低温季节混凝土浇筑仓表面应力应变监测试验及反馈分析

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1、学兔兔www.xuetutu.com水利水电技术第44卷2013年第6期低温季节混凝土浇筑仓表面应力应变监测试验及反馈分析瞿立新，黄耀英，周宜红，高祥泽，周绍武，李金河(1．武汉大学水资源与水电工程科学国家重点实验室，湖北武汉430072；2．三峡大学水利与环境学院，湖北宜昌443002；3．中国长江三峡集团公司，湖北宜昌443002)摘要：结合西南某建设中的混凝土坝工程，通过在混凝土浇筑仓表面埋设多向应变计组及无应力计，监测低温季节混凝土表面应力应变状态。首先对无应力计实测值建立统计模型反演热膨胀系数从而分离

2、出混凝土自生体积变形，然后根据应变计组实测应变，结合无应力计测值获得实际应力，最后建立有限元模型进行温度场、应力场反馈分析，并统计施工过程中混凝土试件劈拉强度，进行开裂风险判断。分析表明，该混凝土坝浇筑仓低温季节保温效果好，总体开裂风险较小，但需要重视揭开保温被时段以及新浇筑预冷混凝土对下层混凝土冷击产生的开裂风险。关键词：混凝土浇筑仓；低温季节；应力应变监测；开裂风险中图分类号：TV332文献标识码：A文章编号：1000—0860(2013)06-0057—06Experimentandfeedbackana

3、lysisonstress-strainmonitoringofconcreteplacingsurfaceduringlow-temperatureseasonQULixin，HUANGYaoying，ZHOUYihong’，GAOXiangze，ZHOUShaowu，LIJinhe(1．StateKeyLaboratoryofWaterResourcesandHydropowerEngineeringScience，WuhanUniversity，Wuhan430072，Hubei，China；2．Coll

4、egeofHydraulic&EnvironmentalEngineeringofThreeGorgesUniversity，Yichang443002，Hubei，China；3．ChinaThreeGorgesCorporation，Yichang443002，Hubei，China)Abstract：InaccordancewithaconcretedamunderconstructionintheSouthwestChina，thestress—strainstateoftheconcretesurfa

5、ceduringthelow·-temperatureseasonismonitoredthroughthemulti·-directionalstraingaugearraysandthenon·-stressmetersembeddedinthesurfaceoftheconcreteplacingarea．Firstly，astatisticalmodelisestablishedwiththemeasuredValuesfromthenon-stressmetersforinvertingtherele

6、vantthermalexpansioncoefficient，SOastoseparateouttheautogenousvolumedeformationoftheconcrete．Secondly，theactualstressisobtainedinaccordancewiththemeasuredvaluesfromthenon—stressmetersbasedontheactuallymeasuredvaluesfromthestraingaugearrays．Finally，afiniteele

7、mentmodelisbuiltupforthefeedbackanalysisonthetemperaturefieldandstressfieldand，moreover，thesplittingtensilestrengthsoftheconcretesamplesgotduringthecon—structionarefiguredoutforjudgingthecrackingrisk．Theanalysisshowsthatthoughtheeffectofthetemperatureinsulat

8、ionmeasurefortheconcreteplacingareaduringthelow—temperatureseasonisbetterwithlesscrackingrisk，theagreatattentiononthecrackingriskfromthecoldshockcausedbyboththenewlyplacedpre—cooledconcreteorthe