CN115629097A - Underground water immersion simulation control method for rock-soil body environment simulation test - Google Patents
Underground water immersion simulation control method for rock-soil body environment simulation test Download PDFInfo
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- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 title claims abstract description 292
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- 239000002689 soil Substances 0.000 title claims abstract description 71
- 238000000034 method Methods 0.000 title claims abstract description 28
- 238000007654 immersion Methods 0.000 title claims description 4
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Abstract
The invention discloses an underground water infiltration simulation control method for a rock-soil body environment simulation test, which is characterized in that one side of a soil body for simulation in a simulation box test area is separated by a retaining wall capable of moving up and down to form an independent water collecting area, underground water for simulation is firstly connected into the water collecting area, then the retaining wall is controlled to be lifted upwards to a space with the lower end exposed out of the required underground water depth, and water is infiltrated and flows into the soil body for simulation according to the exposed height size of the retaining wall from the space to form underground water simulation with the required depth. The invention can better control and realize the simulation of the soil body infiltration condition of the underground water; the simulation reduction of the soil body environment by the soil body freeze-thaw test is better assisted, and the simulation precision and the application range of the soil body freeze-thaw test are improved.
Description
Technical Field
The invention relates to the technical field of research on related performances of freeze-thaw soil bodies, in particular to an underground water immersion simulation control method for a rock-soil body environment simulation test.
Background
Land freeze-thaw refers to a physical geological role and phenomenon in which soil layers freeze and thaw due to temperature falling below zero and rising above zero. In cold regions in the east and west of China, earth surface soil bodies are usually in freeze-thawing environments in stages due to large temperature difference between seasons, day and night and the like. Due to the fact that under the freezing and thawing environment, underground water is formed in the ground generally, and during the freezing process of the soil, moisture in the soil is frozen into ice, and a plurality of ice interlayers and ice mirror bodies are generated, so that relative displacement of soil particles is caused, soil body expansion is generated, and the phenomenon is called frost heaving. The appearance phenomenon of frost heaving is uniform or non-uniform swelling, bulging, cracking and the like of a soil layer; after melting, the alloy obviously sinks, so that the structure is greatly damaged. Generally, when water freezes in the soil, the volume increases by about 9%, causing the foundation soil to expand all around. Therefore, under the condition of repeated freezing and thawing action, larger destructive power can be generated on rock masses in soil layers, concrete building foundations and the like. The former is easy to cause accidents such as collapse and landslide after being damaged, and the latter can directly influence the safety performance of the building after being damaged. Therefore, in the geotechnical field of freeze-thaw areas, the harm caused by freeze-thaw soil is very necessary to be researched; especially, the method researches and discusses the destructive effect of the freeze-thaw soil body on the structure after repeated freeze thawing under the action of underground water. However, in some existing freeze-thaw test methods, for example, patents such as a concrete durability test device disclosed in CN114486512a under the coupling effect of load and multiple environmental factors, a soil erosion test device and a test method disclosed in CN202210056257.3 considering the coupling effect of multiple environmental factors, and the like, can not realize the condition simulation of soil body under the infiltration effect of groundwater, and influence the application range of the test.
Therefore, a method capable of better controlling and realizing the soil body infiltration condition simulated by underground water is needed to be designed, so as to better assist the soil body freeze-thaw test in simulating and restoring the soil body environment, and improve the simulation precision and the application range of the soil body freeze-thaw test.
Disclosure of Invention
Aiming at the defects of the prior art, the technical problems to be solved by the invention are as follows: the method can better control and realize the simulation of the infiltration condition of underground water to a soil body; the simulation reduction of the soil body environment by the soil body freeze-thaw test is better assisted, and the simulation precision and the application range of the soil body freeze-thaw test are improved.
In order to solve the technical problems, the invention adopts the following technical scheme:
the underground water infiltration simulation control method for the rock-soil body environment simulation test is characterized in that one side of a simulation soil body in a simulation box test area is separated by a retaining wall capable of moving up and down to form an independent water collecting area, underground water simulation water is connected into the water collecting area, then the retaining wall is controlled to be lifted upwards until the lower end of the retaining wall is exposed to the interval of the required simulation underground water depth, and water is infiltrated and flows into the simulation soil body from the interval according to the exposed height size of the retaining wall to form the underground water simulation of the required depth.
Therefore, the depth formed by infiltration of groundwater in the soil body for simulation can be better controlled, the simulation reduction of the soil body environment by the soil body freeze-thaw test can be better assisted, and the simulation precision and the application range of the soil body freeze-thaw test are improved.
Further, when the depth of the simulation box for simulation is lower than the depth of the underground water to be simulated, the simulation box is closed, gas is introduced to exert pressure, and the water pressure at the bottom of the simulation box is detected to be consistent with the depth pressure of the underground water to be simulated, so that deeper underground water depth simulation is realized.
