Tool based on the network method for the verification against failure by piping on retaining structures

Abstract

In the design of retaining structures, different geotechnical phenomena must be studied so they can be classified as safe. One of them is pipping, which is a physical process related to seepage under the structure. It leads to unstable situations that might finally end in a failure of the structure. As a way to quantify this risk, an accepted calculation is to compare the critical and the estimated hydraulic gradient. This comparison depends on the geometrical scenario, geotechnical parameters and flow conditions. However, the majority of the available solutions, such as formulations and graphics, have been developed only considering isotropic soils, which means that no realistic results can be obtained since media are commonly anisotropic. The aim of this paper is to provide a methodology with which an estimation of the average exit gradient can be obtained employing a computational model based on the network method. It consists on the analogy between electrical quantities (voltage and intensity) and geotechnical variables, which are water head and groundwater flow. The safety factor is calculated in the same way whether the considered soil is isotropic or anisotropic, and, in this way, the structure can be classified as safe from a geotechnical point of view.