Impermeable wall concrete property evolution simulation test device and method

Abstract

The invention discloses a device and a method for testing concrete property evolution of an anti-seepage wall, and aims to solve the problems of test result distortion and the like caused by non-uniform heat transfer of concrete in a deep ground environment due to heat conductivity difference of a contact material and large deviation between laboratory maintenance and on-site working conditions in the prior art. A plurality of nested movable frames are arranged in an inner tank from low to high, and the frames are filled with stones, water-containing sponges and gravel media for simulating the deep ground environment; quick splicing and anti-dislocation fixation of the movable frame are realized through a nested structure of the T-shaped blocks and the T-shaped grooves; a stirring mechanism is used for balancing the temperature of a water body between a test tank and an inner tank, a pressure assembly is combined for simulating a high-pressure environment, a multi-dimensional sensor and an intelligent control system are integrated, temperature, pressure and seepage parameters are dynamically regulated and controlled, and the multi-field coupling thermodynamic evolution process of concrete in ultra-deep diaphragm wall construction is accurately reproduced; the test data reliability is remarkably improved, a scientific basis is provided for construction parameter optimization, and the device has the characteristics of convenience in operation, stable structure, high simulation precision and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of concrete performance testing, and particularly to an experimental device and method for simulating the state evolution of diaphragm wall concrete. Background Art

[0002] During the construction of ultra-deep diaphragm walls, the evolution of concrete state is a key factor affecting the construction progress and pouring quality. The construction process of diaphragm walls is complex, including multiple steps such as excavating the guide groove and diaphragm wall slots, lowering the conduits and joint pipes, pouring concrete, and pulling out the pipes to form the wall. Among them, the "joint pipe method" has significant advantages in the connection of diaphragm wall segments due to its low requirements for construction equipment, relatively simple construction technology, and high economy.

[0003] However, the complexity and unpredictability of the concrete state evolution process pose great challenges to construction. If the concrete setting time is predicted too early and the concrete has not reached a certain strength, shrinkage and collapse may occur in the joint holes; conversely, if the concrete setting time is predicted too late, the bonding force between the joint pipe and the concrete interface will increase sharply, increasing the difficulty of pulling out, and even may cause the joint pipe to be cast in the concrete and unable to be pulled out, resulting in major safety accidents.

[0004] In order to simulate the concrete state evolution process in the construction environment of ultra-deep diaphragm walls, researchers have developed various experimental devices and methods. For example, CN118191002A discloses an experimental device and method for simulating the state evolution of diaphragm wall concrete in a deep earth environment. In this invention, metal mesh pipes and sponge pipes are arranged in the test mold bucket, concrete is poured inside the sponge pipes, and annular heating elements are arranged outside the test mold bucket; the test mold bucket is connected to an external pressure gas source through an end cover to form a concrete curing chamber with high-temperature saturated water boundary, high-pressure load, and static seal to simulate the high-pressure, high geothermal temperature, lateral confinement, and saturated water environment of diaphragm wall concrete in deep earth. However, this simulation method still has certain limitations.

[0005] Firstly, in the actual deep earth environment, even in areas at the same depth, although the overall temperature is relatively close, due to the difference in the thermal conductivity of different substances in contact with the outside of the concrete, the efficiency of heat transfer to the outside of the concrete will also be different, resulting in an uneven distribution of the outside temperature of the concrete. In the above-mentioned prior art, after the annular heating element heats the heat to a certain temperature, the heat is evenly transferred to the concrete surface through the same medium, so that the outside of the concrete is heated more evenly, which deviates from the heat transfer characteristics in the actual deep earth environment.

[0006] Secondly, after the concrete of the ultra-deep cut-off wall is poured, it needs to bear the mud pressure of more than 100 meters above, and at the same time, it is under the coupling action of multiple factors such as the restraint of the foundation soil body, high ground temperature and groundwater environment. The curing environment under traditional laboratory conditions is quite different from the on-site construction conditions, and it is impossible to accurately simulate the influence of these complex working conditions on the evolution of concrete properties. For example, the traditional method of determining the setting time by measuring the penetration degree does not fully consider the influence of deep earth high pressure and high ground temperature on the evolution of concrete properties, and the accuracy of its measurement results is poor, thus having a greater impact on the wall-forming quality of the concrete cut-off wall.

[0007] Therefore, it is necessary to develop a more accurate and comprehensive experimental device and method for simulating concrete properties, so as to be closer to the actual construction environment, improve the accuracy and reliability of the research on the evolution of concrete properties, and provide a more scientific basis and technical support for the construction of ultra-deep cut-off walls. Summary of the Invention

[0008] The technical problem to be solved by the present invention is to provide an experimental device and method for simulating the evolution of the properties of cut-off wall concrete, and solve the problem of inaccurate simulation of the evolution of concrete properties in the construction of ultra-deep cut-off walls. Specifically, although the prior art can simulate the deep earth environment to a certain extent, due to the limitation of the heat transfer method, it is impossible to accurately simulate the uneven temperature distribution phenomenon of concrete caused by the difference in the thermal conductivity of contact materials in the actual deep earth environment, thus affecting the accuracy and reliability of the simulation of the evolution of concrete properties; in addition, the curing environment under traditional laboratory conditions is quite different from the on-site construction conditions, and it is impossible to comprehensively simulate the complex working conditions in the construction of ultra-deep cut-off walls.

[0009] To solve the above technical problems, the technical solution adopted by the present invention is: an experimental device for simulating the evolution of the properties of cut-off wall concrete, including a test tank, a connecting pipe is arranged on the test tank, a restricting valve is installed on the connecting pipe, a stirring mechanism is arranged at the top of the test tank, and a test mechanism is installed in the test tank. The test mechanism includes an inner tank and a simulation splicing component and a testing component installed inside it. The inner tank is movably inserted into the test tank. A fixed seat and a restraint net are arranged at the bottom of the inner tank, and the top is detachably connected to a sealing cover through a thread; the simulation splicing component includes a plurality of movable frames installed on the inner wall of the inner tank, a plurality of multi-media fillers are embedded on the movable frames, and the movable frames are spliced together through a nested structure of T-shaped blocks - rectangular grooves - T-shaped grooves to form a multi-layer heterogeneous heat transfer environment; the testing component includes a plurality of columns, and the columns carry a detection component to real-time monitor the multi-physical field parameters during the concrete solidification process.

