An experimental method for detecting in-situ creep stress of rock and soil

Abstract

This invention provides an experimental method for detecting in-situ creep stress in rock and soil. A side hole is first drilled in the rock and soil at the survey site using a drilling machine. While ensuring the strength of the rock and soil, a pressure sensor is installed in the side hole using a combination of a hollow cylinder and a silicone mold. A computer is connected to record initial data. A main hole is then drilled using the drilling machine. Expansive cement is then filled into the main hole to exert force on the rock and soil. Expansion bolts are placed in the middle of the cement during filling to facilitate removal. Finally, data analysis is performed to draw conclusions. This method is primarily applicable to survey sites of various rock and soil types.

Description

Technical Field

[0001] The present invention belongs to the technical field of rock mass exploration, and relates to an experimental method for detecting the creep stress of in-situ rock and soil. It is an on-site exploration method for detecting the stress condition and stress change law of the rock and soil without disturbing the rock and soil, and is mainly suitable for on-site exploration of rock and soil. Background Art

[0002] Due to the complexity of geotechnical engineering, the influence of environmental factors, regional factors and external factors, there are many uncertain factors in the geotechnical itself. The complex geological conditions make it difficult to simulate the survey of geotechnical bodies in the laboratory. Commonly used in-situ tests include load tests and lateral pressure tests, which are subject to many restrictions and are more troublesome.

[0003] Furthermore, simulating the actual geotechnical conditions in the laboratory results in significant errors and costs, consuming considerable manpower and material resources. This, in turn, does not align with the profit maximization sought by various departments during actual construction. The numerous geotechnical environmental factors and measurement and testing constraints make experimental operations inconvenient. Summary of the Invention

[0004] The purpose of this invention is to provide an experimental method for detecting in-situ creep stress in rock and soil. This method is primarily targeted at various rock and soil types that are difficult to simulate in the laboratory. Using a drill, a side hole is first drilled in the rock and soil at the survey site. While ensuring rock and soil strength, a pressure sensor is installed in the side hole using a combination of a hollow cylinder and a silicone mold. A computer is connected to record initial data. A main hole is then drilled using the drill. Expansive cement slurry is then filled into the main hole to exert force on the rock and soil. Expansion bolts are placed in the center of the slurry during filling to facilitate removal. Finally, data analysis is performed to draw conclusions. This method is primarily applicable to survey sites of various rock and soil types.

[0005] To achieve the above technical features, the present invention provides a device for detecting creep stress in situ rock and soil, comprising a hollow cylinder having a plurality of circular holes for passing displacement sensors formed at equal intervals along the height direction of the hollow cylinder; a heating wire wrapped around the exterior of the hollow cylinder; and a pressure sensing sheet adhered to the inner wall of the side where the circular holes are located by strong adhesive.

[0006] The combined tube comprises a double-layer leather cover as a mold, and silicone is poured inside the double-layer leather cover to form a mold silicone tube;

[0007] The reaction frame device includes a screw rod, the bottom end of the screw rod is fixed by an anchor, two layers of load-bearing plates are sleeved on the top end of the screw rod, a retractable sleeve is provided between the load-bearing plates, and the load-bearing plate on the top layer is fixed to the top end of the screw rod by a nut;

[0008] It includes an inward contraction cylinder, which is arranged inside the main hole. The main hole is drilled in the center of the rock and soil body by a drilling machine, and multiple circles of evenly distributed side holes are evenly distributed around the periphery of the main hole.

[0009] The reaction frame device is arranged on the top of the rock and soil body.

[0010] The exterior of the hollow cylinder is coated with a lubricating oil layer.

[0011] A film is pasted on the outer wall of the hollow cylinder and at the position of the circular hole where the displacement sensor is located.

[0012] A circular hole is also processed on the combined pipe at a position corresponding to the circular hole on the hollow cylinder, and a sealing treatment is adopted at the position where the circular hole is located to ensure that there is no air leakage.

[0013] The pressure sensing sheet is connected to the computer via a first network cable, and the displacement sensor is connected to the computer via a second network cable.

[0014] The telescopic sleeve includes a lower sleeve, the bottom end of the lower sleeve is sealed by bottom plate welding, the upper sleeve is mounted on the inner top of the lower sleeve, and the top opening of the upper sleeve is sealed by a spiral cover plate; the lower sleeve and the upper sleeve are guided and slidably fitted by a vertical groove rail.

[0015] During the experiment, the interior of the retractable sleeve is filled with expansion cement slurry, which is prepared by mixing mica sheets, expansion cement slurry with a K content, and crushed sand and gravel in a certain proportion, stirring rapidly, and mixing them evenly.

[0016] The inner side wall of the inward shrinking tube is processed with vertically arranged pressure-bearing grooves, and the space between the inward shrinking tube and the main hole is filled with expansion cement slurry, so that the inward shrinking tube shrinks inward under the action of expansion force.

