遮帘式板桩码头结构与土共同作用3D数值模拟分析

3D Numerical modeling of pile-soil interaction for covered sheet-piled wharf

遮帘式板桩码头作为一种全新码头结构,因缺少相关设计规范和计算方法,给工程设计、施工与优化带来很大困难。基于ABAQUS计算软件平台,利用自行二次开发的、能较好地反映土体塑性体应变和剪胀特性的"南水"双屈服面土体本构模型,对遮帘式板桩码头三维数值计算展开研究,探讨该新型码头结构与地基土体间相互作用、墙身与桩体的变形、拉杆力的变化以及桩与墙体土压力及弯矩分布与变化规律。计算结果表明,新型板桩码头结构沉降量较小,水平位移因前沿港池的开挖相对较大,由于设置遮帘桩,结构充分利用了土体自身抗剪力学特性,导致上部土体作用于前墙土压力显著减小,下部土体作用于前墙土压力显著增大,从而极大改善了前墙承受由于前沿港池开挖深度增加而迅速增大的土压力,使得结构更加稳定;同时,遮帘桩承担了较大的弯矩,增强了抗倾覆的能力,使得遮帘式板桩码头得以深水化。

For covered type of sheet pile wharf, an innovative type of sheet pile wharf, there lacks related designing regulation and calculation method. Secondary development was made on the ABAQUS software, numerical simulation was carried out for covered sheet pile wharf, and comparison was performed with the result from the prototype observation to the 32# berth of Jingtang Harbor. The following issues were discussed： interaction between the wharf structure and foundation soil, deformation of the wall and pile, variation of pull rod stress as well as the distribution and variation of soil pressure on the pile and wall. The result indicates that settlement of the wharf structure is extremely small, while the horizontal displacement seems relatively large due to the excavation of the harbor basin. The stress on the front wall was tremendously relieved because of the barrier piles, and decrease of load in the excavation area was proved to be the greatest, meanwhile, a large percentage of moment was transferred to the barrier piles, which enables the deepening of sheet pile wharf.