目前,不少水利水电工程中对水工隧洞的设计一般都采用了限制裂缝开展宽度的计算,为国家节约了大量的资金和钢材。但是所采用的计算方法很不一致。本文对限裂设计提出一个简单的计算方法。钢筋混凝土衬砌的有压水工隧洞,在内水压力不断上升过程中,当衬砌的切向应力接近混凝土抗拉强度平均值 Ri 时,在某一最薄弱的地方即发生第一条裂缝。此时的内水压力为P_1。 At present, many water conservancy and hydropower projects in the design of hydraulic tunnel are generally used to limit the width of the cracks carried out for the country to save a lot of money and steel. However, the calculation method used is very inconsistent. In this paper, a simple calculation method for the crack design is proposed. In a pressurized hydraulic tunnel with reinforced concrete lining, the first crack occurs in one of the weakest places when the lining tangential stress is close to the average value of the concrete tensile strength Ri during the rising of the internal water pressure. The internal water pressure at this time is P_1.