摘要
对大跨预应力混凝土连续梁桥施工控制理论和方法进行了总结与评价,指出参数识别和状态预测均是大跨混凝土连续梁桥自适应施工控制系统内必不可少的功能。以主梁各悬浇梁段高程的理论计算值和实测值建立高程偏差反馈方程,并将其分为测量偏差、参数偏差和系统偏差三大部分;通过引入参数修正系数向量,实现对结构刚度、梁段自重、挂篮刚度、预应力效应和混凝土收缩徐变等参数的实时修正。以移动挂篮阶段的高程反馈偏差计算结构刚度修正系数,以浇注梁段阶段的高程反馈偏差计算主梁自重修正系数和挂篮刚度修正系数,以张拉预应力阶段的高程反馈偏差计算预应力修正系数,再根据各梁段在浇注过程的反馈偏差总值计算梁段系统偏差。基于灰色预测理论的GM(1,1)和修正GM(1,1)模型分别对待浇梁段的参数修正系数和系统偏差进行预测,获得了待浇梁段的立模标高。工程算例验证表明:随着悬浇梁段的增多、样本数量不断增大,提出的参数识别方法和计算公式能够较为迅速、准确地识别出各参数的真实值,而基于灰色理论的预测值也能够较为稳定的围绕在真值附近。
Construction control theory and method of long-span prestressed concrete continuous beam bridge were summarized and estimated,and both of parameter identification and state pre-forest were necessary functions in the self-adaptive construction control system of long-span prestressed concrete continuous beam bridge. The deviation feedback equations were set up by theoretical calculation elevations and measured elevations of every cantilever segments,and the feedback deviations were divided into three parts,including measuring deviation,parameter deviation and system deviation. By introducing the vector of the parameter correction coefficient,the parameters of the beam segment weight,the hanging basket stiffness,the prestressing effects and shrinkage and creep of concrete could be corrected at real time. The correction coefficient of beam stiffness was calculated by the elevation deviation of moving hanging baskets,the correction coefficients of beam weight and hanging-basket stiffness were calculated by the elevation deviation of pouring concrete. The correction coefficient of prestressed effects was calculated by the elevation deviation of tensioning prestressed strands,and the system deviations were calculated by the total deviation of constructing one segment. Finally,every parameter correction coefficients and system deviations of next segment were predicted by the modes of GM（ 1,1） and CGM（ 1,1） based on gray prediction theory; moreover,the formwork erection elevation of the awaiting constructed beam segment was gained. Tested by the engineering example,with the cantilever segments increased,the total number of samples constantly was increased. The methods and formulas of parameter identification were proposed,which could rapidly and accurately identify the true values of every parameters,and predictive values based on gray prediction theory could be relatively stable near the true values.
出处
《重庆交通大学学报（自然科学版）》
CAS
北大核心
2015年第4期28-33,共6页
Journal of Chongqing Jiaotong University(Natural Science)
基金
国家青年科学基金项目(51308156)
博士后面上项目(2012M510969)
中央高校基本科研业务费专项资金资助项目(HIT.NSRIF.2014077)
关键词
桥梁工程
混凝土连续梁
施工控制
参数识别
状态预测
bridge engineering
concrete continuous beam
construction control
parameter identification
state prediction
