172 results about "Soil model" patented technology

The invention discloses a pile-supported embankment transparent soil model testing device and method. The device comprises a model groove, transparent soil, a pile body, a water bag, a water pipe, an industrial camera, and a laser emitter. The box-type water bag is placed on the bottom of the model groove made of organic glass. A pile hole position is reserved in the box-type water bag. A pile hole is reserved in the box-type water bag. A pile can be inserted into the pile hole in the box-type water bag. Under the assistance of transparent soil, the soil arch effect of embankment soil under self-weight load can be simulated by discharging the water in the box-type water bag. The invention also discloses a testing method of the testing device. The testing method comprises steps of installing pile and water bag, constructing a transparent soil embankment, slowly discharging water from the water bag, taking pictures of the laser plane by the industrial camera during the water discharging process, and analyzing the pictures to obtain the three dimensional deformation characteristics. The provided device and method have the advantages that high precision realtime measurement on the internal deformation of soil can be achieved, the macroscopic shape change of spacial soil arch can be observed, multiple work conditions can be simulated, the size of the testing device is small, the test operation is convenient, and the efficiency is improved.

The invention discloses a simulated test unit and method for slope stability with faulting, relating to the technique of rock-soil mechanical test. The test unit is characterized in that: a soil sample in a fault soil model instrument is divided into hanging wall and footwall by the fault surface; a first continuously variable transmission (CVT), a first power transmission system, and a supporting leverage are connected with the hanging wall successively and provide power for displacement to the hanging wall; a second CVT and a second power transmission system are connected with the footwall successively and provide power for displacement to the footwall; a displacement mark, a soil pressure box and a dial indicator are put in the soil sample, and the relative data are recorded. Accordingto the invention, the movement processes of transformation and damage of slope containing fault soil are represented accurately, so that the invention provides a new approach for studying formation mechanism of landslip and other geological disasters under complex geological environmental conditions.

The invention discloses an indoor frozen soil model pile static force loading experimental device and method. The device comprises a workbench, a loading framework, a self-balance lever static force loading device, a refrigerating system, a pile soil model, a displacement measurement system and a strain testing system, wherein the workbench is arranged on a horizontal plane; the loading framework is vertically welded on the workbench; the self-balance lever static force loading device, the refrigerating system and the pile soil model are installed from the top of the outer side to the bottom of the inner side of the overloading framework in a matched mode from top to bottom sequentially; the displacement measurement system and the strain testing system are arranged on the external side wall of the loading framework; the displacement measurement system extends into the loading framework and is connected to the part between the refrigerating system and the pile soil model; the strain testing system extends into the pile soil model. The indoor frozen soil model pile static force loading experimental device and method can overcome defects of high cost, high maintenance expense, long time and the like in the prior art so as to achieve the advantages of low cost, low maintenance expense and short time.

The present invention discloses a test device used for reinforcing a soft soil model with an electrochemical pile-making method. The present invention comprises a metal electrode, a soil sample box, a porous permeable panel and a Markov bottle, wherein, the porous permeable panel is arranged at the bottom part of the soil sample box, and the porous permeable panel and the four walls of the soil sample box are firmly cemented by adopting structural adhesive; the metal electrode is vertically inserted in the soil sample inside the soil sample box, and is connected with a high-power steady voltage and steady flow direct current power supply through a cable, an ammeter is connected in series with the high-power steady voltage and steady flow direct current power supply, a water valve and an exhaust valve are arranged at the lower part of the side wall of the soil sample box, and the water valve is connected with the Markov bottle through a water pipe. The present invention has rational and simple structure and convenient operation, and the conditions of the soft soil foundation at the scene can be simulated to control the underground water level, and the present invention can be used for the test reinforcing the soft soil model with the electrochemical pile-making method.

The invention relates to a transparent soil model pile experimental testing device and an application method thereof. The whole system comprises an experiment table and a model experiment device, wherein the experiment table can be leveled through setting adjustable table legs; a desktop is provided with a bracket and a bracket fixing plate so as to mount an engineering diffuser, a camera and a laser device, and is provided with a slide model fixing plate and a vertical and transverse slide limiting plate so as to position and fix a model testing groove; a counter-force frame is arranged above the model testing groove, is adjusted by an adjustable type screw rod and a fixed screw cap and is fixedly arranged on the tabletop; the counter-force frame is provided with a small-size hydraulic jack and a pressure meter; artificially synthesized transparent soil is arranged in the model testing groove and the model testing groove is provided with a model pile and a model pile loading head so as to carry out a post-period model test. The whole system is reasonably arranged, and a loading test and observation on displacement and deformation conditions can be conveniently carried out on the model pile in the artificially synthesized transparent soil.

