and a bladder anti-seepage membrane 22 that are adhesively bonded to each other. The bladder anti-seepage membrane 22 is arranged on the inner wall of the pressure bladder 20, and the bladder tensile mesh 21 is arranged on the outer wall of the pressure bladder 20. This structure can improve the anti-seepage performance and high-pressure resistance of the pressure bladder 20.

[0168] Meanwhile, a protection tube installation hole 203 and a sensor installation hole 204 that communicate with each other are pre-opened in the pressure bladder 20. The communication device protection tube 51 passes through the protection tube installation hole 203, and the force sensor 60 is installed in the sensor installation hole 204. A circuit is connected between the force sensor 60 and the data acquisition center 50, and the circuit is arranged in the communication device protection tube 51.

[0169] Refer to Figure 7The force sensor 60 includes a waterproof shell 601, a force sensor body 602, and a force sensor fixed end 603. The force sensor body 602 is installed in the waterproof shell 601. The force sensor body 602 is connected to the waterproof shell 601 through the force sensor fixed end 603. A pre-tensioned steel wire 70 is connected between the upper and lower waterproof shells 601. A pre-stressed steel wire 71 is connected to the force sensor body 602 between the upper and lower strata. The readings of the force sensor bodies 602 connected to the upper and lower strata are the same.

[0170] The implementation principle of the device for monitoring stress changes between stratum structural surfaces in the embodiment of the present application is as follows: a pressure bag 20 is used to install a force sensor 60 at the location to be measured in the borehole. The pressure bag 20 is locked with the stratum and moves with the movement of the stratum. When the stratum moves, the pressure bag 20 moves, and the force sensor 60 moves with it. By monitoring the value changes of the force sensor 60, the force changes between the structural surfaces can be determined. The solution of the present application uses the pressure bag 20 as a locking mechanism for the force sensor 60, so that the force sensor 60 is locked with the stratum and can accurately change with the changes in the stratum, thereby improving the accuracy of the monitoring results.

[0171] The above are all preferred embodiments of the present application, and are not intended to limit the scope of protection of the present application. Therefore, any equivalent changes made based on the structure, shape, and principle of the present application should be included in the scope of protection of the present application.

Claims

1. A method for monitoring stress changes between stratum structural surfaces, characterized in that: It includes the following steps: S1. Drill holes and clean the holes; S2. Provide multiple pressure bladder bags (20) with force sensors (60) installed inside; S3. Connect the force sensors (60) between adjacent pressure bladder bags (20) in advance, apply a certain prestress to the connected force sensors (60), and obtain the prestress value between the connected force sensors (60); S4. Lock the pressure bladder bags (20) at predetermined positions in the drill holes so that different pressure bladder bags (20) are in different strata; S5. Measure the change in prestress between the connected force sensors (60) at different times, and determine the change in force between the structural surfaces according to the change in prestress; The strata are divided into stratum A and stratum B. The pressure bladder bags (20) are locked in stratum A and stratum B respectively. Set: A and B are two connected force sensors (60), and the readings of the force sensors (60) are: x1 under A = x1, x2 above B = x2; The readings of the connected force sensors (60) are equal. The step S5 includes: S51. Obtain the values of the force sensors (60) at time t0, time t1, and time t2 respectively. The obtained values are: At time t0, it is measured that x1 = x2 = fAB0; At time t1, it is measured that x1 = x2 = fAB1; At time t2, it is measured that x1 = x2 = fAB2; S52. Calculate the obtained values: If fAB1 - fAB0 = fAB2 - fAB1, it indicates that the adjacent structural surfaces are relatively stable; If fAB1 - fAB0 < fAB2 - fAB1, it indicates that the adjacent structural surfaces expand; If fAB1 - fAB0 > fAB2 - fAB1, it indicates that the adjacent structural surfaces are compressed.

2. The method for monitoring stress changes between stratum structural planes according to claim 1, characterized in that: The step S3 includes: S31. Connect adjacent force sensors (60) in advance using pre-tension steel wires (70) and prestress steel wires (71); S32. Pull the pre-tension steel wire (70) with a certain tension; S33. Obtain the tension value between the connected force sensors (60); After step S4, it further includes: S34. Eliminate the tension on the pre-tension steel wire (70).

3. The method for monitoring stress changes between stratum structural planes according to claim 2, characterized in that: The certain tension in the step S32 refers to not exceeding 1 / 3 of the load of the prestress steel wire (71).

4. The method for monitoring stress changes between stratum structural planes according to claim 1, characterized in that: The step S4 includes: S41. Pre-drill grouting through holes (202) on the pressure bladder bags (20), insert the grouting guide pipes (30) into the grouting through holes (202), and fix multiple pressure bladder bags (20) at predetermined positions on the grouting guide pipes (30); S42. Lower multiple pressure bladder bags (20) along with the grouting guide pipes (30) to the preset positions of the drill holes so that different pressure bladder bags (20) are in different strata; S43. The grouting guide pipe (30) has a one-way conductivity from the inlet to the slurry outlet, and the one-way conductivity can be adjusted according to the slurry pressure in the pressure bladder bag (20). Grout into the pressure bladder bag (20) through the grouting guide pipe (30) to make the pressure bladder bag (20) expand to abut against the inner wall of the drill hole, and make the friction force between the pressure bladder bag (20) and the inner wall of the drill hole reach a certain value.

5. The method for monitoring stress changes between stratum structural planes according to claim 4, characterized in that: The step S43 includes: S431, pre-install multiple groups of first one-way pressure valves (31) and second one-way pressure valves (32) in the slurry guide pipe (30), pre-open a slurry hole (301) connecting the slurry guide pipe (30) and the pressure bag (20) on the side wall of the slurry guide pipe (30) between the first one-way pressure valve (31) and the second one-way pressure valve (32), the pressure conductance value of the second one-way pressure valve (32) is greater than the pressure conductance value of the first one-way pressure valve (31), the pressure conductance value of the second one-way pressure valve (32) is less than a certain level of the maximum pressure to which the pressure bag (20) is subjected, and the liquid outlet end of the second one-way pressure valve (32) faces the pressure bag (20) below.

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