新夏港双线船闸闸室横向渗流稳定性分析

Analysis of lateral seepage stability on the New Xiagang double-lane ship lock chamber

为了研究新夏港双线船闸闸室在非均质成层地基、多道板桩的条件下的横向渗流特性,利用ABAQUS有限元软件建立二维渗流模型,验算运行期和检修期的渗透稳定性,提出合理的防渗减压方案。结果表明,渗流等势线在土层交界处发生折射现象,折射程度与渗透系数的相对比值有关,在边墙后粉细砂层内,有明显的水平向层流。最危险的检修工况时,闸室出口段将会发生流土破坏。只在边墙后、中间墙设置防渗墙时,闸室处于流土破坏的临界状态,增加出口段的减压竖向管可有效提高渗透稳定性。边桩侧沿程渗流方向可能改变,沿程水头出现递减后又递增的现象。中间墙内有局部绕流,大部分为静水区,设置防渗墙后两侧会产生较大水位差。

In order to study the lateral seepage characteristics of the New Xiagang double-lane ship lock chamber under the condition of a non-homogeneous layered ground and several piles, two-dimensional seepage model with ABAQUS finite element software is built. The seepage stability during the period of running and maintenance is checked, and reasonable scheme for seepage-proofing and depressurization is raised.The results show that seepage equipotential lines refract at the junction in the soil which relates to the relative ratio of permeability coefficient.The laminar flow is obvious at the silty sand layer behind the sidewall. In the most dangerous condition of maintenance, soil flow destruction occurs on the outlet section in lock chamber.Impervious walls are only set behind the sidewall and the intermediate lock wall, the lock chamber is in the critical state of soil flow destruction.Adding the vertical tube for depressurization on the outlet section, the seepage stability can be improved efficiently. The flow direction along the side pile may change because the head along the pile may increase progressively after decrease progressively.Local detour flow occurs in the intermediate lock wall, and hydrostatic section account for most.A great water level difference occurs after setting impervious walls.