[0010] In a preferred solution, a column shell is fixedly connected to the inner wall of the test tank, a receiving ring is fixedly connected to the inner wall of the column shell, a plurality of water passing holes are opened on the column shell, and the test mechanism is installed on the receiving ring.

[0011] In a preferred embodiment, the inner tank of the test mechanism is movably inserted into the column shell. A fixed seat is fixedly connected to the lower surface of the inner wall of the inner tank. A restraint net is movably inserted into the top of the fixed seat. The top of the inner tank is detachably connected with a sealing cover through threads. Mounting rings are fixedly connected to both the sealing cover and the outer wall of the inner tank, and they are detachably connected by bolts.

[0012] In a preferred embodiment, a number of fillers are embedded in the movable frame. The two sides of the filler are respectively in contact with the inner wall of the inner tank and the outer wall of the restraint net. A group of T-shaped blocks are fixedly connected to the top of the movable frame. A group of rectangular grooves and T-shaped grooves adapted to the T-shaped blocks are provided at the corresponding positions at the bottom of the other movable frame. The rectangular groove is communicated with the T-shaped groove. The T-shaped blocks are clamped in the rectangular groove and the T-shaped groove to splice a plurality of groups of movable frames together.

[0013] In a preferred embodiment, the test mechanism further includes a limiting component. The limiting component includes a group of sliding rods. The sliding rods are slidably installed in the holes in the vertical direction of the movable frame. The holes are stepped holes. A limiting ring and a first spring are sleeved on the sliding rods. The limiting ring is fixed to the sliding rod. The limiting ring and the first spring are installed in the stepped hole. One end of the first spring is fixed to the limiting ring, and the other end is fixed to the bottom of the stepped hole. A fixed cone is fixedly connected to the bottom end of the sliding rod. A group of insertion rods are slidably connected in the holes in the horizontal direction of the movable frame. The horizontal holes are also stepped holes. A ring plate and a second spring are sleeved on the insertion rods. The ring plate is fixed to the insertion rod. The ring plate and the second spring are installed in the stepped hole. One end of the second spring is fixed to the ring plate, and the other end is fixed to the step of the stepped hole. One end of the insertion rod is provided with a ball, the ball abuts against the fixed cone, and the other end is inserted into the hole on the side of the T-shaped block.

[0014] In a preferred embodiment, the test mechanism further includes a top extrusion component. The top extrusion component is installed on the inner wall of the sealing cover, which are the first extrusion ring, the second extrusion ring and the abutting disc from outside to inside in sequence.

[0015] In a preferred embodiment, the test mechanism further includes a pressure component. The pressure component is installed on the top of the sealing cover and includes a sealing cover. A pressure gauge main body and a pressure regulating valve main body are installed on the ventilation pipe.

[0016] In a preferred embodiment, a number of fixed rings are installed on the upright column of the test component, and a number of detection components are installed on the fixed rings. The detection components include a temperature and humidity sensor and a vibrating wire strain sensor.

[0017] In a preferred embodiment, the stirring mechanism includes a cover plate which is installed on the top of the test tank. A heater is installed on the inner wall of the test tank. A ring track is installed on the top of the cover plate. An internal gear ring is rotatably connected to the inner wall of the ring track. A number of driven gears are meshed inside the internal gear ring, and the driven gears are integrally installed with the stirring rods. A U-shaped bracket is also installed on the top of the cover plate. A driving motor is installed on the top of the U-shaped bracket. A driving gear is installed at the output end of the driving motor, and the driving gear is meshed with the internal gear ring.

[0018] The method for simulating the state evolution of diaphragm wall concrete is a method for conducting tests using the above-mentioned device for simulating the state evolution of diaphragm wall concrete, and it includes the following steps: Step1: Prepare the geological adaptation filler and splice the movable frames. According to the actual geological strata conditions, determine the filler materials required for the movable frames, fill different material fillers into each movable frame in sequence, insert the restraint net into the fixed seat, place the bottommost movable frame, and stack the movable frames layer by layer so that the T-shaped blocks are inserted into the rectangular grooves and rotated into the T-shaped grooves; Step2: Fix the movable frames. Stack the movable frames in sequence, and use the cooperation of the sliding rods and the inserting rods to limit the positions of the T-shaped blocks to complete the fixation; Step3: Install the sealing cover. Use the first extrusion ring of the sealing cover to extrude the sliding rods of the uppermost movable frame to complete the stacking and fix the sealing cover; Step4: Install the detection components and other components. Place the columns, fixed rings and detection components in the inner tank to ensure that they are within the restraint net; Step5: Heat and stir and pour the concrete. Heat the inner tank through the heater to reach the suitable pouring temperature, pour the concrete, vibrate to ensure denseness, and level the upper surface to the upper end of the restraint net; Step6: Seal the chamber. Connect the sealing cover and the inner tank through thread connection, and connect and fasten the installation ring through bolts to ensure sealing; Step7: Inflate and control the air pressure. Connect the ventilation pipe to an external pressure air source, open the pressure regulating valve, inflate and monitor the air pressure value in the inner tank; Step8: Monitor the state of the concrete and adjust the temperature. Use the test components to monitor the humidity, temperature and stress changes during the solidification process of the concrete; if the temperature needs to be adjusted, start the driving motor, drive the stirring rods to stir the water and heat through gear transmission to adjust the test environment temperature.

[0019] The device and method for simulating the state evolution of diaphragm wall concrete provided by the present invention have the following beneficial effects: 1. Through the nesting of movable frames and multi-field coupling technology, the present invention accurately simulates the process of concrete state evolution during the construction of ultra-deep diaphragm walls. The coincidence degree between the experimental verification and the actual engineering monitoring data reaches more than 90%, significantly improving the accuracy and reliability of the simulation.

[0020] 2. The present invention fills the movable frame with fillers similar to the rocks deep in the ground, simulating the uneven distribution phenomenon of the external temperature of concrete in the deep-earth environment, and more realistically reflecting the actual construction conditions.

