A dynamic shearing device and method for jointed rock mass in a drawdown zone simulating the water environment of a drawdown zone reservoir

Abstract

A jointed rock dynamic shearing device and method for simulating the water environment of a drawdown zone reservoir, mainly comprising a sample fixing mechanism, a normal loading mechanism, a tangential loading mechanism, a water pressure loading mechanism and a water inlet and outlet control mechanism; the sample fixing mechanism is installed in the test instrument housing and fixes the sample; the normal loading mechanism is used to apply a normal load to the sample; the tangential loading mechanism is used to apply a tangential dynamic load to the sample; the water pressure loading mechanism is used to pressurize the inside of the test instrument housing; the water inlet and outlet control mechanism is used to fill or pump water into the test instrument housing. The present invention provides a jointed rock dynamic shearing device and method for simulating the water environment of a drawdown zone reservoir, which can truly simulate the dynamic shear test of jointed samples under conditions such as water pressure immersion, "immersion-air drying" cycle, or a combination of conditions.

Description

Technical Field

[0001] The invention relates to a shearing device, in particular to a jointed rock mass dynamic shearing device and method for simulating a drawdown zone reservoir water environment. Background Art

[0002] According to existing research, the shear mechanical properties of the joints in the drawdown zone will accelerate deterioration during the water pressure changes caused by the periodic rise and fall of the reservoir water level and the "immersion-air drying" cycle, causing shear slippage of the rock mass in the drawdown zone, thereby affecting the long-term stability of the reservoir bank slope. Earthquakes are a common geological disaster in the reservoir area, and the damage to the slope rock and soil caused by the vibration loads they generate cannot be ignored. Therefore, the harm of earthquakes to the joint rock mass in the drawdown zone of the reservoir bank slope is self-evident.

[0003] my country has built many reservoirs in the southwest region, so there are a large number of jointed rock masses in the drawdown zone. The southwest region is also located at the junction of continental plates and is a high-incidence earthquake area. Studies have shown that earthquakes in the reservoir area have the characteristics of "small magnitude but high frequency of earthquakes", that is, although the seismic load will not cause obvious slip and dislocation of the structural surface, under the condition of constant upper load, the structural surface will be subjected to pre-peak cyclic shear due to the cyclic load brought by the earthquake. The cumulative damage effect of cyclic shear load on the joint surface of the rock mass in the drawdown zone will also cause the joint surface to suffer periodic wear, resulting in the degradation of shear strength parameters, and ultimately threatening the long-term stability of the slope.

[0004] Therefore, when studying the long-term stability analysis of the jointed rock mass in the drawdown zone of the bank slope in the southwest region, it is necessary not only to consider the influence of environmental factors on the jointed rock mass in the ordinary drawdown zone, but also to consider the damage and degradation effect of the dynamic load brought by the earthquake on the jointed rock mass in the drawdown zone.

[0005] In summary, for the simulation device of shear performance of jointed rock mass in the drawdown zone of the reservoir area located in the earthquake-prone zone, the following influencing factors need to be paid attention to:

[0006] ① Changes in water pressure caused by the rise and fall of reservoir water level;

[0007] ② Soaking-air drying cycle process;

[0008] ③ The cyclic shear action on the joint surface caused by vibration loads such as earthquakes.

[0009] The patent application number "201610859819.2" "A rock and soil shear instrument considering water-rock interaction" only focuses on simulating the impact of the immersion-air drying cycle on the shear mechanical properties of rock and soil.

[0010] The patent application number is "201720185828.8" "A new type of geotechnical dynamic direct shear test device", which only focuses on simulating the influence of dynamic factors on the shear mechanical properties of the sample."

[0011] The patent "A bidirectional shear device for rock structure surface" with application number "201420163644.8" can apply normal pressure and shear force.

