大跨径PC连续梁桥长期下挠敏感性分析

Sensitivity analysis of long-span PC continuous girder bridge

以某大跨径预应力混凝土桥梁为例,采用Midas/Civil有限元软件对其进行仿真模拟,着重分析桥梁纵向预应力损失、混凝土收缩徐变以及混凝土刚度对结构下挠的影响。计算结果表明:边跨和中跨底板预应力对结构下挠影响最大,顶板预应力次之。此外混凝土收缩徐变、混凝土弹性模量也都会影响结构挠度,相对湿度越小,弹性模量越低,结构越容易发生下挠。

Taking a long-span prestressed concrete bridge as an example,Midas/Civil finite element software is used to carry out simulation,focusing on the analysis of the longitudinal prestress loss of the bridge,concrete shrinkage and creep,and the influence of concrete stiffness on the structure downwarp.The results show that the prestress of side span and middle span floor has the greatest influence on the downwarp of structure,followed by the prestress of roof.In addition,the shrinkage and creep of concrete and the elastic modulus of concrete will also affect the structural deflection.The smaller the relative humidity is,the lower the elastic modulus is,and the more prone the structure is to bend down.