Testing Study On Engineering Mechanical Properties Of Basalt Residual Soil In Guizhou

The basalt widely distributed in Guizhou area, which is located in the eastern of MountEmei weathered basalt zone, its characteristic is different clearly from common carbonate rock,the rock fracture developed where basalt distributed. The thickness of basalt residual soil insurface distributes from a few meters to dozens of meters, its color changes along depth, fromreddish brown to dark brown. The weathering degree of soil is great, engineering properties isnot stable, the crack, slope and collapse of soil is serious, landslide in large scale probaly happenon some conditions, is regional unfavorable geological. Due to the hot and humid, rainysubtropical plateau monsoon climate characterized by dry winter and wet summer, the residualsoil in basalt area has weak-strong expansion and clay soil characteristic, the physical propertyis poor and mechanical nature is good. The basalt itself is easy to collapse, the highway andrailway builted in the area are prone to lead to the engineering accidents and geological hazardsin construction and operations process, which is serious threat to national economic constructionand people’s life and property safety. In this article, through field investigation and exploration,in-situ test, a series of indoor soil tests, extenics study and other comprehensive research tools, itcarries on systematic and in-depth study on engineering mechanical properties of basalt residualsoil in construction, provides essential data and theoretical basis for the follow-up studies ofbasalt residual soil.Main work and conclusions are as follows:1. It is systematically summed up that research on the basalt residual soil in Guizhou and itsmechanical characteristics of engineering at home and abroad, the content and direction of studyon engineering mechanical properties of basalt residual soil is identified.With field investigationand exploration as the basis，it has got preliminary understanding of basic physical properties ofbasalt residual soil, and sampling fully to make systematic test.2. By laboratory tests, including the liquid-plastic test, grain size analysis test, specific gravitytest and other tests, physical properties of basalt residual soil in Guizhou area is revealed. Theresidual soil is analyzed, also the physical properties and weathering degree of different kinds ofresidual soil is comparied.3. The basalt residual soil is classified by weathering degree and the physical properties, toreveal the compression index and shear strength parameters and evaluate the engineeringmechanical properties, the soil is analyzed by a series of tests both for the undisturbed soil on thedifferent water content conditions and the remolded soil on the different water content and drydensity conditions.4. Based on extension set theory, combining qualitative and quantitative methods, the extenicsevaluation model considering multiple categories and multiple index parameters on residual soil of basalt was established based on statistical data of physical and mechanic parameter oflaboratory test. The extension evaluation program was built through computer programming andwas verified with data obtained from in-situ test. Meanwhile the possibility of the extensionevaluation model on residual soil was discussed.5. The achievements of the engineering mechanical properties of basalt residual soil aresummarized, the test results are analyzed deeply and comparatively, the later tasks are alsoprospected.