Residual-State Creep Test in Modified Torsional Ring Shear Machine: Methods and Implications

Abstract

Landslide mass are supposed to reach residual state which naturally demands residual-state creep study. To study the creep behavior of landslide soils, a method for residual-state creep test with a modified torsional ring shear machine was developed in laboratory, which can simulate the creeping landslide phenomena. To understand the creeping behavior of landslide soils, three representative landslide soil samples, which have higher percentage of Smectite, Chlorite, and Mica are taken in this study. A series of residual-state creep test (i.e. seven tests) with varying applied constant shear stress for each sample were conducted, the results thus obtained are interpreted in terms of Residual-State Creep Stress Ratio (RCSR), at which the soil samples fail at their residual state. The term RCSR is the ratio of applied constant shear stress with residual strength. The test results show that when RCSR ≤1, the soil does not show creeping behavior where as the soil undergo creeping behavior when RCSR>1.This paper mainly focus on the methods of residual-state creep test, its implications for the study of creeping displacement behavior, and further possibilities of landslide displacement prediction based on experimental findings.