水化作用下矽卡岩动态力学响应及能量耗散特征

Dynamic Mechanical Response and Energy Dissipation Characteristics of Skarn Under Hydration

为探究矽卡岩在水化作用下的冲击力学性能,采用可加载轴围压的分离式霍普金森压杆系统(SHPB),分别对自然和饱水状态的矽卡岩试样开展了三维动静组合冲击试验,研究不同含水状态下矽卡岩试样的动态力学特性、能量耗散特征及破碎形态的差异性。结果表明:饱水状态下矽卡岩的动态抗压强度相比自然状态整体有所弱化,减小了10.47%~16.32%,但水对矽卡岩动态力学强度的影响随应变率的增大而逐渐减弱;水会降低矽卡岩试样对能量的吸收率,当吸能密度足够大时,动态抗压强度将不受矽卡岩内部水的影响;水化作用使得试样在饱水和自然状态冲击后的破裂形态率效应差异明显。

In order to examine the influence of hydration conditions on the mechanical properties of skarn,a Split Hopkinson Pressure Bar(SHPB)system was utilized to apply both axial and confining pressure.Cylindrical samples measuring 50 mm×50 mm were subjected to a combined static-dynamic loading method under natural and water-saturated conditions.The axial pressure applied was 3 MPa,with a confining pressure of 1 MPa.Impact tests were carried out at air pressures of 0.8,0.9,1.0,1.1,1.2 MPa,with three replicates conducted for each pressure level.The research examined the dynamic compressive strength,energy transfer characteristics,and fracture morphology of rock samples subjected to axial and confining pressures in different states.A comparison was made between the dynamic mechanical properties and fracture patterns of skarn samples in their natural and water-saturated states,with an analysis of the softening effect of water on the rock.Furthermore,the study investigated the dynamic mechanical properties,energy dissipation,and fracture morphology of skarn samples with varying water content.The findings suggest that the dynamic compressive strength of water-saturated skarn samples was,typically lower than that of samples in their natural state,with a reduction ranging from 10.47%to 16.32%.Nevertheless,the impact of water on the dynamic mechanical strength of skarn was found to decrease as the strain rate increased.Additionally,water was observed to decrease the energy absorption rate of skarn samples,although when the energy absorption density reached a certain threshold,the presence of water did not affect the dynamic compressive strength of the skarn.The impact fracture morphology of water-saturated and natural state samples exhibited differences in the strain rate effect due to hydration.Specifically,skarn in the natural state displayed more pronounced characteristics at lower strain rates.