Nonproportional Correlative Reduction Finite Element Method for Slope Strength Parameters

To solve the problems presented by the rational determination of the reduction mode in the traditional strength reduction method and to overcome the difficulty in determining double safety factors from the existing double reduction factors method, a nonproportional relationship between the cohesion reduction factor and the internal friction angle reduction factor is established for a case in which the strength parameter distribution obeys the linear attenuation assumption. By introducing this correlation into the traditional strength reduction finite element method, the nonproportional correlative reduction finite element method for slope strength parameters is proposed. To verify the reliability of the proposed method, the nonproportional correlation is introduced into Bishop’s slice method, yielding the nonproportional double safety factors of Bishop’s slice method. For the whole safety storage of the slope based on the double safety factors, a comprehensive safety factor with the contribution of the shear strength parameter to the sliding resistance force as weight is proposed. Finally, in combination with an example and a comparative analysis of the slope sliding surface positions and the comprehensive safety factors for three different types of reduction modes with two types of methods, the rationality and reliability of this method were validated.