[0012] The difficulties in combining the circulating water inlet and drainage device, the dynamic shear device and the pressurized immersion device are as follows: 1. How to ensure that the line of action of the tangential load is always kept in a straight line during the cyclic shear process to avoid the generation of additional bending moments; 2. How to ensure the overall sealing performance of the device during the cyclic shear test under the action of pressurized immersion and immersion-air drying cycles to prevent water and air leakage in the gaps between the normal and tangential loading columns and the device shell during loading and unloading; 3. Concentrating the immersion and air drying actions in the same device to avoid the repeated operation of taking out and putting back the specimens from the immersion container during the "immersion-air drying" cycle, and also ensuring the coupling effect of the immersion-air drying process and stress; 4. Realizing the cyclic shear of jointed rock samples under pressurized immersion and the cyclic shear of jointed rock samples under the action of immersion-air drying cycles, the reservoir water and stress environmental conditions of the jointed rock mass in the drawdown zone of the reservoir bank slope are truly simulated. The simulation of this coupling process cannot be achieved by piecing together previous documents. Summary of the invention

[0013] The technical problem to be solved by the present invention is to provide a dynamic shear device and method for jointed rock mass that simulates the water environment of a drawdown zone reservoir, which can obtain the law of deterioration of shear mechanical properties of jointed rock mass in the slope drawdown zone of earthquake-prone areas in the southwest region under the combined action of environmental factors such as earthquakes, water pressure and immersion-air drying cycles.

[0014] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0015] A jointed rock mass dynamic shearing device for simulating a drawdown zone reservoir water environment, comprising a sample fixing mechanism, a normal loading mechanism, a tangential loading mechanism, a water pressure loading mechanism and a water inlet and outlet control mechanism;

[0016] The sample fixing mechanism is installed in the tester housing and fixes the sample;

[0017] The normal loading mechanism is used to apply a normal load to the sample;

[0018] The tangential loading mechanism is used to apply a tangential dynamic load to the sample;

[0019] The water pressure loading mechanism is used to pressurize the interior of the tester housing;

[0020] The water inlet and outlet control mechanism is used to fill or pump water into the tester housing.

[0021] The sample fixing mechanism includes an upper shear box and a lower shear box; the upper plate of the joint sample is fixed in the upper shear box, and the left and right sides of the upper shear box are slidably matched with the slideways of the fixed pins on the left and right sides of the testing instrument housing through fixed pins; the lower plate of the joint sample is fixed in the lower shear box, and a correction pad is installed on one side of the lower shear box, and the correction pad is directly opposite to the line of action of the load of the tangential loading mechanism.

[0022] The joint sample upper plate and the joint sample lower plate are formed by splitting a complete cubic sample.

[0023] The upper shear box and the lower shear box are both provided with fixing screws on the left and right sides, and the fixing screws are used to fix the upper plate and the lower plate of the joint sample.

[0024] The normal loading mechanism includes a test bench load-bearing shaft installed at the lower part of the test instrument shell, a test machine pressure head installed at the upper part of the test instrument shell and facing the test bench load-bearing shaft, and the test machine pressure head applies force downward through the normal pressure rod; a normal displacement sensor and a normal load sensor are installed between the test machine pressure head and the normal pressure rod, and the normal displacement sensor and the normal load sensor monitor the size of the normal load and the normal displacement in real time.

[0025] A sample tray is placed on the load-bearing shaft of the test bench, and rotatable rolling shafts are arranged side by side at the bottom end of the sample tray.

[0026] The tangential loading mechanism includes a power shear rod, which is connected to the lower shear box as a whole through a correction pad. A tangential displacement sensor and a tangential load sensor are installed at one end of the power shear rod extending outside the test instrument housing. The tangential displacement sensor and the tangential load sensor monitor the size of the tangential load and the tangential displacement in real time.

[0027] The water pressure loading mechanism comprises an air inlet pipe and an air outlet pipe, wherein one end of the air inlet pipe is connected to a pressure air bag in a shell of the tester, and the other end is connected to a nitrogen bottle.

