203 results about "Wet dry cycle" patented technology

The invention discloses a construction method of a soft rock creep damage model, which belongs to the technical field of rock soil and comprises the following steps: S1, classifying soft rock creep damage and establishing various damage equations; s2, dividing the soft rock creep curve into a stable creep stage and an unstable creep stage, and constructing a viscoelastic element, a viscoplastic element and a creep model; s3, establishing creep equations of a stable creep stage and an unstable creep stage; and S4, establishing a three-dimensional creep damage model. The soft rock creep damage model constructed by the method can better represent the nonlinear creep characteristics of the soft rock under the dry-wet cycle effect, the physical significance of parameters is clear, and the influence rule of the dry-wet cycle times, the axial pressure and the time coupling effect on the soft rock creep damage can be accurately reflected.

The invention relates to a micro-nano aggregate based on silanized calcium sulfate whisker in-situ polymerization, the main component of the micro-nano aggregate is acrylate copolymerized CSW / NS-GO, and the preparation method comprises the following steps: loading nano silicon dioxide on the surface of calcium sulfate whisker to obtain CSW / NS; carrying out silanization modification on CSW / NS; preparing graphene oxide by a Hummers method; and carrying out in-situ polymerization to prepare the acrylate copolymerized CSW / NS-GO. Calcium sulfate whiskers are loaded and bonded with epoxy modified nano silicon dioxide and then subjected to in-situ polymerization with graphene oxide in an acrylic monomer, a polymer chain is tightly combined with a functional group of CSW / NS-GO, good interface bonding is formed, and the strength and toughness of the composite material are improved. The acrylate copolymerized CSW / NS-GO has a microscopic three-dimensional network structure and excellent stability, so that the internal structure of the concrete is more compact, the porosity is reduced, the permeation of water is prevented, and the invasion of harmful substances such as chloride ions and sulfate ions into channels is reduced, thereby reducing the structural damage caused by environmental factors such as dry-wet cycle and freeze-thaw cycle; the durability of the concrete is improved.

The invention relates to an iron tower foundation safety analysis method considering the dry-wet cycle effect. The method comprises the following steps that 1, a soil body strength degradation constitutive model is established; 2, determining iron tower foundation structure parameters and soil body parameters; 3, establishing an iron tower foundation-soil body three-dimensional geometric model by utilizing three-dimensional modeling software and rock-soil finite element simulation software; 4, applying a load transmitted to the iron tower foundation by the power transmission iron tower in the iron tower foundation-soil body three-dimensional geometric model, defining initial parameters, and establishing a rainwater seepage and dry-wet cycle coupling effect analysis model; 5, analyzing and predicting the cycle index when the safety coefficient of the iron tower foundation is reduced to a threshold value from the two aspects of tower foundation ultimate bearing performance and iron tower foundation-soil body interaction on the basis of a rainwater seepage and dry-wet cycle coupling effect analysis model; according to the method, an efficient and accurate numerical analysis means can be provided for safety assessment of the power transmission tower foundation in the collapsible loess area.

The invention discloses a structural plane ring shear creep test method under real-time water pressure rise and fall and dry-wet cycle action, which comprises the following steps: S1, applying shear stress step by step to a preset peak strength ratio by adopting a constant normal stress and shear stress graded loading mode; s2, under the working condition of loading each stage of shear stress, performing dry-wet cycle and / or water pressure rising and falling cycle operation synchronously; s3, based on test data, analyzing creep deformation characteristics, long-term strength and failure rules of the structural plane; the device synchronously simulates reservoir water level rising and falling and dry-wet circulation in a ring shear creep test, and can be applied to long-term stability prediction and control measure optimization design of reservoir bank rock slopes and other rock shear tests needing to simulate water pressure change and dry-wet circulation conditions.

The invention provides a water bank slope structural surface rock mass shear creep test system and method under a dry-wet cycle, relates to the technical field of rock mechanical property test, and aims to accurately reproduce a dry-wet cycle-stress coupling working condition of a rock mass structural surface under a complex environment. In the device, the direct shear apparatus comprises a loading frame and a loading and sliding device mounted on the frame, and provides a stable mechanical loading basis for a test; the shear box is used for accommodating a rock sample containing a structural surface, and the lower shear box adopts a lengthened design, so that the shear area in the whole shear process can be ensured to be constant; the dry-wet cycle environment simulation cabin is fixed in the loading frame, hermetically wraps the shear box and is integrated with a water soaking subsystem and a drying subsystem, the water soaking subsystem can adjust the water level height and water pressure in the simulation cabin, and the drying subsystem can dry a rock sample, can reproduce the sun illumination radiation condition and is matched with the water soaking subsystem to realize periodic dry-wet cycle; and the coupling effect of dry-wet cycle and mechanical loading is realized.

