为了定量研究受爆破冲击后岩石在三向应力作用下的力学特性,采用在大块砂岩(600 mm×600 mm×120 mm)中钻眼安装粉状硝铵炸药和火雷管爆破的方式,制备了一批经受过冲击损伤的标准试样;然后开展了3种围压作用下的三轴压缩试验,基于试验结果分析了爆心距和围压对砂岩力学性质的影响.研究表明:①随着爆心距的增加,试样的三轴抗压强度、弹性模量、软化模量、内摩擦角和黏聚力表现出以幂函数强化的趋势,而泊松比呈现出以幂函数弱化的趋势,峰值应变逐渐增大但较为离散;爆心距相同的试样,其宏观力学参数随着围压的增加而增大,而软化模量却减小.②试样的声发射活动随着爆心距的增大变得滞后,且爆心距越小岩石的声发射活动越强烈.③随着爆心距的增大,试样的脆性变形特征不断增强,破坏模式由张拉破坏变为拉剪混合破坏,进一步演化为剪切破坏.%In order to conduct quantitative study on the mechanical behavior of rock that has gone through blasting shock under three-dimensional stress,the method of drilling and installing powdery ammonium nitrate explosive and flash detonator blasting in large blocks of sandstone(600 mm×600 mm×120 mm) is adopted to prepare a group of standard samples for labo-ratory experiment that have gone through the impact damage. The influence of blasting center distance and confining pressure to the mechanical properties of sandstone samples are analyzed through the triaxial compression test under three kinds of confining pressure. The study results show that:①with the increasing of blasting center distance,the triaxial compressive strength,elas-ticity modulus,softening modulus,internal friction angle and cohesion of the samples present a strengthening trend of power function,but Poisson ratio presents a weakening trend of power function,and the peak strain increases gradually but relatively scattered,the macro mechanical parameters of samples with the same blasting center distance increase with the increasing of confining pressure,but softening modulus decreased with the increasing of confining pressure;②AE activity of the samples be-comes lag with the increasing of blasting center distance,and the more smaller blasting center distance is,the more strongly AE activity of the samples is;③With the increasing of blasting center distance,the brittle deformation characteristics of samples is continuously strengthened,and the failure mode changes from tensile failure to tension and shear failure and further evolves shear failure.
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