目前支护优化分析大多数采用有限元进行计算,但有限元将围岩视为均匀介质,其计算结果很难符合以围岩等级为标准的支护设计要求。本文基于块体理论的支护优化分析,充分考虑了围岩中断层、岩脉和节理相对位置,通过块体分析软件(Unwedge)综合评价定位、半定位和随机块体的几何特征、滑动机理和稳定性状。进一步比较了不同支护方案的支护效率和不同块体类型在不同支护方案下平均安全系数的增长率,优选出各种块体类型相对应的支护方案。在此基础上合理调整支护方案空间分布,达到支护优化设计的目的。对某水电站地下主副厂房支护优化分析表明:加密锚杆的布置,可以有效的增加主厂房拱顶块体的安全系数;增加锚杆长度对提围岩安全系数不太明显。 At present, the majority of support optimization analysis is calculated by using finite element method. However, the finite element method considers the surrounding rock as a uniform medium and the calculation results are difficult to meet the support design requirements based on the grade of surrounding rock. In this paper, based on the analysis of support optimization of block theory, the relative positions of faults, dykes and joints in the surrounding rock are fully considered. By means of Unwedge, the geometric characteristics of the positioning, semi-positioning and random blocks are evaluated synthetically. The sliding mechanism And stable traits. The growth rate of the average safety factor under different support schemes is further compared with the support efficiency of different support schemes and the support schemes of different block types. On this basis, the space distribution of the support scheme should be reasonably adjusted to achieve the purpose of supporting optimal design. The analysis on the support of underground main and auxiliary workshop in a hydropower station shows that the arrangement of the encrypted anchor can effectively increase the safety coefficient of the main building’s vault block; and the increase of the bolt length is not obvious to the surrounding rock safety factor.