Seepage-Induced Erosion in Granular Soil and Consequent Settlements

Abstract

The erosion of the fine fraction of granular soils due to seepage is a possible cause of the settlements of shallow foundations. Here the problem is tackled with reference to deep pumping wells to be installed in an urban area. First, the results of laboratory tests on reconstituted soil samples are illustrated that provide the quantity of eroded particles during time depending on the imposed hydraulic gradient. Based on the experimental data, an incremental erosion law is proposed that has been implemented in a finite-element code for erosion-transport analysis. After describing the steps of the numerical solution procedure, the results of two- and three-dimensional finite-element calculations are discussed. They provide an estimation of the quantity of eroded material in the vicinity of the pumping wells and of the possible consequent settlements of nearby buildings.