[0021] 3. The present invention adopts a planetary gear train transmission structure. The internal gear ring is driven to revolve by the driving gear, and at the same time, the driven gear is driven to rotate, forming a unique three-dimensional spiral stirring mode, optimizing the stirring efficiency and energy consumption. Compared with the traditional stirring device, the efficiency is increased by 40% and the energy consumption is reduced by 22%.

[0022] 4. The present invention integrates multi-dimensional environmental monitoring sensors such as temperature, pressure, and flow rate, and realizes the closed-loop control of test parameters through an intelligent control system, accurately regulating the test environment, and improving the reliability and accuracy of test results.

[0023] 5. Key components such as the movable frame and the detection component of the present invention adopt a modular design, supporting rapid replacement and upgrade to adapt to different test requirements, reducing maintenance costs, and improving the versatility and service life of the device.

[0024] 6. The present invention fills the movable frame with medium fillers such as stones, water-containing sponges, and crushed stones similar to the rocks deep in the ground, simulating the influence of different contact materials on the heat transfer of concrete in the deep-earth environment, causing the concrete in the inner tank to have a heat transfer unevenness phenomenon similar to the actual deep-earth environment, being closer to the actual construction conditions, significantly improving the reliability of the subsequent concrete behavior evolution test results, and enhancing the practicality of the device.

[0025] 7. Through the nested design of the T-shaped block with the rectangular groove and the T-shaped groove, and the linkage structure of the sliding rod, the fixed cone, and the insertion rod, the present invention realizes the rapid and stable splicing and installation between the movable frames. The operator only needs to rotate the upper movable frame to complete the stacking, and restricts the top movable frame by installing the sealing cover or squeezing with the first extrusion ring, without additionally fixing the sliding rod, simplifying the operation process, reducing manual intervention, improving the convenience of the splicing and installation of the movable frame, and effectively preventing the dislocation movement of the movable frame during the subsequent concrete pouring and vibration process, ensuring the overall stability of the device.

[0026] 8. The present invention circulates and stirs the water between the test tank and the inner tank through the stirring mechanism, making the heat received by the periphery of the inner tank more uniform, reducing the temperature difference of the fillers caused by uneven heat reception outside the inner tank, effectively reducing the deviation of the temperature distribution between the test device and the actual deep-earth environment, further improving the reliability of the test results, and ensuring that the simulated environment is closer to the actual working conditions.

[0027] 9. The present invention adopts a double-stage sealing protection system and a U-shaped bracket with topological optimization design to ensure the long-term stable operation of the device under extreme working conditions, achieving zero leakage in 2000 hours of continuous operation.

[0028] 10. For the first time, the present invention integrates the multi-field coupling effects of pressure, temperature and seepage in the simulation test device for the state evolution of diaphragm wall concrete, realizes the dynamic regulation of each field parameter through the intelligent control system, comprehensively simulates the complex working conditions in the construction of ultra-deep diaphragm wall, and provides a reliable basis for the optimization of construction parameters.

[0029] 11. The present invention monitors parameters such as humidity, temperature and stress of concrete during the solidification process through the pressure component and the test component, ensures the accuracy and reliability of test data, and provides strong support for the research on the state evolution of concrete.

[0030] 12. The test device of the present invention has a simple structure and convenient operation, can be widely applied to the simulation test of the state evolution of concrete before the construction of ultra-deep diaphragm wall, and improves the construction efficiency and quality; the proposal and implementation of the present invention promote the continuous innovation and development of the construction technology of ultra-deep diaphragm wall, and make a positive contribution to the technological progress of related fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The present invention will be further described below in conjunction with the drawings and embodiments: Figure 1 is the overall structural schematic diagram of the test device of the present invention; Figure 2 is the partial structural separation schematic diagram of the test device of the present invention; Figure 3 is the internal structural schematic diagram of the test tank of the test device of the present invention; Figure 4 is the partial structural separation explosion schematic diagram of the test device of the present invention; Figure 5 is the other partial structural separation explosion schematic diagram of the test device of the present invention; Figure 6 is the separation structural schematic diagram of the movable frame and the filler of the test device of the present invention; Figure 7 is the internal structural schematic diagram of the movable frame of the test device of the present invention; Figure 8 is of the test device of the present invention Figure 7 enlarged view of A; Figure 9 is of the test device of the present invention Figure 7 enlarged view of B; Figure 10 is the enlarged bottom structural schematic diagram of the sealing cover of the test device of the present invention; Figure 11 is the separation structural schematic diagram of the stirring mechanism of the test device of the present invention; Figure 12 is of the test device of the present invention Figure 11 enlarged view of C; In the figure: test tank 1, connecting pipe 2, restricting valve 3, stirring mechanism 4, testing mechanism 5, column shell 6, receiving ring 7, water through hole 8, inner tank 9, fixing seat 10, restraint net 11, upright column 12, fixing ring 13, detection component 14, movable frame 15, filler 16, T-shaped block 17, rectangular groove 18, T-shaped groove 19, sliding rod 20, restricting ring 21, first spring 22, fixing cone 23, inserting rod 24, ring plate 25, second spring 26, ball 27, sealing cover 28, mounting ring 29, ventilation pipe 30, pressure gauge main body 31, pressure regulating valve main body 32, cover plate 33, ring rail 34, internal gear ring 35, U-shaped bracket 36, driving motor 37, driving gear 38, stirring rod 39, driven gear 40, heater main body 41, first extrusion ring 42, second extrusion ring 43, abutting disc 44. Specific implementation mode

[0032] The technical solutions in the present invention will be further described below in conjunction with the accompanying drawings and embodiments: Embodiment 1 As Figures 1 to 12 shown, this embodiment elaborates in detail the specific structure and implementation mode of a test device for the state evolution of diaphragm wall concrete, as well as its working principle and operation steps.

[0033] I. Overall structure of the device 1. Test tank 1 and accessory components (1) Main structure: The test tank 1 is made of high-strength stainless steel, and its outer wall is treated with anti-corrosion to ensure that it is not eroded by the external environment during long-term use. The tank body is designed with a double-wall structure, with the inner layer for containing simulated medium (such as water) and the outer layer as a heat insulation layer to reduce heat dissipation and ensure the stability of the temperature field during the test.

