EXPERIMENTAL STUDY OF DEFORMATION AND STRENGTH PROPERTIES OF LOESS UNDER THE EXCAVATION STRESS PASS OF HIGH SLOPES

To explore the mechanical behavior of loess under excavation of high slopes, the linear finite element method was first utilized to obtain the stress paths of loess on the potential failure zone of an artificial high slope of 150m in Huanneng Country, Huan Town, Qingyang City, Gansu Province. Based on the stress path above, undrained triaxial tests were then performed on soils with natural and saturate water content. By comparison, conventional loading stress path tests (CTC) with the consolidation stress identical with the tests above were also performed. Results show that under the excavation condition, the stress-strain curves of saturate loess are strain-soften and those of soil with natural water content are slightly strain-harden. Under the conventional loading condition, the stress-strain curves of saturate samples have the same characteristic with the tests above. While the natural water content samples display great strain-harden characteristics. In the two types of tests, the effective stress paths, strength envelope and the effective strength parameters are almost the same for the saturate samples. But for the loess with natural water content, the strength envelops are paralleled with the effective internal friction angle almost the same and the higher cohesion for the stress path tests.