地基基礎(chǔ)檢測(cè) 技術(shù) Theoretical knowledge of deep plate load tests for foundation testing technology-深層 平板載荷試驗(yàn)理論知05課件講解

地基基礎(chǔ)檢測(cè)技術(shù)深層平板載荷試驗(yàn)理論知識(shí)

Theoreticalknowledgeofdeepplateloadtestsforfoundationtestingtechnology深層平板載荷試驗(yàn)

Deepplateloadtest010101深層平板載荷試驗(yàn)

Deepplateloadtest1.適用范圍

1.ScopeofApplication深層平板載荷試驗(yàn)

Deepplateloadtest深層平板載荷試驗(yàn)適用于確定深部地基土層及大直徑樁樁端土層在承壓板下應(yīng)力主要影響范圍內(nèi)的承載力和變形參數(shù)。

Thedeepplateloadtestissuitablefordeterminingthebearingcapacityanddeformationparametersofthedeepfoundationsoillayerandthesoillayerattheendofthelarge-diameterpilewithinthemainstressinfluenceunderthebearingplate.深層平板載荷試驗(yàn)

Deepplateloadtest試驗(yàn)深度不應(yīng)小于5m

Thetestdepthshallnotbelessthan5m1.適用范圍

1.ScopeofApplication深層地基土

Deepfoundationsoil大直徑樁的樁端土

Thesoilattheendofthelarge-diameterpile深層平板載荷試驗(yàn)

Deepplateloadtest2.數(shù)量要求

2.Quantityrequirement①單位工程檢測(cè)數(shù)量為每500㎡不應(yīng)少于1點(diǎn)，且總點(diǎn)數(shù)不應(yīng)少于3點(diǎn)；②復(fù)雜場(chǎng)地或重要建筑地基應(yīng)增加檢測(cè)數(shù)量。

①Thetestquantityofunitworksshallnotbelessthan1pointper500m2,andthetotalnumberofpointsshallnotbelessthan3;②Thetestquantityshallbeincreasedforfoundationsofcomplexsitesorimportantbuildings.深層平板載荷試驗(yàn)

Deepplateloadtest3.儀器設(shè)備

3.Instrumentsandequipment試驗(yàn)儀器設(shè)備性能指標(biāo)應(yīng)符合下列規(guī)定：

Theperformanceindicatorsofthetestinstrumentsandequipmentshallmeetthefollowingrequirements:壓力傳感器的測(cè)量誤差不應(yīng)大于1%，壓力表精度應(yīng)優(yōu)于或等于0.4級(jí)；

Themeasurementerrorofthepressuresensorshallnotbegreaterthan1%,andtheaccuracyofthepressuregaugeshallbebetterthanorequaltograde0.4;試驗(yàn)用千斤頂、油泵、油管在最大試驗(yàn)荷載時(shí)的壓力不應(yīng)超過(guò)規(guī)定工作壓力的80%。

Thepressureofjack,oilpumpandoilpipefortestundermaximumtestloadshallnotexceed80%ofthespecifiedworkingpressure.深層平板載荷試驗(yàn)

Deepplateloadtest3.儀器設(shè)備

3.Instrumentsandequipment試驗(yàn)儀器設(shè)備性能指標(biāo)應(yīng)符合下列規(guī)定：

Theperformanceindicatorsofthetestinstrumentsandequipmentshallmeetthefollowingrequirements:荷重傳感器、千斤頂、壓力表或壓力傳感器的量程不應(yīng)大于最大加載量的3.0倍,且不應(yīng)小于最大加載量的1.2倍；

Therangeofloadsensor,jack,pressuregaugeorpressuresensorshallnotbegreaterthan3.0timesofthemaximumloadingcapacityandshallnotbelessthan1.2timesofthemaximumloadingcapacity;位移測(cè)量?jī)x表的測(cè)量誤差不應(yīng)大于0.1%FS，分辨力應(yīng)優(yōu)于或等于0.01mm。

Themeasurementerrorofdisplacementmeasuringinstrumentshallnotbegreaterthan0.1%offullscale,andtheresolutionshallbebetterthanorequalto0.01mm.深層平板載荷試驗(yàn)

Deepplateloadtest4.試驗(yàn)要點(diǎn)

4.Testpoints（1）場(chǎng)地處理

(1)Sitetreatment試井直徑宜等于承壓板直徑,當(dāng)試井直徑需要大于承壓板直徑時(shí),緊靠承壓板周?chē)恋母叨炔粦?yīng)小于承壓板直徑。

Thediameterofthewelltestshallbeequaltothediameterofthebearingplate.Whenthediameterofthewelltestneedstobegreaterthanthediameterofthebearingplate,theheightofthesoilimmediatelyaroundthebearingplateshallnotbelessthanthediameterofthebearingplate.深層平板載荷試驗(yàn)

Deepplateloadtest4.試驗(yàn)要點(diǎn)

4.Testpoints當(dāng)試井直徑需要大于承壓板直徑時(shí),緊靠承壓板周?chē)恋母叨炔粦?yīng)小于承壓板直徑,這是為什么?

