【作者】 刘月妙； 王驹； 谭国焕； 林侨兴；

【Author】 Liu Yue-miao;Wang Ju;Tan Guo-huan;Lin Qiao-xing;Beijing Research Institute of Uranium Geology;Department of Civil Engineering,The University of Hong Kong;

【机构】 核工业北京地质研究院； 香港大学土木工程系；

【摘要】 中国高放废物的最终处置方案是深地质处置,花岗岩为我国高放废物处置库的候选围岩,甘肃北山地区已被初步选定为我国高放废物处置库场址的重点预选区。通过一系列室内蠕变实验,研究在不同温度(室温,50℃,90℃)与围压(单轴,10 MPa,30 MPa)条件下,北山花岗岩在不同恒定应力水平下的变形特征。温度和围压对岩石的力学性能有着重要的影响。随着温度的升高,围压为10MPa和30 MPa时的弹性模量逐渐升高,至70℃左右时达到最高,之后随温度的升高略微降低;裂纹损伤应力呈线性显著降低,而泊松比呈线性明显升高。稳态蠕变阶段的应变速率随着温度的升高而明显加速,在同一应力比下到达破坏的时间相应降低。随着恒载应力的降低,似斑状二长花岗岩达到破坏的时间显著增长。随着围压的增加,轴向蠕变变形量明显增加;在相同的应力比下,导致岩石断裂破坏的时间显著延长。更多还原

【Abstract】 A preliminary R&D program for the deep geological disposal of high-level radioactive waste(HLW) has been proposed in China.The HLW repository concept is shaft-tunnel-silo located in a saturated zone in granite.The Beishan area in a Gobi desert in Gansu province is considered as the most potential candidate area for HLW geological repository in China.The strain behavior of granite under constant loading with different temperatures(room temperature,50℃,90℃) and confining pressures(0 MPa,10 MPa and 30 MPa) are studied through creep test.The results indicate that the effect of temperatures and confining pressure on the mechanical property is significant.When the confining pressure is 10 MPa and 30 MPa,the elastic modulus increases with the temperature increases to about 70℃,and then decreases a little with the temperature increases;the crack damage stress linearly decreases and Poisson’s ratio linearly increases separately with the temperature increases.The steady state creep strain rate increases and the time to failure response at the same stress ratio reduces with the temperature increases.The time to failure increases rapidly as the constant load decreases.Axial creep strain increases and time to failure of granite at the same stress ratio increases rapidly when confining pressure increases.更多还原