三峡升船机塔柱结构施工期仿真计算分析

Simulation and Analysis of Three Gorges Ship Lift Tower Structure in Construction Period

通过三维有限元仿真计算,模拟施工浇筑全过程,分析三峡升船机塔柱结构在施工期的几个关键技术问题,包括:施工进度安排的影响,风荷载的影响,预应力套管的埋设位置,徐变的影响。通过研究得出:10月份开始浇筑筒体混凝土相比 4月份开始浇筑,塔柱结构最大拉应力及变形都有所减小,这 2种浇筑情况最大竖直向位移均出现在高温季节浇筑的混凝土中;在宽槽回填高程与内侧墙浇筑高程存在较大高差时,以及塔体顶部封顶前,风荷载对塔体结构有较明显作用;齿条及螺母柱的竖直向位移与预应力套管的埋设位置直接相关,并且受上部混凝土浇筑自重影响,随年气温的变化呈现周期性变化;徐变对齿条和螺母柱的影响较小,均在安装精度要求的范围内。研究成果可为三峡升船机塔柱施工方案及施工精度控制提供参考。

By numerically simulating the whole process of construction using 3D finite element method, we analyzed some key technical issues of the ship lift tower structure of Three Gorges Project (TGP) in construction period. Such issues include the influences of construction schedule, wind load, embedded position of prestressed sleeves, and creep. According to simulation result, 1) the maximum tensile stress and deformation of tower structure poured in October were smaller than those in April, while the maximum vertical displacement in both cases occurred in the position where concrete was poured in high-temperature season. 2) Wind load had an evident influence on tower structure in the presence of a large height difference between the backfill elevation of wide groove and the casting elevation of inner wall, and before the top sealing of tower body. 3) The vertical displacement of rack and nut column, directly related to the embedded position of prestressed sleeves, was affected by the self-weight of the upper concrete, and such effect changed periodically with atmospheric temperature. 4) Creep had little effect on the rack and the nut column, and stayed within the range of installation accuracy requirements. The research findings offer reference for the construction schedule and accuracy control for the TGP ship lift tower.