Device and method for simulating corrosion of fracture filling materials in reservoir bank slope rock mass

Abstract

The present invention relates to a device and method for simulating the corrosion phenomenon of the filling material in the rock mass fissures on the reservoir bank slope, including: a main pressure box body, a prefabricated bank slope with fissures, a pressure control system, a transparent acrylic recovery plate, and a detection and processing system; the method includes the following steps: fabricating the prefabricated bank slope, closing the upper movable steel plate to seal the main pressure box body, filling water into the main pressure box body, recovering the leachate in the recovery beaker and the solid particles of the filling material in the trapezoidal cross-section channel and detecting them. The beneficial effects of the present invention are: it can complete the simulation of the corrosion process of the filling material under the condition of water level change in the laboratory, and parameters such as fissure aperture, corrosion length of the filling material, corrosion amount, and seepage water volume can be conveniently traced during the experiment, effectively solving the problems of difficult observation, large control difficulty, long experimental period, and high labor consumption in the field corrosion experiment.

Description

Technical Field

[0001] The present invention belongs to the technical field of water conservancy engineering, and particularly relates to a device and method for simulating the corrosion phenomenon of the filling material in the rock mass fissures on the reservoir slope. Background Art

[0002] China continues to promote the adjustment of its energy structure and will also build a large number of hydropower stations, especially pumped-storage power stations. During the operation of these power stations, the reservoirs will face frequent water storage and release, resulting in periodic changes in the reservoir water level. The filling material in the rock mass fissures on the reservoir slope will experience a corrosion phenomenon along with the periodic changes in the reservoir water level. The occurrence of this corrosion phenomenon causes varying degrees of deformation and local damage to the rock mass on the reservoir slope, posing significant challenges to the stability and anti-seepage of the rock mass on the reservoir slope.

[0003] The corrosion phenomenon of the filling material in the rock mass fissures on the reservoir slope is characterized by concealment and long-term nature. It is very difficult to deeply track the internal filling material corrosion process during on-site investigations of the reservoir slope, and the corrosion phenomenon is relatively slow, and long-term on-site observations consume a lot of manpower and material resources. Currently, there is no systematic device and method for simulating the corrosion phenomenon of the filling material in the rock mass fissures on the reservoir slope in the laboratory. There is an urgent need to develop a device that can simulate the changes in parameters such as fissure aperture, filling material corrosion length, corrosion amount, and seepage volume during the corrosion phenomenon.

[0004] Therefore, in the above context, the present invention provides a device and method for simulating the corrosion of the filling material in the rock mass fissures on the reservoir slope to simulate the occurrence of the corrosion phenomenon of the rock mass on the reservoir slope, and obtain the changes in relevant parameters to track the corrosion progress and reveal the corrosion law of the filling material in the rock mass fissures on the reservoir slope. Summary of the Invention

[0005] The object of the present invention is to provide a test device and method for simulating the corrosion phenomenon of the filling material in the rock mass fissures on the reservoir slope.

[0006] The device for simulating the corrosion phenomenon of the filling material in the rock mass fissures on the reservoir slope includes: a main pressure box body, a prefabricated slope with fissures, a pressure control system, a transparent acrylic recovery board, and a detection and processing system;

[0007] The pressure control system includes a two-way water pump, a pressure sensor, and a PLC controller;

[0008] The main pressure box body is a rectangular water tank with an opening at the rear. There is a movable steel plate covering the top of the main pressure box body. A prefabricated slope is placed at the rear opening. A pressure sensor is provided on the movable steel plate covering the top. A baffle on one side of the main pressure box body is connected to the two-way water pump. Both the two-way water pump and the pressure sensor are connected to the PLC controller;

[0009] The prefabricated bank slope is a trapezoidal cross-section bank slope made of concrete. There are Z-shaped fissures on the prefabricated bank slope, and the Z-shaped fissures are filled with fillers. At the bottom of the prefabricated bank slope away from the pressure main box body, an acrylic recovery plate is connected. There is a leachate recovery channel groove on the acrylic recovery plate. A filter screen is provided at the outlet end of the leachate recovery channel groove.

[0010] The detection and processing system includes an automatic balance, detection equipment, and a data processing computer. There is a beaker on the automatic balance, and the beaker is arranged below the outlet end of the leachate recovery channel groove.

[0011] Preferably: There are several Z-shaped fissures with different widths on the prefabricated bank slope. There are several leachate recovery channel grooves on the acrylic recovery plate. The several leachate recovery channel grooves are respectively connected to the bottom ends of several Z-shaped fissures on the prefabricated bank slope. There are several beakers on the automatic balance, and the several beakers are respectively arranged below the outlet ends of the leachate recovery channel grooves.