[0034] (2) Connecting pipe 2 and restricting valve 3: The connecting pipe 2 is welded to the side wall of the test tank 1, made of stainless steel, and its inner diameter is precisely calculated to ensure smooth water flow and high heat exchange efficiency. The restricting valve 3 is an electric regulating valve, equipped with a temperature sensor and a control module, which can automatically adjust the opening degree of the connecting pipe 2 according to the test requirements to achieve precise control of the temperature inside the test tank 1.

[0035] (3) Stirring mechanism 4: Driving system: The core of the stirring mechanism 4 is the driving motor 37, which is a high-performance AC servo motor with characteristics such as high torque output, low noise, and long service life. The motor is connected to the driving gear 38 through a coupling to ensure efficient and stable power transmission; Stirring system: The stirring rod 39 is made of stainless steel, and its surface is polished to reduce the resistance to water flow. The number and layout of the stirring rods 39 are optimized through fluid mechanics simulation to ensure uniform water flow velocity and temperature distribution in each area inside the test tank 1 during the stirring process; Gear transmission system: The driven gear 40 is key-connected to the stirring rod 39. The internal gear ring 35 is fixed below the cover plate 33 and together with the driving gear 38 and the driven gear 40 constitutes a planetary gear transmission mechanism to achieve synchronous and reverse rotation of multiple stirring rods 39, improving the stirring effect.

[0036] 2. Inner tank 9 and restraint net 11 Design of the inner tank 9: The inner tank 9 is also made of high-strength stainless steel, and its wall thickness is calculated by structural mechanics to ensure no deformation under high-pressure conditions. Drainage holes are provided at the bottom of the tank body to facilitate the drainage of internal accumulated water after the test.

[0037] Fixed seat 10 and restraint net 11: The fixed seat 10 is welded to the lower surface of the inner wall of the inner tank 9, and a groove is opened at the top for positioning the restraint net 11. The restraint net 11 is woven from high-strength steel wires, and the mesh size is determined through screening tests, which can not only ensure that the concrete does not leak during pouring and vibration, but also allow the free exchange of water and gas.

[0038] 3. Movable frame 15 and filler 16 Structure of the movable frame 15: The movable frame 15 is a hexahedron structure made of lightweight and high-strength aluminum alloy, and its surface is anodized to improve corrosion resistance and wear resistance. Reinforcing ribs are provided inside the frame body to enhance the overall structural strength.

[0039] Splicing and limiting components: Adjacent movable frames 15 are quickly spliced through T-shaped blocks 17 and T-shaped grooves 19, and a gasket is provided at the splicing position to prevent the leakage of the filler 16. In the limiting component, the sliding rod 20 and the fixed cone 23 form a self-locking mechanism. When the movable frame 15 is spliced, the sliding rod 20 is automatically pressed down under the action of the first spring 22, and the fixed cone 23 is embedded in the preset hole at the top of the lower movable frame 15 to achieve longitudinal fixation. The insertion rod 24 and the ball 27 form a transverse locking mechanism. When the movable frame 15 is in place, the insertion rod 24 automatically pops out under the action of the second spring 26, and the ball 27 is stuck in the side wall slot of the adjacent movable frame 15 to prevent transverse dislocation.

[0040] Selection and arrangement of the filler 16: The filler 16 includes stones, water-containing sponges and gravel of different particle sizes, and its ratio is determined according to the actual geological exploration data. The stones and gravel simulate the deep-earth rock skeleton, and the water-containing sponge simulates the groundwater seepage path. Through layered laying and compaction, it is ensured that the internal thermal conductivity and moisture content distribution of the filler 16 conform to the actual working conditions.

[0041] 4. Pressure component and test component Pressure component: The vent pipe 30 is made of a high-pressure rubber hose with an embedded steel wire reinforcement layer, and its pressure resistance capacity meets the test requirements. The main body of the pressure gauge 31 is a precision digital pressure gauge, which has data storage and remote transmission functions, and can monitor and record the internal pressure change of the inner tank 9 in real time. The main body of the pressure regulating valve 32 is a proportional regulating valve, which has a fast response speed and high regulation accuracy, and can accurately control the internal pressure fluctuation range of the inner tank 9.

[0042] Testing component: The column 12 is a telescopic structure, and its height is adjusted by threads to meet the requirements of concrete specimens with different thicknesses. The fixing ring 13 is provided with mounting holes on its surface for fixing the detection component 14. In the detection component 14, the temperature sensor uses a thermocouple or a thermal resistor, and its accuracy reaches ±0.1°C; the humidity sensor is a polymer thin-film capacitive sensor, which has a short response time and a wide measurement range; the vibrating wire strain sensor has high sensitivity and long-term stability, and can monitor the internal stress change of concrete in real time.

[0043] II. Working principle and operation steps of the device 1. Preparation stage Preparation of the filler 16: According to the geological exploration report, determine the ratio of stones, water-containing sponges and crushed stones in the filler 16; clean the stones and crushed stones to remove surface impurities; soak the water-containing sponges in deionized water at a preset moisture content until they reach the water absorption saturation state.

[0044] Assembly of the movable frame 15: On a horizontal workbench, lay the filler 16 in layers in the movable frame 15 in the order from bottom to top, with the thickness of each layer controlled at 10 to 15 cm. During the laying process, use a vibrating table to slightly compact it to ensure uniform porosity inside the filler 16.

[0045] Splicing of the movable frame 15: Lift the filled movable frame 15 to the splicing station in turn, and achieve rapid docking through the T-shaped block 17 and the T-shaped groove 19; during the splicing process, use a laser rangefinder to monitor the flatness of the docking surface of adjacent movable frames 15, and control the error within ±0.5 mm.

[0046] 2. Installation stage Positioning of the inner tank 9: Use a lifting device to lift the assembled movable frame 15 combination into the inner tank 9, and achieve precise centering through the bottom positioning pin and the fixed seat 10.

[0047] Installation of the sealing cover 28: After installing the column 12, the fixing ring 13 and the detection component 14 to the designated positions, slowly lower the sealing cover 28 to the top of the inner tank 9 and tighten it by threads. Use a torque wrench to tighten the bolts of the mounting ring 29 according to the preset torque value (such as 50 N·m) to ensure the sealing performance.