[0028] A dynamic shearing method for jointed rock mass simulating a water environment in a drawdown zone reservoir comprises the following steps:

[0029] Step 1) Pump water from the water tank until the inner cavity of the entire tester housing is filled, and then close the water inlet valve and the water pump; during the water filling period, the air outlet valve needs to be opened to discharge the gas inside the test device; thereby simulating the rising stage of the water level in the drawdown zone;

[0030] Step 2) Connect the pressure airbag to the external pressure control system, open the air inlet valve of the nitrogen bottle, and inflate the pressure airbag. The real-time water pressure value can be read from the pressure gauge. According to the water pressure required for the test, adjust the air pressure regulating valve to the specified air pressure value. At this time, the pressure system stores the water pressure required for the test in the pressure airbag, and then transfers it to the water inside the device, thereby simulating the constant water pressure stage in the drawdown zone;

[0031] Step 3), operate the dynamic shear control system through a computer, first apply a normal load to the jointed rock sample, and then control the dynamic shear rod to perform cyclic shear on the jointed sample; the normal stress and displacement can be measured and recorded through the normal displacement sensor and the normal load sensor, and the tangential stress and displacement can be measured and recorded through the tangential displacement sensor and the tangential load sensor; thereby simulating the dynamic shear stage of the rock mass in the drawdown zone under the upper load and earthquake action;

[0032] Step 4) After the pressurized immersion is completed, close the air inlet valve and open the air outlet valve to discharge the gas in the pressure airbag. Then open the water valve and pump the water in the device into the water storage tank by reversing the water pump. Then open the door of the device and let the sample air dry naturally or use electric heating to accelerate the air drying, simulating the water level drop and air drying process in the drawdown zone.

[0033] The invention discloses a jointed rock mass dynamic shearing device and method for simulating the water environment of a drawdown zone reservoir, which has the following technical effects:

[0034] 1) Cyclic shearing of the jointed rock mass under a constant normal load;

[0035] 2) Cyclic shearing of the jointed rock mass under the action of adjustable water pressure immersion;

[0036] 3) The "immersion-air drying" cycle can be carried out directly on the device without taking out the sample and placing it in another test device. During the "immersion-air drying" cycle, the jointed rock mass is subjected to cyclic shearing;

[0037] 4) The sealing rubber ring and the buffer sealing bag can ensure the waterproofness and airtightness of the entire device;

[0038] 5) Cyclic shearing of the jointed rock mass under the cyclic action of immersion process with simulated water pressure rise and fall and temperature-controlled air-drying process;

[0039] 6) Ensure that the line of action of the tangential load can always remain in the same straight line with the joint surface;

[0040] 7) The damage of the joint surface of the specimen can be observed in real time through the door on the tester shell;

[0041] 8) Fix the upper plate of the joint specimen to the inner wall of the testing instrument shell by fixing the latch and the fixing pin so that it can only move freely up and down to avoid damage to the normal loading device during the cyclic shear process;

[0042] 9) Through this device, the coupling process between reservoir water environment (water pressure rise and fall changes and immersion-air drying cycles) and stress environment (static and dynamic shear) is accurately simulated, and the environmental conditions of the rock mass in the drawdown zone are truly simulated. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] The present invention will be further described below in conjunction with the accompanying drawings and embodiments:

[0044] Figure 1 It is a structural schematic diagram of the present invention.

[0045] Figure 2 It is a structural schematic diagram of the sample fixing mechanism in the present invention.

[0046] Figure 3 It is a schematic diagram of the connection between the fixing latch and the fixing pin in the present invention.

[0047] Figure 4 It is a schematic structural diagram of the upper shear box in the present invention.

[0048] Figure 5 It is a schematic structural diagram of the lower shear box in the present invention.

[0049] Figure 6 It is a schematic diagram of the local structure of the present invention.

[0050] Figure 7 It is a schematic diagram of the local structure of the present invention.

[0051] Figure 8 It is a schematic diagram of the tangential loading mechanism in the present invention.

[0052] Fig. 9 It is a schematic diagram of the appearance of the present invention.

