【摘要】 以取自拟建大连地铁二号线的石灰岩试件为研究对象,用单轴循环加卸载扰动来模拟交通荷载,进行该加载过程的声发射特性研究,并利用RFPA2D模拟岩石加卸载循环下的破坏过程。试验结果证实该种石灰岩存在Kaiser效应,也证实加卸载下的Felicity效应的存在。将加卸载理论应用于岩石的声发射前兆分析中,将加卸载响应比Y值达到(接近)1作为此种岩石失稳破坏前兆特征;石灰岩破裂过程中声发射能量加速释放现象明显。数值模拟结果能看到明显的Kaiser效应以及各步对应的声发射现象,将模拟结果与试验结果进行对比发现,岩石均质度系数m=5时,二者最为接近。所得结果可望为地下工程的施工安全研究提供理论依据。更多还原

【Abstract】 Take limestone samples from metro Line 2 as research objects,and study acoustic emission(AE) characteristics under uniaxial cyclic load-unload disturbance,which simulate the traffic load disturbance,then carry out numerical simulation of rock failure process under load-unload by RFPA2D.The results confirmed the existence of Kaiser effect of such limestone,also confirmed the existence of Felicity effect under loading-unloading.Loading and unloading theory will be applied to the rock acoustic emission precursor analysis,taken the Y value(load/unload response ratio,LURR) reach(close) to 1 as a precursor of failure characteristics of such rock.The AE energy of such stone accelerated release obviously.The numerical simulation shows evident Kaiser effect,and the corresponding AE event vividly.The comparison of the results of simulation and tests shows that,the two are the most closed when the coefficient of homogeneity m is 5.The results are expected to provide basis for construction safety and to avoid geological disaster in the underground works.更多还原