The invention discloses a method for forecasting DC biasing current influence of multiple DC grounding electrodes on sites in different operation modes. According to the method, a DC online monitoring device is mounted at the neutral point of a transformer near the DC grounding electrodes to grab the actual measurement data of distribution of the DC biasing current; next, the resistivity and the thickness of each layer of soil are adjusted to correct a simulation model according to the actual measurement data, and then the corrected soil model is used for forecasting the influence conditions of the DC biasing of the power grid in the area having multiple DC grounding electrodes under different operating conditions; for the transformer having the DC current exceeding a set value, protection measures can be applied to the transformer in advance, and therefore, the purpose of targeted DC biasing current protection can be achieved. The method has the beneficial effects that the early warning capability on the DC biasing of the power grid transformers is improved and the effective protection measures can be adopted for the transformers having great DC biasing risk conveniently and immediately.

The invention, which belongs to the technical field of the electrical power engineering, particularly relates to a construction method of a resistance reduction and grounding device of a transformer station. The method comprises: a surveyor measures a soil resistivity, a frozen soil depth, and a soil layering situation in a site area of a transformer station to obtain surveying data; a soil model is established according to the surveying data; on the basis of the soil model, a grounding device inside the station is designed in the site area of the transformer station; safety verification is carried out on the grounding device designed at the last step so as to obtain a verification result; if the verification result meets the requirement, a next step is executed; if the verification result does not meet the requirement, a grounding device is arranged externally outside the site area of the transformer station and safety verification is carried out; the verification result is stored; a construction drawing is drawn; and construction is carried out by organizing people. Under the circumstances that no extra collected land is increased, the construction method of the resistance reduction and grounding device of the transformer station is provided. The construction method has characteristics of obvious resistance reduction effect, simple structure, convenient construction, and low cost and the like.

The invention relates to the field of geotechnical engineering model tests, and aims to provide a three-dimensional visualization testing device and method for particle seepage migration based on a trace method. A model casing of the device comprises an upstream liquid level tank, a downstream liquid outlet tank and a model landfill tank; transparent soil particles doped with trace particles inside the model landfill tank is prepared into a dam foundation model, and a dam foundation model is piled and formed at the upper part; and a water bath circulating system consists of a circulating pump,a water bath box, a buffer tank and a plurality of pipelines. The device also comprises the water bath circulating system consisting of the circulating pump, the water bath box, the buffer tank and the pipelines, and a loop is formed by the model box, the buffer tank and the water bath box; and at least two groups of CCD cameras connected to a computer through signal lines respectively are arranged on two sides of the model box respectively. The device effectively solves the problems that a traditional trace particle method is difficult to apply with transparent soil model tests, the occurrence position of particle migration is difficult to capture, the hole fluid refractive index and the glutinousness can change along with temperature and a hole fluid is circulated.

The invention relates to an indoor model test apparatus for ground source heat pump rock soil thermal response testing and an application thereof; the indoor model test apparatus comprises a model case, a soil model for test, a measurement module, a data acquisition module, a thermal cycle module, and a host PC computer; the soil model for test is disposed in the model case; the measurement module is disposed in the soil model for test; the thermal cycle module is connected with the soil model for test; the data acquisition module is connected with the measurement module; the data acquisition module is connected with the host PC computer. Compared with the prior art, the invention has the advantage that the indoor model test apparatus can not only calculate thermophysical parameters of heat exchange soil required by ground source heat pump buried pipe design, but also study environment effect of surrounding soil caused by long-term operation of the ground source heat pump system.

The invention provides a method for calculating frozen soil model thermal parameters based on a similarity theory. The method comprises the steps: with use of specific heat and thermal conductivity coefficients of original soil at different negative temperatures, fitting to obtain a changing curve of the specific heat and thermal conductivity coefficients of the original soil along with the temperature, and calculating latent heat of the original soil with per unit volume; according to a geometric dimension shrinkage ratio of the prototype and a model, determining a geometric similarity constant Cl, namely a; if the density of the prototype soil is [rho]p and the density of the model soil is [rho]m, determining the soil density similarity constant C[rho], namely the ratio of the [rho]p tothe [rho]m; if the cold source temperature of the prototype is Tp and the cold source temperature of the model is Tm, determining the temperature similarity constant CT, namely the ratio of the Tp tothe Tm; and according to the determined similarity constant of the physical parameters, calculating to obtain the thermal parameters of frozen soil. The method has the effects that the calculation method makes up calculation of the thermal parameters of the model soil in the frozen soil temperature field model test, the calculation error is less than 0.1 DEG C, the accuracy satisfies the application of thermal value in actual engineering, and thus the accuracy of the model test results is ensured.