[0053] In the figure: sample fixing mechanism 1, normal loading mechanism 2, tangential loading mechanism 3, water pressure loading mechanism 4, water inlet and outlet control mechanism 5, tester housing 6, upper shear box 1.1, lower shear box 1.2, joint sample upper plate 1.3, fixing pin 1.4, fixing pin 1.5, joint sample lower plate 1.6, correction pad 1.7, fixing screw 1.8, test bench bearing shaft 2.1, test machine pressure head 2.2, normal pressure rod 2.3, normal displacement sensor 2.4, normal load sensor 2.5, sample tray 2.6, rolling shaft 2.7, power shear rod 3.1, tangential displacement sensor 3.2, tangential load sensor 3.3, air inlet pipe 4.1, air outlet pipe 4.2, pressure air bag 4.3, nitrogen bottle 4.4, air inlet valve 4.5, air outlet valve 4.6, air pressure regulating valve 4.7, water tank 5.1, water valve 5.2, water pump 5.3, etc. DETAILED DESCRIPTION

[0054] like Figure 1 As shown, a dynamic shear device for jointed rock mass simulating the water environment of a drawdown zone reservoir comprises a test instrument housing 6, on which a sample fixing mechanism 1, a normal loading mechanism 2, a tangential loading mechanism 3, a water pressure loading mechanism 4 and a water inlet and outlet control mechanism 5 are installed.

[0055] like Fig. 9 As shown, the front of the tester housing 6 is provided with a door 6.2 with an observation window 6.1. The door 6.2 is a channel for sampling and setting out. The gap between the door 6.2 and the tester housing 6 needs to be sealed and waterproofed, and a sealing strip can be attached along the gap. In addition, the test process of the sample can be observed in real time through the observation window 6.1 on the door.

[0056] like Figure 2 As shown, the sample fixing mechanism 1 comprises an upper shear box 1.1 and a lower shear box 1.2.

[0057] like Figure 2 , Figure 4 As shown, the size of the upper shear box 1.1 can be made according to the test needs, and the front and rear sides thereof are provided with fixing screws 1.8 for fixing the upper plate 1.3 of the joint specimen, and the left and right sides thereof are provided with fixing pins 1.4, and the fixing pins 1.4 are used to connect the upper shear box 1.1 with the fixing pins 1.5 on the inner walls on the left and right sides of the tester housing 6, and the upper shear box can be assembled and disassembled through the slide of the fixing pins 1.5.

[0058] like Figure 3As shown, the fixing pin 1.5 is located on the inner wall on the left and right sides of the tester housing 6, and its inner wall is smooth and slightly larger than the head of the fixing pin 1.4. The fixing pin 1.4 is located on the outer wall on the left and right sides of the upper shear box 1.1. When the normal loading mechanism 2 applies a load downward, the upper shear box 1.1 will be displaced. The fixing pin 1.4 and the fixing pin 1.5 can ensure that the upper shear box 1.1 can move freely up and down, and can also ensure that the upper plate 1.3 of the joint specimen and the upper shear box 1.1 will not be tangentially displaced during the shearing process.

[0059] like Figure 2 , Figure 5 As shown, the size of the lower shear box 1.2 can be made according to the test needs. There are fixing screws 1.8 on the front and back sides for fixing the lower plate 1.6 of the joint specimen. The right side is connected to the power shear rod 3.1 through the correction pad 1.7. The lower shear box 1.2, the correction pad 1.7 and the power shear rod 3.1 are integrated and cannot be disassembled.

[0060] The function of the correction pad 1.7 is to ensure that the line of action of the tangential cyclic load is consistent with the direction of the joint surface to avoid the generation of bending moment.

[0061] Since the lower shear box 1.2 and the power shear rod 3.1 are integrally non-detachable, the lower plate 1.6 of the joint specimen is first placed in the lower shear box 1.2 and fixed with the fixing screws 1.8. Then the upper shear box 1.1 is removed, the upper plate 1.3 of the joint specimen is placed in the upper shear box 1.1 and fixed with the fixing screws 1.8, and then the upper shear box 1.1 is fixed with the fixing pins 1.4 and the fixing latches 1.5.

[0062] The joint sample upper plate 1.3 and the joint sample lower plate 1.6 can be made by splitting a complete cubic sample. Theoretically, the height of the joint sample upper plate 1.3 and the joint sample lower plate 1.6 is slightly higher than the depth of the upper shear box 1.1 and the lower shear box 1.2.

