索塔承台大体积混凝土夏季施工的温控防裂数值分析

发布时间：2018-06-13 06:29

本文选题：索塔承台 + 夏季施工　；参考：《天津大学》2014年硕士论文

【摘要】：目前悬索桥和斜拉桥得到了广泛应用，其索塔承台一般尺寸较大，，属于大体积混凝土结构。大体积混凝土承台在施工期容易出现裂缝，在其内部布置冷却水管是工程常用的温控防裂措施之一。本文以某特大悬索桥的索塔承台为例，对其夏季施工的温度场和温度应力场进行分析，探讨其温控防裂的措施。首先利用ANSYS有限元分析软件模拟索塔承台的分层浇筑过程，对其在水管冷却作用下的温度场和应力场进行瞬态分析，并与天然冷却状态下承台的温度场和应力场进行对比；然后重点分析了采用水管冷却措施时水管间距、水管入口水温、通水速率、开始通水时间、管材以及管径对承台的温度场和应力场分布的影响；最后分析探讨了混凝土浇筑层厚度、混凝土的浇筑温度和表面遮阳、层间浇筑间隔三种因素对承台的温度场和应力场的影响规律，并在此基础上提出工程实例的最优方案。研究表明，冷却水管对承台的温控防裂效果显著，其中冷却水管间距和开始通水时间对承台的温度场和应力场影响比较明显。降低混凝土的浇筑温度同时采用表面遮阳能得到比较好的温控防裂效果。
[Abstract]:At present, suspension bridges and cable-stayed bridges have been widely used, and their tower caps are generally large in size and belong to large volume concrete structures. Large volume concrete caps are prone to cracks in the construction period, and cooling water pipes in its interior are one of the commonly used measures for temperature control and crack prevention. The temperature field and temperature stress field of summer construction are analyzed, and the measures of temperature control and crack prevention are discussed.
First, the ANSYS finite element analysis software is used to simulate the layered casting process of the tower cap, the transient analysis of the temperature field and stress field under the water pipe cooling is carried out, and the temperature field and stress field of the cap are compared with the natural cooling state, and then the water pipe spacing and the water pipe into the mouth water are analyzed. The influence of temperature, water rate, water time, pipe and pipe diameter on the temperature field and stress field distribution of the bearing platform; finally, the effects of three factors on the temperature field and the stress field of the bearing platform are discussed, and on this basis, the effect of the concrete pouring layer thickness, the concrete pouring temperature and the surface sun shading, the interlayer pouring interval are discussed. The optimal scheme of the course case.
The research shows that the cooling water pipe has a remarkable effect on the temperature control of the cap, in which the cooling water pipe spacing and the beginning of the water time have a more obvious effect on the temperature field and the stress field of the platform.
【学位授予单位】：天津大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U445.57

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