Application of electrical imaging and multichannel analysis of surface waves methods to survey the structure foundation at the Districts 2 and 9 of Ho Chi Minh City

Abstract

In geophysics, multichannel analysis of surface waves (MASW) is employed to survey the stiffness of soil environment by the values of shear wave velocity (VS), while 2D electrical imaging method is utilized to examine the conductivity of soil environment by the values of resitivity (). In this study presented the results of 1D VS from MASW and 2D section from electrical imaging method to study the soil environment of structure foundation at districts 2 and 9 in Ho Chi Minh city were presented. The results of stratification of geology at two areas obtained from above two approaches were similar. The obtained results revealed that the geology between district 2 and 9 were quite different. For the area at the district 2, from the surface to the depth of 20 m, the resistivity and the shear wave velocity increased 10–50 m and 50–300 m/s, respectively. Moreover, the thick silty layer with the thickness of 1718 m and the small values of resistivity and VS were also detected in this site. For the area at the district 9, the geological foundation was stiffer than the one of the district 2. Concretely, from the surface to the depth of more than 30 m, the resistivity and the shear wave velocity increased from 10300 m and 200450 m/s, respectively. The geological foundation was found to be most of clays. In addition, the silty clay layer at several sites along the survey line was observed, while the stiff sandy clay layer was recognized at the depth of 27 m.