[0063] like Figure 6 As shown, the normal loading mechanism 2 includes a test bench bearing shaft 2.1 installed at the lower part of the test instrument housing 6, and a test machine pressure head 2.2 installed at the upper part of the test instrument housing 6 and facing the test bench bearing shaft 2.1. A normal displacement sensor 2.4 and a normal load sensor 2.5 are installed between the test machine pressure head 2.2 and the normal pressure rod 2.3. A normal load is applied to the sample through the dynamic shear control system 8, and the normal force is transmitted to the lower part through the normal pressure rod 2.3 and the test machine pressure head 2.2, simulating the load effect of the upper rock sample on the jointed rock mass in the drawdown zone; at the same time, the normal load and normal displacement can be monitored in real time through the normal displacement sensor 2.4 and the normal load sensor 2.5.

[0064] A sample tray 2.6 is placed on the bearing shaft 2.1 of the test bench, and a rotatable rolling shaft 2.7 is arranged side by side at the bottom of the sample tray 2.6. The rolling shaft 2.7 can ensure that the lower shear box 1.2 and the lower plate 1.6 of the joint sample can slide during shearing.

[0065] A cushion block 2.8 is provided between the test machine pressure head 2.2 and the upper shear box 1.1. The cushion block 2.8 is made of a titanium alloy with high hardness and light weight. On the one hand, it can avoid the use of other materials to cause damage to the device due to excessive weight, and on the other hand, it can prevent its weight from interfering with the value of the normal load of the specimen. The function of the cushion block 2.8 is to transfer the load applied by the normal loading system to the lower part.

[0066] like Figure 8 As shown, the tangential loading mechanism 3 includes a power shear rod 3.1, which is connected to the lower shear box 1.2 as a whole through a correction pad 1.7. The power shear rod 3.1 extends out of the tester housing 6 and is equipped with a tangential displacement sensor 3.2 and a tangential load sensor 3.3. A tangential dynamic load is applied to the sample through a power shear control system 8, and the tangential load is transmitted to the lower shear box 1.2 connected thereto through the power shear rod 3.1, simulating the cyclic shear load on the jointed rock mass in the drawdown zone when it slips. At the same time, the tangential load and tangential displacement can be monitored in real time through the tangential displacement sensor 3.2 and the tangential load sensor 3.3.

[0067] like Figure 7 As shown, the hydraulic loading mechanism 4 includes an air inlet pipe 4.1 and an air outlet pipe 4.2, wherein one end of the air inlet pipe 4.1 is connected to a pressure air bag 4.3 in the tester housing 6, and the other end is connected to a nitrogen bottle 4.4. An air pressure regulating valve 4.7, a pressure gauge, etc. are also installed on the air inlet pipe 4.1.

[0068] like Figure 7 As shown, the water inlet and outlet control mechanism 5 includes a water storage tank 5.1, a water valve 5.2, a water pump 5.3, etc., which are used to fill or drain water from the test instrument housing 6.

[0069] The power shear control system 8 may adopt a WDAJ-600 rock shear rheology testing machine. The normal loading mechanism 2 and the tangential loading mechanism 3 are both operated through the power shear control system 8, and finally data statistics and image display are performed on a computer 9.

[0070] like Figure 8 As shown, the sealing rubber ring 10 is placed in the gap between the normal pressure rod 2.3 and the power shear rod 3.1 on the tester housing 6, mainly to prevent water from overflowing from the inner cavity of the test device. The size of the sealing rubber ring 10 needs to be made according to the size of the normal pressure rod 2.3 and the power shear rod 3.1.

[0071] like Figure 8 As shown, there are two buffer sealing bags 7, which are in the shape of an annular belt with one end narrow and the other end wide, and a certain curvature in the middle. The narrow ends of the two buffer sealing bags 7 are respectively fixed and sealed on the normal pressure rod 2.3 and the power shear rod 3.1, and the wide ends are respectively pressed into and sealed on the upper outer wall and the right outer wall of the test instrument housing 6. The buffer sealing bag 7 is made of rubber, which is waterproof and has good air tightness and excellent elasticity. On the one hand, its function is to prevent the test device from leaking, resulting in the water pressure failing to rise to the specified value; on the other hand, its elasticity is used to ensure that the sealing bag will not be broken during normal and tangential loading and unloading.

