On the influence of soil strength brittleness and nonlinearity on slope stability

The influence of soil shear strength brittleness and the nonlinearity of the shear strength envelope on factors of the safety of slope stability is investigated for two homogeneous slopes using polygonal and circular trial slip surfaces and three different procedures based on the limit equilibrium method, The results of the investigation show that a slower rate of post peak strength decrease in brittle soil could cause a larger difference in the factors calculated for brittle and ideally plastic soil, Also the nonlinearity of soil strength with changes in compressive stresses is less influential on the factors calculated for soil with a smaller basic angle of friction in drained conditions, For coarse grained soil this difference could be large and cause a discrepancy between the inferred shear strength at slope collapse and the measured strength in the laboratory. (C) 1997 Elsevier Science Ltd.