[0012] Preferably: There are prefabricated fissure one, prefabricated fissure two, and prefabricated fissure three on the prefabricated bank slope, and the widths of the prefabricated fissure one, prefabricated fissure two, and prefabricated fissure three are different.

[0013] Preferably: The upper cover movable steel plate slides and fixes on the top of the pressure main box body. There is an opening on the upper cover movable steel plate, and the pressure sensor is inserted into the pressure main box body through the opening on the upper cover movable steel plate.

[0014] The experimental method of this device for simulating the dissolution phenomenon of the filler in the rock mass fissure of the reservoir bank slope includes the following steps:

[0015] S1. Fabricate the prefabricated bank slope: Combining the fissure distribution in the actual bank slope and the dissolution working conditions to be simulated, insert Z-shaped thin iron sheets with different thicknesses, orientations, and sizes into the mold of the prefabricated bank slope, and pour concrete. After the concrete reaches its strength, remove the iron sheets to form a prefabricated bank slope containing several Z-shaped fissures. Mix the filling material and sand with the same particle size distribution as the fissure filler and fill it into the Z-shaped fissures; thus, obtain the bank slope and fissure model.

[0016] S2. Experimental preparation: Install the prefabricated bank slope in the rear opening of the pressure main box body, close the upper cover movable steel plate to seal the pressure main box body, install a pressure sensor on the upper cover movable steel plate, and set the timer and pressure threshold of the PLC controller according to the cycle of water level and pressure changes in the actual working conditions.

[0017] S3. Start the experiment: Fill water into the main pressure chamber through a two-way water pump. When the pressure sensor and the timer reach the set thresholds of the PLC controller, the two-way water pump changes its direction and pumps water out of the main pressure chamber. After the timer is reset to zero, water is filled into the main pressure chamber again. This process is repeated cyclically to make the water level in the main pressure chamber change periodically. The water in the main pressure chamber seeps out through the Z-shaped cracks on the prefabricated slope and flows into the recovery beaker through the leachate recovery channel. The sand and gravel in the leachate are filtered by the filter screen and remain in the leachate recovery channel.

[0018] S4. Detection and processing: After the corrosion phenomenon ends, the solid particles of the crack filler in the leachate recovery channel in the recovery beaker are collected. Data on the volume, mass of the leachate, and the loss of solid particles of the crack filler are obtained through detection equipment and a data processing computer.

[0019] Preferably, the filling material is mud, sand, or soil. By replacing the mud, sand, or soil filled in the Z-shaped cracks, corrosion experiments with different materials and particle gradations are carried out.

[0020] Preferably, the thresholds of the timer and pressure of the PLC controller are changed to achieve corrosion experiments on crack fillers under different water level change periods and water pressure conditions.

[0021] The beneficial effects of the present invention are as follows:

[0022] 1) This device can simulate the corrosion process of crack fillers under changing water levels in the laboratory. During the experiment process, parameters such as crack aperture, corrosion length of the filler, corrosion amount, and seepage water volume can be conveniently tracked, effectively solving the problems of difficult observation, large control difficulty, long experimental period, and high labor consumption in field corrosion experiments.

[0023] 2) A prefabricated slope that can be disassembled and installed as a whole is designed. The prefabricated cracks can be filled with different types of sand, gravel, mud, and soil, etc., which are fillers similar to the on-site properties. The crack direction, length, aperture, etc. of the slope can be set according to similar experimental rules, and the corrosion phenomenon in the cracks of the reservoir slope can be reproduced. This device can establish a preliminary relationship between different water level change conditions and the degree of corrosion of the slope rock mass. According to the control variable method, it has high practicability and strong operability.

[0024] 3) A device is designed that can use a PLC control system to control the water level fluctuation and the operation program of the water pressure in the main pressure chamber. Through the cooperation of the pressure sensor and the two-way water pump, the water pressure in the main chamber is stabilized, restoring the periodic water level change conditions faced by the real reservoir slope.

[0025] 4) A device for collecting and detecting the dissolution exudate is designed. The water is guided by an acrylic recovery plate with an exudate recovery channel groove. The filter screen at the outlet end of the recovery channel groove intercepts solid substances such as dissolved sand, mud or soil. The exudate enters the beaker on the balance automatically through the recovery channel groove for the detection of the mass and volume of the exudate. This experimental system can directly obtain parameters such as the volume, mass and particle loss of the exudate, which is convenient for analyzing the dissolution situation under different working conditions. Description of the Drawings

[0026] Figure 1 It is the operation flow chart of the PLC control system;

[0027] Figure 2 It is the schematic diagram of a device for simulating the dissolution phenomenon of the filling material in the rock mass fissure of the reservoir bank slope;

[0028] Figure 3 It is the schematic diagram for preparing the prefabricated fissures of the prefabricated bank slope;

[0029] Figure 4 It is the schematic diagram of the acrylic recovery plate;

[0030] Figure 5 It is the schematic diagram of the automatic balance.