The invention relates to a deep excavation expansive soil side slope deformation failure mechanism simulation device and method, the device comprises a model box body, a side slope model, a dry-wet cycle simulation mechanism and a detection mechanism, one opposite surface of the top of the model box body is open, and a permeable module is arranged in the model box body; the slope model comprises a slope soil body arranged on the permeable module and a retaining wall provided with a first permeable area, the slope soil body is provided with a slope surface, and the retaining wall is arranged at the lowest point of the slope surface; the dry-wet cycle simulation mechanism comprises a reservoir, a support, a light source and a rainfall nozzle, the reservoir is provided with a second permeable area communicated with the permeable module, and the support is provided with the light source communicated with the reservoir and the rainfall nozzle; the detection mechanism comprises a sensor and a camera, and the sensor and the camera are used for collecting deformation data of the slope soil body. According to the method, the influence of atmospheric dry-wet circulation and underground water level change on the slope soil body is considered at the same time, and the deformation and failure mechanism of the deep excavation expansive soil slope in the whole process from excavation to operation is revealed more truly.

A use method of the test device for simulating ion erosion of the PCCP protective layer comprises the following steps: S1, region division: selecting a test object, and firstly dividing the test object into four regions, namely a region I, a region II, a region III and a region IV; dividing each subarea into three test areas, namely a test area A, a test area B and a test area C; s2, making a test plan: executing sulfate ion erosion comparison in a partition I, executing chloride ion erosion comparison in a partition II, executing protective measure comparison in a partition III, and executing a mixed comparison test in a partition IV; s3, making a comparison scheme; s4, making a dry-wet cycle scheme; s5, preparing test conditions; s6, liquid filling is executed; s7, executing a dry-wet cycle; s8, judging whether the dry-wet cycle needs to be ended or not: if Seq is equal to L, ending the dry-wet cycle, and continuing S9; otherwise, indicating that all times of dry-wet cycle treatment is not completed, and returning to S6; s9, extracting a sample; and S10, analyzing a result.

The invention discloses a method for modifying red clay by straw fiber composite ecological cement and application thereof. The straw fiber composite ecological cement modified red clay is prepared from air-dried red clay, ecological cement, straw fiber and water. The method comprises the following steps: a, obtaining straw fiber, ecological cement and red clay raw materials; b, testing to obtain the optimal moisture content, specific gravity and liquid-plastic limit index of the red clay; c, setting a plurality of orthogonal test proportions; d, matching the proportioned dry materials, adding a proper amount of water, braising the materials for 24 hours, uniformly stirring one part of the materials to prepare a standard cutting ring sample, and uniformly stirring the other part of the materials for a planting test; and e, performing a direct shear test, a penetration test, a fracture analysis test, a soil-water characteristic curve test and a plant growth test on the cutting ring sample after the dry-wet cycle. According to the method, the shear strength, permeability resistance and water stability of the red clay can be improved, deformation and crack development of the red clay are effectively prevented, and the modified red clay obtained through the method can be applied to channel slope construction.

The invention discloses a soil solidification effect detection and analysis system and method, and relates to the field of soil solidification effect detection.The soil solidification effect detection and analysis method comprises the steps that based on the sedimentation characteristics of a solidification material, soil is divided into a bottom sedimentation sudden change zone, a middle sedimentation gradual change zone and a top sedimentation stable zone in the depth direction, and the minimum operation thickness of a sampling tool serves as the reference layer thickness; dividing non-equidistant sampling layers according to different multiples in each settlement zone to intercept columnar soil samples; performing an initial dynamic load test on the original soil sample, then performing circulating saturated water drying treatment on the same soil sample, and applying the completely same dynamic load mode again; a water circulation effect in a natural environment is simulated by performing vacuum water saturation and constant-temperature drying circulation treatment on a soil sample for multiple times and combining a dynamic load test after water damage. Through non-equal-interval stratified sampling and multi-round dry-wet cycle testing, stratified dynamic and high-precision quantitative evaluation of the water damage resistance of soil solidification is achieved.

