Reliability analysis of deep underground research laboratory in Beishan for geological disposal of high-level radioactive waste

摘要

For underground engineering with complex structure, it is important to carry out reliability analysis to ensure engineering safety. This research takes China's first underground research laboratory (URL) for the geological disposal of high-level radioactive waste (HLW) in Beishan area as engineering background. Firstly, based on a large number of drilling core data of Beishan site, the optimal probability distribution model of the rock mechanical parameters is established by statistical analysis. After that, a typical underground structure of the URL, which consists of a shaft and three intersecting tunnels at the depth of -560 m, is selected as research object. The reliability indexes of the structure are calculated by Response Surface-Monte Carlo method. The results show that after excavation, most of the reliability indexes of the structure are above 4.2. The structure is safe as a whole. Due to the interaction between different tunnels/shaft, the minimum reliability index appears at the intersecting corner of the tunnels/shaft, which indicates that the intersecting areas are the weakest area of the structure. The reliability calculation results are basically in good agreement with the geo-mechanical model test results, which verify the validity of the reliability calculation results.