LSP methodology for determining the optimal stabilizing pile location for step-shaped soil sliding

Abstract

Previous determinations of the optimal stabilizing pile location have generally been based on the idealized assumption of arc-shaped sliding surfaces. This assumption, however, may be inconsistent with the actual situation of most common irregular shapes, such as the step shape; as a result, determinations based on this assumption tend to involve considerable error. This paper presents a strategy, termed the local safety partitioning (LSP) methodology, for accurately determining optimal pile locations for step-shaped configurations. Instead of assuming the sliding surface to be arc-shaped, this strategy considers the actual sliding shapes. A new index termed the local safety factor is introduced for measuring the stabilities of local landslide masses, and this method employs the Swedish slice method to calculate the value of the index. The LSP methodology consists of four procedures: slicing the landslide mass into blocks, calculating the local safety factor of each sliced block, dividing the landslide mass into local partitions based on the previous step, and identifying the optimum pile position using previously identified partitions. The performance of the presented methodology is illustrated using the Jinle No. 2 landslide case for well-rounded demonstration and using the Yancun landslide case for additional validation. The results indicate that analysis of a reinforced landslide employing the LSP methodology acquires the largest safety factor and smallest deflection, shear force and bending moment on the pile body compared with any other case from a series of positions that incorporate traditional positions for arc-shaped sliding surfaces. The presented methodology provides a simple but accurate determination of the optimal stabilizing pile location for stepped sliding surfaces, although it may involve errors and unexpected limitations when applied to arc shapes and peculiar scenarios.