预制桩基质量问题分析与处理_周剑.pdf
特种结构2018年12月|第35卷|第6期
SpecialStructures2018Dec|VOL.35|NO.6
预制桩基质量问题分析与处理
周剑刘洋张建强
710065
(中国电建集团西北勘测设计研究院有限公司西安)
摘要:表层覆有深厚软土、持力层起伏较大的场地,采用静压管桩施工,出现了低应变检测不合格、
单桩静载荷试验检测不合格及斜桩等问题。本文结合施工及地层因素,指出低应变检测不合格的原因
是断桩,断桩发生在焊接接缝处;单桩静载荷试验检测不合格的原因也是断桩,且断桩位置未入岩或
入岩深度不足。随后,对所有桩基均进行低应变检测,根据检测结果,对缺陷深度小于9m的桩按废
桩处理,缺陷深度大于的桩采用混凝土灌芯处理。最后,文章提出采用注浆微型钢管桩进行补桩,
9m
处理后桩基各项指标满足设计要求。
关键词:低应变检测单桩静载荷试验斜桩注浆微型钢管桩
AnalysisandTreatmentofQualityProblemsofPrefabricatedPileFoundation
ZhouJianLiuYangZhangJianqiang
(NorthwestEngineeringCorporationLimitedofPowerChina,Xian710065,China)
ABSTRACT:Problemssuchasunqualifiedlowstraindetection,unqualifiedstaticloadtestofsinglepileand
inclinedpilemayoccuratsitessubjectedtotheconstructionofstaticpressurepipewherethesurfaceiscovered
withadeepsoftsoilandhasalargefluctuationofthebearingstratum.Combinedwithconstructionandforma-
tionfactors,thispaperpointsoutthatthefailureoflowstraindetectioniscausedbybrokenpiles,whichoccur
atweldingjoints.Thefailureofsinglepilestaticloadtestisalsothecauseofbreakingpile,andthepositionof
breakingpileisnotinrockortheembeddeddepthofpileisinsufficient.Subsequently,allpilefoundations
weretestedforlowstrain.Accordingtothetestresults,pileswithdefectdepthlessthan9mweretreatedas
wastepiles,andthosewithdefectdepthgreaterthan9mweretreatedwithconcretecore.Finally,thepaper
proposesthatthegroutingmicro-steelpipepi