[0017] During the experiment, the space between the inward shrinkage tube and the main hole is filled with expansive cement slurry, and a vibrating rod is placed in the hole instead. The vibrating rod is filled with a mold silicone tube around it to fully contact the inner wall of the surrounding rock and soil. After the mold silicone tube solidifies, the vibrating rod is started, and the curves of the two sensing sheets are observed and recorded under continuous vibration force and upper pressure. It is also possible to replace filling the center hole with expansive concrete and the inward shrinkage tube with placing an appropriate amount of explosives in the main hole to fill the main hole, and detonate the explosives after taking protective measures, and observe and record the curves of the two sensing sheets.

[0018] The experimental method of the device for detecting the creep stress of in-situ rock and soil comprises the following steps:

[0019] Step 1: Prepare materials: pressure sensor, displacement sensor, drilling rig, hollow tube, heating wire, double-layer leather cover, mold silicone tube, lubricating oil layer, vibrating rod, explosives, mica sheet, screw, expansion cement slurry, load plate, expansion screw, contraction anchor rod, retractable sleeve and combination pipe;

[0020] Step 2: Install the combined tube: Punch a circular hole on the hollow tube according to the designed size, wrap the heating wire around the outer surface of the hollow tube, apply lubricating oil on the surface of the heating wire, put on a double-layer leather cover, and then stably place it in the center of the hollow tube. Then, install the pressure sensor and displacement sensor side by side on the hollow tube according to the given designed spacing. After the installed displacement sensor, a layer of film should be attached to the circular hole on the outer wall of the hollow tube. After completion, set it aside for use;

[0021] Step 3: Install the displacement sensor: When installing, make sure the stretched size of the displacement sensor is consistent with the size of the circular hole. Ensure that the port of the displacement sensor is in full contact with the side hole wall. After the displacement sensor is installed, attach a layer of film to the contact circular hole.

[0022] Step 4: Drill a positioning side hole: After considering the measurement size within the detection range, drill a positioning side hole vertically towards the ground at any position. Immediately after drilling, insert the combination tube and inject mold silicone to fill the gap between the double-layer leather cover. Make sure that all the surrounding gaps are filled and seal the upper opening. Then, connect the power supply of the heating wire and let the heating wire operate. Allow the silicone to cure within 10 minutes. When the silicone is completely cured, turn off the power supply.

[0023] Step 5: Drill the remaining side holes: Determine the positions of the remaining side holes according to the side hole positioning installation drawing, mark the determined positions, and then drill holes one by one. After each side hole is drilled, proceed as in step 3: insert the combination tube, inject the mold silicone, and use the heating wire to solidify the mold silicone;

[0024] Step 6: Install the network cable and measure the initial curve graph: Connect all pressure sensors and displacement sensors to the network cable, and connect the network cable to the computer in order according to the diagram. Open the corresponding program on the computer, measure and record the initial data of the pressure sensors and displacement sensors in an undisturbed state. After that, the computer keeps working;

[0025] Step 7: Assemble and install the reaction frame device: drill four holes around the area to be measured to form a square the size of the load-bearing plate. Assemble the three materials of nuts, screws and load-bearing plates into the reaction frame device. Finally, screw the upper load-bearing plate to ensure that it cannot be moved. The lower load-bearing plate can be adjusted up and down freely. Place a retractable sleeve between the two load-bearing plates and adjust the sleeve position so that it is located around the main hole. Add an appropriate amount of expansion cement slurry to the retractable sleeve. Then adjust the height of the two load-bearing plates so that they are tightly clamped by the retractable sleeve. The lower load-bearing plate is close to the ground to measure and record the data of each sensor.

[0026] Step 8: Drill the main hole: drill a main hole vertically toward the ground in the center of the side holes. While drilling, measure and record the curves of each sensor piece when the surrounding rock and soil are subjected to fluctuations;

[0027] Step 9: Prepare mixed cement slurry: Unpack the expansion agent and cement on site, take an appropriate amount into a bucket, then add a certain proportion of mica flakes and fine sand into the bucket, and stir quickly to make sure the three are mixed evenly before the expansion cement slurry begins to expand. After completion, place it next to the main hole for later use;

[0028] Step 10: Measure the extrusion pressure: Insert the inward-contracting cylinder vertically into the center of the main hole, then inject a well-mixed expansive cement slurry into the main hole. Quickly install the reaction frame above the entire measured surface. Adjust the horizontal position so that the sleeve is directly above the main hole. Then adjust the load-bearing plate and the retractable sleeve downward to apply a vertical ground pressure to the soil. After the soil begins to expand, observe and record the curves transmitted by the two sensing plates.