Therefore, a smaller simulation box can be better adopted, deeper underground water deep simulation is realized, and the simulation application range is better improved.
Further, the method is realized by means of an underground water depth adjustment simulating device, the underground water depth adjustment simulating device comprises a water collecting tank arranged on the inner side of the side face of a simulation box where a water conveying pipeline is located, the water collecting tank is arranged along the whole length direction of the side wall of the simulation box where the water conveying pipeline is located, the height of the upper surface of the water collecting tank is not lower than the height of the test piece positioning device, a retaining wall on one side, facing the test piece positioning device, of the water collecting tank is integrally arranged to be a movable retaining wall, two sides of the movable retaining wall can be clamped and matched in a retaining wall sliding groove in a vertically sliding mode, and the movable retaining wall is connected with a retaining wall vertical movement control mechanism.
Therefore, when water is input into the water conveying pipeline to simulate underground water, the water can be conveyed into the water collecting tank firstly, and then the movable retaining wall is controlled to be integrally lifted to a preset underground water depth position, so that the water in the water collecting tank flows out from a fixed height position below the movable retaining wall to form underground water. The groundwater simulation that realizes like this is convenient more reliable, and groundwater depth of water precision can control the accuracy better.
Furthermore, the side of the movable retaining wall facing the test piece positioning device is sequentially and outwards fixedly provided with a support grid and sponge materials fixed on the support grid. Therefore, the effect that the sand and soil are isolated from entering the water collecting tank to influence the lifting control of the movable retaining wall but the water in the water collecting tank is not blocked from flowing outwards can be achieved. Meanwhile, the impact of the direct outflow water flow in the water collecting tank on the sand can be avoided to influence the test.
Further, barricade vertical movement control mechanism, including vertical fixing the barricade rack in removal barricade one side both ends position department, two barricade racks respectively with one be located same level for the barricade control gear engagement, two for the barricade control gear fix in the barricade for the control pivot that same level set up, both ends of barricade for the control pivot are rotationally installed on the simulation case and one end is worn out the simulation case and is provided with a barricade for the control rotatory handle.
Like this, can conveniently through rotating barricade control and with rotatory handle, through the meshing of barricade control with gear and barricade rack, drive and remove the barricade and reciprocate along the barricade spout. Simple structure and reliable and stable.
Furthermore, a graduated scale is arranged on the side surface of the simulation box at the position of the movable retaining wall. Therefore, the numerical value of the height of the moving retaining wall lifted upwards can be visually seen, so that the underground water discharge depth can be conveniently and accurately controlled.
Further, groundwater depth adjustment analogue means still keeps away from conduit direction one side and a breakwater that sets up with this side parallel interval including being located the simulation incasement, but in the breakwater spout of breakwater inside wall of the cooperation of joint with sliding from top to bottom at breakwater both ends, the simulation bottom of the case portion of breakwater below is provided with a breakwater heavy groove downwards, and breakwater and a breakwater vertical movement control mechanism link to each other, breakwater vertical movement control mechanism can control the breakwater and upwards stretch out or retract the breakwater heavy groove downwards, and the breakwater upwards stretches out the back and forms a drainage chamber in the one side that deviates from the conduit direction, and drainage pipe sets up in drainage chamber bottom surface.
Therefore, when the groundwater is simulated, the water baffle can be controlled to extend upwards to the depth position of the groundwater to be simulated (or slightly lower than the depth of the groundwater to be simulated by 1-5cm so as to offset the water level height of the part of the water baffle overflowing out of the test area). When the inlet water in the simulation box reaches the height of the water baffle, the inlet water can cross the water baffle to flow into the drainage cavity and be discharged from the drainage pipeline. Therefore, the underground water depth in the test area can be better ensured to meet the simulation requirement. In addition, the process shows that when the water baffle and the water baffle are combined, the outflow depth of water in the water collecting tank is controlled by the water baffle, water is retained by the water baffle, the infiltration depth of the test area by water flow can meet the requirement, and therefore accurate simulation of the underground water depth can be better achieved. More specifically, in the process of the freeze-thaw cycle test, when the underground water is in a frozen state, the operation is simple, and only the water pipeline needs to be closed. However, when groundwater is in a thawing state, because a freezing and thawing area is usually a mountain land environment, groundwater is usually in a slow flowing undercurrent state after being thawed, when the water baffle and the water baffle wall are used together, the underground water slow flowing undercurrent state can be better simulated under the condition that enough groundwater depth is ensured to be maintained by controlling the upper end of the water baffle to extend out to be lower than the lower end of the water baffle wall to reserve a spacing height (namely the groundwater depth to be simulated) for a distance (usually 1-5 cm), and simultaneously opening the water conveying pipeline to supply water according to the flow speed and flow of the actual undercurrent of the groundwater to be simulated. Particularly, when the underground water simulation depth of the simulation box is not enough and the air pressure needs to be increased in the simulation box to increase the underground water simulation depth, the combination of the water retaining wall and the water retaining plate can better ensure that the water can still maintain the sufficient underground water depth and simulate a good undercurrent state under the condition of increasing the air pressure (water flow cannot be pressed away by high pressure); and meanwhile, the increased air pressure can better press the underground water in the area between the water baffle and the water baffle wall, so that a stronger water pressure effect can be better formed at the bottom of the test area, and the effect of increasing the simulated water depth by means of the air pressure is better realized. And when increasing atmospheric pressure in order to strengthen the simulation, can also close drainage pipe in order to avoid atmospheric pressure to produce when great and lose heart, also can rely on the drainage cavity regional retaining that the breakwater formed this moment, satisfy the undercurrent simulation demand in test area.
