80年代以来 ,在长江三峡地区河段沉积了一层厚达十几米的均匀细砂 ,其动力稳定性很值得关注 ,本文研究了三峡高土石围堰下的淤砂层在 7度地震和爆破振动作用下的动力特性以及对围堰工程的影响。通过室内试验和现场实测 ,表明淤砂层在上覆荷载较小的情况下易于液化 ,并削弱围堰的稳定性。对于爆震作用 ,研究表明 ,其影响不如 7度地震的影响大 Since the 1980s, a layer of uniform fine sand with a thickness of over ten meters has been deposited in the reach of the Three Gorges area of ​​the Yangtze River. The dynamic stability of the sand is very much concerned. In this paper, the effects of 7-degree seismic and blasting Dynamic characteristics under vibration and impact on cofferdam engineering. Through laboratory tests and field measurements, it shows that silt layer is easy to liquefy under the overburden load and weakens the stability of cofferdam. For the detonation effect, the research shows that its influence is not as significant as that of the 7-degree earthquake