The invention discloses a method for analyzing longitudinal vibration of tubular pile on the basis of a radial heterogeneous viscous damping soil model. According to the method, outer soil and inner soil are assumed to be a series of thin layers which are independent from each other, and mutual effects among the soil layers are ignored; a soil body around the pile is portioned into an interior area and an exterior area, the interior area is partitioned into an arbitrary number of circular layers, a soil body unit in each circular layer is a homogeneous and isotropic linear elastic body, a soil body in the exterior extend infinitely along a radial direction, viscous damping is adopted for soil body material damping, and radial displacements of the soil bodies are ignored; on two sides of a pile soil face and every circular layer soil face are continuous in displacements and balanced in stress, and vibration of a pile soil system appears as small deformation; concrete in a pile body is linearly elastic, and stress wave propagation in the pile body meets a plane cross-section assumption; according to basic theories of elastokinetics, longitudinal vibration equations for the soil body around the pile, an inner soil body and the pile body are established; by Laplace conversion, the three equations in the step 5 are solved to obtain a time-domain speed response function of any excitation force at the pile top.

The soil-water coupled analysis program of the invention computes a global L matrix and a modified global L matrix regarding a volume change rate of a soil skeleton over time, a global H matrix regarding a water permeability of soil, a global M matrix regarding a mass, and a global K matrix regarding a tangent stiffness of the soil skeleton, based on input settings of soils, such as clay, intermediate soil, and sand, to respective elements of a soil foundation, input settings of a solid soil model, and input settings of analysis conditions (steps S140 to S165). The soil-water coupled analysis program formulates a global tangent stiffness equation (simultaneous linear equations) using all these computed matrixes and determines an unknown ‘jerk field’ and a ‘pore water pressure field’ under given boundary conditions, for example, a given deformation condition and a given stress rate condition (step S170). This enables highly-accurate dynamic and static analyses in soil foundations of various soils from sand to intermediate soils and clay.

The invention discloses a field-circuit coupling-based direct current magnetic bias calculation method for a soil model adopting a three-dimensional asymmetric structure. The method comprises the steps of determining the size of the soil model through a direct current magnetic bias influence range needed to be considered, and discretizing the model into small cubes with side lengths of 2m; throughactual measurement point data, determining block division of the model; mapping inverted three-dimensional resistivity to blocks, and mapping non three-dimensional resistivity data after conversion;determining stream injection point coordinates through stream injection test data, applying stimulation, determining a boundary condition, dividing grids, and performing surface potential calculation;determining an observation path, performing comparison with a stream injection test result, and correcting the soil model; obtaining a peripheral power system wiring diagram of an earth electrode andparameters such as coordinates and the like, and building a direct current circuit model; and inputting node potentials to perform direct current magnetic bias calculation. Starting from an initial model, the direct current magnetic bias calculation precision is improved; the possibility of protection mal-operation or refusal operation is reduced after operation of a direct current project; and the stability of power system operation is improved.

The invention relates to a method for building a horizontal layered soil electrical model, which comprises the steps of building a composite layered soil model according to magnetotelluric three-dimensional inversion soil resistivity data, selecting the earth surface potential to act as a fitting index, fitting the earth surface potential of a composite model acquired by using a finite element method and the earth surface potential of a horizontal model deduced by using a Green function method by adopting a least square method so as to acquire an objective function of the horizontal layered soil electrical model, carrying out optimization solving on the objective function by adopting a genetic algorithm, acquiring a soil resistivity parameter and the corresponding layer depth of each layer in the horizontal layered soil electrical model, and thus realizing conversion from composite layering to horizontal layering of the model. The method provided by the invention reduces the complexity of the model, improves the reliability of the model, and can provide more accurate soil resistivity model data for analysis of an earth electrode.