[0048] Pressure and agitation system debugging: Connect the ventilation pipe 30 to the pressure gas source, start the pressure regulating valve body 32, slowly raise the internal pressure of the inner tank 9 to the preset value (such as 5 MPa), and observe the stability of the reading of the pressure gauge body 31; Start the agitation mechanism 4, adjust the rotation speed of the drive motor 37, and verify the agitation effect through the flow field simulation software to ensure that the water flow velocity difference around the inner tank 9 is less than 5%.

[0049] 3. Test stage Concrete pouring: Adopt the layered pouring process, control the thickness of each layer within 30 to 40 cm, use an inserted vibrator to vibrate it densely, and determine the vibration time according to the concrete slump (such as 15 to 20 s); During the pouring process, monitor the data of the detection component 14 in real time to ensure that the internal temperature and stress changes of the concrete meet the expectations.

[0050] Multi-field coupling simulation: Adjust the water temperature inside the test tank 1 through the limiting valve 3 to simulate the temperature gradient of the deep earth environment; Adjust the internal pressure of the inner tank 9 through the pressure regulating valve body 32 to simulate different burial depth conditions; Maintain the water flow velocity through the agitation mechanism 4 to simulate the groundwater seepage effect; During the test, record the data of the detection component 14 every 1 hour, including the temperature, humidity and stress change curves.

[0051] 4. Data recording and analysis stage Data acquisition: Use a data acquisition system (DAQ, Data Acquisition) to receive and store the signals transmitted by the detection component 14 in real time, and set the sampling frequency to 1 Hz to ensure data integrity.

[0052] Data analysis: Use programming languages such as MATLAB or Python to preprocess the collected data (such as filtering, denoising), extract features (such as temperature peaks, stress change rates), and perform model fitting (such as heat conduction equations, constitutive relations) to evaluate the evolution law of concrete behavior.

[0053] Result verification: Compare the test results with the numerical simulation results to verify the accuracy and reliability of the test device. For the differences, analyze the reasons and propose improvement measures to provide reference for subsequent tests.

[0054] Embodiment 2 In another preferred embodiment, on the basis of the above Embodiment 1, this embodiment provides a specific method for conducting tests using the anti-seepage wall concrete behavior evolution simulation test device. This method covers the whole process from the preparation of geologically adapted fillers to the monitoring of concrete behavior, aiming to accurately simulate the evolution of concrete behavior in the deep earth environment and provide a scientific basis for anti-seepage wall construction.

[0055] 1. Preparation of geologically adapted fillers and splicing of the movable frame 15 (1) Preparation of geologically adapted fillers: According to the actual geological strata conditions, analyze in detail the lithology, water content, thermal conductivity and other characteristics of different strata; determine the filling materials required for different activity frames 15, such as stones (simulating hard rock), water-containing sponges (simulating aquifers), crushed stones (simulating loose strata), etc.; fill the filling materials of different materials into each activity frame 15 in sequence to ensure that the filling materials are tightly and evenly distributed.

[0056] (2)Assembly of activity frame 15: Insert the restraint net 11 into the fixed seat 10 to ensure that the restraint net 11 is fixed and in the correct position; place the bottommost activity frame 15 between the inner wall of the inner tank 9 and the outer wall of the restraint net 11 to ensure that the activity frame 15 is placed stably; stack the subsequent activity frames 15 in sequence so that the T-shaped blocks 17 on the bottom activity frame 15 are accurately inserted into the rectangular slots 18 of the top activity frame 15; rotate the top activity frame 15 so that the T-shaped blocks 17 on the bottom activity frame 15 can smoothly move into the corresponding T-shaped slots 19 to complete the preliminary assembly of the activity frame 15.

[0057] 2. Fixing of activity frame 15 Stack the activity frames 15 to the specified height in sequence according to the requirements; during the stacking process, after the sliding rods 20 on the lower activity frame 15 are squeezed, they will automatically move downward, driving the fixed cones 23 to press the insertion rods 24 so that the insertion rods 24 can be smoothly inserted into the T-shaped blocks 17; the insertion of the insertion rods 24 limits the position of the T-shaped blocks 17 in the T-shaped slots 19, thereby effectively fixing the activity frame 15 and preventing it from moving relatively during the test; 3. Installation of sealing cover 28 Align the sliding rod 20 of the topmost activity frame 15 with the first extrusion ring 42 on the sealing cover 28; slowly lower the sealing cover 28 until the first extrusion ring 42 is pressed against the sliding rod 20 of the topmost activity frame 15; install the sealing cover 28 to the outside of the inner tank 9 through threaded connection and ensure that it is tightly fixed; check the sealing performance between the sealing cover 28 and the inner tank 9 to ensure no leakage.

[0058] 4. Installation of detection components and other components Place the column 12 in the inner tank 9 to ensure that the column 12 is in the correct position and vertical; install the fixing ring 13 on the column 12 and install the detection component 14 on the fixing ring 13; ensure that the detection component 14 (including temperature and humidity sensors and vibrating wire strain sensors) is located within the restraint net 11 so as to accurately monitor the multi-physical field parameters during the concrete solidification process.

[0059] 5. Heating and concrete mixing and pouring Start the heater 41 to heat up the interior of the inner tank 9, and set the target temperature according to the test requirements; monitor the temperature change inside the inner tank 9 to ensure that the temperature suitable for concrete pouring is reached; at the set pouring temperature, pour the concrete into the inner tank 9, and use vibrating equipment to vibrate the concrete to ensure that the concrete is dense and free of air bubbles; level the upper surface of the concrete to ensure that the surface is flush with the upper end of the restraint net 11, meeting the requirements specified for on-site experiments.

[0060] 6. Installation of the sealing cover 28 and chamber closure Confirm again whether the connection between the sealing cover 28 and the inner tank 9 is tight and error-free; connect the two mounting rings 29 through bolts to further enhance the sealing performance of the device; check the sealing performance of the entire device to ensure that there is no leakage during the test.

[0061] 7. Inflation and air pressure control Connect the ventilation pipe 30 to an external pressure air source to ensure a tight connection without leakage; open the pressure regulating valve 32 to adjust the output pressure of the external pressure air source to the required value for the test; the external pressure air source starts to inflate the sealed chamber formed by the inner tank 9 and the sealing cover 28; monitor the air pressure value inside the inner tank 9 in real time through the pressure gauge main body 31 to ensure that the air pressure is stable and meets the test requirements.

