Abstract:

Through analyzing the mechanism of flow slide of loess landslides, it can find the steady state strength (residual strength) plays a major role. The evaluation of residual strength requires a better understanding of undrained saturated loess behavior. The steady strength of saturated loess is discussed under stress-controlled undrained consolidation triaxial test. There are two typical stress-strain behaviors of saturated loess: steady state behavior and quasi-steady state. In majority situations, it exhibits steady state behavior. Only loose loess exhibits quasi-steady state behavior. According to the test results, steady state line and steady state strength line of saturated loess are obtained. These lines can be used to analyze the mechanism of flow slide. The existence and uniqueness of steady state line are proofed. The internal friction angle and cohesion can be used to describe the steady state behavior of saturated loess. The meaning of these parameters is discussed. The difference of saturated loess and sand is analyzed.

Key words: saturated loess, flow slide, steady state line, steady state strength, triaxial test