Landslide Stabilization Using Wick Drains. Final Report for Highway-IDEA Project 76

摘要

A method has been developed to use soil wick drains for a novel application of landslide and slope stabilization. Wick drains are flat, fabric-coated plastic channels, which were initially developed to be vertically driven into the ground using a specially adapted crane. They accelerate consolidation and settlement by an order of magnitude by significantly shortening the flowpath for water to exit a soil layer. An earlier portion of this study developed equipment to install wick drains horizontally, so that they might be used to drain landslides. The equipment was tested at several sites, and the process was shown to be quick, inexpensive, and effective at removing water from slopes. The current portion of the study completed two additional full scale installations in Missouri and Colorado, and developed and tested a pipe gripping device to streamline the installation process. Laboratory experiments to assess potential clogging of wick drains were conducted over a period of two years. Finally, a procedure was developed to estimate the shape of the water table surface for drained landslides, using parameters easily measured in the field and laboratory, and this procedure was applied to computer slope stability analysis of two of the stabilized landslides.