Furthermore, one side of the water baffle, which faces the water pipeline, is sequentially and outwards fixedly provided with a support grid and sponge materials fixed on the support grid.
Therefore, the effect of isolating sand from entering to influence the lifting control of the water baffle can be achieved, and the flow of water is not hindered. Meanwhile, the influence of the sand for the test on the test due to the washing away of the water flow can be avoided.
Further, the up-and-down movement control mechanism for the water baffle comprises water baffle racks vertically fixed at two ends of one side of the water baffle, the two water baffle racks are respectively meshed with a gear for controlling the water baffle located at the same horizontal level, the two water baffle racks are fixed on a rotating shaft for controlling the water baffle arranged at the same level through the gear, two ends of the rotating shaft for controlling the water baffle are rotatably installed on the simulation box, and one end of the rotating shaft penetrates out of the simulation box to be provided with a rotating handle for controlling the water baffle.
Therefore, the rotating handle for controlling the water baffle can be conveniently rotated, and the water baffle is driven to move up and down along the water baffle sliding groove through the meshing of the gear for controlling the water baffle and the water baffle rack. Simple structure and reliable and stable.
Furthermore, a graduated scale is arranged on the side surface of the simulation box at the position of the water baffle. Therefore, the numerical value of the height of the water baffle lifted upwards can be visually seen, so that the depth of underground water can be conveniently and accurately controlled.
Furthermore, the groundwater depth adjustment simulation device further comprises a sealing strip and a top cover pressing and sealing mechanism which are arranged between the top cover and the box body of the simulation box, and further comprises a water pressure detection sensor positioned at the bottom of the simulation box and an air pressure conveying pipeline communicated with the simulation box, wherein the air pressure conveying pipeline is connected with an air compressor outside the simulation box.
Like this, when the simulation case can simulate groundwater degree of depth not enough, can rely on sealing strip and top cap to compress tightly sealing mechanism and compress tightly the top cap, realize the sealed of simulation case, then input atmospheric pressure to the simulation incasement through aerostatic press and pneumatic conveying pipeline, under atmospheric pressure and hydraulic combined action, rely on the water pressure detection sensor of simulation bottom of the case portion to detect here water pressure, make its and the building foundation concrete bottom of awaiting testing actually receive groundwater water pressure unanimously, make it maintain and accomplish the freeze-thaw cycle test under the water pressure condition unanimous with actual conditions, accomplish the simulation to deeper groundwater infiltration condition. The application range of the test is better expanded. Wherein top cap compresses tightly sealing mechanism can be for bolt fastening or connect existing mechanism realization such as buckle is fixed soon, and concrete structure does not detail here.
In conclusion, the invention can better control and realize the simulation of the soil body infiltration condition of the underground water; the simulation reduction of the soil body environment by the soil body freeze-thaw test is better assisted, and the simulation precision and the application range of the soil body freeze-thaw test are improved.
Drawings
Fig. 1 is a schematic structural diagram of a rock mass freeze-thaw cycle test system adopted in the specific embodiment.
Fig. 2 is a schematic structural view of the single underground water depth adjustment simulation apparatus in fig. 1.
Fig. 3 is a schematic structural view of the retaining wall up-and-down movement control mechanism in the side view of fig. 1.
Fig. 4 is a schematic structural view of the water deflector up-down movement control mechanism in the side view of fig. 1.
Fig. 5 is a schematic view of the structure of the single pressing device in fig. 1.
Detailed Description
Because the invention is used for realizing the simulation of underground water in the soil environment freeze-thaw simulation test, the invention is introduced by combining a ground-based concrete freeze-thaw cycle test method in the specific implementation mode. The invention is used in this method for the realization of a simulation of groundwater. The foundation concrete freeze-thaw cycle test method is introduced, so that the function and significance of the foundation concrete freeze-thaw cycle test method in the process of simulating underground water can be better embodied.
The present invention is described in further detail below in connection with a freeze-thaw cycle test method for ground concrete.
