Study On The Resistivity Characteristics And Its Engineering Application Of Typical Silt Layer In FuZhou

Resistivity values,to a certain extent,reflects physical and mechanical properties of the rock and soil.Due to the advantages of convenient,fast and economic,electric prospecting has been applied in many fields in engineerin at the same time.Because of the diversity of regional differences,sedimentary history and formation heterogeneity,the relationship between rock resistivity and localized parameters varys widely in different regional.It is complex and diverse in the sedimentary of basin formation in Fuzhou,especially distribution of thick layer of silt soil in soft soil in MinJiang river.Currently the resistivity change rule in fuzhou soft soil and the research about its impact on the overall stability of foundation pit and its reliability has not been reported.This article is based on "Fuzhou subway line 2" survey projects using the probability and statistics analysis,random theory and reliability theory.The resistivity of soft soil laywer in typical area in FuZhou and the correlation with physical and mechanical indexes were analyzed.The resistivity model of Minjiang River silt soil is established.When the resistivity of the mud have a linear relationship with its mechanics index,the influence of the resistivity of the mud on the stability and reliability of the foundation pit is analyzed.The main contents and conclusions are as follows:Firstly,we studied the geological environment of the silt layer in Fuzhou subway line 2 and drawn the soil profiles along this Line.According to the distribution characteristics of silt layer,the study area is divided into three sections.Eigenvalues of silt soil index in each segment is revealed and the corresponding probability distribution model is established.Secondly,we take field resistivities with WDA-1 super digital DC law instrument.The resistivity curves of the field along the line are obtained.The distribution of soft soil resistivity in each section and its relation with mechanics index is analyzed.Thirdly,we toke a hole of resistivity measurements in Minjiang River as the study.we obtain the relationship between the soil resistivity in silty between its physical and mechanical properties with the correlation analysis.The main influence factors is analyzed by ways of the gray relational theory.Resistivity model of the mucky soil is established.Fourth,Studying the average single layers and resistivity and mechanical index under the linear relationship,the resistivity of the influence of the global stability of the foundation pit.The study finds that the influence is different under different linear relationship.Using the FOSM program in matlab,the change rule of the reliability of the overall stability of foundation and resistivity are studied.Bays Valuation and Random Theory are used to the optimization design of the mechanical parameters.Finally,the influence of different soil depths on the stability and reliability of the foundation pit is analyzed with Shang Yang stations.The research shows that the second layers of mud resistivity have little effect on the overall stability and reliability,while the bottom mud layer has a great influence on the resistance to the mud.Research results enrich the soft soil localized understanding along the rail transit line no.2 in Fu Zhou and push the resistivity in the global stability of foundation pit and its reliability.