Whenthediameterofthewelltestneedstobegreaterthanthediameterofthebearingplate,theheightofthesoilimmediatelyaroundthebearingplateshallnotbelessthanthediameterofthebearingplate.Whyisthis?以盡量保持半無(wú)限體內(nèi)部的受力狀態(tài),避免試驗(yàn)時(shí)土的擠出。

Soastokeepthestressstateinsidethesemi-infinitebodyasmuchaspossibleandavoidsoilextrusionduringtest.深層平板載荷試驗(yàn)

Deepplateloadtest試井截面應(yīng)為圓形,直徑宜取0.8m～1.2m:并有安全防護(hù)措施

Thesectionofthewelltestshallbecircular,andthediametershallbe0.8m~1.2m,withsafetyprotectionmeasures4.試驗(yàn)要點(diǎn)

4.Testpoints深層平板載荷試驗(yàn)

Deepplateloadtest4.試驗(yàn)要點(diǎn)

4.Testpoints承壓板直徑不應(yīng)小于0.8m,應(yīng)具有足夠的強(qiáng)度和剛度。

Thediameterofthebearingplateshallnotbelessthan0.8mandshallbeofsufficientstrengthandstiffness.(2)承壓板面積

(2)Areaofbearingplate深層平板載荷試驗(yàn)

Deepplateloadtest可直接在外徑為800mm的鋼環(huán)或鋼筋混凝土管柱內(nèi)澆筑

Canbecastdirectlyinasteelringwithanouterdiameterof800mmorinareinforcedconcretepipecolumn

4.試驗(yàn)要點(diǎn)

4.Testpoints承壓板直徑取800mm時(shí)，采用厚約300mm的現(xiàn)澆混凝土板或預(yù)制的剛性板

Whenthediameterofbearingplateis800mm,cast-in-placeconcreteslaborprecastrigidslabwithathicknessofabout300mmisadopted深層平板載荷試驗(yàn)

Deepplateloadtest4.試驗(yàn)要點(diǎn)

4.Testpoints承壓板直徑不應(yīng)小于0.8m,應(yīng)具有足夠的強(qiáng)度和剛度。

Thediameterofthebearingplateshallnotbelessthan0.8mandshallbeofsufficientstrengthandstiffness.(3)加載反力裝置

(3)Loadingreactiondevice傳力柱應(yīng)有足夠的剛度

Theforcetransmissioncolumnshallbeofsufficientstiffness傳力柱宜高出地面50cm

Theforcetransmissioncolumnshallbe50cmabovetheground深層平板載荷試驗(yàn)

Deepplateloadtest4.試驗(yàn)要點(diǎn)

4.Testpoints(3)加載反力裝置

(3)Loadingreactiondevice傳力柱宜與承壓板連接成為整體

Theforcetransmissioncolumnshallbeconnectedwiththebearingplateasawhole傳力柱的頂部可采用鋼筋等斜拉桿固定

Thetopoftheforcetransmissioncolumncanbefixedwithdiagonaltierodssuchassteelbars深層平板載荷試驗(yàn)

Deepplateloadtest4.試驗(yàn)要點(diǎn)

4.Testpoints用力柱與地面的加荷裝置連接,亦可利用井壁護(hù)圈作為反力,加荷試驗(yàn)時(shí)應(yīng)直接測(cè)讀承壓板的沉降。

Theforcecolumnisconnectedwiththeloadingdeviceontheground,andtheshaftwallretainercanalsobeusedforreaction.Duringtheloadingtest,thesettlementofthebearingplateshallbedirectlymeasuredandread.深層平板載荷試驗(yàn)

Deepplateloadtest傳力柱

Forcetransmissioncolumn位移測(cè)量桿

Displacementmeasuringrod4.試驗(yàn)要點(diǎn)

4.Testpoints位移傳遞裝置宜采用鋼管或塑料管做位移測(cè)量桿

Steelpipeorplasticpipeshallbeusedasdisplacementmeasuringrodfordisplacementtransmissiondevice(4)沉降測(cè)量

(4)Settlementmeasurement深層平板載荷試驗(yàn)

Deepplateloadtest4.試驗(yàn)要點(diǎn)

4.Testpoints(4)沉降測(cè)量

(4)Settlementmeasurement位移測(cè)量桿的底端應(yīng)與承壓板固定連接

Thebottomofthedisplacementmeasuringrodshallbefixedlyconnectedwiththebearingplate深層平板載荷試驗(yàn)

Deepplateloadtest4.試驗(yàn)要點(diǎn)

4.Testpoints(4)沉降測(cè)量

(4)Settlementmeasurement位移測(cè)量桿宜每間隔一定距離與傳力柱滑動(dòng)相連

Displacementmeasuringrodisconnectedwiththeforcetransmissioncolumnbyslidingatcertaindistance深層平板載荷試驗(yàn)

Deepplateloadtest4.試驗(yàn)要點(diǎn)

4.Testpoints(4)沉降測(cè)量

(4)Settlementmeasurement位移測(cè)量桿的頂部宜高出孔口地面20cm

Thetopofthedisplacementmeasuringrodshallbe20cmabovethegroundoftheorifice深層平板載荷試驗(yàn)