The specific implementation mode is as follows: a freeze-thaw cycle test method for foundation concrete is disclosed, wherein, a corresponding concrete test piece is prepared according to the performance requirement of the foundation concrete of a building to be tested, and the concrete test piece is fixed in a simulation box; simulating the soil condition of the construction environment of the foundation concrete of the building, and embedding the concrete test piece into a simulated soil material; simulating the actual infiltration condition of the foundation concrete of the building by using the infiltration water at the lower part of the simulation box; applying pressure to the concrete sample according to the pressure bearing size (which can be obtained by calculation) of the foundation concrete of the building to finish the preparation work; during the test, cold air is introduced and cooled until the infiltrated water body is frozen, after the test is maintained for a period of time, the frozen water body is heated by applying electric heating radiation on the concrete test piece to finish unfreezing, and the operation is repeated after the operation is continued for a period of time to form freeze-thaw cycle, until the freeze-thaw test time is over, the concrete test piece is taken out and the performance of the concrete test piece is tested, and compared with the same concrete test piece which is not tested, the performance change parameters of the foundation concrete of the building, which are influenced by the freeze-thaw environment, are obtained.
The test method better simulates the condition that the concrete structure of the building foundation is buried by the soil body and infiltrated by the underground water. Meanwhile, the test is carried out by simulating the freezing and thawing condition that the thawing is actually completed by cold air blowing at night and by solar illumination radiation in the daytime. The actual freezing and thawing situation of the foundation concrete of the building can be better simulated. The performance parameter change obtained by testing after the test can better reflect the influence of the actual freeze-thaw situation on the performance. The method can be better used for safety monitoring of concrete foundations of actual buildings or pre-construction safety performance evaluation. The safety of the building is improved.
During the test, the temperature of the test environment cooled by introducing cold air is determined by the lowest temperature of the foundation concrete of the building in spring and autumn.
In this way, the simulation is performed with the extreme environmental parameters, so that the test results can be better used for safety evaluation.
The temperature of the heating in the mode of electric heating radiation is determined by the highest temperature of the foundation concrete of the building in spring and autumn in the day and the local.
In this way, the simulation is carried out by using the limit environmental parameters, so that the test result can be better used for building safety assessment.
When the concrete test piece is prepared, the building foundation concrete to be tested is poured according to the same concrete formula to obtain the cylindrical test piece.
Therefore, the test result of the concrete test piece can better reflect the performance change condition of the actual freezing and melting influence of the foundation concrete of the building. The test reliability is improved.
In the experiment, the simulated soil body material is prepared by adopting broken stones, silt and clay materials and simulating the actual soil body condition around the foundation concrete of the building. Preferably, the actual soil around the foundation concrete of the building is directly excavated to obtain a simulated soil material, and the simulated soil material contains corresponding microorganisms, so that the influence effect of the rock mass microorganisms on the concrete can be kept consistent.
Therefore, the actual situation can be better simulated, and the test reliability is improved.
During the test, when the depth of the simulation box (which refers to the depth capable of being used for the test) is greater than the infiltration depth of the foundation concrete of the building to be tested under the groundwater, the infiltration depth of the lower part of the simulation box is consistent with the actual groundwater infiltration depth; when the depth of the simulation box (which refers to the depth capable of being used for testing) is less than the infiltration depth of the foundation concrete of the building to be tested by the underground water, the simulation box is closed, gas is introduced for pressurizing, and the water pressure at the bottom of the simulation box is detected to ensure that the water pressure is consistent with the actual water pressure (the actual water pressure value can be obtained through actual detection or calculation) at the lowest part of the foundation concrete of the building to be tested.
Therefore, when the infiltration depth of the foundation concrete of the building to be tested by the underground water is larger, the deeper underground water infiltration condition can be simulated by adopting a smaller simulation box, and the application range of the test is greatly improved. When a pressure applying mode is adopted for simulation test, the height of the concrete test piece can be set to be consistent with the testable depth of the simulation box, then the simulation soil body material is covered until the height of the simulation soil body material is consistent with the height of the concrete test piece, and then the lower part of the simulation box is infiltrated until 5-10cm of non-infiltrated soil body material is reserved above the simulation box, so that the actual condition that the concrete test piece is infiltrated by underground water can be well simulated.
Specifically, the one-time freeze-thaw cycle time is 24 hours, including 12 hours of freezing and 12 hours of thawing; the number of freeze-thaw cycles was set to 7, 15, 30, 60 or 90 times according to the study, corresponding to a period of 7, 15, 30, 60 or 90 days.
This is because it is generally difficult to react to a change for less than seven days. And if the time is more than 90 days, the time is too long, and the significance of the test is difficult to play. After the freeze-thaw test is completed within a limited time, the performance change condition of the concrete test piece can be obtained by detecting the performance parameters of the concrete test piece, and the performance change condition caused by more time of freeze-thaw action can be reasonably calculated so as to guide actual safety monitoring.