[0031] Description of the reference numerals in the drawings: two-way water pump 1, pressure sensor 2, PLC controller 3, upper movable steel plate 4, pressure main box 5, prefabricated bank slope 6, acrylic recovery plate 7, leachate recovery channel groove 8, filter screen 9, automatic balance 10, beaker 11, detection equipment 12, data processing computer 13, prefabricated fissure one 61, prefabricated fissure two 62, prefabricated fissure three 63. Detailed Description of the Invention

[0032] The present invention will be further described below in conjunction with the embodiments. The description of the following embodiments is only for helping to understand the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several modifications can still be made to the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

[0033] Embodiment 1

[0034] As an embodiment, as Figures 2 to 5 shown, this device for simulating the dissolution phenomenon of the filling material in the rock mass fissure of the reservoir bank slope includes: a pressure main box 5, a prefabricated bank slope 6, a pressure control system, an acrylic recovery plate 7 and a detection and processing system;

[0035] As Figure 1 shown, the pressure control system includes a two-way water pump 1, a pressure sensor 2 and a PLC controller 3;

[0036] The main pressure box body 5 is a cuboid water tank with an opening at the rear. A movable steel plate 4 is slidably fixed on the top of the main pressure box body 5, which is convenient for the setting of the precast bank slope 6 and the Z-shaped crack, and is also convenient for the maintenance and debugging of the main pressure box body 5. There is an opening on the movable steel plate 4 on the upper part. The pressure sensor 2 is inserted into the main pressure box body 5 through the opening on the movable steel plate 4 on the upper part. After the main pressure box body 5 is filled with water, the two-way water pump 1 continues to flush water into the main pressure box body 5, which can increase the water pressure in the main pressure box body 5. At this time, the detected value of the pressure sensor 2 is the water pressure in the main pressure box body 5.

[0037] A precast bank slope 6 is placed at the opening at the rear end of the main pressure box body 5, and the width and height of the main pressure box body 5 are adapted to the model of the precast bank slope 6. A baffle on one side of the main pressure box body 5 is connected to the two-way water pump 1, and both the two-way water pump 1 and the pressure sensor 2 are connected to the PLC controller 3; the bottom of the precast bank slope 6 away from the main pressure box body 5 is connected with an acrylic recovery plate 7.

[0038] As Figure 3 shown, the cracks in the reservoir bank slope rock mass are mostly irregular in shape. In order to simulate the dissolution phenomenon of the filling materials in the cracks of the real reservoir bank slope rock mass, the precast bank slope 6 is completed by concrete pouring. The cross-section of the precast bank slope 6 is trapezoidal. The precast bank slope 6 is a trapezoidal cross-section bank slope made of concrete. There are a precast crack one 61, a precast crack two 62 and a precast crack three 63 on the precast bank slope 6. The precast crack one 61, the precast crack two 62 and the precast crack three 63 are all Z-shaped cracks, but with different widths, which are 3mm, 4mm and 5mm respectively. The widths of the precast cracks are different, and the connectivity rates of the precast cracks are also different. The same filling material, that is, sand with the same material and particle gradation, is filled in the precast crack one 61, the precast crack two 62 and the precast crack three 63, and an experiment on the dissolution phenomenon with the variable of the width of the Z-shaped crack can be carried out. By filling sands with different materials and particle gradations in the Z-shaped cracks in multiple experiments, different variables can be set to conduct a controlled variable experiment.

[0039] As Figure 4 shown, there are three leachate recovery channels 8 on the acrylic recovery plate 7, and each leachate recovery channel 8 is respectively connected to the bottom end of the Z-shaped crack on the precast bank slope 6; a filter screen 9 is provided at the outlet end of the leachate recovery channel 8;

[0040] The detection and processing system includes an automatic balance 10, a detection device 12 and a data processing computer 13. There are three beakers 11 on the automatic balance 10, and the beakers 11 are respectively arranged below the outlet ends of the leachate recovery channels 8. The mass of the seepage water in the beakers 11 is observed by real-time weighing with the automatic balance 10.

