大跨度连续刚构桥参数敏感性分析

Parameter Sensitivity Analysis of Long Span Continuous Rigid Frame Bridge

为充分了解施工过程中大跨度连续刚构桥的结构影响,文中以王家庄大桥作为研究对象,采用Midas/Civil 2015软件建立模型进行有限元分析。在所成模型中,对参数进行既定改变幅度调整,再通过控制变量法将其一一赋予桥梁,由此得到所选控制截面的弯矩值、应力值和挠度,而后对各项数值进行对比分析。对所选因素包括主梁自重、混凝土收缩徐变、主梁弹性模量等结构参数进行参数敏感性分析,得出相关结论为:在所研究的几个参数中,当将参数调整至相同幅度时,主梁自重,混凝土收缩徐变对桥梁结构影响较大,视为主要敏感性参数;弹性模量变化对结构影响较小,视为次要敏感性参数。建议在实际工程中,着重监控主梁自重、混凝土收缩徐变等参数在施工阶段的变化,弹性模量的变化可作为次要因素考虑。

In order to fully understand the influence of various factors on the structure of long span continuous rigid frame bridge,this paper takes the Wangjiazhuang bridge as the research object and uses the Midas/Civil 2015 software to establish the model for the finite element analysis. In the model,the parameters are adjusted,and then given to the bridge one by one by the control variable method. Then the bending moment,stress and deflection of the selected control section are obtained,and the values are compared and analyzed. Parameter sensitivity analysis is carried out on the selected structural parameters including the dead weight of the main beam,shrinkage and creep of concrete,and elastic modulus of the main beam. Relevant conclusions are drawn as follows： when the parameters are adjusted to the same amplitude,the weight of the main beam,shrinkage and creep of concrete have a greater impact on the bridge structure,which is regarded as the main sensitivity parameter;the change of elastic modulus has a smaller impact on the structure,which is regarded as the secondary sensitivity parameter. It is suggested that in practical engineering,the main beam weight,shrinkage and creep of concrete should be monitored,and the change of elastic modulus should be considered as a secondary factor.