The invention relates to the technical field of concrete durability evaluation, in particular to a compound green concrete salt freezing resistance durability evaluation system under a frozen soil environment, which comprises a data input unit, a decision information table storage unit, a rough set analysis processing unit and an evaluation output unit, the data input unit receives a sample data set containing freeze-thaw cycle times, dry-wet cycle times, freeze-thaw-dry-wet cycle times, long-term soaking time, composite salt concentration, gas content and fly ash mixing amount, and the decision information table storage unit stores a decision information table constructed based on a rough set theory. The influence factor combination and the relative dynamic elastic modulus percentage are associated, the rough set analysis processing unit establishes a mapping relation through attribute reduction and rule extraction and quantifies the weight of each factor, and the evaluation output unit outputs a relative dynamic elastic modulus predicted value, durability grade classification and key factor contribution sorting. And the salt freezing resistance durability of the concrete under the multi-factor coupling effect is accurately evaluated.

The utility model relates to the technical field of water and soil conservation, and particularly discloses an ecological slope protection water and soil conservation device. Comprising grating blocks arranged on the surface of a soil layer of the ecological slope protection, the adjacent grating blocks are connected through mortise and tenon joint structures, and a plant protection area is formed in a central grating groove of each grating block; and the separating and positioning assembly is arranged in the soil layer on the lower side of the grating block, vertically penetrates through the slope protection floating soil layer and extends to the bearing layer. Through the arrangement of the grating blocks, the adjacent grating blocks are spliced through mortise and tenon joint structures, and an integral protective layer is formed on the surface soil layer of the ecological slope protection. And through the arrangement of the separating and positioning assemblies, the lower soil body can be divided into independent units, and the independent units are matched with the upper grating blocks to form a three-dimensional water and soil conservation frame, so that the overall stability of the slope protection is enhanced, and local water and soil loss and diffusion are prevented. The problems that a traditional slope protection structure is poor in synergistic protection effect and continuous water and soil conservation function, and interlayer slippage is likely to be generated under the long-term dry-wet cycle effect are solved.

The invention discloses a multi-scale research method for soil body strength degradation under the dry-wet cycle effect. The multi-scale research method comprises the following steps: S1, preparing a sample from collected test soil under the dry-wet cycle effect; s2, testing the macroscopic shear strength of the soil body by using the triaxial sample prepared in the step S1; s3, the cutting ring sample prepared in the step S1 is used for soil microcosmic fracture testing; s4, carrying out a soil body micro-pore test by utilizing the microstructure sample prepared in the step S1; and S5, analyzing the soil body strength degradation rule of the collected test soil under the dry-wet cycle action by using the test results of the soil body macroscopic shear strength test, the soil body microcosmic crack test and the soil body microcosmic pore test. According to the method, through multi-scale analysis, related enterprises can more comprehensively evaluate the degradation rule of the soil body under the dry-wet cycle effect, so that an engineering construction design scheme is optimized, and the risks of landslide, collapse and other engineering accidents caused by soil body strength reduction are reduced.

The invention provides a dangerous rock degradation and collapse simulation test system and method under a multi-field coupling effect, and the system comprises a flexible stress loading device which provides a vertical stress for a dangerous rock mass sample to enable the sample to have the same stress level as a natural state; a dangerous rock mass sample is used for simulating various collapse modes by controlling the angle of a soft belt and a hollowed-out area; the corrosion device is used for providing a dry-wet cycle and osmotic pressure environment for the dangerous rock mass sample; the data acquisition device is used for recording surface displacement, acoustic characteristics and external factors of the rock mass along the soft zone; the damage degree calculation device is used for calculating the damage degree of the dangerous rock mass under multi-field coupling; the safety coefficient calculation device is used for obtaining the safety coefficient of the dangerous rock mass under multi-field coupling; and the safety evaluation device is used for constructing an evaluation model and evaluating the safety state of the dangerous rock mass. According to the method, collapse simulation caused by degradation of the soft belt under the multi-field coupling effect is achieved, and the problems of early-stage safety evaluation and graded early warning of dangerous rock instability based on multi-index fusion are solved.

