预应力下组合试件冲击荷载试验能量耗散研究

Study on Energy Dissipation in Impact Load Test of Composite Specimen under Prestress

为研究矿房爆破回采时,爆破动荷载对相邻尾砂胶结矿柱的稳定性影响,基于分离式霍普金森(SHPB)实验系统,对矿岩-胶结充填体组合试件开展三维动静组合SHPB实验,研究冲击荷载穿过矿岩对不同强度胶结充填体能量传递特性。试件在0.45MPa、0.50MPa、0.55MPa和0.60MPa四种冲击气压下,三种轴围压组合(Z_(0.9)-W_(1.8)、Z_(1.8)-W_(3.6)和Z_(2.7)-W_(5.4))条件下的能量传递特性经实验研究表明:Z_(0.9)-W_(1.8)时吸收能随着冲击气压增大,Z1.8-W3.6时吸收能随着冲击气压先增后减,透射能有细微增大。引入了实验的能量比例N_(X),发现80%以上的能量以反射能的形式返回入射杆;并建立四级筛分系统,统计分析试件破坏后的不同直径大小碎块的质量分数。

To study the effect of blasting dynamic load on the stability of the adjacent tailings cemented column during blasting and retrieval in the mine,based on the SHPB experimental system,the effects of impact load on the physical capacity transfer with different strength were studied.The energy transfer characteristics of specimens under three axial confining pressures(Z_(0.9)-W_(1.8)、Z_(1.8)-W_(3.6)and Z_(2.7)-W_(5.4))with the impact pressure of 0.45MPa,0.50MPa,0.55MPa,0.60MPa were experimentally studied under the three-dimensional dynamic and static combination SHPB.Experimental results show that:The absorption energy increases with the impact pressure when Z_(0.9)-W_(1.8),absorption energy with the impact of air pressure first increase and then decrease when Z1.8-W3.6,The experimental energy ratio is introduced,and it is found that more than 80%of the energy is returned to the incident rod in the form of reflected energy.A four-stage screening system was established to analyze the mass fraction of broken pieces with different diameters.