Deepplateloadtest4.試驗(yàn)要點(diǎn)

4.Testpoints預(yù)壓荷載：宜為最大加載量的5%

Preloadingload:5%ofthemaximumloadingcapacity預(yù)壓時(shí)間：宜為5min

Preloadingtime:5min一切正常

EverythingisOK卸載至零

Unloadingtozero記錄位移測(cè)試儀表初始讀數(shù)

Recordtheinitialreadingofthedisplacementmeasuringinstrument讀數(shù)穩(wěn)定

Stablereading(5)

預(yù)壓

(5)Preloading預(yù)

壓

Preloading正式加載

Formalloading深層平板載荷試驗(yàn)

Deepplateloadtest4.試驗(yàn)要點(diǎn)

4.Testpoints地基土平板載荷試驗(yàn)的分級(jí)載荷宜為最大試驗(yàn)載荷的1/8~1/12。

Thesteploadoftheplateloadtestoffoundationsoilshallbe1/8~1/12ofthemaximumtestload.最大加載量不應(yīng)小于設(shè)計(jì)要求的2倍。

Themaximumloadingcapacityshallnotbelessthan2timesofthedesignrequirements.(6)加卸載

(6)Loadingandunloading主要出于安全系數(shù)的考慮,一般取土層地基安全系數(shù)K=2

Consideringthesafetyfactor,thesafetyfactorofsoilfoundationisgenerallytakentobeK=2深層平板載荷試驗(yàn)

Deepplateloadtest(6)

加卸載

(6)Loadingandunloading第一級(jí)荷載可取分級(jí)荷載的2倍

Theloadoffirststepcanbetwicethestepload每級(jí)卸載量為分級(jí)荷載的2倍;當(dāng)加載等級(jí)為奇數(shù)級(jí)時(shí),第一級(jí)卸載量宜取分級(jí)荷載的3倍

Eachstepofunloadshallbe2timesthestepload;whentheloadinglevelisodd,theunloadingamountoffirststepshallbe3timesofthestepload加、卸載時(shí)應(yīng)使荷載傳遞均勻、連續(xù)、無(wú)沖擊,每級(jí)荷載在維持過(guò)程中的變化幅度不得超過(guò)分級(jí)荷載的±10%

Duringloadingandunloading,theloadshouldbetransmitteduniformly,continuouslyandwithoutimpact.Thevariationofloadofeachstepduringthemaintenanceprocessshallnotexceed±10%ofthestepload4.試驗(yàn)要點(diǎn)

4.Testpoints逐級(jí)等量加載

Equivalentloadingstep-by-step逐級(jí)等量加載

Equivalentloadingstep-by-step深層平板載荷試驗(yàn)

Deepplateloadtest4.試驗(yàn)要點(diǎn)

4.Testpoints每級(jí)加載后應(yīng)按第10min、20min、30min、45min、60min測(cè)讀承壓板的沉降量,以后應(yīng)每隔半小時(shí)測(cè)讀一次沉降量。

Aftereachstepofloading,thesettlementofthebearingplateshallbemeasuredandreadat10min,20min,30min,45minand60min,andthesettlementshallbemeasuredandreadeveryhalfanhourthereafter.當(dāng)在連續(xù)兩小時(shí)內(nèi),每小時(shí)的沉降量小于0.1mm時(shí),則認(rèn)為已趨穩(wěn)定,可加下一級(jí)荷載。

Whenthesettlementshallbelessthan0.1mmperhourwithintwoconsecutivehours,itisconsideredtobestableandtheloadofnextstepcanbeapplied.(6)加卸載

(6)Loadingandunloading深層平板載荷試驗(yàn)

Deepplateloadtest4.試驗(yàn)要點(diǎn)

4.Testpoints卸載時(shí)，每級(jí)荷載維持1h，應(yīng)按第10min、30min、60min測(cè)讀承壓板沉降量；卸載至零后，應(yīng)測(cè)讀承壓板殘余沉降量,維持時(shí)間為3h，測(cè)讀時(shí)間應(yīng)為第10min、30min、60min、120min、180min。

Duringunloading,theloadateachstepshallbemaintainedfor1h,andthesettlementofthebearingplateshallbemeasuredandreadat10min,30minand60min;Afterunloadingtozero,theresidualsettlementofthebearingplateshallbemeasuredandread,andtheholdingtimeis3h,andthemeasuringandreadingtimeshallbe10min,30min,60min,120minand180min.(6)加卸載

(6)Loadingandunloading深層平板載荷試驗(yàn)

Deepplateloadtest4.試驗(yàn)要點(diǎn)

4.Testpoints當(dāng)出現(xiàn)下列情況之一時(shí),即可終止加載:

Loadingcanbeterminatedwhenoneofthefollowingconditionsoccurs:①本級(jí)荷載的沉降量大于前級(jí)荷載沉降量的5倍，荷載-沉降(p-s)曲線出現(xiàn)明顯陡降；

①Thesettlementoftheloadatthislevelisgreaterthan5timesthesettlementoftheprevi