混凝土衬砌高压水道的设计准则与岩体高压渗透试验

DESIGN CRITERIA FOR CONCRETE-LINING HIGH PRESSURE HYDROPOWER TUNNEL AND HIGH PRESSURE PERMEABILITY TEST ON ROCK MASS

钢筋混凝土衬砌地下高压水道设计中,最主要的问题是防止高压水外渗造成的水量损失和对山体边坡、电站建筑物等潜在的危害,其核心是要对地形地质条件、最小主应力和高压水作用下围岩渗透性、围岩水力稳定性等进行充分的研究。对钢筋混凝土衬砌高压水道设计中的最小覆盖厚度准则、水力劈裂准则、最小主应力准则,以及各个准则之间的关系和运用条件进行讨论。结合天荒坪抽水蓄能电站的研究和实践,重点介绍围岩高压渗透试验的具体实施方法,并对试验成果进行分析,同时给出由节理构造等引起的局部地应力偏低问题的工程处理措施。

The engineering design for concrete-lining tunnels should focus on the investigation and utilization of the surrounding rock geotechnical conditions governed by topography and in-situ stress state, as well as the permeability of rock mass under high water pressure, etc.. Some critical design criteria applied to the design of concrete-lining high pressure hydropower tunnels are discussed, such as the minimum overburden criterion, hydraulic fracturing criterion and minor principal stress criterion, and their application .conditions and relations are also discussed. As an illustration, the application of the above criteria to the design of Tianhuangping Pumped Storage Power Station is introduced. Field test method and results of high pressure permeability tests carried out at Tianhuangping pumped storage power station are discussed. At last, the engineering treatments for some locations with comparatively low in-situ stress mainly caused by joint structure are presented.