A Simplified Technique for Slope Stability Assessment Based on Insitu S-Wave Velocity Measurement

Abstract

Earthquakes rapidly impose cyclic loading and soils respond in undrained conditions during seismic performance. Geotechnical earthquake engineering historically has focused extensively on evaluation of liquefaction resistance in sandy soils since deformations tend to be large when sandy soils experienced liquefaction. Recently, the role of unsaturated soil mechanics in geotechnical earthquake engineering is required for unsaturated soil structures subjected to cyclic loading or earthquake motion. The shear strength theory of unsaturated soils has been formulated in terms of two independent stress state variables (i.e., net normal stress and matric suction). This study conducted out undrained cyclic triaxial tests for compacted unsaturated soil. Both excess pore-water pressure and excess pore-air pressure were measured in unsaturated soil and described changing of matric suction during cyclic loading. The cyclic triaxial test was performed for saturated soil in order to compare with excess pore water pressure behaviour of unsaturated soil. This study focuses excess pore-water pressure as one component of effective stresses in unsaturated soil and saturated soil. The influence of matric suction on occurrence of excess pore-water pressure was appeared.