CN109163985B - In-situ testing device and method for testing shear strength and long-term creep deformation of rock sample - Google Patents
In-situ testing device and method for testing shear strength and long-term creep deformation of rock sample Download PDFInfo
- Publication number
- CN109163985B CN109163985B CN201810929869.2A CN201810929869A CN109163985B CN 109163985 B CN109163985 B CN 109163985B CN 201810929869 A CN201810929869 A CN 201810929869A CN 109163985 B CN109163985 B CN 109163985B
- Authority
- CN
- China
- Prior art keywords
- shearing
- rock
- shear
- vertical
- box
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N3/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N3/24—Investigating strength properties of solid materials by application of mechanical stress by applying steady shearing forces
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B5/00—Measuring arrangements characterised by the use of mechanical techniques
- G01B5/30—Measuring arrangements characterised by the use of mechanical techniques for measuring the deformation in a solid, e.g. mechanical strain gauge
Abstract
The invention discloses an in-situ test device and a method for testing the shear strength and long-term creep deformation of a rock sample, wherein a test platform is cut out of a region where a surrounding rock is located, and the surrounding rock is provided with the shear rock sample, a smooth surrounding rock surface and upper surrounding rock; a horizontal shearing box is arranged at the top of the flat surrounding rock surface and on the side edge of the sheared rock sample; a horizontal shearing device is arranged between the horizontal shearing box and the side wall of the sheared rock sample; a vertical load loading box is arranged on the lower end face of the upper surrounding rock, and a vertical shearing device is arranged between the lower end face of the vertical load loading box and the sheared rock sample; the horizontal shearing device and the vertical shearing device adopt the same structure, and the power sources of the horizontal shearing device and the vertical shearing device both adopt expansive cement slurry. The self-expansion performance of the expanding agent is innovatively utilized to provide a load source for a field in-situ shear test, and the expansion force generated by the expanded cement paste is utilized to transfer the expansion load to a field rock sample through a loading probe of the dumbbell-shaped shear rod, so that the shear strength index on a specific shear surface of a rock body can be measured.
Description
Technical Field
The invention relates to an in-situ shear test and direct shear test device for rock under a vertical load condition of a rock sample in geotechnical engineering, in particular to an in-situ test device and method for testing the shear strength and long-term creep deformation of the rock sample.
Background
The shear test of rock under the compression condition is a basic method for obtaining the peak shear strength and the residual strength of the rock under different normal pressures, and is an important means for obtaining the shear strength parameter of the rock. Therefore, it has been widely used in geotechnical engineering and different compression-shear test equipment has been developed. Common devices are a large direct shear apparatus applied to indoor tests and a small portable direct shear apparatus applied to field in-situ tests.
The existing indoor compression-shear test equipment is complex, and comprises bonding of a rock test piece, limitation of a loading mode of normal shear force on lateral deformation and the like, the stress on a shear surface is uneven, and the accuracy of a test result is influenced; and because the test distance in the horizontal direction is limited by the size of the instrument, the size range of the shear displacement which can be tested is greatly limited in the detection process of the direct shear apparatus, and the shear resistant test data with larger size cannot be provided.
The on-site in-situ shear test is a necessary test for searching the real strength of the rock-soil body, the size of a shear sample is large, the disturbance is small, and the test result has higher reliability. The common in-situ direct shear apparatus mainly comprises a vertical pressure system, a horizontal shear system and a data acquisition system. Due to the fact that the size of a field sample is large, the loading capacity (weighing several tons) required by the vertical load required by the sample is large, and the vertical load must be moved along with the sample when the position of the sample is changed, the workload is large, and time and labor are wasted. Therefore, how to conveniently and quickly provide accurate and stable vertical load for the test process becomes a key problem of the field direct shear test.
In the two modes, the accurate and constant vertical pressure is difficult to provide for the test, the stability in the shearing process is poor, the stress on the shearing surface is uneven, and the accuracy of the test result is influenced; and the long-term shear creep of the on-site rock sample cannot be monitored for a long time, and most importantly, the cost required in the monitoring process is overhigh and the operation is complex.
Disclosure of Invention
The invention aims to provide an in-situ test device and a method for testing the shear strength and long-term creep deformation of a rock sample, wherein a load source is provided by innovatively utilizing the self-expansion performance of an expanding agent to carry out an in-situ shear test on site, and an expansion load is transmitted to the in-site rock sample through a loading probe of a dumbbell-shaped shear rod by utilizing the expansion force generated by expanded cement slurry; the method is characterized in that a vertical load is applied to a rock sample to be sheared on site, the rock sample is destroyed by applying a horizontal shearing force after the rock sample is stabilized, and meanwhile, the shearing stress of the rock sample during the destruction is recorded, so that the shearing strength index on a specific shearing surface of a rock mass can be measured.
In order to achieve the technical features, the invention is realized as follows: an in-situ test device for testing the shear strength and long-term creep deformation of a rock sample comprises surrounding rocks needing to be subjected to a shear test, wherein a test platform is cut out of the region of the surrounding rocks, and the surrounding rocks are provided with the shear rock sample, a smooth surrounding rock surface and upper surrounding rocks; a horizontal shearing box is arranged at the top of the flat surrounding rock surface and on the side edge of the sheared rock sample; a horizontal shearing device is arranged between the horizontal shearing box and the side wall of the sheared rock sample; a vertical load loading box is arranged on the lower end face of the upper surrounding rock, and a vertical shearing device is arranged between the lower end face of the vertical load loading box and the sheared rock sample; the horizontal shearing device and the vertical shearing device adopt the same structure, and the power sources of the horizontal shearing device and the vertical shearing device both adopt expansive cement slurry.
