Research On Physical And Mechanical Properties Of Magnetic Similar Material And Its Application In Geomechanics Magnetic Model Test

At present, the study of magnetic similar material is less, especially in the application of magnetic force model test. based on the existing GTS300 gravel soil geotechnical test system, developed the SDTS100 double pressure chamber similar material test system. By using SDTS100 conducted the physical and mechanical properties experiment of magnetic similar material, to research the influence of different components on the material experiment results. according to the similarity ratio, made up a magnetic similar material ISC which met Jinping hydropower station arch dam left bank slope rock mass and structure conditions; Optimized the existing gradient magnetic field generator, selected iron powder, quartz sand and clay content were 47%, 23% and 20% as mixture ratio of standard cuboid model material, By conducting magnetic model test and numerical simulation, to research the load capacity and verify that it is feasible to use the magnetic similar materials in the magnetic model test.The main research results are as follows:1. On the basis of the existing GTS300 gravel soil geotechnical test system, according to the requirements of the magnetic similar material test, developed SDTS100 double pressure chamber similar material test system, and used the SDTS100 conducting physical and mechanical properties experiment of the magnetic similar material. The experiment results showed that: iron powder content had the significant effects on the test results, the material density, compressive strength increased with the increase of the iron powder content, cohesive force and the elastic modulus increased in certain range; the finer the iron powder particles, the greater the density, strength of materials as a whole, the bigger the iron powder, the greater the internal friction angle and poisson ratio; the material density decreased with the increase of quartz sand content. when quartz sand content was less than 30%, the compressive strength and elastic modulus decreased with the increase of its content, while the cohesive force and the poisson ratio increased; the more clay content, the bigger the cohesive force; there is a reasonable curing time for the similar material, if curing time is too long which can damage the internal structure of similar material and reduce the material’s strength and other properties;the similar materials can simulate magnetic density in the range of 2.46~2.85 g/cm3, compressive strength 0.26~0.26 MPa, cohesive force 38.1~124.1 kPa, internal friction Angle 6~57 °, elasticity modulus 15.9~72.5 MPa, poisson ratio 0.23~0.41, which satisfied the demand of model experiment of high density, low strength, low elastic modulus.2. According to the similarity theory and magnetic similar material physical and mechanical test result, developed a magnetic similar material ISC met Jinping hydropower station arch dam left bank slope rock mass and structure conditions, ISC material is composed of iron powder, quartz sand, clay. When iron powder, quartz sand, clay content are 47%, 23% and 47% respectively, the mechanical parameters can meet Jinping hydropower station arch dam left bank slope IV1 rock mass parameters requirements; When iron powder, quartz sand, clay content are 10%, 65% and 15% respectively, the result can meet Jinping hydropower station arch dam left bank slope V rock mass parameters requirements; When the content are 55%, 25% and 10% respectively, the mechanical parameters can meet Jinping hydropower station arch dam left bank slope X rock mass parameters requirements; if iron powder, quartz sand, clay content are 20%, 62% and 8% respectively, the result can meet f5, f8, f42-9 rock mass parameters requirements.3. Optimized the existing gradient magnetic field generator, using the magnetic magnetic similar material which meet Jinping hydropower station arch dam left bank slope IV1 rock mass to conduct the geological mechanics model test verification test, and numerical simulation with finite element method. The model test results showed that the gradient magnetic field generator under the condition of the 16 A electric current, the similar material strength can be increased by 1.59 times on average which fit with the results of numerical simulation. the deviation between model test results and numerical simulation results is mainly caused by the parameters selection. In general, the magnetic model validation test and the results of numerical simulation illustrates that the magnetic similar material is feasible in geological mechanics model test study, which provides a guidance and reference for later experimental research.