Xianghongdian concrete gravity - arch dam was analyzed using numerical simulation in this paper . in different place of dam crack with different stripe and various depth was simulated and corresponding vibration frequency and shape were given . the frequency of damaged dam polluted by noise was also discussed and the results were presented using statistical neural network to identify 本文对响洪甸重力拱坝进行数值模拟分析,在大坝的不同位置模拟了条数不等的、张开度不同的各种裂缝,并给出了相应的振动频率和振型,考虑了测试噪声的影响,并用统计神经网络进行了识别。