The surrounding rock selects field rock mass to adopt cutting equipment to cut out an overexcavation test platform, its shape is the hollow cube structure of recessed rule.
The shearing area of the sheared rock sample is not less than 2500cm2And the height is not less than 2/3 of the side length.
The both sides of horizontal shear box are fixed with the trompil steel sheet, the trompil steel sheet is through taking screw thread earth anchor fixed mounting at the top of level and smooth surrounding rock face, and the top locking of taking screw thread earth anchor is fixed with the nut.
The horizontal shearing box adopts a cuboid structure without a top cover.
The horizontal shearing device comprises a dowel plate arranged on the side wall of the horizontal shearing box, a dowel bar is connected to the side wall of the dowel plate, an adjustable belleville spring is connected to the other end of the dowel bar, a dumbbell-shaped shearing bar is connected to the other end of the adjustable belleville spring, and the other end of the dumbbell-shaped shearing bar is in contact with the side wall of the shearing rock sample through a loading probe.
The vertical shearing device comprises a dowel plate arranged on the lower end face of the vertical load loading box, a dowel bar is connected to the side wall of the dowel plate, an adjustable belleville spring is connected to the other end of the dowel bar, the other end of the adjustable belleville spring is connected with a vertical dumbbell-shaped shearing bar, and the other end of the vertical dumbbell-shaped shearing bar is in contact with the top end of the sheared rock sample through a loading probe.
The expanded cement slurry adopts an expanded cement slurry material with a large mixing amount, and the expanded cement slurry material is filled in the horizontal shearing box and the vertical load loading box.
A layer of asbestos is laid on the inner walls of the horizontal shearing box and the force transmission plate of the horizontal shearing device, and a layer of rubber gasket is laid between the force transmission plate and the expansion cement slurry.
A layer of asbestos is laid on the inner walls of the vertical load loading box and the force transmission plate of the vertical shearing device, and a layer of rubber gasket is laid between the force transmission plate and the expansion cement slurry.
The center of the inner wall of the force transmission plate is provided with a pressure sensor, and each pressure sensor is connected with a pressure acquisition and processing device; the shear displacement dial indicator is installed in three axial directions of the shear rock sample, and the vertical displacement dial indicator is installed in the vertical direction of the top of the shear rock sample.
The test method of the in-situ test device for testing the shear strength and the long-term creep deformation of the rock sample comprises the following steps:
step 1: surrounding rock cleaning: selecting a surrounding rock surface with better lithology, and cleaning weeds and gravels on the surrounding rock to be cut;
step 2: cutting a rock sample and testing a platform: cutting and grinding an overexcavation test platform by utilizing cutting equipment, wherein the overexcavation test platform is a concave regular hollow cube and comprises a sheared rock sample, a flat surrounding rock surface and upper surrounding rocks;
step 3: prefabricating a horizontal shearing box and a vertical load loading box: welding a cuboid without a top cover by using a steel plate with larger strength according to a proper size, and welding a steel plate with a central hole extending out on one side surface of the cuboid, namely a horizontal shearing box and a vertical load loading box;
step 4: prefabricating a dumbbell-shaped shearing rod: cutting a force transmission plate which is prefabricated and matched with the horizontal shearing box according to the size of the horizontal shearing box, wherein the force transmission plate extends into the horizontal shearing box through a uncovered gap, welding a force transmission rod with a certain length at the center of the force transmission plate, welding an adjustable belleville spring at the other end of the force transmission rod, and welding a loading probe at the other end of the spring;
step 5: preparing asbestos and rubber: paving a layer of asbestos on the inner surfaces of the horizontal shearing box and the vertical load loading box;
step 6: pasting a pressure sensor: a pressure sensor is stuck to the right center of the force transmission plate and is connected with a pressure acquisition system;
step 7: pouring expanded cement paste: preparing expansive cement slurry with the content of an expansive agent A%, and pouring the expansive cement slurry in a horizontal shearing box;
step 8: installing a vertical dumbbell-shaped shearing rod: after the pouring is finished, the expansion cement paste is pressed and coated by the force transmission plate, and a layer of rubber gasket is laid between the force transmission plate and the expansion cement paste;
step 9: installing a vertical load loading box: installing a vertical load loading box between a rock sample and surrounding rocks, adjusting a vertical loading probe to enable the vertical loading probe to be stressed uniformly, maintaining expanded cement slurry for a period of time, adjusting an adjustable belleville spring to adjust the expansion force, ensuring that the load applied to the rock sample is a design value for applying the load, applying different normal loads to the rock sample to be sheared, monitoring a vertical deformation value by using a displacement dial indicator, and when the cumulative sum of two continuous vertical deformations for 15min is not more than 0.05mm, considering that the vertical deformations are stable, and installing a horizontal shearing box;
step 10: pouring expanded cement paste and installing a horizontal shearing box: preparing expanded cement slurry with the content of an expanding agent of B%, pouring the expanded cement slurry in a horizontal shearing box, pressing and coating the expanded cement slurry by using a force transmission plate after pouring is finished, and paving a layer of rubber gasket between the force transmission plate and the expanded cement slurry; placing the horizontal shearing box on a flat surrounding rock surface of the side surface of the rock sample to be sheared, inserting the threaded ground anchor into a hole of the surrounding rock through the perforated steel plate, and fixing the horizontal shearing box by using a nut;
step 11: adjusting a loading probe and a load: and adjusting the horizontal loading probe to act on the rock sample, adjusting the horizontal adjustable belleville spring according to the design value of the test horizontal load, and immediately measuring and recording the vertical deformation, the shear load and the shear deformation after the application of each level of shear load is finished.
