下游坝面浅槽式压力管道施工仿真研究

Study on the construction simulating of downstream shallow slot SRC penstock

本文以三峡水电站下游坝面浅槽式钢衬钢筋混凝土压力管道为研究对象 ,通过混凝土施工仿真计算的方法 ,重点研究了管道与坝体的相互作用、管道施工期温度场与应力场、管道在充水受荷前的初始温度与应力状态以及管道施工方案的优化等四个问题。结果表明 ,后浇筑管道与大坝接缝面会出现较大的拉应力 ,同时会使大坝迎水面竖向压应力不断减小 ;管道在施工期将出现环向及轴向拉应力 ,尤以斜直段表现最为明显 ;管道在充水受荷前存在不可忽视的初始状态 ,不同部位的初始温度与应力状态不同 ,在设计时应分别参考使用 ;根据温度场与应力场的计算结果 ,提出了一种较优的施工计划 ,以使管道在施工期以及受荷前处于较佳的初始状态。

By alive simulating the process of concrete construction,the downstream shallow slot Steel-lined Reinforced Concrete(SRC) penstocks of Three Gorges Hydro-station is studied.Four aspects referring to the interaction between penstock and dam,the temperature field and stress field of penstock during construction period,the initial temperature and stress status of penstock before subjected to internal water pressure,as well as the optimization of the penstock construction,are researched preliminarily.The simulating results indicate the following conclusions:high tension stress occure in the seam facet between post-placement penstock and dam.The vertical compressive stress of the dam upstream facet decreases with constructing of the penstocks.Circular and axial tension stress do exist during the construction period,especially in the middle part of penstocks.The initial status of penstocks can not be ignored before subjected to loads,but different parts are proved to be in different status.An advanced construction plan is presented according to the temperature field and stress field,which can benefit the initial status as well as the running period of penstocks.This optimization construction plan can be referenced by the engineers.