After the freeze-thaw test time is finished, taking out the concrete test piece, carrying out a uniaxial compression test or a triaxial compression test on the concrete test piece, testing the mechanical properties of the concrete test piece after the freeze-thaw cycle, including compressive strength and elastic modulus parameters, and comparing the mechanical property parameters of the concrete test piece which is not subjected to freeze-thaw to obtain the degradation degree of the mechanical properties of the foundation concrete of the building, which is influenced by the freeze-thaw environment.
In specific implementation, the test method is realized by means of a foundation concrete freeze-thaw cycle test system shown in fig. 1-5, the foundation concrete freeze-thaw cycle test system comprises a simulation box 1, an openable top cover 2 is arranged at the upper end of the simulation box 1, a test piece positioning device is arranged at the middle lower part in the simulation box 1, and a pressure device is also arranged above the positioning device in a facing manner; one side of the middle lower part of the side surface of one end of the simulation box is communicated with a water conveying pipeline 4 with a switch valve, the other end of the water conveying pipeline 4 is connected with a water storage box 5, and the bottom surface of the other end of the simulation box 1 is communicated downwards with a drainage pipeline 6 with a switch valve; the simulation box is characterized by further comprising a refrigeration evaporator 7 arranged at the upper part of the simulation box, wherein a built-in fan is arranged in the refrigeration evaporator 7, an air inlet and an air outlet which form internal circulation in the simulation box chamber are formed in the refrigeration evaporator 7, and the refrigeration evaporator 7 is connected with a compressor 8 externally arranged outside the simulation box to form a refrigeration circulation system; the electric heating tube 9 is fixed on the inner surface of the top cover of the simulation box; the simulation box also comprises a groundwater depth regulation simulation device for realizing groundwater depth regulation simulation in the simulation box.
Like this, among the above-mentioned device, the concrete test piece is conveniently fixed a position temporarily in order to do benefit to the simulation soil body and bury the setting by the dependence with test piece positioner, relies on the pressure device can exert pressure to the concrete test piece and simulate its actual pressurized condition, relies on water storage box water injection and drainage pipe drainage can conveniently pour into and discharge the groundwater of simulation, then relies on groundwater degree of depth to adjust analogue means control and adjust groundwater degree of depth and actual conditions unanimity. The simulation box is used for realizing the cooling and freezing of the interior of the simulation box by virtue of a refrigeration cycle system, and the electrothermal radiation thawing of the frozen and thawed soil is realized by virtue of the electrothermal tube, so that the actual working frozen and thawed conditions of the concrete foundation of the building can be better simulated. Therefore, the test system can be well used for the simulation test method, is simple, reliable and effective to operate, can better improve the test convenience degree and the simulation effect, and better improves the test result accuracy.
The test piece positioning device comprises a positioning ring 10 positioned in the middle, the inner diameter of the positioning ring 10 is larger than the outer diameter of the test piece by 1-10mm, and the periphery of the positioning ring is fixed on the inner side wall of the simulation box through a horizontally arranged fixing rod. Therefore, the structure is simple, and the test piece can be conveniently placed and positioned.
The pressing device comprises a pressing head 11 which is arranged above the positioning ring, the upper part of the pressing head 11 is connected with a hydraulic tank 12 through a telescopic pressing rod, the side surface of the hydraulic tank 12 is fixedly arranged on the inner side wall of the simulation box 1 through a supporting arm 13, and the hydraulic tank 12 is connected with a control oil tank 3 outside the simulation box through a hydraulic pipeline.
Like this, conveniently control the hydraulic tank through the control oil tank for the pressure head stretches out downwards and applys pressure to the concrete test piece of location in the locating ring, simulates its actual work atress condition.
Wherein, the lower surface of the pressure head 11 is provided with a test piece pressure detection sensor 14. The size of applying pressure to the concrete test piece is conveniently detected.
Wherein, the upper surface of the drainage pipeline is provided with a gauze. Thus, the silt can be prevented from leaking along with the water during drainage.
Wherein, 4 refrigeration evaporators are arranged at four corner positions at the top of the simulation box. This results in a more rapid and uniform cooling.
Wherein, the simulation box 1 is made of transparent materials. Thus, the test condition inside the simulation box can be conveniently observed.
Wherein, simulation case 1 at least one side is provided with vertical scale 15. Therefore, the underground water level condition is convenient to observe.
Wherein, groundwater depth control analogue means, including being located a water catch bowl 16 that simulation case side inboard that conduit place set up, water catch bowl 16 sets up along the whole length direction of the simulation case lateral wall at conduit place, and the water catch bowl upper surface height is not less than test piece positioner place height, and the water catch bowl sets up to removing barricade 17 to the barricade of one side of test piece positioner is whole, removes the barricade both sides and can slide ground joint cooperation from top to bottom in barricade spout 18, removes barricade 17 and a barricade vertical movement control mechanism and links to each other.