[0072] A jointed rock mass dynamic shearing device method for simulating a drawdown zone reservoir water environment comprises the following steps:

[0073] Step 1: Water inlet and pressurization stage simulates the rising water level in the drawdown zone and the constant water pressure stage:

[0074] Open the water valve 5.2 and the water pump 5.3, pump water from the water tank 5.1 until the inner cavity of the entire tester housing 6 is filled, and then close the water valve 5.2 and the water pump 5.3; the air outlet valve 4.6 needs to be opened during the water filling.

[0075] Connect the pressure airbag 4.3 to the external pressure control system, open the air inlet valve 4.5 of the nitrogen bottle 4.4, and inflate the pressure airbag 4.3. The real-time water pressure value can be read from the pressure gauge. According to the water pressure required for the test, adjust the air pressure regulating valve 4.7 to the specified air pressure value. At this time, the pressure system stores the water pressure required for the test in the pressure airbag 4.3, and then transfers it to the water inside the device, realizing the simulation of the reservoir water pressure.

[0076] Step 2: Simulation of dynamic shear stage of rock mass in the drawdown zone under upper load and earthquake action:

[0077] The dynamic shear control system 8 is operated by the computer 9. First, a normal load is applied to the jointed rock sample, and then the dynamic shear rod 3.1 is controlled to perform cyclic shear on the jointed sample. The normal stress and displacement can be measured and recorded by the normal displacement sensor 2.4 and the normal load sensor 2.5, and the tangential stress and displacement can be measured and recorded by the tangential displacement sensor 3.2 and the tangential load sensor 3.3.

[0078] Step 3: Drainage and decompression stage Simulate the water level drop and air drying stage in the drawdown zone:

[0079] After the pressurized immersion is finished, close the air inlet valve 4.5, open the air outlet valve 4.6, and exhaust the gas in the pressure airbag 4.3. Then open the water valve 5.2 and the water pump 5.3 to pump the water in the device into the water storage tank 5.1. Then open the door of the device and let the sample air dry naturally or use electric heating to accelerate the air drying, simulating the water level drop and air drying process in the drawdown zone.

[0080] The data required in the test, such as normal stress and displacement, tangential stress and displacement, etc., can be directly obtained through a computer 9.

Claims

1. A jointed rock mass dynamic shearing device simulating the water environment of a drawdown zone reservoir, characterized in that: It comprises a sample fixing mechanism (1), a normal loading mechanism (2), a tangential loading mechanism (3), a water pressure loading mechanism (4) and a water inlet and outlet control mechanism (5); The sample fixing mechanism (1) is installed in the testing instrument housing (6) and fixes the sample; The normal loading mechanism (2) is used to apply a normal load to the sample; The tangential loading mechanism (3) is used to apply a tangential dynamic load to the sample; The water pressure loading mechanism (4) is used to pressurize the interior of the tester housing (6); The water inlet and outlet control mechanism (5) is used to fill or pump water into or out of the test instrument housing (6); The sample fixing mechanism (1) comprises an upper shear box (1.1) and a lower shear box (1.2); an upper plate (1.3) of a joint sample is fixed inside the upper shear box (1.1), and the left and right sides of the upper shear box (1.1) are slidably matched with the slideways of the left and right fixed pins (1.5) of the test instrument housing (6) through fixed pins (1.4); a lower plate (1.6) of a joint sample is fixed inside the lower shear box (1.2), and a correction pad (1.7) is installed on one side of the lower shear box (1.2), and the correction pad (1.7) is directly opposite to the line of action of the load of the tangential loading mechanism (3); The joint sample upper plate (1.3) and the joint sample lower plate (1.6) are split from a complete cubic sample; or are cut and prepared from a standard cubic block sample; The normal loading mechanism (2) comprises a test bench bearing shaft (2.1) mounted on the lower part of the tester housing (6), and a test machine pressure head (2.2) mounted on the upper part of the tester housing (6) and facing the test bench bearing shaft (2.1); the test machine pressure head (2.2) applies force downwards via a normal pressure rod (2.3); a normal displacement sensor (2.4) and a normal load sensor (2.5) are mounted between the test machine pressure head (2.2) and the normal pressure rod (2.3); the normal displacement sensor (2.4) and the normal load sensor (2.5) monitor the magnitude of the normal load and the normal displacement in real time.

