Examining the Effects of Reinforcement in U.S. Forest Service Deep-Patch Landslide Repair Technique: Full-Scale Model Tests

A study was undertaken to investigate the effectiveness of the geosynthetic reinforcement in a skin-flow landslide repair method, known as the U.S. Forest Service deep-patch technique. A test apparatus, which can model a full-scale patched slope in the plane stain configuration, was devised and manufactured for the study. The test apparatus allows the behavior of the patched slope to be investigated in well-controlled test conditions. The base panel of the test apparatus contains a section that can be lowered gradually to simulate progressive failure underneath the patched slope subsequent to the repair work. Two tests, one with layers of geosynthetic reinforcement incorporated into the patched slope and one without any reinforcement, were conducted under otherwise identical conditions. Both tests were instrumented to monitor their behavior as the movable section of the base panel was being lowered. The effectiveness of the geosynthetic reinforcement, in terms of its potential for alleviating subsequent failures and its effects on the response of a patched slope during a subsequent failure, is discussed.