[0029] Step 11: Expanding and contracting the soil: When the expansive cement slurry expands to a certain extent, it reaches the maximum bearing capacity of the inward shrinkage tube, and the inward shrinkage tube is destroyed. The expansive cement slurry expands toward the center, and the expansion force toward the surrounding areas decreases;

[0030] Step 12: Measure the vibration force: dig a hole in the middle main hole to insert a vibrating rod, insert the vibrating rod, adjust the power of the vibrating rod to within the measurable range, and measure the pressure and displacement curve of the soil during vibration multiple times;

[0031] Step 13: Measure the impact force: Dig a hole in the middle main hole to accommodate a string of explosives. Place all items in a safe range and detonate the explosives. Measure the impact pressure and displacement curve of the explosives on the surrounding soil when suddenly detonated.

[0032] The present invention has the following beneficial effects:

[0033] 1. In view of the complex factors of rock and soil, as well as the complex operation and many limitations of existing equipment, this invention innovatively proposes a technology and method for detecting in-situ rock and soil stress. This technology can be used to measure various rock and soil bodies.

[0034] 2. The present invention can realize unpowered testing, reducing the transportation of equipment in places with complex terrain and conditions.

[0035] 3. The present invention has the advantages of simple operation and wide application range.

[0036] 4. The present invention realizes the application of bidirectional pressure during in-situ detection, which can obtain more data.

[0037] 5. During the experiment of the present invention, the vibrating rod wrapped with the hollow tube is wrapped with lubricating oil, which can be easily pulled out after the experiment, thereby protecting the experimental device, recycling the device and reducing damage to the experimental instrument.

[0038] 6. The vibrating rod device is used to generate artificially controllable force, which can simulate the stress conditions of rock and soil when subjected to different forces, and has a wide measurement range.

[0039] 7. The present invention utilizes mold silicone to fill the gap between the combined pipe and the side wall, which can minimize the impact of the excavated drilled gap and more accurately detect displacement and stress.

[0040] 8. The inward shrinking tube manufactured by the present invention has the pressure-bearing notches made by controlling the depth of the notches according to the test confining pressure, so as to control whether damage occurs under different confining pressures.

[0041] 9. The device proposed in the present invention has a simple structure, low cost, and is easy to operate. It can easily detect the stress conditions of in-situ rock and soil bodies and is widely used in engineering projects with complex rock and soil factors. It has broad practical significance and application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] The present invention will be further described below with reference to the accompanying drawings and examples.

[0043] Figure 1 It is a structural schematic diagram of the hollow cylinder of the present invention.

[0044] Figure 2 This is a cross-sectional view of the installation of the displacement sensor of the present invention.

[0045] Figure 3 This is a schematic diagram of the assembled pipe after installation of the present invention.

[0046] Figure 4 It is a schematic cross-sectional view of the mold silicone of the present invention.

[0047] Figure 5This is a simulated top view of the in-situ rock and soil hole detection method of the present invention.

[0048] Figure 6 This is a simulated side view of the in-situ rock and soil hole detection method of the present invention.

[0049] Figure 7 This is a diagram of the punching arrangement of the reaction frame of the present invention.

[0050] Figure 8 This is a simulated side view of the in-situ rock and soil body detected by the present invention.

[0051] Figure 9 Schematic diagram of the retractable sleeve of the present invention.

[0052] Figure 10 It is a schematic diagram of the pressure-bearing notch of the inward shrinking tube of the present invention.

[0053] Figure 11 This is a schematic diagram of placing a vibrating rod in the main hole of the present invention.

[0054] In the figure: pressure sensing piece 1, first network cable 2, drilling rig 3, expansion cement slurry 4, displacement sensor 5, vibrating rod 6, combination tube 7, lubricating oil 8, super glue 9, inward shrinking tube 10, heating wire 11, mold silicone tube 12, explosive 13, double-layer leather case 14, mica sheet 15, screw 16, nut 17, force plate 18, retractable sleeve 19, hollow tube 20, circular hole 21, film 22, second network cable 23, lower sleeve 24, upper sleeve 25, main hole 26, spiral cover plate 27, side hole 29. DETAILED DESCRIPTION

[0055] The embodiments of the present invention will be further described below with reference to the accompanying drawings.

[0056] Example 1:

[0057] See also Figure 1-11A device for detecting creep stress of in-situ rock and soil, comprising a hollow cylinder 20, with a plurality of circular holes 21 for passing displacement sensors 5 being machined at equal intervals along the height direction of the hollow cylinder 20; a heating wire 11 being wound around the outside of the hollow cylinder 20; a pressure sensing sheet 1 being adhered to the inner wall of the side where the circular hole 21 is located by means of a strong adhesive 9; a combined tube 7, wherein the combined tube 7 uses a double-layer leather cover 14 as a mold, and silicone is poured inside the double-layer leather cover 14 to form a mold silicone tube 12; and a reaction frame device, wherein the reaction frame device comprises The screw 16 has its bottom end fixed by an anchor, and two layers of load-bearing plates 18 are mounted on the top of the screw 16. A retractable sleeve 19 is provided between the load-bearing plates 18, and the load-bearing plate 18 on the top layer is fixed to the top of the screw 16 by a nut 17; it includes an inward shrinkage tube 10, which is arranged inside the main hole 26. The main hole 26 is processed in the center of the rock and soil body by a drilling rig 3, and multiple circles of evenly distributed side holes 29 are evenly distributed on the periphery of the main hole 26; the reaction frame device is arranged on the top of the rock and soil body.

