Study on the Microstructure of Loess in Meizoseismal Zone

INTRODUCTIONAn earthquake with magnitude of5.8struck Qishan Townin Yongdeng County,Lanzhou,at06:44,July22,1995.The region affected by the earthquake is located in the loess hills with sparsevegetation cover.The region also lags behind economically.The meizoseismal intensity reachedⅧ.For its shallowsource,the earthquake caused relatively heavy damage,though it was a moderateevent.Ground cracks with a widthlargerthan10cmare a commonsight onthe hills aroundthe town,some looks as if they …

Study on the Microstructure of Loess in Meizoseismal Zone

In this paper, quantitative study on the microstructure of loess is done based on the study of seismic subsidences of the Yongdeng M_S5.8 earthquake in 1995. Using SEM and image processing techniques, a comparison analysis on the microstructure of loess is done and distribution curves of loess pores are obtained. Based on laser grain analyzer test and trellis structure changes under earthquake effect, the dynamic properties of loess are explained. At the same time, pore distribution of loess from seismic zone and non-seismic zone is compared. The result shows that the pore distribution features of different meizoseismal zones are different, and even that loess at the similar depths has substantial differences, too.