..................................从根本上减少断桩基础补强处理1钻孔桩断桩的原因分析1analysisofthecausesofdrillingpilebrokenpile1.1钻孔桩成孔质量问题造成的断桩原因分析1.1drillingpileholequalityproblemcausedbythefaultreasonanalysis由于泥浆护壁差、孔内水头压力不够等原因，在清孔后灌注混凝土过程中出现孔壁坍塌，造成断桩。由于清孔过程中未对孔内泥浆含砂率进行严格控制，造成在灌注混凝土过程中混凝土上沉渣过厚，导管内混凝土压力不足以推动该部份沉渣，致使混凝土浇注中断。部分在河床上通过筑岛法施工的钻孔桩基础，由于河床表面有一层流塑性淤泥层，在混凝土浇筑过程中河床淤泥层顺孔壁流进钻孔内，致使混凝土浇注中断。Duetopoorslurry-supported,holeheadpressureisnotenough,theholecleaningafterthecollapseof..................................holewall,appearedintheprocessofpouringconcretepilebreaking.Duetotheblackholetoholethemudintheprocessofsandratiotocarryonthestrictcontrol,causeintheprocessofpouringconcreteonconcretetothetoothicknessofsediment,intraductalconcretepressureisnotenoughtopushtheministryofsediment,theconcretepouring.Partontheriverbuiltbyislandconstructionmethodofboredpilefoundation,becausethesurfaceoftheriveralaminarflowplasticitysiltlayer,riverbedsiltlayerintheprocessofconcretepouringflowinthewallofholeindrilling,theconcretepouring.1.2钢筋笼及浇筑混凝土用导管的问题造成断桩的原因分析1.2reinforcingcageandconcreteanalysisofthecauseofbrokenpilewithcatheterquestions..................................导管接头严重漏水，造成导管外泥浆及水进入导管，使导管内混凝土离析，导管堵塞，混凝土浇筑中断，造成断桩。Outsidethepipejointseriousleaks,causingcathetermudandwaterintothepipe,thepipeinsidetheconcretesegregation,catheterblockage,concretepouring,causedthebrokenpile.由于钢筋笼主筋焊接及箍筋绑扎存在问题，在混凝土浇筑过程中，钢筋笼卡住导管，致使导管难以提起，混凝土浇筑中断，形成断桩。Becauseofreinforcingcageofmainreinforcementweldingandstirrupbindingproblemexists,intheprocessofconcretepouring,steelreinforcementcagestuckpipe,causingthemtomention,concretepouring,formthebrokenpile.1.3浇筑用混凝土的问题造成断桩的原因分析..................................1.3castingwithconcreteproblemsanalysisofthecauseofbrokenpile混凝土塌落度过小，或和易性较差，造成导管堵塞，混凝土浇筑中断，造成断桩。由于混凝土供应问题，造成浇筑时间过长，浇注混凝土时首盘混凝土已经凝固，混凝土浇筑难以继续，造成断桩。由于混凝土中出现凝结的水泥块或石头等大块杂物，造成导管堵塞，混凝土浇筑难以继续，造成断桩。Fallthroughsmallconcrete,orpoorworkability,causingcatheterblockage,concretepouring,causedthebrokenpile.Causedbysupplyproblemsofconcrete,pouringtimeistoolong,whenpouringconcretebeforeconcretehassolidified,concretepouringisdifficulttocontinue,causedthebrokenpile.Duetocondensationofconcreteofconcreteblocksorstones,etc.Largepiecesofdebris,causingcatheterblockage,concretepouringisdifficulttocontinue,causedthebrokenpile...................................2钻孔桩断桩的预防措施2drilledpilepilebreakingpreventionmeasures2.1加强成孔质量控制2.1tostrengthenqualitycontrolintoahole护筒采用钢板制作，采用人工开挖埋设，护筒底部与土层相接处用粘土夯实，护筒外面与原土之间用粘土填满、夯实，土工布严防地表水从该处渗入。为保证护筒内外水头的压力差护筒内水位应高出护筒外水位1.5m，护筒埋设深度3m以上，同时，如果在成孔范围内有流塑性淤泥等软弱夹层，应将护筒埋设穿越该软弱层。..................................Buriedlinersmadeofsteelplatebyartificialexcavation,protectionandsoilla...