Therefore, when water is input into the water conveying pipeline to simulate underground water, the water can be conveyed into the water collecting tank firstly, and then the movable retaining wall is controlled to be integrally lifted to the preset underground water depth position, so that the water in the water collecting tank flows out from the position with the fixed height below the movable retaining wall to form the underground water. The groundwater simulation that realizes like this is convenient more reliable, and groundwater depth of water precision can control the accuracy better.
Wherein, the side of the movable retaining wall 17 facing the test piece positioning device is also sequentially and outwardly fixedly provided with a support grid 19 and sponge materials fixed on the support grid. Therefore, the effect that the sand and soil are isolated from entering the water collecting tank to influence the lifting control of the movable retaining wall but the water in the water collecting tank is not blocked from flowing outwards can be achieved. Meanwhile, the impact of the direct outflow water flow in the water collecting tank on the sand can be avoided to influence the test.
Wherein, barricade vertical movement control mechanism, including vertical fixing at the barricade rack 20 that removes barricade one side both ends position department, two barricade racks 20 respectively with one be located same level for the control gear 21 meshing of barricade, two for the control gear 21 fix on the barricade for the control pivot 22 that same level set up, barricade for the control pivot 22 both ends rotationally install on the simulation case and one end is worn out the simulation case and is provided with a barricade for the control rotatory handle 23.
Like this, can conveniently through rotating barricade control and with rotatory handle, through the meshing of barricade control with gear and barricade rack, drive and remove the barricade and reciprocate along the barricade spout. Simple structure and reliable and stable.
Wherein, the scale that the simulation case side set up is located the position that removes the barricade. Therefore, the numerical value of the height of the moving retaining wall lifted upwards can be visually seen, so that the underground water discharge depth can be conveniently and accurately controlled.
Wherein, groundwater depth control analogue means, including being located the simulation incasement keep away from conduit direction one side and with a breakwater 25 that this side parallel interval set up, but breakwater 25 both ends joint cooperation with sliding ground from top to bottom is in the breakwater spout 26 of simulation incasement lateral wall, and the simulation bottom of the case portion of breakwater 25 below is provided with a breakwater heavy groove 27 downwards, and breakwater 26 and a breakwater up-and-down motion control mechanism link to each other, breakwater up-and-down motion control mechanism can control the breakwater upwards to stretch out or retract breakwater heavy groove 27 downwards, and the breakwater upwards stretches out the back and forms a drainage chamber in the one side that deviates from the conduit direction, and drainage pipe sets up in the drainage chamber bottom surface.
Therefore, when the groundwater is simulated, the water baffle can be controlled to extend upwards to the depth position of the groundwater to be simulated (or slightly lower than the depth of the groundwater to be simulated by 1-5cm so as to offset the water level height of the part of the water baffle overflowing out of the test area). When the inlet water in the simulation box reaches the height of the water baffle, the inlet water can cross the water baffle to flow into the drainage cavity and be discharged from the drainage pipeline. Therefore, the underground water depth in the test area can be better ensured to meet the simulation requirement. In addition, the process shows that when the water baffle and the water baffle are used together, the outflow depth of water in the water collecting tank is controlled by the water baffle, the water is retained by the water baffle, the infiltration depth of the water in the test area can meet the requirement, and therefore accurate simulation of the depth of underground water can be better achieved. More specifically, in the process of the freeze-thaw cycle test, when the underground water is in a frozen state, the operation is simple, and only the water pipeline needs to be closed. However, when groundwater is in a thawing state, because a freezing and thawing area is usually in a mountain environment, groundwater is usually in a slow flowing underflow state after being thawed, when the water baffle and the water baffle wall are used together, the water baffle plate and the water baffle wall are controlled to extend out of the upper end of the water baffle plate to a certain distance (usually 1-5 cm) lower than the reserved spacing height (namely the depth of groundwater to be simulated) of the lower end of the water baffle wall, and meanwhile, water is supplied by opening a water pipeline according to the flow speed and the flow of actual underflow of groundwater to be simulated, so that the slow flowing underflow state of groundwater can be better simulated under the condition of ensuring that enough groundwater depth is maintained. Particularly, when the underground water simulation depth of the simulation box is not enough and the air pressure needs to be increased in the simulation box to increase the underground water simulation depth, the combination of the water retaining wall and the water retaining plate can better ensure that the water can still maintain the sufficient underground water depth and simulate a good undercurrent state under the condition of increasing the air pressure (water flow cannot be pressed away by high pressure); and meanwhile, the increased air pressure can better press the underground water in the area between the water baffle and the water baffle wall, so that a stronger water pressure effect can be better formed at the bottom of the test area, and the effect of increasing the simulated water depth by means of the air pressure is better realized. And when increasing atmospheric pressure in order to strengthen the simulation, can also close drainage pipe in order to avoid atmospheric pressure to produce when great and lose heart, also can rely on the drainage cavity regional retaining that the breakwater formed this moment, satisfy the undercurrent simulation demand in test area.
