Statistically Analysis for the Stability of Various Protection Modes of Expansive Soil Cutting Slope

Expansive soils are widely distributed in southwest of China and are used frequently in highway construction. The stability of protection mode for expansive soil cutting slope is widely concerned by engineers. Through a large number of field research, laboratory tests, test section construction and monitoring, especially the use of statistical analysis, this research identified the most suitable protection mode is arch skeleton for expansive soil cutting slope of highway. According to the logistic regression, t-test, and other statistical analysis results, this study concluded that the slope stability rate reached 86.84% after protection with arch skeleton. Therefore, arch skeleton is significantly better than other modes of protection, p=0.0581. In addition, this study found that the height and slope rate had a great influence on the stability of expansive soil cutting slope. It is recommended that the slope rate of expansive soil cutting slope should not be steeper than 1:1.5 and the slope height should not exceed 6m.