20 results about "Permeability coefficient" patented technology

Provided herein is a magnetic permeability measuring method including measuring a measured permeability coefficient of the magnetic material using a measuring probe; setting an analysis model corresponding to a measurement condition, and calculating, using finite element analysis, a calculated permeability coefficient of the magnetic material in the analysis model and the magnetic permeability of the magnetic material corresponding to the calculated permeability coefficient; acquiring a first set including a plurality of pairs of real-parts and imaginary-parts of the magnetic permeability corresponding to a real-part of the calculated permeability coefficient that matches a real-part of the measured permeability coefficient; acquiring a second set including a plurality of pairs of real-parts and imaginary-parts of the magnetic permeability corresponding to an imaginary-part of the calculated permeability coefficient that matches an imaginary-part of the measured permeability coefficient; and determining the magnetic permeability whose real-part and imaginary-part match in the first and second sets.

The present application relates to the technical field of sealing material testing, and specifically discloses a system and method for testing the air tightness and deformation performance of sealing materials under crack lapping, which comprises a gas pressure adjusting module, a sealing box module, a temperature environment control cabin and a monitoring module. The monitoring module is used to collect data such as the temperature, pressure, volume and deformation of the sample of each component. The collected data can be used to calculate the intrinsic permeability coefficient of the sealing material sample, the displacement deformation when the crack is lapped, the puncture failure pressure and the permeability coefficient when the crack is lapped. The sample pad component in the system is an important part of the sealing box module. It can simulate the size and shape of the crack lapped with the sealing material according to the need. In combination with the gas pressure adjusting module and the monitoring module, the system can realize the testing of the permeability, deformation and puncture failure resistance performance of the sealing material under various working conditions.

This invention relates to a sensor-based method for determining the flushing timing of permeable asphalt pavements. The method includes: preparing asphalt mixture specimens; testing the capacitance value of the specimens using a planar capacitance sensor; testing the permeability coefficient of the specimens; conducting multiple in-situ clogging tests; testing the capacitance value and permeability coefficient of the specimens after the clogging tests; correcting the permeability coefficient and calculating the degree of clogging after each set of tests; finally, fitting the relationship between the degree of clogging and the capacitance value, optimizing and establishing a fitting formula suitable for actual conditions, and then detecting actual permeable asphalt pavements. Based on the clogging degree standard, a flushing timing decision is made for the permeable asphalt pavement. This invention allows the actual pavement capacitance value obtained by a planar capacitance sensor to be converted into the corresponding degree of clogging through a fitting formula, achieving non-destructive continuous detection of the clogging state of asphalt pavements, improving pavement detection efficiency, and having significant implications for determining the flushing timing of permeable asphalt pavements.

This invention discloses an analytical method for micro-water testing and permeability coefficient inversion considering a finite-thickness negative thin-walled layer and the non-Darcy effect within the layer. A mathematical model for micro-water testing considering the finite-thickness negative thin-walled layer and the non-Darcy effect within the layer is constructed. Based on the radial dual-zone medium assumption, seepage within the negative thin-walled layer is generalized as Forchheimer-type seepage, while seepage within the aquifer is linear Darcy flow. The Laplace transform and Brady method are introduced to handle the nonlinear terms, and the well water level is derived. H ( t Semi-analytical solutions in semi-infinite and finite domains. During parameter inversion, high-frequency, high-precision water level gauges deployed in the test well are used to collect water level response data after excitation, generating... H Follow t The permeability coefficients of the negative thin-walled layer and the aquifer are calculated simultaneously by comparing the measured curves with the standard curves and then performing inversion calculations. K i This invention is the first to achieve simultaneous inversion of the permeability coefficients of negative thin-walled layers and aquifers, and significantly improves the efficiency of permeability coefficient measurement in micro-water tests. K i The accuracy of the value.

