The deformation and field shear test research of red clay slope under rainfall

Abstract

The deformation characteristics and shear strength of slope soil is an important basis for slope stability analysis. In order to study the deformation characteristics and shear strength of laterite clay slope under rainfall, the actual red clay slope engineering is taken as an example, considering the influence of rainfall on the deformation and shear strength of the slope soil, and the creep characteristics of the red clay slope are obtained through the lateral deformation monitoring of the typical borehole of the slope.Field shear tests on three groups of pre-slope samples and three groups of slope samples of the laterite clay slope are conducted. The results show that during the monitoring period, the lateral deformation of the red clay slope at the same borehole depth gradually increases with the infiltration of rainfall, and the lateral deformation of the same borehole soil layer decreases with the increase of borehole depth. The shear stress-shear displacement relationship curve of slope soil develops and changes according to the four stages of "elastic deformation, yield deformation, hardening deformation and failure deformation" has significant stress-strain softening characteristics, and there are obvious peak strength and stable residual strength. The empirical model of the peak and residual strength of the pre-slope specimen has been provided and the slope specimen and the empirical shear strength index of the pre-slope soil body are given as c_f=38.760 kPa、φ_f=15.9°、c_fr=34.577 kPa、φ_fr=12.6°, and the empirical values of shear strength index of soil body of slope body c_f=33.522 kPa、φ_f=10.2°, and c_fr=30.234 kPa、φ_fr=9.5°. The research result can provide theoretical and data reference for the stability analysis of red clay slopes, determination of shear strength parameters and similar engineering construction.

Keywords

slope engineering / red clay / rainfall action / lateral deformation / shear strength / field shear tests