The invention discloses a testing device for an interactive impact model of a lander and a soil body, which comprises a crossbeam, a cotton thread, a side column, an upper crossbeam supporter, an impact barrel, a lower crossbeam supporter, a glide guide rail, a computer, a signal processor, a soil box, a movable sliding rail and a displacement meter, wherein the crossbeam and the movable sliding rail are respectively fixed at the top and the bottom of the side column; a center below the crossbeam is fixedly connected with the displacement meter; the upper crossbeam supporter and the lower crossbeam supporter are riveted on the side column; the glide guide rail is fixed through the upper crossbeam supporter and the lower crossbeam supporter; the impact barrel is mounted on the glide guide rail and is tensioned and stabilized through the cotton thread; and the soil box is arranged below the impact barrel. By using the testing device, through controlling a height and the mass of a weight, the soil body is impacted with a predetermined impact speed and an impact mass; the testing parameters needed by an impact are conveniently measured in real time; and the interactive power characteristics in an impact process are reflected.

The invention, which belongs to the technical field of the grounding grid of the transformer substation, especially relates to a distributed substation grounding grid detecting and evaluating method.The method comprises the following steps that: according to a substation grounding grid design file, inversion of a soil model in the substation and a power-frequency ground impedance value of a substation grounding grid is carried out; a ground potential rising value, a step voltage and contact voltage characteristic parameters in the substation are calculated on the condition of occurrence of aground fault; when a ground conductor is broken, ground potential rising values, step voltages and contact voltage characteristic parameters in the substation are calculated by using simulation software on the conditions of fault occurrence at different places; the operating state of the ground conductor in the grounding grid is detected by combining a distributed grounding grid state evaluation device and characteristic parameters of the grounding grid are calculated at different fault sites when the ground conductor is in a current state; and the current state of the conductor is compared and identified to obtain an overall evaluation result of a ground device in the current substation. According to the invention, the operation state of the ground conductor in the grounding grid can be tracked and thus measures are taken timely, thereby eliminating an accident affecting the safety of the equipment and the staff.

The invention discloses a soil equivalent resistance model modeling method in combination of repeated multipoint actual measured data of a power grid and simulation modeling calculation. The method ischaracterized in that an existing soil equivalent resistance model construction method is improved by use of a mixed modeling method in combination of the actual measured data and the simulation modeling calculation; repeated multipoint measurements are performed on an alternating-current power grid by changing a topological structure of the alternating-current power grid, that is, sequentially switching off any return circuit of alternating current circuits between two transformer substations with direct electrical contact in a modeling range to obtain multiple groups of direct current distribution data of a main transformer neutrality point of each transformer substation in the modeling range; and a soil equivalent resistance model is constructed by simulating calculation and inversionmeans. According to the soil equivalent resistance model modeling method, detailed soil parameters are unnecessary to collect, the calculation accuracy degree is high, the problem that a non-uniform layered soil model is difficult to establish accurately in previous methods is overcome, and the method is suitable for accurate calculation of distribution of direct currents in an alternating currentsystem in the case of complex soil compositions.

The invention discloses a ground resistance calculation method of a double-layer soil containing a massive medium. A double-layer soil model containing the massive medium comprises a ground, upper layer soil, lower layer soil and the massive medium which are arranged under the ground and at least one cylindrical ground body. The massive medium is evenly distributed in the upper layer soil and the lower layer soil, and the ground body is vertically inserted into the ground surface and is completely wrapped by the massive medium. A moment method is adopted to disperse an integral equation to be calculated by building the model, a matrix equation is calculated, and finally the ground resistance is obtained. The method is smaller in error and accurate in calculation result.

The invention relates to a pipe-soil model tester for use under impact of site settlement and faulting, comprising a fixed box, a vertical moving box and a horizontal moving box arranged in order. Soil in the three boxes is an organically combined whole. A test pipe penetrates the three boxes. The fixed box is welded or anchored to a fixed table. The vertical moving box is disposed on a temporary support rack. The horizontal moving box is disposed on a line position rail through roller modules mounted at the bottom of the horizontal moving box. A loading portion comprises an MTS power apparatus, a vertical loading jack and a transverse loading jack. The whole structure is fixed on a ground anchor. The tester is capable of simulating the impact of two site environments, namely non-uniform settlement and faulting, upon lines buried in the tester and also capable of simulating the impact of coupling action of the two environments upon mechanical properties of the lines, simulation similarity is satisfied, complex site conditions such as non-uniform settlement and faulting are simplified, indoor testing operations are facilitated, and simulating stress condition of the buried lines is facilitated.