磴口黄河特大桥T构墩梁结合处空间应力状态研究  

Research on the Spatial Stress State of Pier Beam Consolidation in the T-Shaped Rigid Frame of the Dengkou Yellow River Extra Large Bridge

作　　者：张帅 ZHANG Shuai(China Railway 18th Bureau Group 1st Engineering Co.Ltd.,Zhuozhou Hebei 072750,China)

机构地区：[1]中铁十八局集团第一工程有限公司,河北涿州072750

出　　处：《铁道建筑技术》2023年第11期153-157,共5页Railway Construction Technology

基　　金：中国铁建股份有限公司科技研发计划项目(2015-A03)。

摘　　要：以磴口黄河特大桥为例,运用现场实测和数值模拟手段,研究大桥T构墩梁固结位置处空间应力变化规律。结果表明:施工阶段,0#块顶板纵向应力呈分段式近线性增加,腹板和底板的竖向应力、底板纵向应力均呈近线性增加,底板横向应力呈近线性减小;墩梁固结浇筑阶段,顶板、底板和腹板的温度变化过程均在26 h内迅速增加,温度达到峰值后,呈非线性降低,并在300 h后收敛于环境温度;顶板、底板和腹板的主拉应力变化过程与温度一致,但主拉应力峰值相对温度峰值延后;底板和腹板在浇筑早期出现主拉应力大于理论抗拉强度的现象;施工阶段,墩梁固结处0#块在弯矩最不利施工时,其正应力为-10.95-0.32 MPa;在最大悬臂施工时,其正应力为-15.43-0.35 MPa;在合龙施工时,其正应力为-14.71-0.19 MPa。研究成果可为连续刚构桥墩梁结合应力优化设计以及施工控制提供参考。Taking the Dengkou Yellow River Extra Large Bridge as an example,the spatial stress variation law at the consolidation position of the T-shaped pier beam of the bridge was studied using on-site measurement and numerical simulation methods.The results show that during the construction phase,the longitudinal stress of the top plate of 0#block increases in a segmented nearly linear manner,while the vertical stress of the web and bottom plate,as well as the longitudinal stress of the bottom plate,both increase in a nearly linear manner,while the transverse stress of the bottom plate decreases in a nearly linear manner;during the consolidation pouring stage of pier beams,the temperature changes of the top plate,bottom plate,and web plate all rapidly increase within 26 hours.After reaching the peak temperature,it shows a nonlinear decrease and converges to the ambient temperature after 300 hours;the variation process of the main tensile stress of the top plate,bottom plate,and web plate is consistent with the temperature,but the peak value of the main tensile stress is delayed relative to the temperature peak;the phenomenon that the main tensile stress of the bottom plate and web plate is greater than the theoretical tensile strength occurs in the early stage of pouring;during the construction phase,the 0#block at the consolidation point of the pier beam has a normal stress of-10.95-0.32 MPa when the bending moment is the most unfavorable for construction;at the maximum cantilever construction,the normal stress is-15.43-0.35 MPa;during the closure construction,the normal stress is-14.71-0.19 MPa.The research results can provide reference for the optimization design and construction control of the combined stress between piers and beams of continuous rigid frame bridges.

关 键 词：黄河特大桥 T构 墩梁结合 空间应力 数值模拟 现场实测 温度应力 

分 类 号：U441.5[建筑科学—桥梁与隧道工程] U448.23[交通运输工程—道路与铁道工程]