EXPERIMENTAL STUDY OF DYNAMIC MECHANICAL PROPERTY OF DAGANGSHAN GRANITE
(State Key Laboratory of Geomechanics and Geotechnical Engineering，Institute of Rock and Soil Mechanics，Chinese Academy of Sciences，Wuhan，Hubei 430071，China)
Abstract：Taking the Dagangshan granite specimens for example，the conventional(static) triaxial compression tests and dynamic triaxial compression tests are both carried out to analyze the relationships of some important parameters such as compressive strength，Young¢s modulus，Poisson¢s ratio and their corresponding ultimate stress with strain rate. The research results show that under different confining pressures，with the increase in strain rate，lateral failure strain keeps invariant within the range of 0.002–0.004，axial failure strain increases a little and compressive strength of the granite increases significantly. The results also show that the increase in Young¢s modulus tends to reduce with the confining pressures，and the Poisson¢s ratio has no evident relation with the increase in strain rate. Based on the static complete stress-strain curves and damage mechanical analysis of Dagangshan granite，it is found that the brittle rock damages mainly are lateral damage types. Through regression analysis，damage evolution equation of the Dagangshan granite under static triaxial compression is set up. The rate-correlation between dynamic damage and static damage is further established according to damage theory. Considering the correlation between dynamic strength and initial Young¢s modulus，the experiential dynamic damage constitutive model for rock is established，which can be used as a basis for analyzing the attenuation law and strain wave spreading of rock mass under earthquake loads.
CHONG K P，HOYT P M，SMITH J W，et al. Effects of strain rate on oil shale fracturing[J]. International Journal of Rock Mechanics and Mining Sciences，1980，17(5)：35-43.
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2010, Vol. 29 
