预应力混凝土曲线梁桥的时效分析

Time-dependent Analysis for Curved Continuous Prestressed Concrete Bridges

根据纯扭转理论，导出了每节点三个自由度的曲梁单元刚度矩阵，利用随时间调整的有效模量法，采用BP－2模式对任意时段混凝土由于收缩、徐变产生的影响进行时效分析。用平面曲杆有限元法编写、调试了预应力混凝土曲线架桥的时效分析程序。在程序中考虑了施工外荷载、建造新单元、张拉预应力筋、结构体系转换的影响以及各节段混凝土龄期的不同所导致的收缩、徐变差异，可以计算曲桥结构从施工到成桥这一整个过程中任一时刻的内力与变形，从而实现对结构从施工到成桥这一整个过程的跟踪分析。

In the light of the theory of simple torsion,this paper develops the element stiffness matrix of curved beam bridge with 3-freedom at every nodal point. By means of age-adjusted ef fective modulus method,the BP-2 Mode is adopted to make the time-dependent analysis of the ef fects resulting from the shrinkage and creep character of concrete at any period of time. Accord ing to the finite element method for the plane curved members, a program of time-dependent analysis for prestressed concrete curved beam bridges is developed. The program can deal with the influences of the external loads of contruction,the ereting of new elements,the stressing of the prestressed reinforcement and the transformation of structual system, and the differences in shrinkage and creep character of each segmental concrete owing to different ages. The program can be used for analizing the internal forces and deformation of curved bridges at any period of time from its construction to its completion. So,the program is able to make follow-up anaiysis of the structure during the whole construction course.