APP下载

浅谈预应力混凝土连续桥的施工

2012-10-15牛纪栋姜成祥

城市建设理论研究 2012年16期

牛纪栋 姜成祥

摘要:当前,预应力混凝土桥梁已被广泛的应用于路桥施工工程建设中,在这里仅介绍一下预应力混凝土桥梁。预应力混凝土桥梁分为连续、悬臂拼装以及支架现浇等多种类型。首先要着重讲一下连续体系,其施工难度比悬臂拼装体系为容易,并且由于连续体系无论是在力学性能还是在运营条件等,都比支架现浇法占更多优势,所以连续体系会更易被普遍的使用在的预应力混凝土桥梁中。在这篇文章中结合连续体系,就在预应力混凝土桥梁工程建设中应该注意的几大要点谈谈自己的看法。

关键词:预应力 ,连续体系 , 混凝土桥梁 ,孔道压浆 ,操作规程

Abstract: at present, prestressed concrete bridge has been widely used in road &bridge construction project construction, here only to introduce prestressed concrete bridge. Prestressed concrete bridge into continuous, cantilever assembly and stents cast-in-situ, etc. Various types. First of all it shows about the continuous system, its construction difficulty cantilever assembly system than for easy, and because the continuous system whether in mechanical properties in operation or conditions than stents cast-in-situ method of more advantage, so continuous system will be more likely to be common in the use of the prestressed concrete bridge. In this paper, combined with continuous system, in the prestressed concrete bridge engineering construction should be paid attention to some of the main points about their own opinions.

Keywords: prestressed, continuous system, concrete bridge, passageways grouting, operation procedures

中图分类号:TU37文献标识码:A 文章编号:

桥梁基础是预应力混凝土桥梁的施工重点。连续体系在受力上属于超静定体系,由超静定体系的力学性质可知:墩台基础的不均匀沉降会使主梁内产生不利的附加内力(此种内力会因混凝土的塑性减小而逐渐减小),故连续体系桥梁对基础的要求比较严格。灌注桩基础是目前应用较为广泛的桥梁基础,若在施工中考虑不周、操作不当或因其他因素造成的缺陷很难弥补,往往需要补桩或钻孔压浆,费时费力,使工程陷于被动。因此,严格进行事前准备工作的检查,在施工中及时发现事故端倪并采取有效措施是这一阶段控制的任务。首先要核实地面高程,设计图纸中一般一排桩只提供一个地面高程,而同排的地势往往变化很大,所以技术人员要根据各桩位的实测地面高程,结合预计钢筋笼外露长度及搭接焊长度,核查施工方钢筋笼下料长度,以保证笼底高程的准确性,而钢筋笼是否达到设计深度对桩基的使用性能影响很大。……

登录APP查看全文