Evaluation Of Engineering Properties And Microscopic Characteristics Of Jiangsu Marine Saline Soil Based On Resistivity Testing

In China,saline soils are widely distributed and have different mineral composition,and engineering characteristics,whose impacts on local engineering construction are also different.As a region with rapid economic development in eastern China,Jiangsu Province is also increasing in construction projects,and the marine salty soils distributed here have caused increasingly serious damage to the project construction.The systematic research on the formation and evolution of marine salt in Jiangsu,and using the latest testing methods to study the characteristics and engineering characteristics of saline soil has become an urgent issue.First,a preliminary understanding of the genesis mechanism and evolution process of the soil is formed,and a systematic understanding of its mineral composition,evolution process,and source of salt is formed.Then select reasonable and effective testing methods and carry out corresponding in-depth exploration tests on the soil.Resistivity method is a new method that has been widely used in recent years for studying soil.Different mineral components and structural characteristics of the soil will show different resistivity characteristics.Using the resistivity characteristics to establish a relationship with the engineering characteristics of the soil,a new evaluation angle of the engineering characteristics can be proposed.The indoor resistivity test can determine the change of the soil resistivity with the variable by using the controlled variable methods,so as to obtain the correlation between the resistivity and the research variable.Based on a large number of test data,the Mathematical model of volume resistivity of soil is established under the combined effect of multiple factors.In-situ multi-functional Resistivity Piezocone Penetration Test(RCPTU)technology can accurately obtain the soil resistivity characteristics while accurately dividing the soil layer and quickly obtaining the engineering characteristics of the soil.Moreover,this test method is convenient and fast.It can also save manpower and material resources,and has the characteristics of high accuracy and rich data collection.With the help of RCPTU to study the correlation between engineering characteristics and resistivity characteristics,a new supplementary and perfect means for the evaluation of soil engineering characteristics can be provided.The analysis of soil expansion from the micro-scale can more intuitively and accurately analyze the qualitative and quantitative characteristics of the microstructure characteristics of its mineral components,particles,and pores,so as to further explain the performance of macro characteristics.In this context,the paper conducts related research on marine saline soils in Jiangsu.The main research contents are as follows:(1)Through literature research,the distribution characteristics,formation mechanism,salt composition,and evolution direction of marine saline soils in Jiangsu were studied,and their salt accumulation process and desalination process were analyzed in combination with factors such as climate,environment,vegetation types,and human economic activities.A systematic understanding of it was formed.(2)Indoor tests were carried out by a self-designed size adjustable indoor soil resistivity test box.The marine salty soils in Jiangsu were simulated under different salt content and moisture content conditions.The resistivity data of 24 groups of soil samples with different water-salt ratios were measured,and the test data was analyzed after being corrected the errors.The resistivity model of Jiangsu marine saline soil based on the generalized Archie formula was determined.(3)Micro-tests were carried out to conduct qualitative and quantitative investigations on the micro-characteristics of marine saline soils in Jiangsu.The X-ray diffraction test was used to quantitatively analyze the mineral composition of Jiangsu marine saline soil.By combining the scanning electron microscope test with the mercury intrusion test,the size,morphology and structure of Jiangsu marine saline soil particles and pores were explored,and the complexity of the microstructure was evaluated.(4)Based on a high-grade highway construction project in Jiangsu Province,insitu RCPTU testing was carried out on site.Based on the analysis of the values of cone tip resistance,side friction resistance,pore water pressure,and resistivity obtained by in-situ testing,the site soil layer was divided,and the engineering characteristics and in-situ resistivity of the corresponding sampling points of each layer were studied For correlation studies.