PC连续箱梁桥0号块考虑纵向预应力孔道影响的水化热温度场及温度效应研究

发布时间：2018-02-28 05:55

本文关键词： 零号块预应力孔道水化热温度应力温度场温控措施　出处：《南昌大学》2016年硕士论文　论文类型：学位论文

【摘要】：随着我国桥梁施工技术的日益成熟,PC连续梁桥能适应的跨径越来越大,而对于大跨径PC连续梁桥,其0#块体积一般较大,可被视为大体积混凝土结构,而大跨径PC连续梁桥大多使用高强混凝土,0#块浇筑后水化热热效应成为不容忽视的问题。随着0#块浇筑完成,在其内部的各预应力孔道也随着形成,密集布设的预应力孔洞贯穿整个0#块。对箱梁截面而言,孔洞的存在削弱了箱梁截面,改变箱梁截面对称性及箱梁截面的受力特性。孔洞周边往往出现应力集中现象,对截面是非常不利的。本论文以此为出发点,以神龙高架四桥及龙坊高架主桥为工程背景,运用ANSYS有限元软件模拟0#块浇筑施工并研究含纵向预应力孔道0#块在水化热作用下其孔洞周边及其他部件温度场及温度应力分布情况并进行强度分析。在浇筑后第4天龄期,0#块悬臂端截部分孔道周边出现明显的应力集中现象,主拉应力超出对应龄期抗拉强度较大值,很容易出现温度裂缝。本文还对影响0#块水化热温度场及温度应力因素进行参数分析,并提出相对应的防治措施。
[Abstract]:With the development of bridge construction technology in China, the span of PC continuous beam bridge can be adapted more and more, but for long span PC continuous beam bridge, its block size is generally larger, which can be regarded as mass concrete structure. However, the hydration heat effect of PC continuous beam bridges with long span after pouring with high strength concrete block has become a problem that can not be ignored. With the completion of the construction of the block, the prestressing channels in the PC continuous girder bridges are also formed. For the section of box girder, the existence of holes weakens the section of box girder, and changes the symmetry of section of box girder and the stress characteristics of section of box girder. This paper takes this as the starting point and takes the fourth bridge of the Shenlong viaduct and the main bridge of the Longfang viaduct as the engineering background. The finite element software ANSYS was used to simulate the pouring construction of block 0# and to study the temperature field and temperature stress distribution around the hole and other parts of the block with longitudinal prestressed channel 0# under the action of hydration heat. After pouring, the distribution of temperature field and temperature stress was analyzed. On the 4th day, the stress concentration appeared around the end of the cantilever and the surrounding of the hole in the block of Yu0# block. The main tensile stress is larger than the tensile strength of the corresponding age, and it is easy to appear temperature cracks. This paper also analyzes the factors affecting the hydration heat temperature field and the temperature stress factors of 0# block, and puts forward the corresponding prevention measures.
【学位授予单位】：南昌大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：U441;U448.213

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