先简支后结构连续T梁主梁间不均匀收缩效应分析

预应力混凝土先简支后结构连续T梁桥在T梁预制、存放、架设安装及后期梁体更换过程中,各主梁间易因龄期差而在梁内产生次内力。为计算T梁桥各主梁间因龄期差产生的不均匀收缩效应,通过合理选择收缩预测模型、理论推导及有限元计算,对该效应进行了分析。结果表明,各主梁间不均匀收缩效应对结构影响较大,效应值可达梁内预应力效应22%及以上,应在结构设计及施工过程中加以控制,减小该效应对结构的不利影响。

Analysis of Non-uniform Shrinkage Effect Between Main Beams of Continuous T-Beams with Simply Supported Structures

In the process of T-beam prefabrication, storage, erection and installation, and later beam replacement, the age difference between the main girders is prone to occur and secondary internal forces occur in the girders of the prestressed concrete continuous T-beam with simply supported structures. In order to calculate the non-uniform shrinkage effect caused by age difference among the main girders of T-girder bridge, the effect is analyzed through reasonable selection of shrinkage prediction model, theoretical derivation and finite element calculation. The results show that the non-uniform shrinkage effect between the main beams has a great influence on the structure. The effect value can reach 22% or more of the pre-stress effect in the beam. It should be controlled in the process of structural design and construction to reduce the adverse effect of the effect on the structure.