Influence of material dilation angle on stability of homogeneous slope with surcharge load

 

Hang Lin

School of Resources & Safety Engineering; Central South University, Changsha, 410083, China
Engineering Research Center of Catastrophic Prophylaxis and Treatment of Road & Traffic Safety, Ministry of Education, Changsha, Hunan, 410114, China; e-mail: linhangabc@126.com

Ping Cao

School of Resources & Safety Engineering, Central South University, Changsha, 410083, China; e-mail: pcao_csu@163.com

ABSTRACT

Dilatancy is a well-known characteristic of geomaterials, and is an increase in volume during the process of deformation. But in slope stability analysis, the widely used methods like limit equilibrium method and limit analysis method can not reflect the soil dilatancy characteristic properly. So the present paper tries to solve this problem, and find out the influence of material dilatancy on stability of slope. In the paper, numerical modelling for the homogeneous soil slope is conducted in plane strain mode, and the parametric analysis is done, the only varied parameter is the dilation angle of the soil with all other soil properties values remain as the same, the corresponding slip surfaces and safety factors are obtained, then finally concluded that, (1) under the situation without surcharge load P on the top surface of slope, when dilation angle increases, relationship between safety factor and dilation angle represents the discipline of parabola form, whose curve first increases then decreases, the distance between superior margin of slip surfaces and vertex of slope become smaller; differences between the safety factor for associated flow rule and non-associated flow rule represents the discipline of parabola curve form with the increase of friction angle; (2) under the situation with surcharge load P on the top surface of slope, when P increases, safety factor for non-associated flow rule reduces gradually, and the effect of dilation angle to the safety factor is lagged behind with the increase of friction angle; slip surface become steeper while the superior margin come closer to the slope vertex.
KEYWORDS: Slope; Surcharge load; Safety factor; Slip surface; Dilation

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