[0058] Furthermore, the exterior of the hollow cylinder 20 is coated with a lubricating oil layer 8 .

[0059] Furthermore, a film 22 is attached to the outer wall of the hollow cylinder 20 and located at the position of the circular hole 21 where the displacement sensor 5 is located.

[0060] Furthermore, a circular hole is also processed at a position on the combined tube 7 corresponding to the circular hole on the hollow cylinder 20, and a sealing treatment is adopted at the position where the circular hole is located to ensure that there is no air leakage.

[0061] Furthermore, the pressure sensing sheet 1 is connected to the computer via a first network cable 2 , and the displacement sensor 5 is connected to the computer via a second network cable 23 .

[0062] Furthermore, the retractable sleeve 19 includes a lower sleeve 24, the bottom end of the lower sleeve 24 is sealed by bottom plate welding, the inner top end of the lower sleeve 24 is fitted with an upper sleeve 25, and the top opening of the upper sleeve 25 is sealed by a spiral cover plate 27; the lower sleeve 24 and the upper sleeve 25 are guided and slidably fitted by a vertical groove rail.

[0063] Furthermore, during the experiment, the interior of the retractable sleeve 19 is filled with expansion cement slurry 4, which is prepared by mixing mica sheets 15, expansion cement slurry with a K content, and crushed sand and gravel in a certain proportion, stirring rapidly, and mixing them evenly.

[0064] Furthermore, vertically arranged pressure-bearing notches 28 are processed on the inner side wall of the inward-shrinking tube 10 , and the space between the inward-shrinking tube 10 and the main hole 26 is filled with expansive cement slurry, so that the inward-shrinking tube 10 shrinks inward under the action of the expansion force.

[0065] Furthermore, during the experiment, the space between the inward shrinking tube 10 and the main hole 26 is filled with expansive cement slurry, and a vibrating rod 6 is placed in the hole instead, and the vibrating rod is filled with a mold silicone tube 12 around the vibrating rod to fully contact the inner wall of the surrounding rock and soil. After the mold silicone tube 12 solidifies, the vibrating rod 6 is started, and the curves of the two sensing sheets are observed and recorded under continuous vibration force and upper pressure. It is also possible to replace filling the center hole with expansive concrete and the inward shrinking tube 10 with placing an appropriate amount of explosives 13 in the main hole to fill the main hole, and detonate the explosives 13 after taking protective measures, and observe and record the curves of the two sensing sheets.

[0066] Example 2:

[0067] This embodiment is an experimental method for detecting in-situ rock and soil stress using a single main hole, which includes the following steps:

[0068] Step 1: Prepare materials: pressure sensor 1, displacement sensor 5, drilling rig 3, hollow tube 20, heating wire 11, double-layer leather cover 14, mold silicone tube 12, lubricating oil layer 8, vibrating rod 6, explosive 13, mica sheet 15, screw 16, expansion cement slurry 4, load plate 18, expansion screw, contraction anchor rod, retractable sleeve 19 and combination tube 7;

[0069] Step 2: Install the combined tube: Punch a circular hole 21 in the hollow tube 20 according to the designed dimensions. Wrap the heating wire 11 around the outer surface of the hollow tube 20. Apply lubricant to the surface of the heating wire 20, cover it with a double-layer leather cover 14, and then stably position it in the center of the hollow tube 20. Then, install the pressure sensor 1 and displacement sensor 5 side by side on the hollow tube 20 according to the given designed spacing. After the installed displacement sensor 5, a layer of film 22 should be attached to the circular hole on the outer wall of the hollow tube 20. After completion, set it aside for future use.

[0070] Step 3: Install the displacement sensor 5: During installation, ensure that the stretched size of the displacement sensor 5 is consistent with the size of the circular hole 21. Ensure that the end of the displacement sensor 5 is in full contact with the side hole wall. After the displacement sensor is installed, attach a layer of film to the contact circular hole.

[0071] Step 4: Drill a positioning side hole: After considering the measurement size within the detection range, drill a positioning side hole vertically toward the ground at any position. Immediately after drilling, insert the combined tube 7 and inject the mold silicone to fill the gap between the double-layer leather cover 14. Make sure that all the surrounding gaps are filled and the upper opening is sealed. Then, turn on the power of the heating wire 11 and let the heating wire 11 operate to allow the silicone to cure within 10 minutes. When the silicone is completely cured, turn off the power.