Step 12: and (3) testing: when reaching the peak value of the applied shear stress or the shear deformation is increased sharply or the shear deformation is greater than 1/10 of the diameter or the length of the test piece, the test is terminated after the shear failure is considered;
step 13: processing data: recording the shear stress when the rock sample is damaged:
drawing a relation curve of shear stress and normal stress, so as to obtain the shear strength parameters of the rock mass on a specific failure surface, namely an internal friction angle and cohesive force;
drawing a relation curve of the shearing stress and the shearing displacement: shear strength versus normal stress curve;
thirdly, by utilizing a relation curve of the shearing stress and the shearing displacement, the peak shearing strength and the residual strength on the shearing failure surface under a certain normal stress condition can be determined;
fourthly, determining the internal friction angle and cohesive force of the rock mass on the shearing surface by utilizing the relation curve of the shearing strength and the normal stress;
testing the long-term creep shear deformation of the rock sample through stable expansion load to obtain the change rule of the internal friction angle and cohesive force of the rock mass along with time under the action of load.
The invention has the following beneficial effects:
1. the invention creatively utilizes the expanding agent cement paste to generate larger load, provides a load source through the self-expansion performance of the expanding agent cement paste, performs in-situ shear test on site, is simple and efficient, and solves the problem of applying power to the load of the existing field equipment.
2. The expansive force provided by the invention has long-term stability, avoids stress drop and stress relaxation applied in a long-term test process, can carry out long-term shear creep on a field rock sample, obtains the change rule of the strength parameter of the rock sample along with time, and solves the defects of the existing field rock sample long-term shear creep research.
3. The invention can measure the shear strength index on the specific shear surface of the rock mass and draw the relation curve of the shear stress and the normal stress, thereby obtaining the shear strength parameters of the rock mass on the specific failure surface, namely the internal friction angle and the cohesive force.
4. The load generated by the expansive cement slurry can be adjusted through the adjustable belleville springs, so that the load applied to the rock sample is ensured to be a design value of a test load, and the accuracy of the applied load is also ensured.
5. The method has small disturbance to the field rock sample, and the shearing area is much larger than that of an indoor test, so that the method can better meet the natural state compared with the indoor test, the obtained result better meets the technical requirements of the actual engineering, the stability in the shearing process is good, the stress on the shearing surface is uniform, the test result has higher reliability, the cost of the existing equipment is greatly reduced, and the operation is simple.
6. The pressure transmission box bodies of the device can be combined in various modes, such as horizontal side-by-side arrangement and axial vertical arrangement, the number of the pressure bearing boxes can be increased or reduced according to specific conditions, the grade of applied load can be regulated and controlled, and the device can be repeatedly used.
7. The device and the method can be used for carrying out various shear tests: the test method has the advantages of simple operation, low cost, higher data measuring precision, wide engineering practice significance and application prospect.
Drawings
The invention is further illustrated by the following figures and examples.
FIG. 1 is a schematic view of the overall structure of the device according to the present invention.
Fig. 2 is a schematic detail view of a horizontal shear box according to the present invention.
Fig. 3 is a schematic detail view of the ground anchor perforated steel plate according to the present invention.
In the figure: the device comprises surrounding rocks 1, a sheared rock sample 2, a flat surrounding rock surface 3, a horizontal shearing box 4, a perforated steel plate 5, an adjustable belleville spring 6, a dumbbell-shaped shearing rod 7, a threaded ground anchor 8, a nut 9, a loading probe 10, a dowel steel 11, a dowel plate 12, expansion cement slurry 13, a vertical dumbbell-shaped shearing rod 14, upper surrounding rocks 15, a vertical load loading box 16, asbestos 17, a rubber gasket 18, a pressure sensor 19, a shearing displacement dial indicator 20 and a vertical displacement dial indicator 21.
Detailed Description
Embodiments of the present invention will be further described with reference to the accompanying drawings.
Referring to fig. 1-3, example 1:
an in-situ test device for testing the shear strength and long-term creep deformation of a rock sample comprises surrounding rocks 1 and a rock sample 2 to be sheared, a horizontal shear box 4 is fixed on a flat surrounding rock surface 3 through a threaded ground anchor 8, expansive cement slurry 13 with a large amount of swelling agent is poured on the horizontal shear box 4 and a vertical load loading box 16, the generated expansive force applies vertical load and horizontal shear load on the rock sample 2 to be sheared through a force transmission plate 12 of a dumbbell-shaped shear rod 7, a force transmission rod 11, an adjustable belleville spring 6 and a loading probe 10, data in the test process are monitored through a pressure sensor 19 and a shear displacement dial indicator 20, a relation curve of the shear stress and the normal stress is drawn, and accordingly the shear strength parameters, namely the internal friction angle and the cohesive force, of the rock mass on a specific failure surface can be obtained.
Furthermore, the device can be used for carrying out various shear tests, namely: direct shear test of shearing damage of the field test piece along the shearing surface under the action of normal stress; ② friction test of shear test: a shear test of continuously shearing the field test piece along the shear surface after the field test piece is sheared; cutting resistance test: direct shear test was performed on the test bodies with a normal stress of 0.
Further, when a rock sample is prepared, if a weak structural surface or a weak rock is disturbed, the measurement result is seriously influenced. Therefore, the specimen should be strictly prevented from being disturbed during the preparation process, so as to obtain reliable test results.
Furthermore, the flatness of the shearing surface has an important influence on the shearing strength, and the fluctuation difference of the prepared shearing surface is regulated to be not more than 1-2% of the side length in the shearing direction.