The invention provides a loess foundation dry-wet cycle settlement dynamic monitoring device and a using method thereof, and relates to the technical field of foundation settlement monitoring. The loess foundation dry-wet cycle settlement dynamic monitoring device comprises a first datum point, a liquid spraying assembly and a mounting base; the number of the first datum points and the number of the second datum points are both two, the two first datum points and the two second datum points are both fixed to the detected ground, and the two second datum points are located on the rear sides of the two first datum points. The mounting base and the liquid spraying assembly are both mounted on the ground, the liquid spraying assembly is composed of a mounting base, a mounting block, a liquid spraying pipe and an electric cylinder, the mounting base is fixed to the ground, the mounting block is slidably arranged on the mounting base, and the liquid spraying pipe is fixed to the right end face of the mounting block. According to the device, the two first datum points and the two second datum points are arranged and matched with the liquid spraying assembly, soil around the second datum points can be accurately wetted, foundation dry-wet cycle settlement monitoring is achieved, the monitoring range is effectively expanded, and a foundation is provided for comprehensively mastering the foundation settlement condition.

The invention provides a rockfill material crushing strength prediction method and system considering a stress-dry-wet cycle coupling effect. The method comprises the following steps: S1, obtaining multiple groups of rockfill material samples; s2, carrying out stress-dry-wet cycle coupling tests under different dry-wet cycle times N and different stresses P on each group of rockfill material samples; s3, performing a crushing test on each group of rockfill material samples subjected to the stress-dry-wet cycle coupling test; s4, constructing to obtain a rockfill material crushing strength prediction model considering the coupling influence of the stress and the number of dry-wet cycles; and S5, predicting the crushing strength of the rockfill material to be predicted under different dry-wet cycles and different stresses. According to the method, the coupling effect of stress and dry-wet circulation on the rockfill material in the actual environment of the rockfill dam is fully considered, so that the data more conforming to the crushing strength of the rockfill material can be predicted.

The invention relates to the technical field of environmental engineering, and discloses a reservoir area landslide accumulation body mechanical property analysis method and system based on dry-wet cycling, and the method comprises the steps: carrying out the simulation of the dry-wet cycling effect on a reservoir area landslide accumulation body; measuring the strength and deformation characteristics of the slide band soil with different water saturations; and analyzing macromechanical response and structural evolution characteristics of the slip band, and revealing a degradation mechanism of reservoir area water action on the strength of the slip band. According to the method, comprehensive research on the dynamic characteristics and the action mechanism of the landslide soil body in the reservoir area is achieved, a scientific basis is provided for landslide instability risk assessment through fine water level regulation and control, mechanical monitoring, pore structure analysis, macroscopic response assessment and decision support, and effective prevention and treatment work is promoted.

The invention relates to a bridge sling dry-wet cycle accelerated corrosion test device and test method under the stretch-bending coupling effect in the technical field of bridge component testing. The device comprises a sealing box, a support is arranged in the sealing box, baffles are arranged on the two sides of the support, a plurality of spray heads are arranged on the support, and the spray heads are connected with a corrosive liquid box through a pipeline and a conveying pump; a plurality of bent pipelines for placing bridge sling test pieces are arranged in the sealing box, a plurality of through holes are circumferentially formed in the middle of each bent pipeline to communicate the inside and the outside of the bent pipeline, and connecting plates at two ends of each bent pipeline are fixed on baffles; when the bridge sling test piece is placed in the bent pipeline, one end of the bridge sling test piece is relatively fixed with the baffle through the fixing piece, and the other end is connected with the tension stretching mechanism. According to the device, the corrosion working condition of the bridge sling under the stretch-bend coupling action is simulated through an artificial accelerated corrosion test, so that the corrosion resistance of a bridge sling test piece is more comprehensively evaluated, and the device has important practical application value.

The utility model relates to a testing device for simulating a dry-wet cycle of pavement concrete in a gobi environment, and belongs to the technical field of dry-wet cycle simulation devices. Aiming at the problem of complicated operation of the concrete dry-wet cycle experiment in the gobi environment at present, a partition plate and a hollow bracket are arranged in a box body, the box body is divided into an upper cavity and a lower cavity by the partition plate, the hollow bracket is positioned above the partition plate, a connecting channel is arranged on the partition plate, and an electromagnetic valve is mounted on the connecting channel; the upper cavity and the lower cavity are communicated with each other; a feeder, a water circulation mechanism, a wind generation mechanism and a timing controller are arranged outside the box body, the feeder is located at the top of the box body, a sealing door is arranged on the front side of the box body, the water circulation mechanism is communicated with the interior of the box body, the wind generation mechanism is communicated with the upper cavity, and the timing controller is electrically connected with the water circulation mechanism, the wind generation mechanism and the electromagnetic valve. The device can meet the requirements of various dry-wet cycle conditions, and the operation difficulty of testers is greatly reduced.