[0072] Step 5: Drill the remaining side holes: Determine the positions of the remaining side holes 29 according to the side hole installation drawing, mark the determined positions, and then drill holes one by one. After each side hole is drilled, proceed as in step 3: insert the combination tube 7, inject the mold silicone, and use the heating wire to solidify the mold silicone;

[0073] Step 6: Install the network cable and measure the initial curve graph: Connect all the pressure sensing pieces 1 and displacement sensors 5 to the network cable, and connect the network cable to the computer in order according to the drawing. Open the corresponding program on the computer, measure and record the initial data of the pressure sensing piece 1 and displacement sensor 5 in an undisturbed state. After that, the computer keeps working;

[0074] Step 7: Drilling the main hole 26: Drill a main hole 26 vertically toward the ground in the center of the side holes. While drilling, measure and record the curves of each sensor sheet when the surrounding rock and soil are subjected to fluctuations.

[0075] Step 8: Prepare the mixed expansive cement slurry: Unpack the expansive agent and cement on site, take an appropriate amount into a bucket, then add a certain proportion of mica flakes 15 and fine sand into the bucket, and stir quickly to make the three mixed evenly before the expansive cement slurry begins to expand. After completion, place it next to the main hole 26 for later use;

[0076] Step 9: Vertically insert the inward contraction tube into the center of the main hole, then inject evenly mixed expansion cement slurry into the main hole. Quickly install the reaction frame device above the main hole 26, assemble the nut, screw, and load-bearing plate into a reaction frame, place the telescopic sleeve 19 between the two load-bearing plates, adjust the horizontal position so that the telescopic sleeve 19 is directly above the main hole, then adjust the load-bearing plate and telescopic sleeve 19 downward to apply a vertical ground pressure to the surface above the main hole. After the expansion begins, observe and record the curves transmitted by the two sensor plates;

[0077] Step 11: Expand and contract the soil: When the expansive cement expands to a certain extent, the confining pressure applied to the internal inward shrinkage tube reaches its maximum, and the inward shrinkage tube is destroyed. The expansive cement slurry then continues to expand inward, and the outward expansion force decreases. Observe and record the changes recorded by the two sensor sheets during the entire process.

[0078] Example 3:

[0079] This embodiment is a method for detecting in-situ rock and soil stress using dual main holes, which includes the following steps:

[0080] Step 1: Prepare materials: pressure sensor, displacement sensor, drilling rig, hollow tube, heating wire, mold silicone, vibrating rod, explosives, expansion cement slurry, inward shrinking tube, and combination tube;

[0081] Step 2: Install the combined tube: Punch a circular hole on the hollow tube according to the drawing, wrap the heating wire around the outer surface of the hollow tube, apply lubricating oil on the surface of the heating wire, put on a double-layer leather cover, and then stably place it in the center of the hollow tube. Then, install the pressure sensor and displacement sensor side by side on the hollow tube according to the given drawing, with a distance. After the installed displacement sensor, a layer of film should be attached to the circular hole on the outer wall of the hollow tube. After completion, set it aside for use;

[0082] Step 3: Drill a positioning side hole: After considering the measurement size within the detection range, drill a positioning side hole vertically toward the ground at any position. Immediately after drilling, insert the combined tube and inject mold silicone to fill the gap between the heating wire and the hollow tube, and seal the upper opening. Then, connect the power supply of the heating wire to operate the heating wire and allow the silicone to cure within 10 minutes. When the silicone is completely cured, turn off the power.

[0083] Step 4: Drill the remaining side holes: Determine the positions of the remaining side holes according to the side hole positioning installation drawing, mark the determined positions, and then drill holes one by one. After each side hole is drilled, follow the same steps as in step 3, insert the combination tube, inject the mold silicone, and use the heating wire to solidify the mold silicone.

[0084] Step 5: Install the network cable and measure the initial curve graph: Connect all the sensors to the network cable and connect the network cable to the computer in order according to the diagram. Open the corresponding program on the computer, measure and record the initial data of the displacement sensor and pressure sensor in an undisturbed state. After that, the computer keeps working.

[0085] Step 6: Drill the main hole: drill two main holes vertically toward the ground in the center of the side holes. While drilling, measure and record the curves of each sensor sheet when the surrounding rock and soil are subjected to fluctuations;

[0086] Step 7: Assemble the reaction frame: Assemble the nut, screw, and load-bearing plate to form a reaction frame. Place a retractable sleeve between the two load-bearing plates. Adjust the sleeve so that it is located in the center of the load-bearing plates. Add an appropriate amount of expansive cement slurry to the sleeve. Adjust the height of the two load-bearing plates so that they tightly clamp the retractable sleeve.