Wherein, one side of the water baffle 25 facing to the water pipeline is also sequentially and outwards fixedly provided with a support grid 28 and sponge materials fixed on the support grid.
Therefore, the effect of isolating sand from entering to influence the lifting control of the water baffle can be achieved, and the flow of water is not hindered. Meanwhile, the influence of the sand for the test on the test due to the washing away of the water flow can be avoided.
The up-and-down movement control mechanism for the water baffle comprises water baffle racks 29 which are vertically fixed at two ends of one side of the water baffle, the two water baffle racks 29 are respectively meshed with a gear 30 for controlling the water baffle at the same horizontal height, the two gears 30 for controlling the water baffle are fixed on a rotating shaft 31 for controlling the water baffle arranged at the same horizontal level, two ends of the rotating shaft 31 for controlling the water baffle are rotatably installed on a simulation box, and one end of the rotating shaft 31 penetrates out of the simulation box to be provided with a rotating handle 32 for controlling the water baffle.
Therefore, the rotating handle for controlling the water baffle can be conveniently rotated, and the water baffle is driven to move up and down along the water baffle sliding groove through the meshing of the gear for controlling the water baffle and the water baffle rack. Simple structure and reliable and stable.
Wherein, the side of the simulation box is provided with a graduated scale at the position of the water baffle. Therefore, the numerical value of the height of the water baffle lifted upwards can be visually seen, so that the depth of underground water can be conveniently and accurately controlled.
The groundwater depth adjusting and simulating device further comprises a sealing strip and a top cover pressing and sealing mechanism 35 which are installed between the top cover 2 and the box body 1 of the simulation box, a water pressure detection sensor (not shown in the figure) which is positioned at the bottom of the simulation box and an air pressure conveying pipeline 36 which is communicated with the simulation box, wherein the air pressure conveying pipeline is connected with an air compressor (not shown in the figure) outside the simulation box.
Like this, when the simulation case can simulate groundwater degree of depth not enough, can rely on sealing strip and top cap to compress tightly sealing mechanism and compress tightly the top cap, realize the sealed of simulation case, then input atmospheric pressure to the simulation incasement through aerostatic press and pneumatic conveying pipeline, under atmospheric pressure and hydraulic combined action, rely on the water pressure detection sensor of simulation bottom of the case portion to detect this place water pressure, make its and the building foundation concrete bottom of waiting to test actually receive groundwater water pressure unanimously, make it maintain and accomplish freeze-thaw cycle test under the water pressure condition unanimous with actual conditions, accomplish the simulation to deeper groundwater infiltration condition. The application range of the test is better expanded. The top cover pressing and sealing mechanism can be realized by the existing mechanisms such as bolt fixing or quick-connection buckle fixing, and the specific structure is not detailed here.
More specifically, when the test system is used for a specific test (taking the example that the depth of underground water meets the simulation depth of the simulation box), firstly, the top cover of the simulation box is opened, then, the prepared concrete test piece is positioned and erected in the simulation box by virtue of the test piece positioning device, the vertical positioning of the concrete test piece is maintained, and the pressure head is controlled to extend downwards and is pressed at the upper end of the concrete test piece until the detection pressure reaches the test pressure; and then, the simulated soil body material is poured into the simulation box until the periphery of the concrete test piece is buried. Then adjusting the water baffle to extend upwards from the water baffle sink tank to a depth 0-5cm lower than the preset water depth; and then opening a switch valve on the water conveying pipeline to inject water in the water storage tank into the water collection tank, controlling the movable retaining wall of the water collection tank to be lifted upwards until the lower end of the movable retaining wall is exposed to a preset water depth position, enabling the water in the water collection tank to flow out from the lower end of the movable retaining wall until the water flows over the water baffle and flows to the water conveying pipeline, closing the water conveying pipeline until the water level in the water collection tank drops to the height position of the lower port of the movable retaining wall, and then closing the water conveying pipeline. Controlling a refrigeration cycle system to start to refrigerate the inside of the simulation box, so that frozen soil is formed by the simulation soil body materials, and then maintaining the environment temperature in the simulation box to be the lowest temperature of the foundation concrete of the building in spring and autumn at night until the freezing time is finished (usually 12 hours); then closing the refrigeration cycle system, starting the electric heating tube for heating, so that the temperature in the simulation box rises for thawing, and maintaining the highest temperature of the temperature in the simulation box in the local spring and autumn of the foundation concrete of the building until the thawing time is finished (usually 12 hours); then repeating the freeze thawing cycle until the test days are over; the top cover of the simulation box can be opened, the concrete sample is taken out, the performance of the concrete sample is tested, and the performance change parameter characteristic is obtained.
