高压引水隧洞衬砌的透水设计研究

国内大都采用荷载结构法及限裂设计的方法对水工高压隧洞的衬砌进行不透水设计。而实践证明，不透水设计并不适合于高压引水隧洞，它将导致过高的配筋量。目前，国内水工高压隧洞结构透水设计尚无适用的规范可循，因此，有必要寻求一种合理、安全的透水设计方法。针对水工高压隧洞，基于体力理论，提出一种对衬砌结构进行透水设计的有限元计算方法，并将其应用于某水电站工程。该方法可模拟隧洞的施工过程和运营检修工况，考虑渗流场和应力场的直接耦合作用，根据内力值计算衬砌裂缝的开展宽度以及相应的配筋量等。通过对比分析，说明在衬砌透水设计中隧洞满水状态为对其进行配筋的控制工况，且结果更符合工程实际，并能大大节省配筋量。

Design of permeable lining for high pressure hydraulic tunnel

For the design of impervious lining system of seepage tunnel, load-structure method and crack limit verification method are mostly recommended in China. However, the impervious design criteria is proved to be unreasonable for high pressure concrete lining system resulting in an over estimation of steel ratio. Thus, the research on a reasonable and safe permeable design for concrete lining of seepage tunnel is necessary. But, the suitable criterion is not confirmed in the design of high pressure hydraulic tunnel. Based on body force theory, a method of FEM is presented to design the permeable lining in high pressure hydraulic tunnel. The method can simulate the construction and security operation and repair process of the tunnel. The direct coupling of seepage field and stress field may be analyzed. Then, it is used in a real project. The crack width of concrete and the reinforcement of lining can be calculated by means of internal force. By comparison of the reinforcement, it is demonstrated that the results are satisfactory and the presented method is reasonable and effective.