[0087] Step 8: Prepare mixed cement: Unpack the expansive cement slurry on site, take an appropriate amount into a bucket, then add a large amount of mica flakes and a small amount of crushed sand and gravel into the bucket, and stir quickly to ensure that the three are evenly mixed before the expansive cement slurry begins to expand. After completion, place it next to the main hole for later use;

[0088] Step 9: Measure the extrusion pressure: Insert the inward contraction cylinder vertically into the center of the two main holes, then inject a well-mixed expansive cement slurry into the main holes. Quickly install the reaction frame device above the main holes and adjust the horizontal position so that the sleeve is directly above the main holes. Then adjust the load plate and sleeve downward to apply a vertical ground pressure to the surface above the main holes. After the expansion begins, observe and record the curves transmitted by the two sensor plates. At the same time, observe and record the creep curve of the rock mass between the two holes under tension.

[0089] Step 10: Expand and contract the soil: When the expansive cement expands to a certain extent, the confining pressure applied to the internal inward shrinkage tube reaches the maximum, and the inward shrinkage tube is destroyed. The expansive cement slurry then continues to expand inward, and the outward expansion force decreases. At the same time, observe and record the curves of the changes recorded by the two sensor sheets and the creep curve of the rock and soil during the entire process.

[0090] Example 4:

[0091] The experimental method for detecting the stress of in-situ vibrating rock and soil includes the following steps:

[0092] Step 1: Prepare materials: pressure sensor, displacement sensor, drilling rig, hollow tube, heating wire, mold silicone, vibrating rod, explosives, expansion cement slurry, inward shrinking tube;

[0093] Step 2: Install the combined tube: Punch a circular hole on the hollow tube according to the drawing, wrap the heating wire around the outer surface of the hollow tube, apply lubricating oil on the surface of the heating wire, put on a double-layer leather cover, and then stably place it in the center of the hollow tube. Then, install the pressure sensor and displacement sensor side by side on the hollow tube according to the given drawing, with a distance. After the installed displacement sensor, a layer of film should be attached to the circular hole on the outer wall of the hollow tube. After completion, set it aside for use;

[0094] Step 3: Drilling positioning side holes: After considering the measurement size within the detection range, drill a positioning side hole vertically toward the ground at any position. Immediately after drilling, insert the combined tube and inject mold silicone to fill the gap between the hollow tubes and seal the upper opening. Then, connect the power supply of the heating wire to operate the heating wire and allow the silicone to cure within 10 minutes. When the silicone is completely cured, turn off the power supply.

[0095] Step 4: Drill the remaining side holes: Determine the positions of the remaining side holes according to the side hole installation drawing, mark the determined positions, and then drill holes one by one. After each side hole is drilled, proceed as in step 3: insert the combination tube, inject the mold silicone, and use the heating wire to solidify the mold silicone;

[0096] Step 5: Install the network cable and measure the initial curve: Connect all the sensors to the network cable and connect the network cable to the computer in order according to the diagram. Open the corresponding program on the computer, measure and record the initial data of the sensor in an undisturbed state. After that, the computer keeps working.

[0097] Step 6: Drill the main hole: drill a main hole in the center of the side holes, pointing vertically toward the ground. While drilling, measure and record the curves of each sensor sheet when the surrounding rock and soil are subjected to fluctuations.

[0098] Step 7: Measure the vibration force: Leave enough space in the main hole to fit the vibrating rod, insert the vibrating rod, adjust the power of the vibrating rod to within the measurable range, and measure the pressure and displacement curves of the soil during vibration multiple times;

[0099] Example 5:

[0100] Experimental method for testing the stress of rock and soil under in-situ impact load:

[0101] Step 1: Prepare materials: pressure sensor, displacement sensor, drilling rig, hollow tube, heating wire, mold silicone, vibrating rod, explosives, expansion cement slurry, inward shrinking tube;

[0102] Step 2: Install the combined tube: Punch a circular hole on the hollow tube according to the drawing, wrap the heating wire around the outer surface of the hollow tube, apply lubricating oil on the surface of the heating wire, put on a double-layer leather cover, and then stably place it in the center of the hollow tube. Then, install the pressure sensor and displacement sensor side by side on the hollow tube according to the given drawing, with a distance. After the installed displacement sensor, a layer of film should be attached to the circular hole on the outer wall of the hollow tube. After completion, set it aside for use;

[0103] Step 3: Drill a positioning hole: After considering the measurement size within the detection range, drill a positioning hole vertically toward the ground at a location. Immediately after drilling, insert the combined tube and inject mold silicone to fill the gap between the hollow tubes. Seal the upper opening. Then, connect the power supply of the heating wire to operate the heating wire and allow the silicone to cure within 10 minutes. When the silicone is completely cured, turn off the power supply.

[0104] Step 4: Drill the remaining side holes: Determine the positions of the remaining side holes according to the side hole installation drawing, mark the determined positions, and then drill holes one by one. After each side hole is drilled, proceed as in step 3: insert the combination tube, inject the mold silicone, and use the heating wire to solidify the mold silicone;

[0105] Step 5: Install the network cable and measure the initial curve: Connect all the sensors to the network cable and connect the network cable to the computer in order according to the diagram. Open the corresponding program on the computer and measure and record the initial data of the sensors in an undisturbed state. After that, the computer will remain in working condition.

