Abstract: As “the cancer of the engineering”, expansive soil is widely distributed in China. To systematically evaluate the risk grade of expansive soil cut slope stability during construction, based on research results of 22 expansive soil road sections constructed in Guangxi, Yunnan, Henan, Beijing of China, the risk surroundings, factors and feedback information of risk management are analyzed; and the hierarchy model is established consisting of two indexes layer with 8 main evaluation indices. Grading standard of evaluation indices are established by statistics and theoretical analysis; and the weights of evaluation indices are obtained by using analytic hierarchy process. The dynamic recognition model of expansive soil cut slope stability is eventually established by using fuzzy recognition theory and analytic hierarchy process (FAHP). The preliminary assessment of risk surroundings and secondary dynamic assessment of risk factors and feedback information of expansive soil cut slope of Nanyou road was carried out by using the established model; and then the calculated results are compared with field situation. The results indicate that the assessment results are basically in a good agreement with the observed results, so as to verify the rationality and practicability of the proposed model. The dynamic risk assessment methodology and model can provide a powerful tool for quantitative assessment of expansive soil cut slopes stability during the whole construction process.

Key words: expansive soil cut slope, dynamic risk assessment of slope stability, Fuzzy-AHP theory, evaluation indices, engineering applications