由于地下水封洞库多为大跨度、高边墙、不衬砌或少衬砌的地下洞室，因此建库岩体多为质量较好的花岗岩、花岗片麻岩等，但现有岩体质量分级体系不能很好地针对此类工程进行岩体分级。在确定了影响地下水封洞库工程岩体质量分级因素的基础上，考虑RQD值、结构面空间分布、粗糙度、地下水、地应力和储存压力等因素，提出了适用于地下水封洞库岩体质量分级体系（UWCQ），并应用该分级体系进行黄岛地下水封洞库工程的岩体质量评价。证明UWCQ体系对评价地下水封洞库岩体质量是可行的，能满足工程需求。这对地下水封洞库的开挖方式选择、支护方案确定和安全性评价具有重要工程意义。

Since underground water-sealed caverns are mostly of large span, high sidewall, with no lining or less lining, the building rock are mostly granite and granitic gneiss of good quality. The existing rock mass classification could not well distinguish the levels of rock quality. Having determined the main factors affecting rock mass quality, we proposed a rock mass classification system of Underground Water-sealed Caverns Quality (UWCQ). The RQD (rock quality designation), spatial distribution and roughness of joints, groundwater, geostress and pressure were taken into consideration in the system. The system was applied to evaluate the rock mass quality of Huangdao underground water-sealed caverns. Results show that the UWCQ system is feasible and could meet the engineering requirements. It’s of engineering significance for the excavation, support, and safety evaluation of underground water-sealed caverns.