[0106] Step 6: Drill the main hole: drill a main hole in the center of the side holes, pointing vertically toward the ground. While drilling, measure and record the curves of each sensor sheet when the surrounding rock and soil are subjected to fluctuations.

[0107] Step 7: Measure the impact force: Place a string of explosives in the main hole, place everything in a safe area, and then detonate the explosives. Measure the impact pressure and displacement curve of the explosives on the surrounding soil when they suddenly explode.

Claims

1. An experimental method for detecting the creep stress of in-situ rock and soil, characterized in that: The method is realized by means of a device for detecting creep stress of an in-situ rock and soil mass, wherein the device comprises a hollow cylinder (20), and a plurality of circular holes (21) for passing a displacement sensor (5) are processed at equal intervals along the height direction of the hollow cylinder (20); a heating wire (11) is wound around the outside of the hollow cylinder (20); and a pressure sensing sheet (1) is adhered to the inner wall of the side where the circular hole (21) is located by means of a strong glue (9); The combined tube (7) comprises a double-layer leather cover (14) as a mold, and silicone is poured inside the double-layer leather cover (14) to form a mold silicone tube (12); The invention comprises a reaction frame device, wherein the reaction frame device comprises a screw rod (16), the bottom end of the screw rod (16) is fixed by anchoring, two layers of force plates (18) are sleeved on the top end of the screw rod (16), a retractable sleeve (19) is provided between the force plates (18), and the force plate (18) located on the top layer is fixed to the top end of the screw rod (16) by a nut (17); The invention comprises an inward shrinking cylinder (10), wherein the inward shrinking cylinder (10) is arranged inside a main hole (26), wherein the main hole (26) is machined in the center of the rock and soil body by a drilling machine (3), and a plurality of evenly distributed side holes (29) are evenly machined on the periphery of the main hole (26); The reaction frame device is arranged on the top of the rock and soil mass; The experimental method comprises the following steps: Step 1: Prepare materials: prepare pressure sensing sheet (1), displacement sensor (5), drilling rig (3), hollow tube (20), heating wire (11), double-layer leather cover (14), mold silicone tube (12), lubricating oil layer (8), vibrating rod (6), explosive (13), mica sheet (15), screw (16), expansion cement slurry (4), load plate (18), expansion screw, contraction anchor rod, retractable sleeve (19) and combination tube (7); Step 2: Install the combined tube: Punch a circular hole (21) on the hollow tube (20) according to the design size, wind the heating wire (11) around the outer surface of the hollow tube (20), apply lubricating oil on the surface of the heating wire (11), put on a double-layer leather cover (14), and then stably place it in the center of the hollow tube (20). Then, install the pressure sensor (1) and the displacement sensor (5) side by side on the hollow tube (20) according to the given design spacing. The installed displacement sensor (5) should be attached with a layer of film (22) on the outer wall of the hollow tube (20) that contacts the circular hole. After completion, put it aside for use; Step 3: Install the displacement sensor (5): When installing, pay attention to the stretching size of the displacement sensor (5) to be consistent with the size of the circular hole (21). Make sure that the port of the displacement sensor (5) is in full contact with the side hole wall. After the displacement sensor is installed, attach a layer of film to the contact circular hole. Step 4: Drilling a positioning side hole: After considering the measurement size within the detection range, drill a positioning side hole in a direction vertical to the ground at any position. Immediately after drilling, insert the combined tube (7) and inject the mold silicone to fill the gap between the double-layer leather cover (14). Make sure that all the surrounding gaps are filled and the upper opening is sealed. Then, turn on the power of the heating wire (11) and let the heating wire (11) operate to allow the silicone to cure within 10 minutes. When the silicone is completely cured, turn off the power. Step 5: Punch the remaining side holes: Determine the positions of the remaining side holes (29) according to the positioning side hole installation drawing, mark the determined positions, and then punch holes one by one. After each side hole is punched, proceed as in step 3: insert the combination tube (7), inject the mold silicone, and use the heating wire to solidify the mold silicone; Step 6: Install the network cable and measure the initial curve graph: Connect all the pressure sensing pieces (1) and displacement sensors (5) to the network cable, and connect the network cable to the computer in order according to the drawing. Open the corresponding program on the computer, measure and record the initial data of the pressure sensing piece (1) and displacement sensor (5) in an undisturbed state. After that, the computer keeps working; Step 7: Assemble and install the reaction frame device: drill 4 holes around the area to be measured to form a square the size of the force plate, install the nut (17), screw (16) and force plate (18) into a reaction frame device, and finally screw the upper force plate to ensure that it cannot be moved, and the lower force plate can be adjusted up and down freely. Place a telescopic sleeve (19) between the two force plates, adjust the sleeve position so that it is located around the main hole (26), add an appropriate amount of expansion cement slurry to the telescopic sleeve (19), and then adjust the height of the two force plates (18) so that they can tightly clamp the telescopic sleeve (19). The lower force plate is close to the ground to measure and record the data of each sensor piece; Step 8: Drilling the main hole (26): Drill a main hole (26) vertically toward the ground in the center of the side holes. While drilling, measure and record the curves of each sensor sheet when the surrounding rock and soil are subjected to fluctuations; Step 9: Prepare mixed cement slurry: Unpack the expansion agent and cement on site, take appropriate amounts into a bucket, then add a certain proportion of mica flakes (15) and fine sand into the bucket, and stir quickly to make the three mixed evenly before the expansion cement slurry begins to expand. After completion, place it next to the main hole (26) for later use; Step 10: Measure the extrusion pressure: insert the inward contraction cylinder (10) vertically into the center of the main hole (26), and then inject the mixed expansion cement slurry into the main hole (26). Quickly install the reaction frame device above the entire measured surface, adjust the horizontal position so that the sleeve is located directly above the main hole, and then adjust the load-bearing plate and the retractable sleeve (19) downward to apply a vertical ground pressure to the soil. After the expansion begins, observe and record the curves transmitted by the two sensor sheets. Step 11: Expanding and contracting the soil: When the expansion cement slurry expands to a certain extent, the maximum bearing capacity of the inward shrinkage tube (10) is reached, the inward shrinkage tube is destroyed, and the expansion cement slurry expands toward the center, and the expansion force toward the surrounding areas is reduced; Step 12: Measure the vibration force: excavate a hole in the middle main hole (26) to insert the vibration rod, insert the vibration rod (6), adjust the power of the vibration rod (6) to within the measurable range, and measure the pressure and displacement curve of the soil during vibration for multiple times; Step 13: Measure the impact force: dig a hole in the middle main hole to allow a string of explosives to be placed (13). Place all items within a safe range and then detonate the explosives. Measure the impact pressure and displacement curve of the explosives on the surrounding soil when they suddenly explode.