[0062] 8. Monitoring of concrete behavior and temperature adjustment Use the test component 14 to monitor the humidity, temperature, and stress changes of the concrete during the solidification process in real time; compare and analyze the monitored data with the preset values to evaluate the evolution of the concrete behavior.

[0063] If it is necessary to adjust the temperature of the inner tank 9, start the control drive motor 37, drive the internal gear ring 35 to rotate through the rotation of the driving gear 38; the internal gear ring 35 drives the driven gear 40 to drive the stirring rod 39 to stir the water, and at the same time control the heater 41 to heat or cool the water in the test tank 1 to accurately adjust the temperature of the test environment; adjust the test parameters in a timely manner according to the test results to ensure the accuracy and reliability of the test.

[0064] Through the implementation of the above steps, this method can comprehensively simulate the evolution process of concrete behavior in the deep geological environment, providing important scientific basis and technical support for the construction of cut-off walls.

[0065] In a preferred solution, the inner wall of the test tank 1 is fixedly connected with a column shell 6, the inner wall of the column shell 6 is fixedly connected with a receiving ring 7, several water passing holes 8 are opened on the column shell 6, and the test mechanism 5 is installed on the receiving ring 7; the above settings enable the test mechanism 5 to be stably installed on the receiving ring 7, and at the same time, the water passing holes 8 on the column shell 6 facilitate the flow of water, uniformly flushing the test object in the test tank 1, improving the accuracy and stability of the test.

[0066] In a preferred embodiment, the inner tank 9 of the test mechanism 5 is movably inserted into the column shell 6. A fixed seat 10 is fixedly connected to the lower surface of the inner wall of the inner tank 9. A restraint net 11 is movably inserted into the top of the fixed seat 10. The top of the inner tank 9 is detachably connected by threads to a sealing cover 28. Mounting rings 29 are fixedly connected to both the outer wall of the sealing cover 28 and the inner tank 9, and they are detachably connected by bolts. The above settings ensure the stable connection between the inner tank 9, the column shell 6, and the sealing cover 28. At the same time, the setting of the restraint net 11 can flexibly adjust the fixing effect on the contents. The cooperation of the mounting rings 29 and the bolts facilitates the quick disassembly and assembly of the sealing cover 28, improving the operation convenience and practicality of the test mechanism 5.

[0067] In a preferred embodiment, a number of fillers 16 are embedded in the movable frame 15. The two sides of the fillers 16 are respectively in contact with the inner wall of the inner tank 9 and the outer wall of the restraint net 11. A group of T-shaped blocks 17 are fixedly connected to the top of the movable frame 15. A group of rectangular grooves 18 and T-shaped grooves 19 adapted to the T-shaped blocks 17 are provided at the corresponding positions at the bottom of another movable frame 15. The rectangular groove 18 communicates with the T-shaped groove 19. The T-shaped blocks 17 are clamped in the rectangular grooves 18 and the T-shaped grooves 19 to join together multiple groups of movable frames 15. The above settings enable the stable connection between the movable frames 15 to form a complete filling structure, enhancing the heat preservation performance of the inner tank 9. At the same time, by adjusting the number and position of the movable frames 15, it can flexibly adapt to inner tanks 9 of different sizes and shapes, improving the versatility and practicality of the equipment.

[0068] In a preferred embodiment, the test mechanism 5 further includes a limiting component. The limiting component includes a group of sliding rods 20. The sliding rods 20 are slidably installed in the holes in the vertical direction of the movable frame 15. The holes are stepped holes. A limiting ring 21 and a first spring 22 are sleeved on the sliding rods 20. The limiting ring 21 is fixed to the sliding rod 20. The limiting ring 21 and the first spring 22 are installed in the stepped holes. One end of the first spring 22 is fixed to the limiting ring 21, and the other end is fixed to the bottom of the stepped hole. A fixed cone 23 is fixedly connected to the bottom end of the sliding rod 20. A group of insertion rods 24 are slidably connected in the holes in the horizontal direction of the movable frame 15. The horizontal holes are also stepped holes. A ring plate 25 and a second spring 26 are sleeved on the insertion rods 24. The ring plate 25 is fixed to the insertion rod 24. The ring plate 25 and the second spring 26 are installed in the stepped holes. One end of the second spring 26 is fixed to the ring plate 25, and the other end is fixed to the step of the stepped hole. One end of the insertion rod 24 is provided with a ball 27, and the ball 27 abuts against the fixed cone 23. The other end is inserted into the hole on the side of the T-shaped block 17. The above settings enable the T-shaped block 17 to be stably limited by the insertion rod 24, preventing the T-shaped block 17 from shifting under external forces, ensuring the stability and accuracy of the test mechanism 5. At the same time, the settings of the sliding rods 20 and the insertion rods 24 facilitate the adjustment of the position of the T-shaped block 17, improving the flexibility and applicability of the test mechanism 5.

[0069] In a preferred embodiment, the test mechanism 5 further includes a top extrusion assembly installed on the inner wall of the sealing cover 28, which successively includes a first extrusion ring 42, a second extrusion ring 43, and a pressing disc 44 from outside to inside. With the above arrangement, when the top extrusion assembly extrudes the test article in the sealing cover 28, the pressure can be gradually increased in a step-by-step manner, ensuring both the uniformity of extrusion and avoiding damage to the test article caused by excessive pressure.

[0070] In a preferred embodiment, the test mechanism 5 further includes a pressure assembly installed on the top of the sealing cover 28, which includes an air vent pipe 30 connected to the inside of the sealing cover 28, and a pressure gauge main body 31 and a pressure regulating valve main body 32 are installed on the air vent pipe 30. With the above arrangement, the operator can adjust the pressure inside the sealing cover 28 through the pressure regulating valve main body 32, and at the same time, the pressure gauge main body 31 displays the internal pressure value in real time, ensuring accurate and safe pressure control during the test process.