Claims (10)
1. The underground water infiltration simulation control method for the rock-soil body environment simulation test is characterized in that one side of a simulation soil body in a simulation box test area is separated by a retaining wall capable of moving up and down to form an independent water collecting area, underground water simulation water is connected into the water collecting area, then the retaining wall is controlled to be lifted upwards until the lower end of the retaining wall is exposed to the interval of the required simulation underground water depth, and water is infiltrated and flows into the simulation soil body from the interval according to the exposed height size of the retaining wall to form the underground water simulation of the required depth.
2. The method for simulating and controlling the groundwater infiltration for the rock-soil body environment simulation test as claimed in claim 1, wherein when the depth of the simulation box for simulation is lower than the depth of the groundwater to be simulated, the simulation box is closed and gas is introduced to pressurize, and the water pressure at the bottom of the simulation box is detected to make the water pressure consistent with the depth pressure of the groundwater to be simulated, so as to realize deeper groundwater depth simulation.
3. The groundwater infiltration simulation control method for rock-soil body environment simulation test of claim 1, wherein the method relies on an groundwater depth adjustment simulator for realization, the groundwater depth adjustment simulator comprises a water collecting tank disposed at the inner side of the simulation box where the water pipeline is located, the water collecting tank is disposed along the whole length direction of the side wall of the simulation box where the water pipeline is located, the height of the upper surface of the water collecting tank is not lower than the height of the test piece positioning device, the whole retaining wall at the side of the water collecting tank facing the test piece positioning device is disposed as a movable retaining wall, the two sides of the movable retaining wall are slidably engaged with the retaining wall sliding groove, and the movable retaining wall is connected with a retaining wall up-and-down movement control mechanism.
4. The method for simulating and controlling the infiltration of groundwater for the simulation test of the rock-soil body environment according to claim 3, wherein the side of the movable retaining wall facing the test piece positioning device is further sequentially and outwardly fixedly provided with a support grid and sponge materials fixed on the support grid.
5. The groundwater simulation control method for a rock-soil body environment simulation test as claimed in claim 3, wherein the retaining wall vertical movement control mechanism comprises retaining wall racks vertically fixed at two ends of one side of the movable retaining wall, two retaining wall racks are respectively engaged with a retaining wall control gear at the same level, two retaining wall control gears are fixed on a retaining wall control rotating shaft arranged at the same level, two ends of the retaining wall control rotating shaft are rotatably mounted on the simulation box, and one end of the retaining wall control rotating shaft penetrates through the simulation box to be provided with a retaining wall control rotating handle.
6. The groundwater simulation control method for a rock-soil body environment simulation test as claimed in claim 3, wherein a scale is provided on a side surface of the simulation box at a position where the movable retaining wall is located.
7. The method as claimed in claim 3, further comprising a water guard plate disposed in the simulation chamber and spaced from and parallel to the water pipe, wherein two ends of the water guard plate are slidably engaged with the water guard plate slot of the inner side wall of the simulation chamber, a water guard plate slot is disposed at the bottom of the simulation chamber below the water guard plate, the water guard plate is connected to a water guard plate up-and-down movement control mechanism, the water guard plate up-and-down movement control mechanism can control the water guard plate to extend upward or retract downward, a water discharge cavity is formed at the side deviating from the water pipe after the water guard plate extends upward, and the water discharge pipeline is disposed at the bottom of the water discharge cavity. .
8. The method for simulating and controlling the infiltration of groundwater for use in a geotechnical body environment simulation test of claim 7, wherein the side of the water baffle facing the water pipe is further sequentially and outwardly fixedly provided with a support grid and a sponge material fixed on the support grid.
9. The underground water immersion simulation control method for rock-soil body environment simulation test according to claim 7, wherein the water baffle up-and-down movement control mechanism comprises water baffle racks vertically fixed at two ends of one side of the water baffle, the two water baffle racks are respectively engaged with a water baffle control gear at the same level, the two water baffle control gears are fixed on a water baffle control rotating shaft arranged at the same level, two ends of the water baffle control rotating shaft are rotatably mounted on the simulation box, and one end of the water baffle control rotating shaft penetrates through the simulation box and is provided with a water baffle control rotating handle;
and a graduated scale is arranged on the side surface of the simulation box at the position of the water baffle.
10. The method for controlling simulation of infiltration of groundwater for geotechnical body environment simulation test of claim 7, wherein the groundwater depth adjustment simulation device further comprises a sealing strip and a top cover pressing sealing mechanism installed between the top cover and the box body of the simulation box, a water pressure detection sensor located at the bottom of the simulation box and an air pressure transmission pipeline communicated with the simulation box, the air pressure transmission pipeline is connected with an air compressor outside the simulation box.
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN117109362A (en) * | 2023-10-20 | 2023-11-24 | 哈尔滨龙江特种装备有限公司 | Immersion environment simulation test device |
| CN117109362B (en) * | 2023-10-20 | 2024-01-09 | 哈尔滨龙江特种装备有限公司 | Immersion environment simulation test device |
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