Cracks With The Mechanical Properties Of Loess And Binary Medium Model To Establish

The author in this thesis, according to the field investigation and by doing the indoor and outdoor mechanical tests, such as the compression test, the direct shear test and the triaxial shear test, studied on the fissured loess with dif ferent embedded depths in Sanyuan ground fissure hazard early-warning testing field, discovered the macro-geology and micro-geology characters and development regularity of fissured loess and analyzed the strength and deformation of the loess, and at the same time, built the binary medium model of fissured loe ssBy analyzing the different angles of cracks, the confining pressure and the water content in unconsolidated-undrained triaxial test, the author got the strength and deformation characteristics of fissured loess. And based on this, classified the deforming failures into four types, for example, the axial deformation, the flexural deformation, the rotary deformation and the torsional deformation, and found the deforming modes are related to the moisture content, the formation age, the angle and position and confining pressure. According to failure mechanism, classified the deformations as elastic deformation, plastic deformation and breakage deformation.Based on the geomaterial breakage mechanics, the author regarded the fissured loess as a binary medium formed by cementing block and soft belt, and created a binary medium model. By measuring and selecting the model's parameters and comparing with the triaxial drained shear test, drew a conclusion that the binary medium model could describe the failure and deformation characteristics of fissured loess.