The application discloses a micro water test model analysis and permeability coefficient value inversion calculation method based on a nonlinear seepage theory, establishes a complete well micro water test analysis model of a confined aquifer which can explicitly describe the influence of the global non-Darcy effect in the aquifer, adopts a Forchheimer equation to describe a nonlinear seepage field, processes the nonlinear term by using a Laplace transform and a Brady method, and realizes accurate solution of well water level H(t) by using a Talbot algorithm for numerical inversion. High-frequency and high-precision water level pressure sensors arranged in a test well and at different observation points are used to collect and record water level distribution of an initial background seepage field and water level response data after a micro water test is excited, so that the seepage state of the seepage field in the aquifer is determined. In the inversion process of the permeability coefficient value of the aquifer, a change rule curve of the well water level H with time t is generated based on the water level response data of the test well, and the permeability coefficient K value of the aquifer is inverted by comparing the fitting of the measured value with a standard curve.

The application discloses a method for predicting the characteristics of a slurry membrane closed gas and stratum deformation of a shield with pressure opening, and belongs to the technical field of tunnel engineering. Based on the Biot poroelasticity mechanics framework, a fluid-solid coupling simulation model of a slurry membrane-soil composite system is established, the dispersing effect of high-pressure gas on interstitial water is characterized by a water holding capacity function, and the whole process of gas breaking through the slurry membrane and seeping to the ground surface and the stratum deformation response are reproduced. By preparing slurry and collecting stratum samples, the porosity, density, permeability coefficient, elastic modulus, Poisson's ratio and soil water characteristic curve parameters are obtained through permeation, triaxial, water holding capacity and other tests, and the test parameters are assigned to a geometric model established according to the engineering burial depth, shield diameter and underground water level; under the boundary conditions of setting the initial displacement of self-weight, the pore water pressure distribution of the underground water level and the transition of the excavation face from slurry support to gas pressure support, numerical calculation is carried out under different gas pressures, slurry membrane thicknesses, burial depths and underground water levels, and the high-pressure gas seepage path and stratum deformation are predicted. The technology can reveal the failure mechanism of the slurry membrane closed gas performance and the development law of the stratum deformation, and provides a theoretical basis and technical support for the support gas pressure design of the shield with pressure opening.

This utility model relates to the field of testing equipment technology, specifically a simple testing device for the permeability coefficient of fractured media. The testing device provided by this utility model includes a two-dimensional test chamber for containing fractured media and the inflow of water. A water valve is located at the bottom of the two-dimensional test chamber for collecting outflow flow data. It also includes an overflow tank located on one side of the top of the two-dimensional test chamber, test pieces distributed on both sides of the two-dimensional test chamber, and a support component for supporting the bottom of the two-dimensional test chamber. It records outflow flow data, top head data, and pressure head data on both sides, and calculates the permeability coefficient at different heights on both sides of the medium using Darcy's law. This invention uses a simple and low-cost two-dimensional testing device that can simultaneously achieve constant head control, automatic multi-point head monitoring, and simple analysis of fracture distribution, meeting the rapid diagnostic needs of engineering scenarios such as slope stability assessment and tailings dam seepage prevention detection.

This invention relates to the field of water conservancy engineering technology, and in particular to a method, apparatus, electronic device, and medium for inverting the permeability coefficient of a rockfill dam with a concrete panel. The method includes: acquiring the dam construction material parameters and seepage prevention structure of the rockfill dam with a concrete panel, and constructing a three-dimensional steady-state seepage model; generating a permeability coefficient-permeability behavior dataset through Latin hypercube sampling, and optimizing the SSA-XGBoost surrogate model to meet the preset accuracy; based on the optimized surrogate model, obtaining the optimal permeability coefficient Pareto solution set through hybrid multi-objective optimization, and then combining it with the three-dimensional seepage model to complete the current permeability behavior assessment of the dam body. This solves the problems of low accuracy and computational efficiency of inversion results in related technologies, and improves the inversion efficiency and accuracy.

The application discloses a reef underground fresh water lens model test calcareous sand permeability coefficient prediction method and system, belongs to the technical field of coral reef island fresh water lens model test, and comprises the following steps: determining a geometric similarity ratio according to the geometric scales of a prototype and a model; deriving a permeability coefficient similarity ratio based on dimension analysis, and determining a target permeability coefficient of the model; constructing a multi-parameter coupling prediction model with effective particle size, uneven coefficient and porosity as inputs; obtaining grading parameters and permeability coefficients of different proportioning calcareous sand samples through orthogonal test, and solving undetermined coefficients of the model; and determining a model calcareous sand proportioning scheme according to the target permeability coefficient and the calibrated prediction model. The application establishes a permeation similarity criterion, constructs a three-time correction prediction model considering the double-pore structure of calcareous sand, realizes directional control of the permeability coefficient, and solves the problems of imperfect similarity design and unreasonable material substitution in the prior art.

