Basic physico-mechanical properties and time-temperature effect of deep intact rock from Beishan preselected area for high-level radioactive waste disposal
Basic physico-mechanical properties and time-temperature effect of deep intact rock from Beishan preselected area for high-level radioactive waste disposal
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发表时间：
2007
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通讯作者：
Y. Liu;J. Wang;L. Tham;M. Cai
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作者：
Y. Liu;J. Wang;L. Tham;M. Cai
物理力学性质是高放废物处置场选址、设计、施工和性能评价的重要依据之一，通过全国范围的筛选和比较，甘肃北山地区是我国高放废物地质处置场的候选地，北山地区的主要岩性为斑状二长花岗岩和英云闪长岩，北山地区深部完整岩石具有高密度、低孔隙度、高强度、低应变、高脆性等特点，在不同温度下，花岗岩在恒定载荷作用下的应变和声发射行为，（室温、50 ℃、90 ℃）和围压结果表明，温度和围压对岩石的力学性能影响显著，当围压分别为10和30 MPa时，在70 ℃左右，弹性模量随温度的升高而增大，然后随温度的升高略有减小;随着温度的升高，裂纹损伤应力线性减小，泊松比线性增大，稳态蠕变应变速率增大，相同应力比下的失效响应时间缩短随着围压的增加，相同应力比下花岗岩的轴向蠕变应变增加，破坏时间迅速增加。
Physico-mechanical property is one of the important aspects for site selection,design,construction and performance assessment of high-level radioactive waste(HLW) disposal.Through a nationwide screening and comparison,Beishan area,a Gobi desert in Gansu Province,is considered as a suitable candidate for HLW geological repository in China.The dominant lithology in Beishan area is porphyritic monzonitic granite and tonalite,with high homogeneity.The deep intact rock of Beishan area has the properties of high density,low porosity,high mechanical strength,low strain and high brittleness.The strain and acoustic emission behavior of granite under constant loading with different temperatures(room temperature,50 ℃,90 ℃) and confining pressures(0,10 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 and 30 MPa respectively,the elastic modulus increases with temperature increasing to about 70 ℃,and then decreases a little with the temperature increasing higher;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 increasing.The time to failure increases rapidly as the constant load decreases.The axial creep strain increases and time to failure of granite at the same stress ratio increases rapidly when confining pressure increases.