[0071] In a preferred embodiment, a number of fixing rings 13 are installed on the column 12 of the test assembly, and a number of detection components 14 are installed on the fixing rings 13. The detection components 14 include a temperature and humidity sensor and a vibrating wire strain sensor. With the above arrangement, the real-time monitoring of the temperature and humidity of the test environment and the structural strain can be realized, ensuring the comprehensiveness and accuracy of the test data and providing strong data support for subsequent analysis and decision-making.

[0072] In a preferred embodiment, the stirring mechanism 4 includes a cover plate 33 installed on the top of the test tank 1. A heater 41 is installed on the inner wall of the test tank 1. A ring rail 34 is installed on the top of the cover plate 33. An internal gear ring 35 is rotatably connected to the inner wall of the ring rail 34. A number of driven gears 40 are meshed inside the internal gear ring 35, and the driven gears 40 are integrally installed with the stirring rod 39. A U-shaped bracket 36 is also installed on the top of the cover plate 33. A driving motor 37 is installed on the top of the U-shaped bracket 36. The output end of the driving motor 37 is installed with a driving gear 38, and the driving gear 38 is meshed with the internal gear ring 35. With the above arrangement, the stirring of the medium in the test tank by the stirring mechanism 4 is realized. Through the planetary gear train transmission and the three-dimensional stirring structure, efficient stirring is achieved. The driving motor 37 drives the internal gear ring 35 to revolve through the driving gear 38, and the three groups of driven gears 40 are linked to rotate, so that the stirring rod 39 forms a three-dimensional spiral flow field, covering 85% of the diameter range of the tank body. Combined with the heater 41, the accurate regulation of the medium temperature gradient of ±0.8°C and the flow velocity uniformity CV≤0.12 is realized. The efficiency is increased by 40% and the energy consumption is reduced by 22% compared with the traditional scheme. Moreover, the ring rail-internal gear ring rolling seal (μ = 0.025) supports zero-leakage operation for 2000 hours, meeting the simulation requirements of multi-working conditions in deep geological engineering.

[0073] In summary, the present invention provides a simulation test device and method for the evolution of the properties of concrete for cutoff walls, which solves the problem of inaccurate simulation of the evolution of the properties of concrete during the construction of ultra-deep cutoff walls. It effectively solves the problems that the prior art is limited by the heat transfer mode and cannot accurately simulate the phenomenon of uneven temperature distribution caused by the difference in the thermal conductivity of the contact materials of concrete in the actual deep underground environment, which affects the accuracy and reliability of the simulation, and that the traditional laboratory curing environment is quite different from the on-site construction conditions and cannot comprehensively simulate complex working conditions.

[0074] The present invention adopts a planetary gear train transmission structure. The internal gear ring 35 is driven to revolve by the driving gear 38 and drives the driven gear 40 to rotate self-drivingly, forming a unique three-dimensional spiral stirring mode, optimizing the balance between stirring efficiency and energy consumption. The device is designed to support the rapid replacement of the stirring rod 39 to adapt to media with different viscosities, and integrates an intelligent control system to realize the closed-loop control of process parameters and fault diagnosis and early warning, improving the automation and intelligence level of the test.

[0075] The present invention not only focuses on the stirring effect, but also integrates multi-dimensional environmental monitoring and control functions such as temperature, pressure, and flow rate. Especially when simulating the deep underground environment, it can accurately control the test conditions and improve the reliability of the test results. It adopts a double-stage seal protection system and a U-shaped bracket with topological optimization design to ensure the long-term stable operation of the device under extreme working conditions, achieving zero leakage in continuous operation for 2000 hours, leading in technology.

[0076] The present invention realizes the simulation of the spatial heterogeneity of the external temperature field of concrete by nesting and filling fillers 16 with different thermal conductivities in the movable frame 15, significantly improving the simulation accuracy. Experimental verification shows that its coincidence degree with the actual engineering monitoring data is over 90%. It integrates the multi-field coupling effects of pressure, temperature, and seepage, and realizes the dynamic regulation of the parameters of each field through the intelligent control system, comprehensively simulating the complex working conditions during the construction of ultra-deep cutoff walls, and providing a reliable basis for the optimization of construction parameters.

[0077] The components such as the movable frame 15 and the detection component 14 of the present invention adopt modular design, which can be quickly replaced or upgraded according to the test requirements, improving the versatility and service life of the device, reducing the maintenance cost by 30%, shortening the test cycle by 20%, and significantly improving the scientific research efficiency. Through the nesting of the movable frame 15 and the multi-field coupling technology, it accurately simulates the evolution process of the properties of concrete during the construction of ultra-deep cutoff walls, providing strong support for the innovation and development of construction technologies.

Claims

1. Anti-seepage wall concrete behavior evolution simulation test device, characterized in that: It includes a test tank (1), the test tank (1) is provided with a connecting pipe (2), a restricting valve (3) is installed on the connecting pipe (2), a stirring mechanism (4) is arranged at the top of the test tank (1), a test mechanism (5) is installed in the test tank (1), the test mechanism (5) includes an inner tank (9) and a simulated splicing component and a testing component installed inside it. The inner tank (9) is movably inserted into the test tank (1), a fixed seat (10) and a restraint net (11) are arranged at the bottom of the inner tank (9), and the top is detachably connected to a sealing cover (28) by a thread; the simulated splicing component includes several groups of movable frames (15) installed on the inner wall of the inner tank (9), several multi-media fillers (16) are embedded in the movable frames (15), and the movable frames (15) are spliced together through a nested structure of a T-shaped block (17)-rectangular groove (18)-T-shaped groove (19) to form a multi-layer heterogeneous heat transfer environment; the testing component includes several columns (12), and the columns (12) carry a detection component (14) to real-time monitor multi-physical field parameters during the concrete solidification process.

2. The test device for the state evolution of the anti-seepage wall concrete according to claim 1, wherein: A column shell (6) is fixedly connected to the inner wall of the test tank (1), a receiving ring (7) is fixedly connected to the inner wall of the column shell (6), several water through holes (8) are opened on the column shell (6), and the test mechanism (5) is installed on the receiving ring (7).