This invention discloses an experimental device, experimental method, and measurement and calculation method for hydrogeological parameters of underground reservoirs, including water holding capacity, storage coefficient, water yield, and permeability coefficient. It belongs to the fields of hydrological laboratory testing technology and geotechnical testing measurement technology. The device includes: a support platform; a test cylinder housed within the support platform; a pressure end and an upper permeable plate arranged sequentially from top to bottom at the upper end of the test cylinder; an axial pressure machine positioned between the pressure end and the support platform; a test sample placed between the upper and lower permeable plates; strain gauges installed on the axial pressure machine; an inlet tank and an outlet tank; the inlet tank having a main inlet pipe section equipped with a constant pressure inlet pump; and upper and lower outlet pipe sections converging at the main outlet pipe section, the other end of which is connected to the outlet tank. This invention can measure hydrogeological parameters such as water holding capacity, water yield, and permeability coefficient of a sample, saving on experimental instruments, space, manpower, and testing time.

This invention provides a seepage experimental apparatus for a layered low-permeability system and a method for in-situ determination of permeability coefficient, relating to the field of layered media seepage technology. The seepage experimental apparatus for a layered low-permeability system includes: a fixing unit, a pressure stabilizing unit, an overflow unit, a monitoring unit, and a data acquisition unit. The fixing unit includes a side-confining column and several independent sub-settling devices. Each independent sub-settling device includes a settling plate, a rotating shaft, and a settling rod. The settling plate includes several settling plate blades, which are stacked and engaged on the rotating shaft and can rotate independently around the shaft. One end of the settling rod is connected to the rotating shaft, and the settling plate, along with one end of the settling rod, is inserted into the interior of the side-confining column. The other end of the settling rod extends beyond the top of the side-confining column. The seepage experimental apparatus for a layered low-permeability system provided by this invention can easily achieve in-situ acquisition of the permeability coefficient of each layer of a layered low-permeability medium and long-term, continuous, and high-precision monitoring of seepage flow.

This invention discloses a method and system for determining the hydraulic parameters of an aquifer based on pumping tests, relating to the field of formation detection technology. The method includes: conducting pumping tests based on pumping wells in a target area, recording test parameters at various time points during the pumping test, including the static water level of the pumping well, pumping flow rate, wellbore water level changes, and pumping time; the pumping well penetrating the aquifer; constructing a mathematical model for the pumping test considering the decrease in aquifer permeability coefficient with depth based on the test parameters at each time point; deriving an analytical solution to the mathematical model of the pumping test using the Green's function method, obtaining an analytical formula; constructing an optimization model based on pressure data collected by sensors at different depths of the pumping well during the pumping test; and inverting the hydraulic parameters of the aquifer based on the analytical formula and the optimization model to obtain the hydraulic parameters of the aquifer. This invention improves the accuracy of monitoring data.

The application discloses a tunnel fault fracture zone seepage parameter determination method based on a double medium model, which comprises the following steps: 1, according to the seepage characteristics of the tunnel water-rich fault fracture zone, a double medium model in a continuous medium model is used to determine the fracture zone seepage parameter; 2, the double medium model is modified to build a modified double medium model of the tunnel fault fracture zone seepage basic model; 3, the permeability coefficient of the modified double medium model system is determined; the method can effectively determine the seepage parameter by dividing the rock mass and the fracture into a matrix system and a fracture system respectively, the matrix system and the fracture system respectively obeying the matrix flow of the Darcy law and the non-Darcy law seepage of the Forchheimer binomial equation, establishing the double medium seepage model, and has the characteristics of good robustness of the calculation result, accurate and true description of the seepage condition of the fault fracture zone geology, early warning and prevention and control effect on the fault fracture zone geological disaster.

