地基基礎(chǔ)檢測 技術(shù) Basic knowledge of static load test of foundation piles for foundation testing technology-基樁 靜載試驗的基本知73課件講解

地基基礎(chǔ)檢測技術(shù)基樁靜載試驗的基本知識

Basicknowledgeofstaticloadtestoffoundationpilesforfoundationtestingtechnology基樁的分類

Classificationoffoundationpiles01基樁靜載試驗的一般規(guī)定

Generalprovisionsforstaticloadtestoffoundationpiles02基樁的分類

Classificationoffoundationpiles0101基樁的分類

Classificationoffoundationpiles按承載性狀分

Classificationbybearingproperties摩擦樁：

Frictionpile:在承載能力極限狀態(tài)下，樁頂豎向荷載由樁側(cè)阻力承受,樁端阻力小到可忽略不計

Underthelimitstateofbearingcapacity,theverticalloadonthepiletopisbornebytheresistanceonthepileside,andtheresistanceofpileendisnegligible端承摩擦樁：

End-bearingfrictionpiles:在承載能力極限狀態(tài)下，樁頂豎向荷載主要由樁側(cè)阻力承受

Underthelimitstateofbearingcapacity,theverticalloadonthepiletopismainlybornebytheresistanceonthepileside端承樁：

End-bearingpiles:在承載能力極限狀態(tài)下，樁頂豎向荷載由樁端阻力承受,樁側(cè)阻力小到可忽略不計

Underthelimitstateofbearingcapacity,theverticalloadonthepiletopisbornebytheresistanceonthepileend,andtheresistanceofpilesideisnegligible摩擦端承樁：

Frictionend-bearingpiles:在承載能力極限狀態(tài)下，樁頂豎向荷載主要由樁端阻力承受

Underthelimitstateofbearingcapacity,theverticalloadonthepiletopismainlybornebytheresistanceonthepileend基

樁

FoundationPiles摩擦型樁

Frictionpiles端承型樁

End-bearingpiles基樁的分類

Classificationoffoundationpiles按成樁方法分

Classificationbythemethodofpileforming基

樁

FoundationPiles①干作業(yè)法鉆(挖)孔灌注樁

①Bored(digging)cast-in-placepilewithdryoperationmethod②泥漿護壁法鉆(挖)孔灌注樁

②Bored(digging)cast-in-placepilewithslurrywallmethod③套管護壁法鉆(挖)孔灌注樁

③Bored(digging)cast-in-placepilewithcasingwallmethod鉆孔擠擴灌注樁

Boredandexpandedcast-in-placepiles攪拌勁芯樁

Stirredcorepiles預(yù)鉆孔打入(靜壓)預(yù)制樁

Pre-boreddriven(staticpressure)precastpiles打入(靜壓)式敞口鋼管樁

Driven(staticpressure)opensteelpipepiles敞口預(yù)應(yīng)力混凝土空心樁

OpenprestressedconcretehollowpilesH型鋼樁

H-shapedsteelpiles沉管灌注樁

Pipe-sinkingcast-in-placepiles沉管夯(擠)擴灌注樁

Pipe-sinkingtamping(extrusion)expandingcast-in-placepiles打入(靜壓)預(yù)制樁

Driven(staticpressure)precastpiles閉口預(yù)應(yīng)力混凝土空心樁

Closedprestressedconcretehollowpiles閉口鋼管樁

Closedsteelpipepiles擠土樁

Displacementpiles部分擠土樁

Partialdisplacementpiles非擠土樁

Non-soil-displacedpiles基樁的分類

Classificationoffoundationpiles按樁徑大小分

Classificationbythepilediameter基樁

FoundationPiles小直徑樁

Smalldiameterpilesd≤250mm中等直徑樁

Mediumdiameterpiles250mm<d<800mm大直徑樁

Largediameterpilesd≥800mm基樁的分類

Classificationoffoundationpiles按樁的功能分

Classificationbythefunctionofthepile基樁

FoundationPiles承壓樁

Bearingpiles橫向受荷樁

Transverselyloadedpiles抗拔樁錨樁

Uplift-resistentpilesandanchorpiles護坡樁

Slopeprotectionpiles基樁的分類

Classificationoffoundationpiles按樁的制作和施工方法分

Classificationbytheproductionandconstructionmethodsofpiles基

樁

FoundationPiles預(yù)制樁

Precastpile灌注樁

Cast-in-placepile基樁靜載試驗的一般規(guī)定

Generalprovisionsforstaticloadtestoffoundationpiles0102基樁靜載試驗的一般規(guī)定

Generalprovisionsforstaticloadtestoffoundationpiles1、靜載試驗的目的

1.Purposeofstaticloadtest在樁頂部逐級施加豎向壓力、豎向上拔力或水平推力，觀測樁頂部隨時間產(chǎn)生的沉降、上拔位移或水平位移，以確定相應(yīng)的單樁豎向抗壓承載力、單樁豎向抗拔承載力或單樁水平承載力的試驗方法。

