三峡二期围堰下淤砂层的动力特性及有关工程问题的研究

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

The study on dynamic properties of deposited sand layer and the related engineering problems for TGP cofferdam

Since 80′s, a very uniform fine sand layer has deposited, with the thickness of 10 m or more, in the Three Gorges Area of Yangtze River. The dynamic stability of that fine sand has come to the attention of engineering constructers.In this paper, the dynamic characteristics of the fine sand under the earthquake and/or the excavation blasting effect are studied, and those impacts on the high earthrock cofferdam is considered. According to both the lab and insitu experiments and measurements and to numerical analysis as well, this sand layer might readily be liquified where the overlying load is relatively low or where the ground is loadfree.It will weaken the stability of cofferdam.As for the problem of blast loading, it seems to have a lower bearing on the project than a grade 7 earthquake does.