[0041] Exudate will appear in the prefabricated fissures on the back surface of the prefabricated slope 6. The exudate flows along the exudate recovery channel groove 8 on the acrylic recovery board 7. The filter screen 9 separates the eroded mud, sand or soil particles and seepage water. The seepage water flows into the beaker 11, and the sand and stones remain in the exudate recovery channel groove 8. The cross-section of the exudate recovery channel groove 8 is trapezoidal.

[0042] Embodiment 2

[0043] As another embodiment, the experimental method of the device for simulating the dissolution phenomenon of the filling material in the rock mass fissure of the reservoir slope proposed in Embodiment 1 is as Figure 1 shown and includes the following steps:

[0044] S1. Fabricate the prefabricated slope: Since the widths of the Z-shaped fissures are different, the connectivity rates of the Z-shaped fissures are also different. Set Z-shaped fissures with different widths to compare the dissolution phenomena. Use Z-shaped thin iron plates with thicknesses of 3 mm, 4 mm, and 5 mm respectively and insert them into the mold of the prefabricated slope 6, and pour concrete to obtain the prefabricated slope 6. After the concrete reaches the 28-day strength, remove the iron sheets. The widths of the prefabricated fissures on the prefabricated slope 6 are 3 mm, 4 mm, and 5 mm respectively. The fissure width can be determined with reference to the on-site situation and the model similarity ratio. In a single experiment, fill the artificial prefabricated fissures with a mixture of sand with the same filling material and particle size distribution. The filling material is mud, sand or soil.

[0045] S2. Experimental preparation: Install the prefabricated slope 6 in the rear opening of the pressure main box body 5, close the upper movable steel plate 4 to seal the pressure main box body 5, install the pressure sensor 2 on the upper movable steel plate 4, and set the timer and pressure set threshold of the PLC controller 3; Set the timer and pressure threshold of the PLC controller 3 according to the cycle of water level and pressure changes in the actual working condition;

[0046] S3. Start the experiment: Flush water into the pressure main box body 5 through the two-way water pump 1. When the pressure sensor 2 and the timer reach the set threshold of the PLC controller 3, that is, the pressure in the pressure main box body 5 reaches the simulation condition and after maintaining for a certain time, the two-way water pump 1 changes direction and pumps water out of the pressure main box body 5; Repeat this cycle. Through the two-way water pump 1 and the PLC controller 3, the pressure main box body 5 is filled with water and pumped out to create periodic water level fluctuations, simulating the periodic change of the reservoir water level. The water pressure and water flow cause the filling material in the Z-shaped fissures to undergo a dissolution phenomenon. The water in the pressure main box body 5 seeps out from the fissures on the prefabricated slope 6 and flows into the recovery beaker 11 through the exudate recovery channel groove 8. The sand and stones in the exudate are filtered by the filter screen 9 and remain in the exudate recovery channel groove 8;

[0047] S4. Detection and processing: After the corrosion phenomenon ends, the seepage liquid in the recovery beaker 11 and the sand and gravel in the seepage liquid recovery channel 8 are sent to the detection device 12 for preliminary detection of the seepage liquid. The seepage liquid can also be sent to the laboratory for further detection, and the relevant experimental data is further processed by the data processing computer 13. The processing of relevant data such as the quality of the seepage liquid, the particle size distribution of the corroded solid particles, the volume, and the particle loss amount is completed.

[0048] Multiple experiments are carried out. In each experiment, different experimental parameters are manually set, such as changing the filling material, the particle size distribution of the filling material, the hydrophilicity of the filling material, etc. Under the premise of controlling variables, the water pressure setting of the prefabricated bank slope 6 can also be changed. Moreover, prefabricated bank slopes 6 with various different Z-shaped crack widths can be further fabricated to conduct corrosion phenomenon experiments under different variable conditions. Finally, the relationships between the pre-set parameters such as the water pressure, the opening degree of the prefabricated crack, the connectivity rate, and the corrosion length and the parameters such as the mass of the filtered solid particles and the seepage volume of the seepage liquid are established.