Thetestmethodofapplyingverticalpressure,verticalupliftforceorhorizontalthruststepbystepatthepiletop,andobservingthesettlement,upliftdisplacementorhorizontaldisplacementofthepiletopovertimetodeterminethecorrespondingverticalcompressivebearingcapacityofsinglepile,verticalupliftbearingcapacityofsinglepileorhorizontalbearingcapacityofsinglepile.靜載試驗

Staticloadtest基樁靜載試驗的一般規(guī)定

Generalprovisionsforstaticloadtestoffoundationpiles1.靜載試驗的目的

1.Purposeofstaticloadtest確定單樁豎向極限承載力。

Theverticalultimatebearingcapacityofsinglepileshallbedetermined.試驗加載至樁側(cè)及樁端的巖土阻力達到極限狀態(tài)；當(dāng)樁的承載力由樁身強度控制時，可按設(shè)計要求的加載量進行加載。

Testloadinguntilthegeotechnicalresistanceofthepilesideandpileendreachesthelimitstate;Whenthebearingcapacityofthepileiscontrolledbythestrengthofthepilebody,itcanbeloadedaccordingtotheloadingcapacityrequiredbythedesign.試樁靜載試驗

Staticloadtestoftestpiles基樁靜載試驗的一般規(guī)定

Generalprovisionsforstaticloadtestoffoundationpiles1.靜載試驗的目的

1.Purposeofstaticloadtest判定單樁承載力是否滿足設(shè)計要求。

Determinewhetherthebearingcapacityofsinglepilemeetsthedesignrequirements.通過現(xiàn)場試驗的方法，檢測基樁在預(yù)估(設(shè)計)荷載作用下達到破壞狀態(tài)前或者出現(xiàn)不適于繼續(xù)承載的變形時所對應(yīng)的最大荷載。

Themaximumloadcorrespondingtothefoundationpilebeforereachingthefailurestateundertheestimated(design)loadordeformationnotsuitableforcontinuedbearingshallbetestedbythefieldtestmethods.工程樁靜載試驗

Staticloadtestoftheengineeringpiles基樁靜載試驗的一般規(guī)定

Generalprovisionsforstaticloadtestoffoundationpiles①設(shè)計等級為甲級的樁基;

①DesigngradeofthepilefoundationisrankedasgradeA;②無相關(guān)試樁資料可參考的設(shè)計等級為乙級的樁基;

②DesigngradeofthepilefoundationisrankedasgradeBwithoutrelevanttestpiledataforreference;③地質(zhì)條件復(fù)雜、基樁施工質(zhì)量可靠性低;

③Complexgeologicalconditionsandlowqualityreliabilityoffoundationpileconstruction;④本地區(qū)采用的新樁型或采用新工藝成樁的樁基。

④Newpiletypeadoptedinthisareaorpilefoundationformedbynewprocess.當(dāng)設(shè)計有要求或有下列情況之一時，施工前應(yīng)進行試驗樁檢測并確定單樁極限承載力:

Whentherearedesignrequirementsoroneofthefollowingconditions,thetestpileshallbetestedandtheultimatebearingcapacityofsinglepileshallbedeterminedbeforeconstruction:2.試驗樁檢測規(guī)定

2.Provisionsfortestingoftestpiles基樁靜載試驗的一般規(guī)定

Generalprovisionsforstaticloadtestoffoundationpiles①檢測數(shù)量應(yīng)滿足設(shè)計要求，且在同一條件下不應(yīng)少于3根；

①Thetestquantityshallmeetthedesignrequirementsandshallnotbelessthan3underthesameconditions;②當(dāng)預(yù)計工程樁總數(shù)小于50根時，檢測數(shù)量不應(yīng)少于2根。

②Whentheestimatedtotalnumberofengineeringpilesislessthan50,thetestquantityshallnotbelessthan2.2.試驗樁檢測規(guī)定

2.Provisionsfortestingoftestpiles數(shù)量要求

Quantityrequirement基樁靜載試驗的一般規(guī)定

Generalprovisionsforstaticloadtestoffoundationpiles3、工程樁驗收規(guī)定

3.ProvisionsonAcceptanceofEngineeringPiles①設(shè)計等級為甲級的建筑樁基；

①DesigngradeofthebuildingpilefoundationisrankedasgradeA;②未按照試樁要求進行單樁靜載試驗的工程;

②Worksnotsubjecttosinglepilestaticloadtestasrequiredfortestpiles;③施工前進行了單樁靜載試驗，但施工過程中變更了工藝參數(shù)或施工質(zhì)量出現(xiàn)了異常;

③Singlepilestaticloadtestwascarriedoutbeforeconstruction,however,theprocessparametersarechangedortheconstructionqualityisabnormalduringconstruction;④地質(zhì)條件復(fù)雜、樁施工質(zhì)量可靠性低;

④Complexgeologicalconditionsandlowqualityreliabilityofpileconstruction;⑤本地區(qū)采用的新樁型或新工藝;