The invention relates to the technical field of high polymer materials, in particular to a single-component polyurethane grouting reinforcement material as well as a preparation method and application thereof. According to the reinforcement material, polymethylene polyphenyl polyisocyanate, epoxy resin, low-functionality polyether polyol, high-functionality polyether polyol and polyester polyol are mainly used as raw materials, the adding proportion of all the raw materials is adjusted in a targeted mode, and the prepared single-component polyurethane grouting reinforcement material permeates into a permafrost region roadbed structure; the permeable material-soil stone body formed by chemical reaction with roadbed moisture has the properties of high strength and toughness, good freeze-thaw resistance, good dry-wet cycle property and low heat release. According to the formula system, the contradiction between high strength and low heat release in the traditional technology is successfully solved through the fine matching and synergistic effect of all the components, and an unexpected technical effect is achieved.

The utility model provides a pre-stressed anchor cable axial force loss and anchoring force deterioration test device under dry-wet cycle, which comprises a test water tank for accommodating a standard rock mass test block; the water injection and drainage device is arranged on the test water tank and used for controlling water level change in the water tank; the anchoring structure is composed of an anchor cable implanted into a preset hole channel of the rock mass test block and a grouting body poured between the preset hole channel and the anchor cable; the strain gauges are arranged at intervals in the axial direction of the anchoring section of the anchor cable; the pressure gauge is sleeved on the anchor cable; the plurality of hygrometers are buried in the grouting body; the strain gauges, the hygrometer and the pressure meter are connected with the data acquisition instrument through cables; and the heating assembly is arranged in the rock mass test block and the test water tank and is used for simulating a temperature change environment. According to the invention, the simulation of the dry-wet cycle working environment of the rock mass test block is realized, the drying process of the rock mass test block is accelerated through the heating assembly, the test time consumption is shortened, meanwhile, the hygrometer is matched to accurately control the dry-wet index of the test sample, and the accurate and controllable test variable is realized.

The invention discloses a chitin-silicon-calcium-based modified material for rammed earth wall repair and a weather resistance evaluation method thereof, and belongs to the technical field of rammed earth wall repair, the chitin-silicon-calcium-based modified material comprises metakaolin, calcium oxide, quartz and chitin; the ratio of chitin to metakaolin to calcium oxide to quartz is 1: 1: 2: 4; the method comprises the following steps: pre-treating at the earlier stage of a test, evaluating freeze-thaw cycle performance, evaluating dry-wet cycle performance, evaluating salt corrosion resistance, analyzing association between a microstructure and a strength performance, and finally, revealing a material degradation rule and mechanism by combining scanning electron microscope observation, unconfined compressive strength test and crack rate analysis. When the freezing and thawing cycle number N is less than or equal to 5, the dry and wet cycle number I is less than or equal to 9, and the salt solution concentration c is less than or equal to 0.3 mol / L, the characteristics of freezing and thawing resistance, dry and wet resistance, salt erosion resistance and the like of the modified material are obviously improved; after the modified material is added, internal pores of plain soil can be filled, unconfined compressive strength of a soil body is enhanced, and long-term durability of the soil body is improved.

The invention relates to an unsaturated soil pile foundation bearing characteristic model test device and method under a dry-wet cycle, and the device comprises a model box which is filled with model soil; the dry-wet circulation system comprises a drying system and a humidifying system, the drying system and the humidifying system are used for controlling drying and humidifying of the model soil respectively and used for simulating multiple dry-wet circulation working conditions, and at least one of dry-wet circulation paths, dry-wet circulation duration and dry-wet circulation times of any two dry-wet circulation working conditions is different; the model pile is inserted into the model soil; the loading device is fixed through a test reaction frame and is used for providing a vertical load for the pile sinking penetration and static load test of the model pile; and the data acquisition system comprises multiple types of sensors, and each sensor is arranged in the model soil or on the model pile. Compared with the prior art, the device can directly simulate the influence of the dry-wet cycle effect on the pile sinking, bearing and deformation characteristics of the pile foundation in the unsaturated soil in actual engineering, and is suitable for a large-scale model test with a relatively large soil layer thickness.

