开挖及渗流作用下围堰稳定性数值模拟研究

Study on Numerical Simulation on Stability of Cofferdam under the Actions of Excavation and Seepage

介绍了饱和—非饱和流—固耦合的有限差分方法的基本原理 ,并对泰安抽水蓄能电站进出水口围堰进行了三维饱和—非饱和流—固耦合数值模拟。分析结果具有良好的规律性 ,表明了该方法可用于大型土石坝的三维饱和—非饱和流—固耦合分析。同时 ,也分析了基础开挖过程对围堰和基础边坡稳定的影响 ,指出了在浅地表基础开挖对结构破坏影响不大 ,但对渗流的影响确是明显的。开挖只在局部产生一定的影响 ,因此在基础开挖侧必须预留一定宽度的平台 ,计算结果表明此项工程预留平台宽度不得小于 3m 。

In this paper,the principle of finite difference method in coupling saturated-unsaturated fluid with solid is given in detail,and the numerical simulation of 3D Coupbe of saturated-unsaturated fluid and solid for the cofferdam at inflow and outflon mouths of Taian Hydropower station.The method is confirmed to be effective and feasible and can be applied to analyze 3D couple of saturated-unsaturated fluid and solid for large soil-rock dam.At one time,the effect of the excavating process on the slope of cofferdam and foundation is analyzed.Numerical results give a conclusion that excavation of foundation at shallow ground has little influence on the failure of the foundation,but an obvious effect on seepage of the dam.Excavating process has a local effect, thus it must pre-reserve a platform with a width of 3m in order to make the slope table.