FUZZY-AHP METHOD BASED EVALUATION OF ACCUMULATION SLOPE STABILITY

This paper aims to quickly evaluate the stability of accumulation slope and adopt scientific preventive maintenance countermeasure. It considers the scientific matters of evaluation model and maneuverability of expressway slope maintenance. It summarizes the existing research achievements domestic and abroad about accumulation slope. It then sets up a reasonable accumulation slope stability evaluation index Fuzzy-AHP analysis model. This model is established on the basis of extensive field investigation of accumulation slope disturbed to several expressways in Hunan province. The stability gradation model for accumulation slope stability analysis has been established. The hierarchy model consists of two indexes layers: five main evaluation indexes and 17 basic examination indexes. They are (1) structural characteristics of deposit body (basement lithologic, contact surface character, content of gravel, the thickness of deposit soil, and cementation degree of deposit soil);(2) the section characteristics of accumulation slope (slope gradient, height of slope, the relationship of slope direction and rock stratum occurrence);(3) hydraulic characteristics (drainage system, rainfall, groundwater);(4) engineering protection and vegetation protection(protection structure, reinforcement structure, vegetation coverage)and, (5) other factors (slope failure history, seismic intensity, excavation method). Based on fuzzy math and analytic hierarchy process, the weight of every index is obtained by making use of analytic hierarchy process. The fuzzy math method is used to calculation the relative membership degree vector and to make a comprehensive evaluation of accumulation slope stability. Thus the slope stability classification can be determined. Finally, the application to an engineering example verifies the accuracy and the rationality of the model. Its result is reliable. The results show that the application of this model can make evaluation of accumulation slope stability more scientific, more reasonable, more corresponded to expressway slope engineering practice. This method is simple and feasible. The result is reliable, and has certain superiority to conventional mechanics analysis method. It can provide scientific basis for slope of expressway maintenance decision-making.