预应力混凝土连续梁分析----外文翻译.doc

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预应力混凝土连续梁分析----外文翻译,1、 introductionthis conference is devoted to the development of structural analysis rather than the strength of materials, but the effective use of prestressed ...
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此文档由会员 wanli1988go 发布

1、 Introduction
This conference is devoted to the development of structural analysis rather than the strength of materials, but the effective use of prestressed concrete relies on an appropriate combination of structural analysis techniques with knowledge of the material behaviour. Design of prestressed concrete structures is usually left to specialists; the unwary will either make mistakes or spend inordinate time trying to extract a solution from the various equations.
There are a number of fundamental differences between the behaviour of prestressed concrete and that of other materials. Structures are not unstressed when unloaded; the design space of feasible solutions is totally bounded; in hyperstatic structures, various states of self-stress can be induced by altering  the cable profile, and all of these factors get influenced by creep and thermal effects. How were these problems recognised and how have they been tackled?
Ever since the development of reinforced concrete by Hennebique at the end of

1 绪论
这次会议是专门讨论结构分析的发展,而不是讨论材料强度,但对材料的认识并用适当的技术分析结构的组成,有助于有效地利用预应力混凝土。预应力混凝土结构的设计通常是留给专家;粗心将会导致错误或花费更多时间用各种方法寻求解决的方案。
有一些根本性的分歧在预应力混凝土和其他材料之间。在没有作用荷载下结构依然是受力;可行的解决方案是有限的,在超静定结构,缆索外形的改变会引起不同的自应力,所有这些要素都是受到徐变和温度效应的影响。如何判别这些问题和如何解决他们呢?
自从在十九世纪末Hennebique对钢筋混凝土进行了研究(库萨克1984年) ,它表明了钢筋和混凝土能更有效地结合起来,如果钢先预制然后把混凝土灌进去。开裂可以减少,如果可以很好的粘结在一起 ,这将增加刚度和提高耐久性。早期尝试,所有失败的原因是由于初始预应力很快消失,留下的结构必须具备一定的承受能力;关于这些情况Leonhardt和Abeles已做出了尝试。
这是Freyssinet对三座桥梁的观察结果,它坐落在维希附近的Allier河上,1927年完成。用的是预应力混凝土( Freyssinet 1956年) 。只有Boutiron这座桥在二战中保留下来(图1 ) 。迄今,它一直假定混凝土的杨氏模量仍然是固定的,但他承认说由于变形的存在,这也解释为何在早期的检测预应力已经损失。