高放废物处置北山预选区地表岩体结构与岩体质量相关性及其应用研究

岩体工程质量是影响高放废物地质处置（HLW）工程长期稳定性和安全性的关键因素，也是处置库场址比选的重要依据。在地表岩体节理调查统计的基础上，采用RMR(relative metabolic rate)分级方案，探讨北山高放废物处置预选区内以花岗岩为主体围岩的岩体质量与岩体结构的对应特征，建立结构面间距D与RMR岩体质量总评分值之间的定量关系，对北山预选区芨芨槽地表岩体质量分布进行研究。研究结果表明，RMR与D值的点群分布具有扇形发散的正相关特征，随D值的增大，RMR亦呈增长趋势，但低级序岩体结构与岩体质量比高级序岩体表现出更好的对应关系。研究认为，选用RMR与D的点群中心线对应的线性方程评价花岗岩候选区的岩体质量可达到快速评价岩体质量、查明各级岩体空间分布特征的目的，同时也便于对不同候选场区进行大范围岩体质量对比。分析结果显示，北山芨芨槽预选地段BS16钻孔周边3 km2范围内主要以Ⅰ、Ⅱ级岩体为主，岩体质量总体较好且分布相对较为均匀。

Study of relationship between rock structure and rock quality and its application to site evaluation of Beishan HLW repository

As the natural barrier of the high-level radioactive waste(HLW) disposal project, the host rock is essential to ensure the stability and safety of the project in long-term. With the purpose to establish an effective method for evaluating the rock quality for site characterisation, the relation between the average structure spacing D, which is used as a quantitative index to describe the fracture distribution of rock mass, and the scores of relative metabolic rate(RMR) system is set up. It is shown that the point set, which is composed of the values of RMR and D, has a fan-shaped positive correlation. The value of D increases with the score of RMR. Moreover, the index of structure spacing D in lower order area shows a better corresponding relation with its rock mass quality than in higher order area. The method is used in the evaluation of rock mass quality around the borehole BS16 in Beishan area; and a good accordance between the distribution of D and RMR is obtained. The results suggest that it can be used as an effective and alternative approach of rock quality evaluation in the site characterization of HLW disposal project.