水工压力隧洞结构复杂，进行有限元分析时其前后处理及计算的工作量巨大，因此寻求一种有效的简化算法尤为重要。水工压力隧洞在受内水压力作用时，衬砌将压力部分传递给围岩，同时受到围岩的被动抗力。在进行有限元分析时，主要关注的是压力隧洞衬砌及其外围一定范围内围岩的应力和变形情况。对于均质连续岩体，通过模拟围岩抗力，可以仅取衬砌及其附近围岩作为分析对象，将水工压力隧洞应力分析转化为受内、外压的厚壁圆筒。从而仅对厚壁圆筒划分有限元网格，大大减少了前后处理和计算的工作量。

A hydraulic pressure tunnels structure is very complex. The work of FEM of pre-or post-processing is too much. So it is very important to find an effective simplification algorithm. When the hydraulic pressure tunnel is pressed by water, the concrete of tunnel transfers the pressure to the surrounding rock mass, and it also is pressed by the rock reaction force at the same time. In the analysis of FEM, much attention is paied to the strain and stress of the lining and surrounding rock mass nearby. The rock mass is regarded as isotropically continual body. Through simulating rock reaction force, the stress analysis of hydraulic pressure tunnel can be converted into thick-wall cylinder pressurized both inner and outer,so the preparation and calculation work using the thick-wall cylinder in stead of the lining and surrounding rock mass nearby are much decreased.