江西建材试验与研究·59·2023年1月作者简介：罗洪义（1974-），男，本科，山东泰安人，工程师，主要研究方向为公路、市政工程技术。超长旋挖灌注桩极限承载力现场试验研究罗洪义中铁二十一局集团有限公司，甘肃兰州730070摘要：为探究超长旋挖灌注桩极限承载力情况，文中基于实际工况对注浆桩和未注浆桩进行加压荷载沉降分析，对比未注浆和注浆桩的荷载沉降关系、桩侧摩阻力关系以及桩端阻力与位移的关系，分析其相关提升系数，得出以下结论：超长灌注桩在注浆后可以提升桩本身的承载力以及减少地层沉降，周边土壤更加密实，注浆后桩的回弹率是未注浆的两倍；无论注浆与否，桩顶荷载与桩侧摩阻力呈反比；桩端位移与桩端阻力呈正相关，未注浆试验桩最大桩端阻力超过1200kPa；注浆桩端阻力接近1200kPa时才出现桩端位移变化；总承载力和桩侧摩阻力的提升系数与桩顶位移呈正相关，桩端阻力的提升系数则随着桩顶位移增大而增大，之后降低。关键词：灌注桩；极限承载力；摩阻力；现场试验中图分类号：TU753.3文献标志码：A文章编号：1006-2890（2023）01-0059-04FieldTestStudyontheUltimateBearingCapacityofSuper-longRotaryExcavationPileLuoHongyiChinaRailway21stBureauGroupCo.Ltd.,Lanzhou,Gansu730070Abstract:Toexploretheultimatebearingcapacityofultra-longrotaryexcavationpile,Settlementanalysisofgroutingpileandungroutingpilebasedonactualworkingconditions,Comparingtheloadsettlementrelationshipbetweenpiles,pilesidefrictionresistanceandpileendresistanceanddisplacementofungroutingandgroutingpiles,Thusanalyzingthecorrelationimprovementcoefficient,Thefollowingconclusionsaredrawn:theultra-longcast-in-placepilecanimprovethebearingcapacityofthepileitselfandreducetheformationsettlementaftergrouting,Thesurroundingsoilismoredense,Thereboundrateofthepileaftergroutingistwicethatofungrouting;Withorwithoutthegrouting,Theproportionofpiletoploadandpilesidefrictionresistanceisinaninverseproportion;Thepileenddisplacementispositivelycorrelatedwiththepileendresistance,Themaximumpileendresistanceofungroutingtestpileexceeds1200kPa;Theenddisplacementresistanceofthegroutingpileiscloseto1200kPa;Theliftingcoefficientofthetotalbearingcapacityandthepilesidefrictionresistanceispositi...
