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?
1　緒論
這次會議是專門討論結(jié)構(gòu)分析的發(fā)展，而不是討論材料強(qiáng)度，但對材料的認(rèn)識并用適當(dāng)?shù)募夹g(shù)分析結(jié)構(gòu)的組成，有助于有效地利用預(yù)應(yīng)力混凝土。預(yù)應(yīng)力混凝土結(jié)構(gòu)的設(shè)計(jì)通常是留給專家；粗心將會導(dǎo)致錯(cuò)誤或花費(fèi)更多時(shí)間用各種方法尋求解決的方案。
有一些根本性的分歧在預(yù)應(yīng)力混凝土和其他材料之間。在沒有作用荷載下結(jié)構(gòu)依然是受力；可行的解決方案是有限的，在超靜定結(jié)構(gòu)，纜索外形的改變會引起不同的自應(yīng)力，所有這些要素都是受到徐變和溫度效應(yīng)的影響。如何判別這些問題和如何解決他們呢？