173 results about "Soil model" patented technology

The invention provides a large frozen soil model test system with a moisturizing function and a frost heaving test function. A moisturizing system and a refrigeration system of the model test system are arranged in a model tank box body; a loading system capable of vertically moving is arranged at the top of the model tank box body; a temperature field test device is arranged at the periphery of the refrigeration system; a frost heaving three-dimensional stress-strain test device is arranged on the inner side wall in the model tank box body; and a frost heaving and thaw collapse observation device is fixedly arranged at the top of the model tank box body. The large frozen soil model test system has the beneficial effects that a platform for scientific research is provided for researching the physical and mechanical properties of artificially frozen soil and optimizing an artificial freezing method; the large frozen soil model test system can be widely applied to freezing method construction model tests in the fields of geotechnical engineering, underground construction, traffic engineering and the like, for example, simulation tests are carried out on underground construction such as shield tunnel inlet and outlet freezing reinforcement, contact passage freezing method construction, and deep foundation pit freezing support; in addition, the natural frozen soil can also be simulated by adjusting control parameters of refrigerating machines; and large frozen soil model test system is applied to research on damages and effects on buildings and structures caused by seasonally frozen ground and frozen soil in permafrost regions.

A system for remote moisture monitoring and control includes: a measurement vehicle, including a vehicle body, a vehicle control unit, a transmitter antenna, and a receiver antenna; a moisture control server, including a processor, a non-transitory memory, an input / output, and antenna manager, a multi spectrum analyzer, a sensor manager, an irrigation manager, a soil simulator and a data bus; a vehicle storage facility; an irrigation controller; irrigation valves; a mobile control device; ground sensors. Also disclosed is a method including piloting measurement vehicle; obtaining moisture measurements, including controlling outbound transmission, determining reflected power, calculating dielectric constant via reflection calculation, determining soil moisture via lookup in soil calibration table; obtaining sensor measurements; calculating soil model; and adjusting irrigation.

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 light splitting model test device capable of measuring a transparent spoil internal three dimensional displacement field, and a test method thereof. The light splitting model test device comprises an optical platform and a laser light splitting system, a transparent soil model test device and a PIV test system which are all arranged on the optical platform. The test device can split a single beam laser source into double beam laser sources, form vertical planar light beams through a lens assembly, and vertically slice soil samples. The device can truly realize monitoring of a spoil body internal three dimensional deformation field in a spoil body natural state; referred instruments have simple structures, and are convenient to operate and easy to master.

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 discloses a slant-slip-fault simulating device. A fixed disc model box of the slant-slip-fault simulating device is fixed onto a cuboid pedestal, a dislocation disc model box is movably arranged on prism pedestals, and the fixed disc model box is aslant matched with one side of the dislocation disc model box and communicated with the side of the dislocation disc model box to form a cavity for containing a soil model; slant guide rails are arranged on the slopes of the prism pedestals, and triangular sliding blocks are fixed to the bottom end of the dislocation disc model box and slide along the slant guide rails under the effect of jacks so that the dislocation disc model box can be pushed to be aslant dislocated relative to the fixed disc model box; internally-arranged air bags are arranged in the fixed disc model box and the dislocation disc model box respectively and apply vertical pressure to the soil model. The invention further discloses a simulating method based on the device. The vertical displacement component and the horizontal displacement component of two discs of a slant slip fault can be simulated at the same time, the proportion of the bidirectional displacement components can be changed, and the damage, caused by the slant slip fault, to an underground structure can be truly simulated.

The invention belongs to the technical field of model tests of geotechnical engineering and in particular relates to a testing device for observing deformation of three-dimensional space in a transparent soil model and an application method thereof. The device is mainly prepared from a loading system, a shoe model, a model casing, a lifting visual testing platform, a CCD industrial camera, a transmission system a, a transmission system b, a transmission system c, a laser and a computer. The operating height is adjusted by means of the lifting visual testing platform and the three transmissionsystems control the CCD industrial camera and the laser to move synchronously. The device provided by the invention is simple in structure, clear in principle, easy to operate and relatively low in cost; the transparent soil model are sliced and photographed from two directions, separately, to acquire displacement components of each node in the three-dimensional space in three directions conveniently; the change process of the deformation of the three-dimensional space of a soil mass can be monitored continuously in a non-invasive mode, so that the deformation of the three-dimensional space ofthe soil mass is measured truly.

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 discloses a method for analyzing horizontal dynamic response of a single pile in layered soil based on a Pasternak foundation model. A layered Pasternak foundation model is adopted to simulate the shearing effect of a soil body around a pile, a segmented Timoshenko beam model is adopted to simulate the pile body so as to consider bending and shearing deformation of the pile body, meanwhile, it is assumed that a pile-soil model meets the small deformation condition, a pile-soil interface is in complete contact and free of relative sliding, and the pile bottom is a fixed end constraint. According to the invention, on the basis of the assumption; firstly, a horizontal dynamic balance equation of segmented pile body units is established; secondly, establishing a relationship among a pile body corner, a bending moment, a shearing force and a pile body horizontal displacement, establishing a coefficient matrix equation set of a segmented pile body unit according to the continuity of the horizontal displacement, the bending moment, the bending moment and the shearing force of the pile, and finally obtaining the horizontal displacement of each segment of the pile body and thebending moment and the shearing force on any section of the pile body according to boundary conditions. The method can provide theoretical guidance and reference for pile foundation power detection.

