A Novel Approach for Determining Pile Spacing considering Interactions among Multilayered Sliding Masses in Colluvial Landslides

Abstract

It is reported that there are many colluvial landslides with multilayered sliding masses; however, previous studies of the pile spacing of stabilizing piles mainly focus on the single-layered sliding mass, which may lead to design errors for pile spacing. Consequently, the paper presents a novel method to determine the pile spacing with considering interactions of multilayered sliding masses in colluvial landslides. Based on a generalized landslide model, equations for calculating stability coefficients of multilayered sliding masses were improved by examining the interactions among sliding masses. An accordingly colluvial landslide model with double-layered sliding masses was established by the finite differential method. The distribution of vertical landslide driving force and horizontal loading between adjacent piles were studied based on the colluvial landslide. A novel method of calculating the maximum pile spacing and minimum pile spacing was deduced by considering the soil arching effect and the interactions among multilayered sliding masses. The reasonable pile spacing was obtained considering cost and performance of stabilizing piles. The calculational process, which determines optimal pile spacing in multilayered masses, were shown based on the Bazimen landslide. The variations in pile spacing affected by various soil-layer sequences was illustrated by employing the Bazimen landslide model. The calculation results indicate that the pile spacing is positively correlated with the depth of soil with the maximum resistance sliding force. Effectiveness and significance of the presented method were proved through verify the calculational results by using numerical modeling approaches.