预制箱梁存放时长对反拱及静载试验结果的影响分析  

Analysis of the Impact of Storage Duration on Camber and Static Load Test Results of Precast Box Girders

作　　者：王镇锐 WANG Zhenrui(Guangdong Hualu Transport Technology Co.,Ltd.,Guangzhou Guangdong 510420,China)

机构地区：[1]广东华路交通科技有限公司,广东广州510420

出　　处：《广东公路交通》2024年第6期18-24,共7页Guangdong Highway Communications

摘　　要：为避免混凝土预制梁在存梁期产生过大反拱以及提高静载试验结果的可靠性,以25m小箱梁为代表,研究了存梁时长对反拱及静载试验结果的影响。反拱影响分析方面,利用数值分析、实验验证的方法,分析了存梁时长、混凝土强度发展对反拱的影响;静载试验结果影响分析方面,对6片存放时长为20~70天的混凝土预制箱梁进行静载试验,对比分析了存梁时长对挠度、应变校验系数、相对残余变形、中性轴高度的影响。结果表明,反拱实测值约为计算值的80%,混凝土强度发展对反拱的影响不足6%,挠度、应变校验系数随存梁时长的增加而减小,50天的存梁时长差异导致的校验系数减小量约0.14,相对残余变形、中性轴高度随存梁时长的增加先减小后增大,时间拐点为存梁40天。In order to avoid the excessive camber of the precast concrete box girder during the storage period and improve the reliability of the static load test results,this study investigated the influence of the storage duration on the camber and static load test results by taking a 25-meters box girder as representative.In terms of the influence analysis of the camber,the effects of the storage duration and the development of concrete strength on the camber were analyzed by numerical analysis and experimental verification.In terms of the influence analysis of the static load test results,the static load test was carried out on the 6 pieces of concrete precast box girders with a storage duration of 20 to 70 days,and the effects of the storage duration on the deflection,strain calibration coefficient,relative residual deformation and neutral axis height were compared and analyzed.The results showed that the measured value of the camber was about 80%of the calculated value,and the influence of concrete strength development on the camber was less than 6%.The calibration coefficient of deflection and strain decreased with the increase in storage duration,and the reduction of the calibration coefficient caused by the difference of the storage duration of 50 days was about 0.14.The relative residual deformation and the height of the neutral axis first decreased and then increased with the increase in storage duration,with a time inflection point of 40 days.

关 键 词：预制箱梁 静载试验 存梁时长 反拱 校验系数 相对残余 中性轴高度 

分 类 号：U446[建筑科学—桥梁与隧道工程]