The invention provides a novel transparent soil model test device for simulating tunnel excavation and a test method thereof. The test device comprises a model case arranged on a test platform, a simulated tunnel structure and an imaging apparatus. The model case is a transparent rectangular box. Holes are prefabricated on two opposite side wall surfaces of the model case. Two ends of the simulated tunnel structure are respectively embedded into the holes on the two side wall surfaces of the model case. The model case is filled with transparent soil. During test, two laser emitters form two speckle sections inside the transparent soil. The test method of the device includes the steps of design of an experimental scheme, installation of the simulated tunnel structure, allocation of transparent soil, test and the like. In the process of moving an organic glass tube, the device reads the scale value on the organic glass tube surface so as to obtain the stratum loss generated by each movement, can well verify the engineering practice, reduces the disturbance of organic glass tube to the transparent soil body, and improves the experimental accuracy.

The invention provides a real-time dynamic calculation method and system for cable carrying capacity. The method comprises steps as follows: load current with a preset load value is input into a cable, and a first surface temperature value of the cable as well as an air temperature value, a wind power value and a solar radiation value of the soil surface is collected; iterative processing is performed on a preset first soil heat conductivity coefficient with a data iterative algorithm according to the values, a second soil heat conductivity coefficient is obtained, and an equivalent thermal resistance coefficient of soil is obtained; the soil is subjected to layering treatment, a layered soil model is established, external heat resistance of the soil is obtained through equivalent thermal resistance coefficient treatment; a cable body thermal circuit model is established according to scheduled rules, and the cable carrying capacity of the cable is obtained according to the cable body thermal circuit model and soil external heat resistance treatment. The method and the system have the beneficial effects as follows: a soil water migration based layered soil model analysis method and a numerical iteration analysis method are introduced into the cable thermal circuit model, so that the cable carrying capacity is calculated more accurately.

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 dynamic-static loading variable-scale similar material test and multi-field dynamic monitoring analysis system, and relates to the technical field of similar material simulation tests. The system comprises a similar simulation test frame, a dynamic-static loading system, a multi-node dynamic internal displacement response monitoring system, a multi-node dynamic surface displacement digital measurement system, a full-domain whole-process internal fracture evolution monitoring system and a multi-node dynamic stress response monitoring system. The multi-field time-varyingmonitoring and analysis of the stope overlying rock structure characteristics and migration law, the rock fracture development degree, the ground surface settlement characteristics, the mine pressure, the mine pressure display, and the like can be realized in a dynamic-static loading variable-scale similar material test; the problems in collection and vectorization processing of multi-field multi-node dynamic data of full-domain and whole-process stress, displacement, fracture and the like in the existing similar material test can be solved; the real-time monitoring and analysis of the internal deformation damage characteristics and a stress evolution law of a rock-soil model under the action of dynamic and static loads are realized; and therefore, the system has important practical research guiding values.

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 physical model for simulating soil slope instability induced by groundwater and belongs to the field of physical model tests. The physical model comprises a model case and ischaracterized by further comprising an external water tank and a lifter, wherein a base is fixedly arranged on the inner bottom wall of the model case; an impervious layer is fixedly arranged on thebase; a soil layer is arranged on the impervious layer; a pore-water pressure sensor, a soil pressure sensor and a differential displacement sensor are arranged in the soil layer; an internal water tank is arranged on one side of the base; water level scales are etched on one side wall of the internal water tank; a plurality of water seeping holes are formed in the other side wall of the internalwater tank; porous stones and geotechnical cloth are sequentially arranged between the water seeping holes and the soil layer; a stainless steel hose is connected to the internal water tank; a water flow sensor is fixedly arranged on the stainless steel flexible hose. According to the physical model disclosed by the invention, underground water level height can be accurately adjusted in real time;in addition, the infiltration capacity of a slope body at certain water level height can be maintained, scouring to a soil model can be effectively avoided, and a good test effect is realized.

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 multidimensional and multipoint anti-seismic experimental method for considering soil-structure interaction, belonging to the field of anti-seismic experiments for architectural structures. The method comprises the following steps of: by taking a semi-infinite soil mass as a numerical experiment model and an architectural structure as a physical experiment model, organically combining the soil mass and an upper architectural structure by means of the transmission of interface counter force and an interface dynamic response; seamlessly connecting a soil model with the upper architectural structure by means of an optimized design of a substructure system controller; and performing a local control policy on a multi-vibrating-table system so as to realize a multi-vibrating-table based real-time dynamic substructure experiment to be used for multidimensional and multipoint anti-seismic performance experimental researches for considering the soil-structure interaction for long and large structures. The method provided by the invention greatly lowers the requirements of experimental equipment, and can be used for more comprehensively researching the anti-seismic performance influence factors of architectural structures.

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.