堆载作用下桥梁被动桩偏移受力分析及处理措施.pdf

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1、桥梁建设2014年第44卷第4期(总第227期)22BridgeConstruction，Vo1．44，No．4，2014(TotallyNo．227)文章编号：1003—4722(2014)04—0022—05堆载作用下桥梁被动桩偏移受力分析及处理措施马远刚，王艳芬，陈晨。(1．中铁大桥局集团桥科院有限公司，湖北武汉430034；2．武汉理工大学，湖北武汉430063)摘要：为研究堆载对桥梁被动桩的影响，以某桥为背景，采用有限差分法进行被动桩偏移受力分析，判断基桩能否继续使用并提出处理措施。采用有限差分法建立

2、下部结构模型，计算堆载作用下桥墩偏移并与实测值对比，分析基桩内力及偏移，按圆形截面钢筋混凝土偏心受压构件计算最大裂缝宽度并评估基桩状态，根据评估结果提出处理措施。结果表明：堆栽导致桥墩偏移，墩顶横向偏移计算值与实测值比较吻合；堆载作用下，基桩产生了较大偏移和弯矩，桩顶轴力和桩身轴力分布不均，并产生不同程度的负摩阻力(距堆载越近负摩阻力越大)；最大裂缝宽度为0．08mm，小于规范限值，判断基桩可以继续使用，提出堆载反压和应力释放孔联合纠偏，开挖卸载、水平顶推结合应力释放孔纠偏等处理措施。关键词：桥梁基础；被动桩；

3、堆载；位移；轴力；负摩阻力；裂缝宽度；纠偏；有限差分法中图分类号：U443．15文献标志码：AForceAnalysisandHandlingMeasuresforOffsettingofBridgePassivePilesUnderActionofStackedLoadMAYuan-gang，WANGYan—fen，CHENChen。(1．BridgeScienceResearchInstituteLtd．。ChinaRailwayMajorBridgeEngineeringGroup，Wuhan430034

4、，China；2．WuhanUniversityofTechnology，Wuhan430063，China)Abstract：Tostudytheinfluencesofstackedloadonthebridgepassivepiles，abridgewastakenastheresearchobject，theforceanalysisofoffsettingofthepassivepileswasconductedbythefinitedifferencemethod，thepileswerejudge

5、diftheycouldbecontinuouslyusedandthecor—respondinghandlingmeasureswereproposed．Themodelsforthesubstructureofthebridgeweresetupalsobythefinitedifferencemethod，theoffsettingofthepiersofthebridgeundertheac—tionofthestackedloadwascalculatedandthecalculatedvalues

6、werecomparedtothemeasuredones．Theinternalforcesandoffsettingofthepileswereanalyzed．Intermsofthecircularrein—forcedconcreteeccentriccompressioncomponents，themaximumcrackwidthofthepileswascal—culated，theforceconditionsofthepileswereassessedandbasedontheassessm

7、ent，thehandlingmeasureswereproposed．Theresultsshowthatthestacked1oadcausestheoffsettingofthepiersandthecalculatedandmeasuredvaluesofthelateraloffsettingofthepiertopsareaccordant．Un—dertheactionofthestackedload，thegreatoffsettingandbendingmomentoccurinthepile

8、s，theaxialforcedistributioninthepiletopsandpileshaftsisnotuniformandthenegativefrictionalre—sistanceofdifferentdegreesOCCURS(theclosertothestackedload，thegreaterthenegativefric—tionalresistancew