⑤Newpiletypeornewprocessisadoptedinthisarea;⑥施工過程中產(chǎn)生擠土上浮或偏位的群樁。

⑥Grouppileswithsoilsqueezefloatingordeviationduringconstruction.當(dāng)符合下列條件之一時，應(yīng)采用單樁豎向抗壓靜載試驗進行承載力驗收檢測：

Whenoneofthefollowingconditionsismet,theverticalcompressivestaticloadtestofsinglepileshallbeadoptedforacceptancetestofbearingcapacity:基樁靜載試驗的一般規(guī)定

Generalprovisionsforstaticloadtestoffoundationpiles①檢測數(shù)量不應(yīng)少于同一條件下樁基分項工程總樁數(shù)的1%，且不應(yīng)少于3根；

①Thetestquantityshallnotbelessthan1%ofthetotalnumberofpilesinthepilefoundationsubdivisionalworksunderthesameconditions,andshallnotbelessthan3;②當(dāng)總樁數(shù)小于50根時，檢測數(shù)懸不應(yīng)少于2根。

②Whenthetotalnumberofpilesislessthan50,thetestquantityshallnotbelessthan2.數(shù)量要求

Quantityrequirement3、工程樁驗收規(guī)定

3.ProvisionsonAcceptanceofEngineeringPiles基樁靜載試驗的一般規(guī)定

Generalprovisionsforstaticloadtestoffoundationpiles基樁承載力檢測前的休止時間，除應(yīng)符合樁身強度外，當(dāng)無成熟的地區(qū)經(jīng)驗時，尚不應(yīng)少于下表規(guī)定的時間。

Theresttimebeforethetestofbearingcapacityoffoundationpiles,inadditiontomeetingthestrengthofpilebody,itshallnotbelessthanthetimespecifiedinthetablebelowwhenthereisnomatureregionalexperience.4、檢測時間規(guī)定

4.Provisionsfortesttime土的類別

Soiltype休止時間(d)

Resttime(d)砂土

Sandysoil7粉土

Silt10粘性土

Clayeysoil非飽和

Unsaturated15飽和

Saturated25注：對于泥漿護壁灌注樁，宜延長休止時間。

Note:Forthecast-in-placepilewithslurryretainingwall,theresttimeshouldbeextended.基樁靜載試驗的一般規(guī)定

Generalprovisionsforstaticloadtestoffoundationpiles樁的承載力時間(或歇后)效應(yīng)：成樁后樁的承載力隨時間而變化的現(xiàn)象。

Thetime(orrelaxation)effectofthebearingcapacityofthepile:thephenomenonthatthebearingcapacityofpilechangeswithtimeafterpileformation.時間效應(yīng)可使樁的承載力比初始值增長40%~400%。

Thetimeeffectcanincreasethebearingcapacityofpilesby40%~400%comparedwiththeinitialvalue.4、檢測時間規(guī)定

4.Provisionsfortesttime初期增長速度較快，隨后漸慢，待達到一定時間后趨于相對穩(wěn)定，其增長的快慢和幅度，除與土性和類別有關(guān)，還與樁的施工工藝有關(guān)。

Theinitialgrowthrateisrelativelyfastandthenslow,andtendstoberelativelystableafteracertainperiodoftime.Thegrowthrateandmagnitudearerelatednotonlytothenatureandtypeofsoil,butalsototheconstructionprocessofpiles.變化規(guī)律

Changerule基樁靜載試驗的一般規(guī)定

Generalprovisionsforstaticloadtestoffoundationpiles樁的承載力

Bearingcapacityofpile樁身結(jié)構(gòu)承載力

Bearingcapacityofpilebodystructure支撐樁結(jié)構(gòu)的地基巖土承載力

Bearingcapacityofthefoundationrockandsoilsupportingthepilestructure樁身混凝士齡期

Ageofpilebodyconcrete(或設(shè)計強度)

(ordesignstrength)地基土休止時間

Resttimeoffoundationsoil承載力檢測

Bearingcapacitytest同時滿足

Satisfysimultaneously4、檢測時間規(guī)定

4.Provisionsfortesttime基樁靜載試驗的一般規(guī)定

Generalprovisionsforstaticloadtestoffoundationpiles5、幾種承載力的說明

5.Descriptionofseveralbearingcapacities《建筑地基基礎(chǔ)設(shè)計規(guī)范》(GB50007-2011)附錄Q.0.11，將單樁豎向極限承載力除以安全系數(shù)2，為單樁豎向承載力特征值。

InAppendixQ.0.11ofCodeforDesignofBuildingFoundation(GB50007-2011),thecharacteristicvalueofsingle-pileverticalbearingcapacityistheverticalultimatebearingcapacityofsinglepiledividedbysafetyfactor2.單樁豎向承載力特征值

Characteristicvalueofsingle-pileverticalbearingcapacity單樁在豎向荷載作用下達到破壞狀態(tài)前或出現(xiàn)不適于繼續(xù)承載變形時所對應(yīng)的最大荷載,它取決于土對樁的支承阻力和樁身承載力。

Themaximumloadcorrespondingtothesinglepi