摘要
由于衬砌水电站压力隧洞费用极高,如果能取消、即使部分取消压力隧洞的钢板衬砌,将能得到极大的经济效益。然而破坏实例分析表明当前采用的设计方法之不足,需要更合理的设计方法.本文对无衬砌压力隧洞破坏机理进行了分析,并提出一套综合设计方案,包括现场勘测,解析解,数值分析及施工过程中的监测.
Considering the high cost for Iining pressure tunnel a considerabie economic advantage can be obtained if pressure tunnels keep unlined completely or only partly. However, case studies about the failure of unlined pressure tunnels shows the shortcomings of current approaches in pressure tunnel design. Undoubtedly, arational design method is required for future
Analytical results based on the Kirsch solutions are used to determine the critical water pressure for opening and hydraulic jacking of joints Charts based on this simple elastic analysis provide a useful and preliminary desien tool.
It is helpful to use a special joint element in FE calculation for further design analysis. The numerical method simulates three major failure modes of unlined pressure tunnels-hydraulic jacking, hydraulic shearing of joints, and uplift of the ground surface, which are identified in numerical analyses of many cases. A brief description for the mechanism of hydraulic shearing is given specially.
According to the studies a general approach is developed, which includes field investigation, laboratory test, analytical solutions, and numerical analyses Some specific suggestions for unlined pressure tunnel design are also presented related to rock type, pre-existing joint distributions, joint fillings in situ stresses and conditions of rock cover
出处
《岩石力学与工程学报》
EI
CAS
CSCD
1989年第1期1-9,共9页
Chinese Journal of Rock Mechanics and Engineering