This invention provides a pumping device and a method for calculating the permeability coefficient. The pumping device includes a packing system, a pumping control system, a sealing system, and an observation system. The packing system includes an upper packer, a lower packer, and a packer pressurization device. The pumping control system includes terminal equipment and a variable frequency pump. The outlet of the variable frequency pump is connected to the ground via an outlet pipe. The sealing system includes a lower conversion chamber, an upper conversion chamber, a connecting pipe, and a sealing device. The observation system is used to collect first pressure data of the test layer, second pressure data of the upper part of the test layer, and flow rate data of the outlet pipe. The test layer is located between the upper and lower packers. The terminal equipment is connected to the observation system and the variable frequency pump, respectively, and is used to control the variable frequency pump to pump water based on the first pressure data and to calculate the permeability coefficient based on the relevant data. This invention is applicable to multi-layer aquifer testing and improves the accuracy of permeability coefficient calculation.

This invention discloses a high-precision intelligent detection method and system for well casing permeability coefficient, relating to the field of well casing engineering performance testing technology. The invention includes the following steps: deploying a detection component on the target well casing and using the detection component to collect monitoring data of the target well casing; pre-setting two location frames, and activating a pre-set mapping disk with the monitoring data through the location frames based on a preset acquisition cycle to obtain a layout disk; this invention transmits only the layout disk through the transmission channel, rather than transmitting specific numerical values, thereby achieving lightweight transmission while avoiding data inaccuracies caused by signal interference during transmission, ensuring the accuracy of the monitoring data; by inputting accurate monitoring data into the well casing permeability coefficient calculation model, the accuracy of the target well casing's permeability coefficient can be ensured.

The application provides a geotechnical bag dynamic construction process simulation method, and belongs to the technical field of hydraulic engineering. The method comprises the following steps: based on the topological structure of the geotechnical bag, a geotechnical bag construction process simulation model is constructed; a periodic slurry generation boundary is set to construct a calculation background network, a full-coupling simulation is performed to obtain a filling process simulation result, and the periodic slurry generation boundary is deleted; according to actual engineering conditions, the initial porosity and permeability coefficient of solid particles are obtained and updated to obtain a dynamic consolidation process simulation result; three-dimensional coordinate data of the bag particles are collected, surface reconstruction is used to obtain bag shape and tensile stress data, and the tensile strength margin is quantified to obtain geotechnical bag dynamic construction process simulation quantitative results. The application solves the problems that the existing geotechnical bag construction process simulation cannot determine the single filling height that the bag can withstand, the final shape and thickness distribution of the bag, and the problems of generated quality and engineering safety.

The application discloses an intelligent drainage control system based on environment perception, and relates to the technical field of intelligent control, which comprises a construction module, a calculation module and a control module, the construction module calculates the permeability coefficient, sets the drainage working condition, and constructs the corresponding relationship between the drainage working condition and the drainage parameter, the calculation module sets the equipment parameter and sends the drainage instruction, the control module regulates and controls the equipment parameter, and the execution time of the regulation and control is optimized based on the ant colony algorithm. The application dynamically calculates the permeability coefficient by real-time sensing of the environmental parameter, intelligently sets the current optimal drainage working condition, introduces the fluid mechanical energy conservation equation, reversely solves the required water pump lift, flow, power and other key equipment parameters after the drainage working condition is determined, realizes on-demand energy supply, applies the ant colony algorithm to the drainage regulation and control timing optimization, regards each regulation and control action as a path selection problem, and iteratively optimizes through the pheromone mechanism.

This application discloses a method and system for shield tunneling under reservoir water level control, relating to the interdisciplinary fields of urban underground engineering and water conservancy safety. The method includes: before the shield enters the reservoir's influence zone, the reservoir water level is controlled to a dead water level; the initial support pressure of the slurry chamber is set based on the initial permeability coefficient and effective stress of the strata; during tunneling, the degree of soil disturbance ahead is determined by the change in cutterhead torque, the fluctuation range of penetration depth, and the deviation value of slurry return flow; the degree of disturbance is converted into an increment in the permeability coefficient, the required pressure compensation value is calculated, and the slurry chamber pressure is increased; the adjusted pressure is continuously applied until the shield completely passes through the reservoir's influence zone. This method enables the slurry chamber pressure to respond to the real-time disturbance state of the soil ahead, avoiding the risk of water inrush caused by a sudden increase in permeability, while also preventing surface heave caused by excessive support.