Mechanical Response And Comprehensive Treatment Technique For Expansive Soil Cut Excavation

Expansive soil is one kind of special clay, which has over consolidated, fracture and swell-shrinking characteristics. Expansive soil cutting landslide has always been a difficult problem in highway construction. Expansive soil cutting is stable in the early excavation, but after cyclic dry-wet process the slope which is not addressed of fern instability failure. We must understand the process and mechanism of landslide, which has important directive significance to the design of slope reinforcement measures.This article takes expansive soil cutting slope in Nanning to Baise expressway as the research object, based on the expansive soil sections in-situ test and laboratory test experiment, we master the genetic type and basic physical and mechanical parameters of nan-bai soil. In view of the conventional limit equilibrium method only can solve the overall stability of the slope analysis, this article use finite difference software FLAC research the change of stress, strain, displacement in the expansive soil cutting excavation process. As times we study progressive failure of slope excavation and wet and dry cutting cycle on the effects of expansive soil, analysis of wet and dry cycles posterior instability of cutting the reasons for the treatment of expansive soils provides a theoretical basis for landslide. Because of a part of the cutting excavation of Nan-bai expressway did not take timely protective measures, after wet and dry cycles occur a lot of landslide. According to this situation, we carried out dynamic control measures which include slope protection, surface water protection and retaining structures to protect slope and have received the good result.