Shimian-Luding Section Physical And Mechanical Parameters Of Granite Weathering And Microscopic Study On Correlations Between Characteristic Index

Thesis supervisor research project "Evaluation and disaster Southwest mechanism of deep geological hazard survey Slope Valley region" as the basis, the main content is (Shimian to Luding section) weathered granite study law Dadu River, with different degrees of weathering by means of quantifying granite classification, combined with scanning electron microscopy and image recognition technology to analyze the relationship between the various quantitative indicators and microscopic characteristics between investigate whether there is some correlation between the extent of the study area microscopic characteristics of weathered granite and quantitative indicators, so as to more accurately predict the mechanical properties and degree of weathering of rocks. The main conclusions obtained by studying the following:Through trials for Granites physical properties of dry density, range of valid values correspond to different weathering degree of porosity, and appears in the adjacent weathering grades with varying degrees of overlap. Dry density values increase as the degree of weathering of the overall downward trend between grade iii, iv, v weathering degree of rocks divided you can try with a p value of d. Effective porosity increases with increasing degree of weathering. When weak weathering degree of rock available effective changes of porosity characterization of weathering degree of rock. Weathering grade, the higher the total porosity and the smaller the difference between the effective porosity.With the increase in strength of weathered, uniaxial compressive strength of the downward trend in higher weathering grade overlap. Tangent modulus of elasticity and has very good correlation between uniaxial compressive strength (R2=0.96), but for the evaluation of weathering degree of accuracy, uniaxial compressive strength is superior to a tangent modulus of elasticity.Brazil experiments, through stress-strain characteristics of radial, introduces a new index, called Brazil deformation index (BDI), as weathering increases, BDI in higher weathering grade showed very strong regularities, strong weathering degree of all indicators in the evaluation is the most accurate indicator. Concluded that BDI is a very effective measurements of different degrees of weathering granite.Rebound hammer test, proposes a new specification method for rebound number to offset the influence of gravity. Rebound value are offset by the effect of gravity normalized analytical formula applies to a wide variety of rock materials and through standardization, springback values calculated from measured in any direction. As the degree of weathering and weathering coefficient values for rebound, rebound the decrease as weathering increases. Under the level of all weather, uniaxial compressive strength and shear modulus of elasticity values can pass and rebound a preliminary forecast.As the degree of weathering, Is (50) showed a decreasing trend. At between IV and v levels, overlapping is clear and sharp decline in strength compared with3levels. The experiment again, weathering effect on mechanical strength of rocks is very notable. Point loading has very close ties with uniaxial compressive strength, curve fitting equation is:. And presents the point load test, cone penetration depth in the fresh/hard rock is not able to be ignored, cone penetration depth calculation for further research. For distribution in the different degree of weathering granite in the study area, weathering degree of evaluation using the point load is possible.By analyzing the different content of mineral composition and degree of weathering of granite, finally settled on LQ/SQ from micro-fracture density indicators as measurements. And the indicators associated with the UCS and Eq with a good, therefore can be used to predict mechanical properties of indicators.According to the size of the regression coefficient R2, we can draw the tangent and uniaxial compressive strength and modulus of elasticity is most closely related to the indicator, springback values for the point load strength≥BDI>LQ/SQ>> effective porosity> dry density. BDI almost no overlap between the various weathering grades, point load, like other indicators, will be significant overlap between some weathering grade. From the perspective of microcosmic indicator, at the time of study on mechanical behaviors of rock, micro-cracking plays a very important role, it is also physical and mechanical test results consistent with.