Further, the installation of the horizontal shearing box is ensured on the smooth surrounding rock surface.
Furthermore, the adjustable belleville spring can adjust the expansion force, and the load accuracy applied to the rock sample is guaranteed.
Furthermore, the dowel bar adopts a high-strength rod piece.
Furthermore, the expansion cement slurry is an expansion cement slurry material with a large mixing amount, the volume of the expansion cement slurry material is limited to expand towards the periphery under the side limit condition of five surfaces of the horizontal shearing box, and the expansion force pushes the force transmission plate to move horizontally, namely the horizontal shearing load.
Furthermore, a layer of asbestos is laid on the inner walls of the horizontal shearing box, the vertical load loading box and the force transmission plate, and a large amount of heat can be released in the reaction process of the expansive cement slurry, so that the heat insulation effect is achieved.
Furthermore, a layer of rubber gasket is arranged between the force transmission plate and the expansion cement paste, so that the pressure sensor is prevented from being damaged by heat released by the expansion cement paste.
Furthermore, a pressure sensor is arranged at the center of the inner wall of the force transmission plate, so that the loads vertically and horizontally applied to the rock sample can be measured.
Furthermore, the shear displacement dial indicators are installed in the three axial directions of the shear rock sample, so that the displacement value on the shear surface can be conveniently monitored.
Furthermore, the pressure transmission box bodies of the device can be combined in various ways, such as a plurality of transverse pressure transmission box bodies are arranged side by side, a plurality of axial pressure transmission box bodies are arranged vertically, the number of pressure bearing boxes can be increased or reduced according to specific conditions, and the grade of applied load can be regulated and controlled.
Furthermore, the device can be detached and reused for multiple times.
The invention utilizes the long-term stability of the expansive force to avoid stress drop and stress relaxation applied in the long-term test process, and can carry out long-term shear creep on the on-site rock sample to obtain the change rule of the rock sample strength parameter along with time.
After each level of shear load is applied, the vertical deformation, the shear load and the shear deformation are measured and recorded immediately.
The present invention specifies that when a peak shear stress is reached or the shear deformation increases dramatically or the shear deformation is greater than 1/10 for the specimen diameter (or elongation), the test can be terminated, i.e., it is considered to have failed in shear.
The main achievements of the on-site direct shear test of the invention are as follows:
the relation curve of shear stress and shear displacement is as follows: shear strength versus normal stress curve.
Secondly, by utilizing a relation curve of the shearing stress and the shearing displacement, the peak shearing strength and the residual strength on the shearing failure surface under a certain normal stress condition can be determined.
Thirdly, the internal friction angle and cohesive force of the rock mass on the shearing surface can be determined by utilizing the relation curve of the shearing strength and the normal stress.
Example 2:
the in-situ test device and the method for testing the shear strength and the long-term creep deformation of the rock sample are characterized by comprising the following steps of:
step 1: surrounding rock cleaning: selecting a surrounding rock surface with better lithology, and cleaning weeds and gravels on the surrounding rock to be cut;
step 2: cutting a rock sample and testing a platform: cutting and grinding an overexcavation test platform by using cutting equipment, wherein the overexcavation test platform is a concave regular hollow cube and comprises a sheared rock sample, a flat surrounding rock surface and an upper surrounding rock, and the size of the rock sample to be sheared is 70cmx70cmx70 cm;
step 3: prefabricating a horizontal shearing box and a vertical load loading box: welding a cuboid without a top cover by using a steel plate with larger strength according to a proper size, and welding a steel plate with a central hole extending out on one side surface of the cuboid, namely a horizontal shearing box and a vertical load loading box;
step 4: prefabricating a dumbbell-shaped shearing rod: cutting a force transmission plate which is prefabricated and matched with the horizontal shearing box according to the size of the horizontal shearing box, wherein the force transmission plate can extend into the horizontal shearing box through a uncovered gap, welding a force transmission rod with a certain length at the center of the force transmission plate, welding an adjustable belleville spring at the other end of the force transmission rod, and welding a loading probe at the other end of the spring;
step 5: preparing asbestos and rubber: paving a layer of asbestos on the inner surfaces of the horizontal shearing box and the vertical load loading box;
step 6: pasting a pressure sensor: a pressure sensor is stuck to the right center of the force transmission plate and is connected with a pressure acquisition system;
step 7: pouring expanded cement paste: preparing expansive cement slurry with the content of an expansive agent A%, and pouring the expansive cement slurry in a horizontal shearing box;
step 8: installing a vertical dumbbell-shaped shearing rod: after the pouring is finished, the expansion cement paste is pressed and coated by the force transmission plate, and a layer of rubber gasket is laid between the force transmission plate and the expansion cement paste;
step 9: installing a vertical load loading box: installing a vertical load loading box between a rock sample and surrounding rocks, adjusting a vertical loading probe to enable the vertical loading probe to be stressed uniformly, maintaining expanded cement slurry for a period of time, adjusting an adjustable belleville spring to adjust the expansion force, ensuring that the load applied to the rock sample is a design value for applying the load, applying different normal loads to the rock sample to be sheared, monitoring a vertical deformation value by using a displacement dial indicator, and when the cumulative sum of two continuous vertical deformations for 15min is not more than 0.05mm, considering that the vertical deformations are stable, and installing a horizontal shearing box;
step 10: pouring expanded cement paste and installing a horizontal shearing box: : preparing expansive cement paste with the content of the expanding agent of B%, pouring the expansive cement paste in the horizontal shearing box, pressing and coating the expansive cement paste by using the force transmission plate after pouring is finished, and paving a layer of rubber gasket between the force transmission plate and the expansive cement paste. Placing the horizontal shearing box on a flat surrounding rock surface of the side surface of the rock sample to be sheared, inserting the threaded ground anchor into a hole of the surrounding rock through the perforated steel plate, and fixing the horizontal shearing box by using a nut;
step 11: adjusting a loading probe and a load: adjusting a horizontal loading probe to act on the rock sample, adjusting a horizontal adjustable belleville spring according to a design value of a test horizontal load, and immediately measuring and recording vertical deformation, shear load and shear deformation after each level of shear load is applied;
step 12: and (3) testing: when the peak applied shear stress is reached or the shear deformation increases sharply or the shear deformation is greater than 1/10 for the specimen diameter (or elongation), the test can be terminated, assuming shear failure;
step 13: processing data: recording the shear stress when the rock sample is damaged:
drawing a relation curve of the shear stress and the normal stress, thereby obtaining the shear strength parameters of the rock mass on a specific failure surface, namely an internal friction angle and cohesive force.
