The Analysis Of The Structural Property And The Slope Stability Of The Granite Residual Soil

The granite residual soil is widely spreads among the southeastern coastal area. The granite residual soil showed quite considerabel strong structural property which is closely related to its slope stability. The accumulated impact of the micro transformation of soil structure contributes to the strength of soil and the soil deformation macroscopically. This research focuses on the granite from Fujian province. The experiments are conducted in labs, by the investigation in the related construction sites,, the utilization of the microscope, the X-ray diffraction analysis, the method of SEM scanning, etc.The research reveals the structural characteristics of the two different soil examples from the macro perspective to the micro perspective. Based on the analysis, the dissertation reveals the influence of the structural properties on the slope stability. The main content and the major findings of the research are as follows:(1) The research is focusing on the reconstituted soil sample and the undisturbed soil sample. From macro perspective, the research determines the relationship between structural property of granite residual soil and their mechanical properties by both qualitative and quantitative methods. The results show the structural property of the granite residual soil strengthens its ability of resisting outward damaging forces. With the damage of the structural property, the resisting ability decreases correspondingly. Also, the granite residual soil with stronger structural properties loses its cohesive characteristics faster than those with weaker structural properties.(2) Through XRD ray diffraction method, the research analyzes the mineral compositions of the two samples and then investigates the effect of the mineral composition on the mechanical properties. The results reveal that the percentage of the cohesive materials in the granite residual cohesive soil, which can help to form the structural connection with related clay minerals in soil, is higher than that in the granite residual sandy clay. Also, the adhesive capacity of the granite residual cohesive soil is stronger.(3) The research investigates observed the microscopic morphology of the two types of soils by the SEM scanning. The findings reveal the granite residual cohesive soil mainly has the structure of flocculation polymer, while the granite residual sandy clay basically has the granular texture and the platy texture with mainly mosaicstructures and auxiliary structures and few adhesive flocculent materials between grains, which again explains its poorer adhesive capacity compared with the granite residual cohesive soil. The different structure of the two types of soil determines the different performances of the soils after they encounter with structural damage.(4) Based on the data collected, the research uses a geological model of the granite residual soil slope with the appropriate physical and mechanical parameters. With the help of Slope/W software, the research evaluates the influence of the damage of the granite residual soil structural property on the slope stability. Through the study, it presents the slope stability declines rapidly after the destruction of the granite residual cohesive soil structure which can lead to the decreasing of the resistant capacity again external damages, like excavating, relieving loads, rain seepage, etc.The research reveals the engineering properties of residual soil in depth, analyzes the instability mechanism of the granite residual soil slope, which has an important theoretical and practical significance on the prediction and control regarding landslide in granite residual land area.