中文摘要：

特高拱坝的表面出现裂缝后会对其工作性态产生一些影响。本文结合某300m级特高拱坝施工期上游面出现的一种特殊表面裂缝,对该类裂缝的形成机理进行初步的探究分析。基于非线性迭代法求解该类裂缝的开闭、滑移和扩展问题,同时,基于断裂力学理论计算研究了该类裂缝的稳定性问题。研究结果表明：施工期特高拱坝横缝突然张开容易造成止水带周边混凝土损伤,而横缝接缝灌浆前的压水试验会促使局部损伤进一步扩展成贯穿至表面的裂缝。

英文摘要：

Surface cracks have some impacts on the working performance of super-high arch dams. This paper presents a preliminary reason analysis for a particular type of surface crack in the construction of 300m-level super-high arch dam. A nonlinear iterative method is used for solution of the opening-closing, sliding and expansion of joints and their stability is computed with the fracture mechanics method. The results show that abrupt opening of transverse joints at construction stage easily causes concrete damage in the surrounding region of waterstop and the water-pressure tests preceding transverse joints grouting will cause further crack expansion from local damage to surface crack.