The invention discloses a geotechnical test device and method for simulating different construction rates and dry-wet cycle changes, and relates to the technical field of geotechnical tests.The geotechnical test device comprises a microcomputer processing system, a sample loading, fixing and reading device and a water injection and pumping device. The method comprises the following steps: (1) after a foundation pit is excavated to a certain depth, excavation is suspended or a lower foundation structure is constructed, the surrounding underground water level changes greatly; (2) the surrounding underground water level is greatly changed in the excavation process of foundation pits with different depths and the construction process of a lower foundation structure; (3) in the excavation process of the foundation pits with different depths and the construction process of the lower foundation structure, the construction speeds are different, and the surrounding underground water level is basically stable; (4) in the excavation process of foundation pits with different depths and the construction process of a lower foundation structure, the construction rates are different, and the surrounding underground water level changes drastically, according to the method, through sequential superposition of the change factors of the foundation pit depth, the construction rates and the underground water level, the influence mode of all the factors on foundation soil deformation is judged according to the test result.

The invention discloses a method and equipment for weathering and digesting gravel based on dry-wet circulation, and belongs to the technical field of degraded sand field planting and ecological remediation, the equipment comprises a mounting seat, a liquid storage tank is mounted at the top of the mounting seat, the liquid storage tank is communicated with an equipment box through a pipeline, a pump body is arranged in the equipment box, and the pump body is communicated with a plurality of liquid outlets through pipelines; and the liquid outlet is communicated with a nozzle main body. According to the device, through the designed driving mechanism, an output shaft of a driving motor rotates to drive a driving gear to rotate, the driving gear rotates to drive a driven gear to rotate, the driven gear can drive a bottom equipment box to rotate through a shaft body, and a first electric push rod can drive a moving ring to move when working and extending; the movable ring moves to drive the range adjusting mechanism on the peripheral side to move, the radial spraying range of the range adjusting mechanism and the nozzle body can be controlled, the equipment can achieve accurate spraying control over dry-wet circulation according to different soil and climate conditions, and the spraying treatment effect is improved.

This invention discloses a concrete mix design and manufacturing method for underground engineering concrete in a coupled environment of underground environment and load, relating to the field of underground engineering concrete technology. It aims to address the problem that traditional concrete mix design does not fully consider the coupling effect of underground environment and load. The underground environment includes groundwater erosion, wet-dry cycle, and temperature fluctuation; the load includes stress ratio. α s Dynamic load frequency and dynamic load amplitude α d This leads to technical problems such as insufficient erosion resistance, crack resistance, and mechanical stability of concrete, resulting in a short service life. This mix design is based on quantitative analysis of coupled environmental parameters. With cement, composite admixtures, recycled aggregates, modifiers, water, and additives as core components, the basic mix proportion is determined through a mapping model between "environment-load" coupled parameters and component content. The target mix proportion is then obtained through orthogonal experimental optimization. The manufacturing method includes four core steps: raw material pretreatment, graded mixing, gradient curing, and coupled environmental simulation curing.

The application discloses a kind of equipment for studying the stability of MICP mineralization product under dry-wet-freeze-thaw cycle, comprising: soil column test unit, refrigeration cycle system, heating cycle system, temperature monitoring system and water injection unit;Soil column test unit includes temperature guide plate, soil column sample cylinder, heat preservation layer and water permeable plate;Refrigeration cycle system includes refrigeration device, cooling liquid inlet pipe and cooling liquid outlet pipe;Heating cycle system includes heating device, hot liquid inlet pipe and hot liquid outlet pipe;Temperature monitoring system includes temperature sensor and data acquisition equipment;Water injection unit includes water storage tank and peristaltic pump;Soil column sample cylinder is also provided with water outlet for discharging water in soil column sample cylinder.The equipment can simulate the dry-wet and freeze-thaw cycle environment of soil column sample, obtain the stability parameters of soil column sample under the action of dry-wet cycle and freeze-thaw cycle alone or coupling, and evaluate the stability effect of MICP technology in repairing heavy metal pollution, providing theoretical and practical basis.

