某核电厂工程软弱夹层地基动力特性分析

Dynamic Characteristics Analysis of Foundation with Weak Intercalated Layer at the Nuclear Power Plant

以某核电厂工程为例,运用有限差分软件FLAC3D建立地基三维数值模型,研究了该软弱夹层地基的动力响应。结果表明:在水平地震荷载作用下,该地基主要以沉降模式为主,尽管呈现出明显的位移分层现象,但不会产生破坏;在地震荷载初始阶段软岩发生剪胀变形而出现了向上的位移,在地震荷载输入末段,各软岩Z向位移趋于稳定;黏聚力与抗拉强度对地表加速度放大系数几乎没有影响;随着体积模量、剪切模量与内摩擦角水平的增大,地基的地表加速度放大系数也随之增大。

Taking a nuclear power plant as an example, a three-dimensional numerical model for the foundation was established depending on finite difference software FLAC3D to study the dynamic characteristics of this foundation with weak intercalated layer. The result shows that, under the action of horizontal seismic load, the foundation is mainly in the status of settlement, although it presents obvious displacement stratification, there will not be damaged;in the initial stage of seismic loading, the soft rock is subject to dilatancy deformation, thus upward displacement appears, and at the end of seismic loading input, the Z-direction displacement of soft rocks tend to be stable;the cohesion force and tensile strength almost have no effect on the surface acceleration magnification coefficient;as the bulk modulus, shear modulus and internal friction angle increase, the ground surface acceleration magnification factor increases as well.