Research On Evolution Rule Of Baise Expansive Soil Cutting Slope Excavated And Flexible Supporting Treatment Technology

The collapse took place after some time of cut slope excavation which is completed is a common disease in expansive road construction projects. This destruction has no direct contact with the height and ratio of slope. The flexible retaining method has treated the disaster by engineering practice, but the dealing object is cut for the already slippery slope. In order to apply the flexible supporting structure methods in new expansive soil roads directly, it's necessary to study the deformation and destruction of the law, that the wet and dry to the expansive soil slope of bare, then the implementation of the flexible supporting structure methods and the best time is obtained. Therefore, this dissertation is combined the Bailong expressway which is constructing as research background. The actual evolution of slope cutting in the excavation works site is observed. Expansive soil cutting in the excavation of the variation of stress and strain and geogrid treatment technique for flexible supporting is researched through FLAC.First, the physical geography and regional geological structure of expansive soil in Baise is studied. We study typical expansive soil strength characteristics of soil properties which through the artificial sample and reference materials of geological exploration methods, then the stability analysis and design Treatment programs need to parameters are obtained.Second, the finite difference procedure FLAC is used to analysis the regularity of expansive soil cutting excavation process and the stability of the stress and strain variation, we found that the displacement field, stress field, strain field are growing with the excavation, the safety factor also been reduced, but it's stable when the cutting was completed, which is consistent with the construction site; the dry and wet cycles on the impact of excavating was also studied. The actual evolution of slope cutting in the excavation works site is observed. We use FLCA to simulate the process of landslide after wet and dry cycles of the cutting. If the cutting is not treatment immediately after excavation, the shallow slip will be happen after the wet and dry cycles. These have been verificated by the actual construction site.Finally, the traditional cutting of expansive soil treatment method and disadvantages was analyzed. The flexible supporting structure method is proposed in cutting excavation which was completed quickly of Bailong expressway. The flexible supporting structure method construction technology and technical standards were studied. The flexible supporting structure method use conventional road-building machinery. The construction is simple and no special technical is required. If material, machinery, personnel in place, good weather, the completion of a 10m high and 100m long slope requires only ten days.This article research the feasibility and best time to implementation the flexible supporting structure methods directly using in the new highway engineering and provide a basis and reference of "every cut must slide" in the expansive soil areas.