The invention belongs to the field of inorganic mineral functional materials, and provides a pH-responsive tannic acid / attapulgite composite microsphere and a preparation method thereof. According to the preparation method, the design that epoxy silane grafted attapulgite and tannic acid are subjected to ring opening on epoxy groups through phenolic hydroxyl groups to form C-O-C covalent bond anchoring is adopted, and then spray drying and balling are performed to prepare the composite microspheres, so that low-viscosity atomized processing, controllable particle size balling and excellent mechanical stability and dry-wet cycle stability under the high-solid-content feeding condition are realized; the prepared inorganic mineral-polyphenol composite particles have high processability and mechanical stability and pH response water absorption performance, the problems that traditional inorganic mineral-polyphenol composite particles are difficult to give consideration to coupling contradiction between processability and mechanical stability and performance consistency is insufficient during metal coordination treatment are solved, and the inorganic mineral-polyphenol composite particles have wide application value in the fields of intelligent adsorption materials, environment response type functional fillers and the like.

This invention discloses a flexible wall device and method for measuring the gas permeability and diffusion coefficients of unsaturated soil. It mainly consists of a gas washing device, a confining pressure-volume change system, a wet-dry cycle control system, and a gas measuring device. The wet-dry cycle control system includes a humidity controller and valves. The gas measuring device includes a top cover, a cylindrical wall, a base, an upper cavity, and a lower cavity. The top cover, cylindrical wall, and base are connected by bolts and nuts. The base outlet is connected to the gas washing device, a gas supply device, the wet-dry cycle control system, and the gas measuring device. From bottom to top, the lower cavity, the sample, the upper cavity, and the control rod are arranged between the base and the top cover. This device offers high precision, overcoming the measurement errors of gas permeability and diffusion coefficients caused by the sidewall dominant flow in rigid wall permeameters. It can measure the gas permeability, diffusion coefficient, and volume change of samples under wet-dry cycles and different stress conditions, providing a reliable measurement tool and method for assessing gas migration in unsaturated soil.

The utility model discloses a coarse-grained soil dry-wet cycle shear testing machine which comprises a test bed, a sliding rail is arranged at the upper end of the test bed, a detachable lower shear box is connected to the sliding rail in a sliding mode, an upper shear ring is arranged at the upper end of the lower shear box, and a horizontal servo electric cylinder is installed at the end, located at the sliding rail, of the test bed. The horizontal servo electric cylinder is provided with a horizontal load sensor, the horizontal load sensor is provided with a push-pull shaft, and the test bench is provided with a displacement sensor at the other end of the slide rail; the upper end of the test bed is connected with a mounting frame, a vertical servo electric cylinder is downwards mounted on the mounting frame, a vertical load sensor is downwards arranged on the vertical servo electric cylinder, a rotating motor is arranged at the lower end of the vertical load sensor, and the test bed further comprises a pressing disc and a rotating disc which are detachably connected with the rotating motor. A plurality of hollow stirring rods with holes are arranged at the lower end of the rotating disc. When the coarse-grained soil is subjected to dry-wet cyclic shearing, a sample does not need to be taken out, and the sample can be saturated by directly stirring and injecting water, so that the experiment efficiency is effectively improved.

The invention discloses a test device for simulating long-term durability of a grouting material under the action of a complex coupling environment, the device comprises a test box body, a steel spring plate, a ventilation system and a water circulation system, the test box body comprises a box body, a box cover, an observation window and a pedestal; the ventilation system comprises an air inlet, an air outlet, a hot air pump and a ventilation pipe; the water circulation system comprises an upper water injection port, a lower water outlet, an impermeability test water injection port, a hydraulic pump, a hydraulic pressure gauge and a water pipe. The device can simulate that the grouting material is in a complex environmental condition of dry-wet cycle, load (one-way or two-way), hydrostatic pressure and coupling effect of three factors, and can also be used for an anti-permeability test, a corrosion resistance test and a dynamic water test of a cubic grouting material test block. By assembling common materials and equipment, the effect of simulating the actual occurrence condition after the grouting material is solidified is achieved, and the device is suitable for simulating the situation of long-term action of loads and complex environmental conditions, and is particularly suitable for long-period durability tests with monthly and annual as time units.