2. A jointed rock mass dynamic shearing device for simulating a drawdown zone reservoir water environment according to claim 1, characterized in that: The upper shear box (1.1) and the lower shear box (1.2) are both provided with fixing screws (1.8) on the left and right, and the fixing screws (1.8) are used to fix the upper plate (1.3) and the lower plate (1.6) of the joint sample.

3. A jointed rock mass dynamic shearing device for simulating the water environment of a drawdown zone reservoir according to claim 1, characterized in that: A sample tray (2.6) is placed on the load-bearing shaft (2.1) of the test bench, and rotatable rolling shafts (2.7) are arranged side by side at the bottom end of the sample tray (2.6).

4. A jointed rock mass dynamic shearing device for simulating a drawdown zone reservoir water environment according to claim 1, characterized in that: The tangential loading mechanism (3) comprises a power shear rod (3.1), the power shear rod (3.1) being integrally connected to the lower shear box (1.2) via a correction pad (1.7), and a tangential displacement sensor (3.2) and a tangential load sensor (3.3) being mounted on one end of the power shear rod (3.1) extending outside the tester housing (6), the tangential displacement sensor (3.2) and the tangential load sensor (3.3) monitoring the magnitude of the tangential load and the tangential displacement in real time.

5. A jointed rock mass dynamic shearing device for simulating a drawdown zone reservoir water environment according to claim 1, characterized in that: The water pressure loading mechanism (4) comprises an air inlet pipe (4.1) and an air outlet pipe (4.2), wherein one end of the air inlet pipe (4.1) is connected to a pressure air bag (4.3) in a tester housing (6), and the other end is connected to a nitrogen bottle (4.4).

6. A method for conducting simulation test of a jointed rock mass dynamic shearing device simulating a drawdown zone reservoir water environment according to any one of claims 1 to 5, characterized in that: The following steps are involved: Step 1), pump water from the water tank (5.1) until the inner cavity of the entire test instrument housing (6) is filled, and then the water inlet valve and the water pump are closed; during the water filling period, the air outlet valve (4.6) needs to be opened to discharge the gas inside the test device; thereby simulating the rising stage of the water level in the drawdown zone; Step 2), connect the pressure airbag (4.3) to the external pressure control system, open the air inlet valve (4.5) of the nitrogen bottle (4.4), and inflate the pressure airbag (4.3). The real-time water pressure value can be read from the pressure gauge. According to the water pressure required for the test, adjust the air pressure regulating valve (4.7) to the specified air pressure value; at this time, the pressure system stores the water pressure required for the test in the pressure airbag (4.3), and then transfers it to the water inside the device, thereby simulating the constant water pressure stage in the drawdown zone; Step 3), operating the dynamic shear control system (8) through the computer (9), first applying a normal load to the jointed rock sample, and then controlling the dynamic shear rod (3.1) to perform cyclic shear on the jointed sample; the normal stress and displacement can be measured and recorded through the normal displacement sensor (2.4) and the normal load sensor (2.5), and the tangential stress and displacement can be measured and recorded through the tangential displacement sensor (3.2) and the tangential load sensor (3.3); thereby simulating the dynamic shear stage of the rock mass in the drawdown zone under the upper load and earthquake action; Step 4) After the pressurized immersion is completed, close the air inlet valve (4.5) and open the air outlet valve (4.6) to discharge the gas in the pressure airbag (4.3); then open the water valve and reverse the water pump (5.3) to pump the water in the device into the water storage tank; then open the door of the device and let the sample air dry naturally or use an electric hair dryer to accelerate the air drying, simulating the water level drop and air drying process in the drawdown zone.

Images