悬臂浇筑预应力梁桥施工监控应力误差分析及修正  

Analysis and correction of stress error in construction monitoring of cantilever cast prestressed beam bridge

作　　者：李春清 LI Chun-Qing

机构地区：[1]不详

出　　处：《灾害与防治工程》2019年第2期73-80,共8页Disaster and Control Engineering

摘　　要：为了更加准确修正大跨度预应力混凝土主梁监测应力,综合考虑悬臂施工时桥梁荷载逐步施加的特点,本文提出了一种适用于大跨度预应力混凝土桥梁监测应力的精确修正方法。基于线性徐变理论和爼尔茨曼(L.Boltzman)叠加原理,利用加载临期至计算临期的等效弹性模量替换传统计算用的不变弹性模量,推导了分段应力增量下的混凝土徐变计算公式,并考虑时变弹性模量、混凝土收缩以及温度变化等因素对结构真实应力值的影响,通过从实测应变中分离和剔除无应力应变,准确修正各项应力误差。将该方法应用于某高铁大跨度连续梁主梁的关键截面实测应力计算,并将计算结果与传统修正方法、理论值对比分析。结果表明:修正的应力值与理论值吻合较好,误差显著减小,验证了该修正方法的可靠性与准确性。In order to correct the monitoring stress of long-span prestressed concrete girder more accurately,and considering the characteristics of bridge load gradually applied during cantilever construction,this paper proposes an accurate correction method for monitoring stress of long-span prestressed concrete bridge.Based on the linear creep theory and Bauer boltzmann(L.B oltzman)superposition principle,using in the loading period to calculate the advent of the equivalent modulus of elasticity to replace traditional computing with constant elastic modulus,section was deduced under the stress increment of formula of concrete creep,and considering the time-varying elasticity modulus,concrete shrinkage and temperature change on the influence of the structure of the real stress value,through and eliminate stress free strain was isolated from the measured strain,the stress error accurate correction.This method is applied to the calculation of the measured stress in the key section of the main beam of a long-span continuous beam of a high-speed railway.The results show that the modified stress value is in good agreement with the theoretical value and the error is significantly reduced,which verifies the reliability and accuracy of the modified method.

关 键 词：预应力混凝土梁桥 应力修正 徐变应变 时变弹性模量 误差分析 

分 类 号：U44[建筑科学—桥梁与隧道工程]