The relation curve of the shearing stress and the shearing displacement is as follows: shear strength versus normal stress curve.
And thirdly, determining the peak shear strength and the residual strength on the shear failure surface under a certain normal stress condition by using a shear stress and shear displacement relation curve.
Fourthly, the internal friction angle and the cohesive force of the rock mass on the shearing surface can be determined by utilizing the relation curve of the shearing strength and the normal stress.
Testing the long-term creep shear deformation of the rock sample through stable expansion load to obtain the change rule of the internal friction angle and cohesive force of the rock mass along with time under the action of load.
The above-described embodiments are intended to illustrate rather than to limit the invention, and any modifications and variations of the present invention are within the spirit of the invention and the scope of the claims.
Claims (10)
1. The utility model provides a test rock specimen shear strength and long-term creep deformation's normal position testing arrangement which characterized in that: the test platform comprises surrounding rocks (1) needing to be subjected to a shear test, wherein a test platform is cut in the region of the surrounding rocks (1), and a shear rock sample (2), a flat surrounding rock surface (3) and upper surrounding rocks (15) are arranged on the surrounding rocks (1); a horizontal shearing box (4) is arranged at the top of the flat surrounding rock surface (3) and on the side edge of the shearing rock sample (2); a horizontal shearing device is arranged between the horizontal shearing box (4) and the side wall of the shearing rock sample (2); a vertical load loading box (16) is arranged on the lower end face of the upper surrounding rock (15), and a vertical shearing device is arranged between the lower end face of the vertical load loading box (16) and the sheared rock sample (2); the horizontal shearing device and the vertical shearing device adopt the same structure, and the power sources of the horizontal shearing device and the vertical shearing device both adopt expanded cement slurry (13).
2. The in-situ test apparatus for testing shear strength and long-term creep deformation of a rock specimen according to claim 1, wherein: the surrounding rock (1) is an open-air rock body, and a cutting device is adopted to cut an over-excavation test platform which is of a concave regular hollow cube structure.
3. The in-situ test apparatus for testing shear strength and long-term creep deformation of a rock specimen according to claim 1, wherein: the shearing area of the sheared rock sample (2) is not less than 2500cm2And the height is not less than 2/3 of the side length.
4. The in-situ test apparatus for testing shear strength and long-term creep deformation of a rock specimen according to claim 1, wherein: the both sides of horizontal shear box (4) are fixed with trompil steel sheet (5), trompil steel sheet (5) are fixed mounting at the top of leveling country rock face (3) through taking screw thread earth anchor (8), and the top locking of taking screw thread earth anchor (8) is fixed with nut (9).
5. The in-situ test apparatus for testing shear strength and long-term creep deformation of a rock specimen according to claim 1 or 4, wherein: the horizontal shearing box (4) is of a cuboid structure without a top cover.
6. The in-situ test apparatus for testing shear strength and long-term creep deformation of a rock specimen according to claim 1, wherein: the horizontal shearing device comprises a dowel plate (12) arranged on the side wall of a horizontal shearing box (4), a dowel bar (11) is connected to the side wall of the dowel plate (12), the other end of the dowel bar (11) is connected with an adjustable belleville spring (6), the other end of the adjustable belleville spring (6) is connected with a dumbbell-shaped shearing bar (7), and the other end of the dumbbell-shaped shearing bar (7) is in contact with the side wall of the shearing rock sample (2) through a loading probe (10).
7. The in-situ test apparatus for testing shear strength and long-term creep deformation of a rock specimen according to claim 1, wherein: the vertical shearing device comprises a dowel plate arranged on the lower end face of a vertical load loading box (16), a dowel bar is connected to the side wall of the dowel plate, an adjustable belleville spring is connected to the other end of the dowel bar, the other end of the adjustable belleville spring is connected with a vertical dumbbell-shaped shearing bar (14), and the other end of the vertical dumbbell-shaped shearing bar (14) is in contact with the top end of a sheared rock sample (2) through a loading probe.
8. The in-situ test apparatus for testing shear strength and long-term creep deformation of a rock specimen according to claim 1, wherein: the expanded cement slurry (13) is made of expanded cement slurry materials with large mixing amount, and the expanded cement slurry materials are filled in the horizontal shearing box (4) and the vertical load loading box (16).
