一、前言港口大桥是一座斜拉式预应力混凝土桁架桥。这种新桥型是在斜拉桥和预应力混凝土桁架桥的基础上构思出来的,其外形见照片1。众所周知,混凝土斜拉桥的主梁建筑高度小,在100～400m跨径范围内。与其他桥型相比材料费最省,支点反力小;在密束的情况下梁变成以轴力为主的似桁架梁,使得结构构造 First, the foreword Harbor Bridge is a cable-stayed prestressed concrete truss bridge. This new bridge is conceived on the basis of cable-stayed bridges and prestressed concrete truss bridges. As we all know, the main beam of concrete cable-stayed bridge construction height is small, in the span of 100 ~ 400m range. Compared with other bridge types, the material cost is the lowest, and the fulcrum reaction force is small. In the case of dense beam, the beam becomes a truss girder with axial force as the main factor, so that the structural structure