Analysis of soil nailed earth slope by discrete element method.pdf

ELSEVIER Computers and Georechnics, Vol. 20, No. 1, pp. I-14, 1997 0 1997 Elsevier Science Ltd Printed in Great Britain. All rights reserved PII: SO266-352X(96)00010-9 0266-352X/97 $17.00+ .OO Analysis of Soil Nailed Earth Slope by Discrete Element Method J. S. Kim, J. Y. Kim S. R. Lee Department of Civil Engineering, Korea Advanced Institute of Science and Technology, Taejon, Korea (Received 9 August 1995; revised version received 8 July 1996; accepted 24 July 1996) ABSTRACT Soil nailing has been widely used during the last two decades, to stabilize steep excavated slopes in several countries. In this study, the discrete element method (DEf) has been applied to evaluate the stability of reinforced slopes. This method is capable of not only estimating tensile and shear stresses mobilized in nails but also providing individual safety factors for soil and nails. It has been assumed that the nailed slope is composed of slices connected together with elastoplastic Winkler springs. In replacing nails by spring elements, a function is proposed for evaluating shear and tensile forces in nails which are induced by relative displacements between nail and adjacent soil. Taking into account for the sequence of construction, the developed method can predict the measured tensile forces in nails and hence it properly evaluates both local and overall stabilities of the reinforced slope. 0 1997 Elsevier Science Ltd. All rights reserved. INTRODUCTION Soil nailing technology is currently adopted as a cut slope retaining system, generally in nonplastic soils. The design methods that have been mostly used are Davis [l], German [2], and French methods [3], on which the limit equi- librium approaches are based [4]. Recently, a kinematical limit equilibrium design method has been proposed by Juran [5] and Byrne [6]. This method provides estimated values of maximum tensile and shear forces mobilized in each reinforcement. In Juran’s method, the normal stress