9. The in-situ test apparatus for testing shear strength and long-term creep deformation of a rock specimen according to claim 1, wherein: a layer of asbestos (17) is paved on the inner walls of the horizontal shearing box (4) and a force transmission plate (12) of the horizontal shearing device, and a layer of rubber gasket (18) is arranged between the force transmission plate (12) and the expanded cement slurry (13);
a layer of asbestos (17) is paved on the vertical load loading box (16) and the inner wall of a force transmission plate (12) of the vertical shearing device, and a layer of rubber gasket (18) is arranged between the force transmission plate (12) and the expanded cement slurry (13);
the center of the inner wall of the force transmission plate (12) is provided with a pressure sensor (19), and each pressure sensor is connected with a pressure acquisition and processing device; the shearing displacement dial indicator (20) is installed in three axial directions of the shearing rock sample (2), and the vertical displacement dial indicator (21) is installed in the vertical direction of the top of the shearing rock sample (2).
10. A testing method using the in-situ test apparatus for testing shear strength and long-term creep deformation of a rock sample according to any one of claims 1 to 9, comprising the steps of:
step 1: surrounding rock cleaning: selecting a surrounding rock surface with better lithology, and cleaning weeds and broken stones on the surrounding rock (1) to be cut;
step 2: cutting a rock sample and testing a platform: cutting and grinding an overexcavation test platform by utilizing cutting equipment, wherein the overexcavation test platform is a concave regular hollow cube and comprises a sheared rock sample (2), a flat surrounding rock surface (3) and upper surrounding rocks (15);
step 3: prefabricating a horizontal shearing box (4) and a vertical load loading box (16): welding a cuboid without a top cover by using a steel plate with larger strength according to a proper size, and welding a steel plate with a central hole extending out on one side surface of the cuboid, namely a horizontal shearing box and a vertical load loading box;
step 4: prefabricating a dumbbell-shaped shearing rod: cutting a force transfer plate (12) which is prefabricated and matched with the horizontal shearing box (4) according to the size of the horizontal shearing box, wherein the force transfer plate (12) extends into the horizontal shearing box (4) through a uncovered gap, welding a force transfer rod (11) with a certain length at the center of the force transfer plate (12), welding an adjustable belleville spring (6) at the other end of the force transfer rod (11), and welding a loading probe (10) at the other end of the spring;
step 5: preparing asbestos and rubber: paving a layer of asbestos on the inner surfaces of the horizontal shearing box and the vertical load loading box;
step 6: pasting a pressure sensor: a pressure sensor is stuck to the right center of the force transmission plate and is connected with a pressure acquisition system;
step 7: pouring expanded cement paste: preparing expanded cement slurry (13) with the content of the expanding agent of A%, and pouring the expanded cement slurry in the horizontal shearing box;
step 8: installing a vertical dumbbell-shaped shearing rod: after the pouring is finished, the expansion cement paste is pressed and coated by the force transmission plate, and a layer of rubber gasket is laid between the force transmission plate and the expansion cement paste;
step 9: installing a vertical load loading box: installing a vertical load loading box between a rock sample and surrounding rocks, adjusting a vertical loading probe to enable the vertical loading probe to be stressed uniformly, maintaining expanded cement slurry for a period of time, adjusting an adjustable belleville spring to adjust the expansion force, ensuring that the load applied to the rock sample is a design value for applying the load, applying different normal loads to the rock sample to be sheared, monitoring a vertical deformation value by using a displacement dial indicator, and when the cumulative sum of two continuous vertical deformations for 15min is not more than 0.05mm, considering that the vertical deformations are stable, and installing a horizontal shearing box;
step 10: pouring expanded cement paste and installing a horizontal shearing box: preparing expanded cement slurry with the content of an expanding agent of B%, pouring the expanded cement slurry in a horizontal shearing box, pressing and coating the expanded cement slurry by using a force transmission plate after pouring is finished, and paving a layer of rubber gasket between the force transmission plate and the expanded cement slurry; placing the horizontal shearing box on a flat surrounding rock surface of the side surface of the rock sample to be sheared, inserting the threaded ground anchor into a hole of the surrounding rock through the perforated steel plate, and fixing the horizontal shearing box by using a nut;
step 11: adjusting a loading probe and a load: adjusting a horizontal loading probe to act on the rock sample, adjusting a horizontal adjustable belleville spring according to a design value of a test horizontal load, and immediately measuring and recording vertical deformation, shear load and shear deformation after each level of shear load is applied;
step 12: and (3) testing: when reaching the peak value of the applied shear stress or the shear deformation is increased sharply or the shear deformation is greater than 1/10 of the diameter or the length of the test piece, the test is terminated after the shear failure is considered;
step 13: processing data: recording the shear stress when the rock sample is damaged:
drawing a relation curve of shear stress and normal stress, so as to obtain the shear strength parameters of the rock mass on a specific failure surface, namely an internal friction angle and cohesive force;