Claims

1. An apparatus for simulating the corrosion phenomenon of the fissure filling material in the rock mass of the reservoir slope, characterized in that Comprising: A main pressure box body (5), a precast bank slope (6), a pressure control system, an acrylic recovery board (7) and a detection and processing system; The pressure control system includes a two-way water pump (1), a pressure sensor (2) and a PLC controller (3); The main pressure box body (5) is a cuboid water tank with an opening at the rear. There is a movable steel plate (4) covering the top of the main pressure box body (5). A precast bank slope (6) is placed at the rear opening. A pressure sensor (2) is provided on the movable steel plate (4) covering the top. One side baffle of the main pressure box body (5) is connected to the two-way water pump (1). Both the two-way water pump (1) and the pressure sensor (2) are connected to the PLC controller (3); The precast bank slope (6) is a trapezoidal cross-section bank slope made of concrete. There are Z-shaped fissures on the precast bank slope (6), and the Z-shaped fissures are filled with fillers; at the bottom of the side of the precast bank slope (6) away from the main pressure box body (5), there is an acrylic recovery board (7). An effluent recovery channel groove (8) is provided on the acrylic recovery board (7); a filter screen (9) is provided at the outlet end of the effluent recovery channel groove (8); The detection and processing system includes an automatic balance (10), detection equipment (12) and a data processing computer (13). A beaker (11) is provided on the automatic balance (10), and the beaker (11) is arranged below the outlet end of the effluent recovery channel groove (8); there are several Z-shaped fissures with different widths on the precast bank slope (6), and several leachate recovery channel grooves (8) are provided on the acrylic recovery board (7). The several leachate recovery channel grooves (8) are respectively connected to the bottom ends of several Z-shaped fissures on the precast bank slope (6). Several beakers (11) are provided on the automatic balance (10), and the several beakers (11) are respectively arranged below the outlet ends of the effluent recovery channel grooves (8).

2. The device for simulating the corrosion phenomenon of the fracture filling material of the rock mass on the reservoir bank slope according to claim 1, characterized in that: There are a precast fissure one (61), a precast fissure two (62) and a precast fissure three (63) on the precast bank slope (6), and the widths of the precast fissure one (61), the precast fissure two (62) and the precast fissure three (63) are different.

3. The device for simulating the corrosion phenomenon of the fracture filling material of the rock mass on the reservoir bank slope according to claim 1, characterized in that: The movable steel plate (4) covering the top slides and is fixed on the top of the main pressure box body (5). There is an opening on the movable steel plate (4) covering the top, and the pressure sensor (2) is inserted into the main pressure box body (5) through the opening on the movable steel plate (4) covering the top.

4. The experimental method of the device for simulating the dissolution phenomenon of the fracture filling in the rock mass of the reservoir bank slope according to any one of claims 1 to 3, characterized in that, Including the following steps: S1. Fabricating the precast bank slope: Combining the fissure distribution in the actual bank slope and the corrosion conditions to be simulated, insert Z-shaped thin iron sheets with different thicknesses, orientations and sizes into the mold of the precast bank slope (6), and pour concrete. After the concrete reaches the strength of 28 days, remove the iron sheets to form a precast bank slope (6) containing several Z-shaped fissures. Mix the filling material and sand with the same particle size distribution as the fissure filler and fill it into the Z-shaped fissures; thus obtaining a bank slope and fissure model; S2. Experimental preparation: Install the precast bank slope (6) in the rear opening of the main pressure box body (5), close the movable steel plate (4) covering the top to seal the main pressure box body (5), install the pressure sensor (2) on the movable steel plate (4) covering the top, and set the timer and pressure threshold of the PLC controller (3) according to the cycle of water level and pressure changes in the actual working conditions; S3. Start the experiment: Flush water into the main pressure box body (5) through the two-way water pump (1). When the pressure sensor (2) and the timer reach the set thresholds of the PLC controller (3), the two-way water pump (1) changes its direction and pumps water out of the main pressure box body (5). After the timer is cleared, it flushes water into the main pressure box body (5) again, repeating this cycle to make the water level in the main pressure box body (5) change periodically. The water in the main pressure box body (5) seeps out from the Z-shaped crack on the precast bank slope (6) and flows into the recovery beaker (11) through the leachate recovery channel groove (8). The sand and gravel in the leachate are filtered by the filter screen (9) and remain in the leachate recovery channel groove (8). S4. Detection and processing: After the corrosion phenomenon ends, the solid particles of the crack filler in the leachate recovery channel groove (8) in the recovery beaker (11) are collected, and data on the volume, mass of the leachate, and the loss amount of the solid particles of the crack filler are obtained through the detection device (12) and the data processing computer (13).

5. The experimental method of the device for simulating the corrosion phenomenon of the fracture filling material in the rock mass of the reservoir slope bank according to claim 4, characterized in that, The filling material is mud, sand or soil. By replacing the mud, sand or soil filled in the Z-shaped crack, the corrosion phenomenon experiments with different materials and particle gradations are carried out.

6. The experimental method of the device for simulating the dissolution phenomenon of the fracture filling in the rock mass of the reservoir bank slope according to claim 4, characterized in that Change the thresholds of the timer and pressure of the PLC controller (3) to achieve the corrosion experiment of the crack filler under different water level change cycles and water pressure conditions.

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