The Analysis of the Microstructure and the Mechanical Properties of Land Subsidence Area in Suzhou

The land subsidence is one of the main geological disaster in Suzhou,China.Owing to long-term extraction of groundwater,the land subsidence area has continuously extended which hinders the development of local economy.A series of experiments have been carried out in this study.In order to study the mechanism of land subsidence,the experiment combines the quantitative analysis of soil microstructure with the macroscopic mechanical test,and the soil samples were taken from a 200 mborehole in Shengze,Suzhou.A larger number of SEM images were obtained after using the method of vacuum freeze-drying.The imaging analysis software PCAS was used to acquire the parameters of soil microstructure and the fiber Bragg grating(FBG)techniques were used to monitor the soil layers in the borehole.The data in liquid and plastic limit tests,quick consolidated tests,the quantitative analysis of microscopic structure and the data of distributed fiber optic sensing indicate that the moisture content,the liquid index and the compres