drawing a relation curve of the shearing stress and the shearing displacement: shear strength versus normal stress curve;
thirdly, by utilizing a relation curve of the shearing stress and the shearing displacement, the peak shearing strength and the residual strength on the shearing failure surface under a certain normal stress condition can be determined;
fourthly, determining the internal friction angle and cohesive force of the rock mass on the shearing surface by utilizing the relation curve of the shearing strength and the normal stress;
testing the long-term creep shear deformation of the rock sample through stable expansion load to obtain the change rule of the internal friction angle and cohesive force of the rock mass along with time under the action of load.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810929869.2A CN109163985B (en) | 2018-08-15 | 2018-08-15 | In-situ testing device and method for testing shear strength and long-term creep deformation of rock sample |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810929869.2A CN109163985B (en) | 2018-08-15 | 2018-08-15 | In-situ testing device and method for testing shear strength and long-term creep deformation of rock sample |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN109163985A CN109163985A (en) | 2019-01-08 |
| CN109163985B true CN109163985B (en) | 2020-09-08 |
Family
ID=64895847
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201810929869.2A Active CN109163985B (en) | 2018-08-15 | 2018-08-15 | In-situ testing device and method for testing shear strength and long-term creep deformation of rock sample |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN109163985B (en) |
Families Citing this family (18)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109883779B (en) * | 2019-01-21 | 2021-04-20 | 宁波大学 | Design method for size effect shear test of anchoring structure surface |
| CN110044683B (en) * | 2019-04-08 | 2021-07-27 | 三峡大学 | Device and method for testing tensile and compressive creep of interbore rock bridge by using expanding agent |
| CN110274822B (en) * | 2019-06-28 | 2024-03-15 | 吉林大学 | Rock mass structural plane shear creep instrument |
| CN110296899B (en) * | 2019-07-11 | 2021-07-13 | 三峡大学 | Test method for researching rock creep by unpowered stress locking |
| CN110455170B (en) * | 2019-09-19 | 2021-06-08 | 河南理工大学 | Similar simulation tunnel country rock wall surface removes and warp enlarged measuring device |
| CN110455171B (en) * | 2019-09-19 | 2021-02-19 | 河南理工大学 | Method for monitoring wall deformation of surrounding rock of movable measurement analog simulation roadway |
| CN110907302A (en) * | 2019-11-29 | 2020-03-24 | 三峡大学 | Device and method for in-situ measurement of rock abrasiveness and penetration |
| CN111337644B (en) * | 2019-12-31 | 2022-04-08 | 三峡大学 | Tunnel stepwise excavation analogue means |
| CN111474053B (en) * | 2020-04-13 | 2022-11-08 | 三峡大学 | On-site shear test method |
| CN111982711B (en) * | 2020-08-28 | 2023-03-24 | 四川正达检测技术有限责任公司 | Single shear test method for shear-resistant elastic modulus of plate-type rubber support |
| CN112098236B (en) * | 2020-09-01 | 2023-12-12 | 中国电建集团华东勘测设计研究院有限公司 | In-situ testing device and method for shear strength of concrete-rock mass-spray layer contact surface |
| CN112697611B (en) * | 2020-12-07 | 2022-03-25 | 西南交通大学 | Pile-soil interface shear strength test device considering soil body expansion and contraction behaviors and method thereof |
| CN113109176B (en) * | 2021-03-12 | 2024-03-01 | 中国电建集团西北勘测设计研究院有限公司 | Joint rock mass in-situ shearing test device and method for relaxation process detection |
| CN113340263B (en) * | 2021-06-07 | 2022-09-20 | 中国科学院武汉岩土力学研究所 | Displacement monitoring device and displacement monitoring method |
| CN115165528A (en) * | 2021-06-09 | 2022-10-11 | 三峡大学 | Magnetic self-polymerization slurry pressure relief and water shutoff shear resistance testing method |
| CN114002052A (en) * | 2021-11-04 | 2022-02-01 | 昆明理工大学 | Method for calculating shear strength of full tailings filling body |
| CN114021241B (en) * | 2021-11-17 | 2023-04-11 | 中国电建集团成都勘测设计研究院有限公司 | Non-uniform soft structural surface anti-shearing parameter value taking method and system |
| CN117214004B (en) * | 2023-11-07 | 2024-02-13 | 西南交通大学 | Rock shear strength and creep deformation measuring method and related device |
Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| RU2192006C2 (en) * | 1999-12-14 | 2002-10-27 | Липецкий государственный технический университет | Method and apparatus for determining physicomechanical properties of ground layer preferably of low and average density |
| CN203275213U (en) * | 2013-05-20 | 2013-11-06 | 洛阳理工学院 | Portable confining pressure loading device |
| CN104165799A (en) * | 2014-07-28 | 2014-11-26 | 辽宁省水利水电科学研究院 | Anchoring counterforce device for roller compacted concrete in-situ shear test |
| CN105203410A (en) * | 2015-10-15 | 2015-12-30 | 安徽省建筑科学研究设计院 | Test device for measuring shearing creep characteristic of rock in dry-wet cycling process |
| CN106596290A (en) * | 2016-11-24 | 2017-04-26 | 长江水利委员会长江科学院 | Rock structural surface on-site hydraulic coupling direct shearing test structure device and construction method thereof |
| CN106680115A (en) * | 2017-02-27 | 2017-05-17 | 中国石油大学(北京) | Portable device and method for testing rock shearing strength |
| CN206362645U (en) * | 2016-12-09 | 2017-07-28 | 河北省高速公路管理局 | A kind of shale interlayer creep shear tester |
| CN107014674A (en) * | 2017-06-12 | 2017-08-04 | 福建工程学院 | The loading device and loading method of Geotechnical Engineering model test |
| CN108020473A (en) * | 2018-01-03 | 2018-05-11 | 中国电建集团华东勘测设计研究院有限公司 | Consider the Rock And Soil cutting creep instrument and its test method of drying and watering cycle |
| CN108051294A (en) * | 2017-11-06 | 2018-05-18 | 三峡大学 | A kind of device and method for simulating rock anchorage under high-ground stress and groundwater condition |
-
2018
