An equipment for dynamic direct tension tests of rock material under confining pressure

The dynamic tensile properties of rock material are the basic information to assess the safety of rock structure under dynamic loads such as explosion and earthquake. An apparatus to conduct direct dynamic tension tests with confining pressures for rock is introduced. In addition, a series of trial experiments are conducted by gypsum and granite samples. It is reported the change of strength for the gypsum and granite samples with strain rate and confining pressure are similar with that rock material under indirect dynamic tension tests, as well as the rock like material (concrete) under biaxial tension-compression tests. For this case, the apparatus is available to perform the dynamic direct tension test with confining pressure for rock material.