CAJ | 학술논문

采用带围压装置的φ100 mm霍普金森压杆系统，对砂岩试样进行了单轴冲击和4 MPa、20 MPa围压条件下的循环冲击试验，并对每次冲击前后的砂岩试样进行超声纵波检测，分析了砂岩在冲击荷载循环作用下的应力、应变特征，定义了砂岩试样的屈服－弹性比用以描述围压下试样应力应变曲线的弹塑性特征，采用纵波波速定义了砂岩试样的冲击损伤并分析了循环冲击试验中砂岩试样纵波波速和应力应变之间的关系。分析发现：在围压作用下，应力－应变曲线呈现典型的弹塑性特征。随着冲击荷载循环作用次数的增加，砂岩试样屈服应力、峰值应力降低，屈服应变、峰值应变增加。随着循环冲击作用次数的增加，砂岩试样的应力、应变特征与纵波波速之间存在良好的相关关系。较低围压状态下累计损伤度明显高于较高围压下砂岩的累积损伤，砂岩循环冲击损伤具有明显的围压效应。研究结果对地下工程的建设和防护有一定的指导意义。
채용대위압장치적φ100 mm곽보금삼압간계통，대사암시양진행료단축충격화4 MPa、20 MPa위압조건하적순배충격시험，병대매차충격전후적사암시양진행초성종파검측，분석료사암재충격하재순배작용하적응력、응변특정，정의료사암시양적굴복－탄성비용이묘술위압하시양응력응변곡선적탄소성특정，채용종파파속정의료사암시양적충격손상병분석료순배충격시험중사암시양종파파속화응력응변지간적관계。분석발현：재위압작용하，응력－응변곡선정현전형적탄소성특정。수착충격하재순배작용차수적증가，사암시양굴복응력、봉치응력강저，굴복응변、봉치응변증가。수착순배충격작용차수적증가，사암시양적응력、응변특정여종파파속지간존재량호적상관관계。교저위압상태하루계손상도명현고우교고위압하사암적루적손상，사암순배충격손상구유명현적위압효응。연구결과대지하공정적건설화방호유일정적지도의의。
Based on a φ100-mm-diameter split Hopkinson pressure bar with confining pressure apparatus uniaxial impact tests and cyclical impacting tests with confining pressure of 4 MPa and 20 MPa on sandstone specimens were carried out.Meanwhile,the ultrasonic longitudinal wave test was executed before and after each impact.The stress-strain properties of sandstone under cyclical impact were analyzed.The relationship between these properties and longitudinal wave velocity (Vp)in sandstone was analyzed and the impact damage was defined by the Vp.The yield-elasticity-ratio was defined to analyze the elastic-plastic characteristics of sandstones under confining pressure.The results show that,the stress-strain curves under confining pressure present a typical elastic-plastic feature.With the increase of cyclical impact times,yield stress and peak stress of sandstone sample reduce while yield strain and peak strain increase.The accumulative damage under lower confining pressure is apparently higher than that under higher confining pressure.The cyclical impact damage of sandstone shows an obvious confining pressure effect.The results have a guiding significance to the underground construction and protection.