CAJ | 학술논문

通过岩石加载的室内试验方法,测试不同岩石破裂全过程的力学特征及其声发射特性,得到岩石破坏全过程力学特性--岩石的全应力-应变曲线、声发射事件累积数、声发射事件率等相关曲线及参数,给出声发射事件数、事件率与应力水平、时间之间的关系.着重讨论一次性加载过程中塑性变形阶段明显的岩石在加载接近峰值强度时单位时间内的应力增长速度减小,也即这一阶段出现明显的"耗时"现象;并且在此阶段监测到的声发射事件率出现明显下降,出现声发射相对平静阶段;而对于塑性变形阶段不明显的岩石来说,这一阶段则基本不存在明显的"耗时"现象,声发射的监测中也没有发现声发射相对平静期现象.另外,还运用分形理论,研究分析处于不同加载应力比的岩样在各个阶段的声发射分形维数,特别是研究声发射平静期维数变化情况.指出在加载初期分形维数处于较低值,且分形维数随加载应力增加而逐步增加;在加载到峰值应力的40%左右时,分形维数开始下降;在加载接近到峰值应力时,即处于声发射平静期阶段时分形维数逐步降到最低,且此时预示着岩石的破坏.此外,结合室内试验,还对现场岩体失稳破坏声发射监测中的一些实际问题进行总结和分析,为更好地应用声发射手段进行岩体稳定性现场监测预报提供理论依据、方法和手段.
통과암석가재적실내시험방법,측시불동암석파렬전과정적역학특정급기성발사특성,득도암석파배전과정역학특성--암석적전응력-응변곡선、성발사사건루적수、성발사사건솔등상관곡선급삼수,급출성발사사건수、사건솔여응력수평、시간지간적관계.착중토론일차성가재과정중소성변형계단명현적암석재가재접근봉치강도시단위시간내적응력증장속도감소,야즉저일계단출현명현적"모시"현상;병차재차계단감측도적성발사사건솔출현명현하강,출현성발사상대평정계단;이대우소성변형계단불명현적암석래설,저일계단칙기본불존재명현적"모시"현상,성발사적감측중야몰유발현성발사상대평정기현상.령외,환운용분형이론,연구분석처우불동가재응력비적암양재각개계단적성발사분형유수,특별시연구성발사평정기유수변화정황.지출재가재초기분형유수처우교저치,차분형유수수가재응력증가이축보증가;재가재도봉치응력적40%좌우시,분형유수개시하강;재가재접근도봉치응력시,즉처우성발사평정기계단시분형유수축보강도최저,차차시예시착암석적파배.차외,결합실내시험,환대현장암체실은파배성발사감측중적일사실제문제진행총결화분석,위경호지응용성발사수단진행암체은정성현장감측예보제공이론의거、방법화수단.
Through the load test of rock,different rocks are tested and the mechanical and acoustic emission(AE) characteristics of rocks are studied. Stress-strain curves,AE accumulative total number and AE rate of rock failure are gotten. And AE features including the relationships between AE and time,AE and stress are studied. This study discusses emphatically the AE quiet period of the loading processes to those rocks whose plastic deformation is obvious. In this AE quiet period,the stress increment will be diminished in unit time when stress approaches to peak value strength and it will need more time. Moreover,AE rate will be declined and AE quiet period will also appear in this stage. But for those rocks whose plastic deformation is not obvious,this AE quiet period will not appear. In addition,by fractal theory,the AE values of different stress rates especially at quiet period are calculated and analyzed. It is found that the fractal values are lower in initial loading stages and increase gradually along with stress,about at the 40% of stress rate,fractal values begin to fall down. The fractal values go down to the minimum near the peak value stress and foreshow rock failure. Furthermore,combined with indoor experiment,some problems of in-situ monitoring and prediction are discussed,It gives the theoretical basis and methods for in-situ rock mass monitoring and forecast by AE technology.