Experimental Study On Soil Stress Distribution Model Based On MEMS Pressure Sensor

The stress increment caused by the load of the building is the main reason for the deformation and settlement of the foundation.Due to the limitation of the technical means of geotechnical testing at the present stage,The study of this part of the stress is often carried out through the theoretical calculation and analysis of many hypothetical conditions of the foundation,but the actual change process of the additional stress in the foundation soil can not be seen in the process of loading.In fact,the study of stress transfer distribution of soil in foundation is not only helpful for us to understand the action process and mechanism of foundation settlement and deformation,but also to analyze the stability of bearing capacity.It also provides a favorable basis for the control of disaster prevention and mitigation in urban construction activities.There are many factors that affect the way and mechanism of stress propagation in foundation soil,among which the law and result of stress transfer distribution in different properties of soil are different.In this paper,based on the analysis of the contribution value of each influencing factor,the moisture content of the main factor soil is extracted,the size of the loaded plate is taken as the controlling factor of the experiment,and the medium sand is selected as the experimental soil to carry on the laboratory simulation experiment to the stress distribution transfer process in the soil.In view of the defects of earth pressure sensor commonly used in geotechnical testing,such as large volume and large stiffness,resulting in soil arch effect and resulting in experimental error,small volume and low power consumption are introduced.The MEMS gas pressure sensor with high accuracy is modified for earth pressure measurement.Through a series of calibration tests,the MSP pressure sensor with high linearity,good reproducibility and low lag is selected and used in laboratory model experiment.The reliability of the modified MEMS pressure sensor in geotechnical test is verified by the results of laboratory model experiments on the basic law of additional stress transfer in traditional soil mechanics.Based on ABAQUS finite element analysis software,the physical model of the laboratory experiment is simulated,and the similarities and differences of the transfer law results under different influencing factors are simulated.By comparing the measured results of the model experiment,the theoretical calculation results and the numerical simulation results,it is verified that the change of soil properties,that is,the change ofsoil water content,will change the stress transfer law of foundation soil during the loading process.