【摘要】 对花岗岩样品进行逐次加载的蠕变实验,得到了加载过程中的蠕变曲线和蠕变破裂的全过程曲线.对加载过程中的杨氏模量、蠕变量、蠕变速率等参数用加卸载响应比方法进行了分析,认为有二种不同形态的响应曲线.在中低应力的弹性阶段其响应比都近似为1,而在高应力的膨胀阶段其响应比都随应力而增加.对应力不变时的蠕变破裂全过程曲线进行了分解,在蠕变破裂过程中,瞬态、稳态和加速3个阶段的持续时间分别为全部时间的18%,75%和7%;在加速蠕变阶段蠕变速率及其响应比明显增加.这一结果是预测蠕变破裂的明显指标.更多还原

【Abstract】 Creep experiments with a granite sample were performed by using graded loading method. The creep curve during the gradual loading process and creep fracture curve under uniform stress were obtained. The parameters,such as Young’s modulus,creep value and creep rate,were analyzed with Load/Unload response ratio (LURR) method. There are two different types of response ratio curves,but the LURR value was near 1 at low stress or in elastic deformation phase,then the LURR was increasing at high stress or in rock dilation phase. The whole creep fracture curve under uniform stress was decomposed to three phase: instantaneous,steady and accelerating creep,with the ratio of duration time of each phase over whole time being about 18%,75% and 7% respectively. The creep rate was increasing remarkably in accelerating phase and it was a useful parameter for predicting the creep fracture.更多还原