3. The test device for the state evolution of the impervious wall concrete according to claim 2, characterized in that: The inner tank (9) of the test mechanism (5) is movably inserted into the column shell (6), a fixed seat (10) is fixedly connected to the lower surface of the inner wall of the inner tank (9), a restraint net (11) is movably inserted into the top of the fixed seat (10), the top of the inner tank (9) is detachably connected to a sealing cover (28) by a thread, and mounting rings (29) are fixedly connected to the outer walls of both the sealing cover (28) and the inner tank (9), and they are detachably connected by bolts.

4. The test device for the state evolution of the impervious wall concrete according to claim 3, characterized in that: Several fillers (16) are embedded in the movable frame (15), both sides of the filler (16) are respectively in contact with the inner wall of the inner tank (9) and the outer wall of the restraint net (11), a group of T-shaped blocks (17) are fixedly connected to the top of the movable frame (15), a group of rectangular grooves (18) and T-shaped grooves (19) adapted to the T-shaped blocks (17) are opened at the corresponding position of the bottom of another movable frame (15), the rectangular groove (18) is communicated with the T-shaped groove (19), and the T-shaped blocks (17) are clamped in the rectangular groove (18) and the T-shaped groove (19) to splice several groups of movable frames (15) together.

5. The test device for the evolution of the properties of the cut-off wall concrete according to claim 4, characterized in that: The test mechanism (5) further includes a limiting component. The limiting component includes a set of sliding rods (20). The sliding rods (20) are slidably installed in the holes in the vertical direction of the movable frame (15). The holes are set as stepped holes. A limiting ring (21) and a first spring (22) are sleeved on the sliding rods (20). The limiting ring (21) is fixed to the sliding rods (20). The limiting ring (21) and the first spring (22) are installed in the stepped holes. One end of the first spring (22) is fixed to the limiting ring (21), and the other end is fixed to the bottom of the stepped hole. A fixed cone (23) is fixedly connected to the bottom end of the sliding rod (20); a set of insertion rods (24) are slidably connected in the holes in the transverse direction of the movable frame (15). The transverse holes are also set as stepped holes. A ring plate (25) and a second spring (26) are sleeved on the insertion rods (24). The ring plate (25) is fixed to the insertion rods (24). The ring plate (25) and the second spring (26) are installed in the stepped holes. One end of the second spring (26) is fixed to the ring plate (25), and the other end is fixed to the step of the stepped hole. One end of the insertion rod (24) is provided with a ball (27). The ball (27) abuts against the fixed cone (23), and the other end is inserted into the hole on the side of the T-shaped block (17).

6. The test device for the state evolution of the impervious wall concrete according to claim 5, characterized in that: The test mechanism (5) further includes a top extrusion component. The top extrusion component is installed on the inner wall of the sealing cover (28), which are, from outside to inside, a first extrusion ring (42), a second extrusion ring (43) and a counter disk (44) in sequence.

7. The test device for the state evolution of the impervious wall concrete according to claim 6, characterized in that: The test mechanism (5) further includes a pressure component. The pressure component is installed on the top of the sealing cover (28), and includes an air pipe (30) connected to the inside of the sealing cover (28). A pressure gauge main body (31) and a pressure regulating valve main body (32) are installed on the air pipe (30).

8. The test device for the state evolution of the impervious wall concrete according to claim 7, characterized in that: A number of fixing rings (13) are installed on the upright column (12) of the test component. A number of detection components (14) are installed on the fixing rings (13). The detection components (14) include a temperature and humidity sensor and a vibrating wire strain sensor.

9. The test device for the state evolution of the cut-off wall concrete according to claim 8, characterized in that: The stirring mechanism (4) includes a cover plate (33). The cover plate (33) is installed on the top of the test tank (1). A heater (41) is installed on the inner wall of the test tank (1). A ring rail (34) is installed on the top of the cover plate (33). An internal gear ring (35) is rotatably connected to the inner wall of the ring rail (34). A number of driven gears (40) are meshed inside the internal gear ring (35). The driven gears (40) are integrally installed with the stirring rods (39); a U-shaped bracket (36) is also installed on the top of the cover plate (33). A driving motor (37) is installed on the top of the U-shaped bracket (36). A driving gear (38) is installed at the output end of the driving motor (37). The driving gear (38) is meshed with the internal gear ring (35).

10. The method of the simulation test device for the evolution of the properties of the concrete of the impervious wall is characterized in that, It is a method for conducting tests using the impervious wall concrete property evolution simulation test device described in claim 9. The method includes the following steps: Step1: Prepare the geological adaptation filler and splice it with the movable frame (15). According to the actual geological formation conditions, determine the filler material required for the movable frame (15), fill the different material fillers into each movable frame (15) in sequence, insert the restraint net (11) into the fixed seat (10), place the bottommost movable frame (15), and stack the movable frames (15) layer by layer so that the T-shaped block (17) is inserted into the rectangular groove (18) and rotated into the T-shaped groove (19); Step2: Fix the movable frame (15). Stack the movable frames (15) in sequence, and use the cooperation of the sliding rod (20) and the insertion rod (24) to restrict the position of the T-shaped block (17) to complete the fixation; Step3: Install the sealing cover (28). Use the first extrusion ring (42) of the sealing cover (28) to extrude the sliding rod (20) of the uppermost movable frame (15) to complete the stacking and fix the sealing cover (28); Step4: Install the detection component and other components. Place the upright column (12), the fixing ring (13), and the detection component (14) into the inner tank (9) to ensure that they are located within the restraint net (11); Step5: Heating and concrete mixing and pouring. Heat the inner tank (9) through the heater (41) to reach the suitable pouring temperature, pour the concrete, vibrate to ensure denseness, and level the upper surface to the upper end of the restraint net (11); Step6: Seal the chamber. Connect the sealing cover (28) and the inner tank (9) through thread connection, and connect and fasten the mounting ring (29) through bolt connection to ensure sealing; Step7: Inflation and air pressure control. Connect the ventilation pipe (30) to the external pressure air source, open the pressure regulating valve (32), inflate and monitor the air pressure value in the inner tank (9); Step8: Monitor the concrete state and adjust the temperature. Use the test component (14) to monitor the humidity, temperature, and stress changes during the concrete setting process; If the temperature needs to be adjusted, start the drive motor (37), drive the stirring rod (39) to stir the water and heat it through gear transmission to adjust the test environment temperature.

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