- 2018-08-15 CN CN201810929869.2A patent/CN109163985B/en active Active
Patent Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| RU2192006C2 (en) * | 1999-12-14 | 2002-10-27 | Липецкий государственный технический университет | Method and apparatus for determining physicomechanical properties of ground layer preferably of low and average density |
| CN203275213U (en) * | 2013-05-20 | 2013-11-06 | 洛阳理工学院 | Portable confining pressure loading device |
| CN104165799A (en) * | 2014-07-28 | 2014-11-26 | 辽宁省水利水电科学研究院 | Anchoring counterforce device for roller compacted concrete in-situ shear test |
| CN105203410A (en) * | 2015-10-15 | 2015-12-30 | 安徽省建筑科学研究设计院 | Test device for measuring shearing creep characteristic of rock in dry-wet cycling process |
| CN106596290A (en) * | 2016-11-24 | 2017-04-26 | 长江水利委员会长江科学院 | Rock structural surface on-site hydraulic coupling direct shearing test structure device and construction method thereof |
| CN206362645U (en) * | 2016-12-09 | 2017-07-28 | 河北省高速公路管理局 | A kind of shale interlayer creep shear tester |
| CN106680115A (en) * | 2017-02-27 | 2017-05-17 | 中国石油大学(北京) | Portable device and method for testing rock shearing strength |
| CN107014674A (en) * | 2017-06-12 | 2017-08-04 | 福建工程学院 | The loading device and loading method of Geotechnical Engineering model test |
| CN108051294A (en) * | 2017-11-06 | 2018-05-18 | 三峡大学 | A kind of device and method for simulating rock anchorage under high-ground stress and groundwater condition |
| CN108020473A (en) * | 2018-01-03 | 2018-05-11 | 中国电建集团华东勘测设计研究院有限公司 | Consider the Rock And Soil cutting creep instrument and its test method of drying and watering cycle |
Also Published As
| Publication number | Publication date |
|---|---|
| CN109163985A (en) | 2019-01-08 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN109163985B (en) | In-situ testing device and method for testing shear strength and long-term creep deformation of rock sample | |
| CN204439474U (en) | The field direct shear test device of landslide rock mass shearing strength | |
| CN103175742B (en) | A kind of frozen soil dynamic loading direct shear apparatus | |
| CN206399740U (en) | Rock sample long-term stress loading device | |
| CN109781773B (en) | Detection method for realizing layered telescopic type frost heaving detection device | |
| CN203551406U (en) | Soil-rock mass in-situ direct shear test device with automatic data acquisition system | |
| CN111157356B (en) | Rock mass ice-containing crack frost heaving force evolution test device under stress disturbance effect | |
| CN106759547B (en) | Integral Abutment, pile foundation and soil interaction pseudo-static experimental measuring device and its installation method | |
| Iscimen et al. | Shearing behaviour of curved interfaces | |
| CN113281190A (en) | Hydraulic engineering asphalt concrete direct tensile test device and application method thereof | |
| Aldaeef et al. | Pile-soil interface characteristics in ice-poor frozen ground under varying exposure temperature | |
| CN104729988A (en) | Device and method for testing bond-slip performance of new concrete and old concrete | |
| CN108562501A (en) | One kind being suitable for Rock And Soil in-situ direct shear test device and method in tunnel | |
| JPH10325788A (en) | Apparatus and method for test of shear strength of bedrock in original position | |
| CN113089624A (en) | Adjacent foundation pit asynchronous excavation simulation test device and test method | |
| CN109799140B (en) | On-site test determination method for strength characteristic of unsaturated soil | |
| CN110411804A (en) | A kind of contact face mechanical property test sample, preparation method and the test method of the soil body and structure | |
| CN207937274U (en) | A kind of device of the irregular rock mass sample deformation parameter of test | |
| CN110849729B (en) | Active and passive soil pressure model test device for limited cohesive soil behind foundation pit flexible retaining wall | |
| CN109765260B (en) | Flexible non-contact frost heaving monomer for detecting soil, detection device and detection method thereof | |
| CN109470565B (en) | Method for testing dynamic Poisson's ratio of asphalt mixture | |
| CN110132714B (en) | Device and method for testing deformation parameters of irregular rock mass sample | |
| CN211668976U (en) | Rock mass contains ice crack frozen-expansion force evolution testing arrangement under stress disturbance effect | |
| CN215296993U (en) | Multi-connected rock-soil in-situ shear testing device for full-stress path tracking | |
| CN114965251A (en) | Self-balancing concrete and rock friction coefficient measuring system and testing method |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| TR01 | Transfer of patent right | ||
| TR01 | Transfer of patent right |
Effective date of registration: 20201202 Address after: 402760 No. 92 Donglin Avenue, Biquan Street, Bishan District, Chongqing (No. 52 Factory Building) Patentee after: Chongqing high tech Industry Research Institute Co.,Ltd. Address before: Unit 2414-2416, main building, no.371, Wushan Road, Tianhe District, Guangzhou City, Guangdong Province Patentee before: GUANGDONG GAOHANG INTELLECTUAL PROPERTY OPERATION Co.,Ltd. Effective date of registration: 20201202 Address after: Unit 2414-2416, main building, no.371, Wushan Road, Tianhe District, Guangzhou City, Guangdong Province Patentee after: GUANGDONG GAOHANG INTELLECTUAL PROPERTY OPERATION Co.,Ltd. Address before: 443002, 8, University Road, Xiling District, Hubei, Yichang Patentee before: CHINA THREE GORGES University |
|
| TR01 | Transfer of patent right | ||
| TR01 | Transfer of patent right |
Effective date of registration: 20210802 Address after: 402760 Qinggang Avenue, Qinggang street, Bishan District, Chongqing Patentee after: Chongqing Bishan Jiangyuan Machinery Co.,Ltd. Address before: 402760 No.92 Donglin Avenue, Biquan street, Bishan District, Chongqing Patentee before: Chongqing high tech Industry Research Institute Co.,Ltd. |