三峡水利枢纽地下电站主厂房施工期顶拱围岩块体研究

对于大跨度地下洞室,顶拱围岩的稳定关系施工过程顺利和安全。三峡地下电站主厂房围岩为裂隙化硬质岩体,开挖后易产生块体,对局部围岩稳定不利。依据顶拱分部分序开挖支护过程,采用信息化施工地质工作流程,运用三维块体分析程序GeneralBlock,对开挖揭露断裂结构面组合构成块体进行快速搜索定位和稳定性分析,及时指导顶拱支护设计和施工。研究结果为:顶拱揭露可动块体43个,其中有11个为不稳定块体,16个为潜在不稳定块体,需及时加固处理。

STUDY ON THE CROWN BLOCK OF THREE GORGES UNDERGROUND POWERHOUSE IN CONSTRUCTION PERIOD

The stability of crown surrounding rock masses of great span underground caverns is important to successfully and safely construct. The crown blocks going against stability of surrounding is prevalent because that the surrounding rock masses of Three Gorge underground powerhouse is heavy jointed and very hard. Adopting working process of information construction geology, the crown blocks incised by uncovering structure plane are fleetly searched and located and their stabilities analyzed by the program (GeneralBlock) of 3D-blocks, it is the guidance to shorting and construction of crown. The investigations to crown blocks show that: 43 movable blocks are revealed, hereinto, 11 blocks is instable and 16 blocks is potentially instable, the measures of reinforcing are implemented in time. The flow and method of the investigation can be consulted by analogous projects.