Effect of dynamic load and geo-stresses on dynamic energy evolution characteristics of red sandstone
During the process of blasting excavation in underground rock masses,dynamic loads and geo-stresses are affected by the distance from the blast source,leading to different dynamic energy evolution characteristics in rocks.To study the impact of dynamic load and geo-stresses on the energy evolution characteristics of red sandstone during dynamic fracture,this paper conduct impact compression tests on red sandstone used a combined dynamic and static loading test system.During the tests,five impact velocity and axial static stress levels were set.The research results show that reflected energy and transmitted energy increase according to a power function with increasing impact velocity,while absorbed energy increases according to a logarithmic function with increasing impact velocity.When the impact velocity is constant,absorbed energy decreases with increasing axial static stress.When the axial static stress equals 20％of the uniaxial compressive strength of red sandstone(13.5 MPa),the absorbed energy coefficient is the highest.This indicates that a reasonable ratio between dynamic and static loads can improve energy utilization of the red sandstone during dynamic facture process.
rock dynamicsSHPBimpact velocitythree-dimensional static stressenergy evolution
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