2. The experimental method for detecting in-situ creep stress of rock and soil according to claim 1, characterized in that: The exterior of the hollow cylinder (20) is coated with a lubricating oil layer (8).

3. The experimental method for detecting in-situ creep stress of rock and soil according to claim 1, characterized in that: A film (22) is adhered to the outer wall of the hollow cylinder (20) at the position of the circular hole (21) where the displacement sensor (5) is located.

4. The experimental method for detecting in-situ creep stress of rock and soil according to claim 1, characterized in that: A circular hole is also machined on the combined tube (7) at a position corresponding to the circular hole on the hollow cylinder (20), and a sealing treatment is adopted at the position where the circular hole is located to ensure that there is no air leakage.

5. The experimental method for detecting in-situ creep stress of rock and soil according to claim 1, characterized in that: The pressure sensing sheet (1) is connected to the computer via a first network cable (2), and the displacement sensor (5) is connected to the computer via a second network cable (23).

6. The experimental method for detecting in-situ creep stress of rock and soil according to claim 1, characterized in that: The telescopic sleeve (19) comprises a lower sleeve (24), the bottom end of the lower sleeve (24) is sealed by bottom plate welding, the upper sleeve (25) is sleeved on the top end of the inner portion of the lower sleeve (24), and the top opening of the upper sleeve (25) is sealed by a screw cover plate (27); the lower sleeve (24) and the upper sleeve (25) are guided and slidably fitted by a vertical groove rail.

7. The experimental method for detecting in-situ creep stress of rock and soil according to claim 6, characterized in that: During the experiment, the interior of the retractable sleeve (19) is filled with expansion cement slurry (4), and the expansion cement slurry (4) is prepared by mixing mica sheets (15), expansion cement slurry with a K content, and crushed sand and gravel in a certain proportion, stirring rapidly, and mixing them evenly.

8. The experimental method for detecting in-situ creep stress of rock and soil according to claim 1, characterized in that: The inner side wall of the inward shrinking tube (10) is processed with vertically arranged pressure-bearing notches (28), and the space between the inward shrinking tube (10) and the main hole (26) is filled with expansion cement slurry, so that the inward shrinking tube (10) shrinks inward under the action of the expansion force.

9. The experimental method for detecting in-situ creep stress of rock and soil according to claim 8, characterized in that: During the experiment, the space between the inward contraction tube (10) and the main hole (26) is filled with expansion cement slurry, and a vibrating rod (6) is placed in the hole instead, and the mold silicone tube (12) is filled around the vibrating rod to fully contact the inner wall of the surrounding rock and soil. After the mold silicone tube (12) solidifies, the vibrating rod (6) is started, and the curves of the two sensor sheets are observed and recorded under the continuous vibration force and the upper pressure. It is also possible to replace the filling of the central hole with expansion concrete and the inward contraction tube (10) with the filling of the main hole with an appropriate amount of explosives (13) and the detonation of the explosives (13) after the protective work is done, and the curves of the two sensor sheets are observed and recorded.

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