本科畢業(yè)設(shè)計(jì)論文英語(yǔ)翻譯譯文題目FOUNDATIONS基礎(chǔ)姓名專業(yè)勘查技術(shù)與工程班級(jí)學(xué)號(hào)指導(dǎo)老師指導(dǎo)教師職稱教授2013年5月20日FOUNDATIONSSTRUCTURESOROTHERCONSTRUCTEDWORKSARESUPPORTEDONTHEEARTHBYFOUNDATIONSTHEWORD“FOUNDATION”MAYMEANTHEEARTHITSELF,SOMETHINGPLACEDINORONTHEEARTHTOPROVIDESUPPORT,ORACOMBINATIONOFTHEEARTHANDTHEELEMENTSPLACEDONITTHEFOUNDATIONFORAMULTISTORYOFFICEBUILDINGCOULDBEACOMBINATIONOFCONCRETEFOOTINGSANDTHESOILORROCKONWHICHTHEFOOTINGSARESUPPORTEDTHEFOUNDATIONFORANEARTHFILLDAMWOULDBETHENATURALSOILORROCKONWHICHTHEDAMISPLACEDCONCRETEFOOTINGSORPILESANDPILECAPSAREOFTENREFERREDTOASFOUNDATIONSWITHOUTINCLUDINGTHESOILORROCKONWHICHORINWHICHTHEYAREPLACEDTHEINSTALLEDELEMENTSANDTHENATURALSOILORROCKOFTHEEARTHFORMAFOUNDATIONSYSTEMTHESOILANDROCKPROVIDETHEULTIMATESUPPORTOFTHESYSTEMFOUNDATIONSTHATAREINSTALLEDMAYBEEITHERSOILBEARINGORROCKBEARINGTHEREACTIONSOFTHESOILORROCKTOTHEIMPOSEDLOADSGENERALLYDETERMINEDHOWWELLTHEFOUNDATIONSYSTEMFOUNDATIONINDESIGNINGTHEINSTALLEDPORTIONS,THEDESIGNERMUSTDETERMINETHESAFEPRESSUREWHICHCANBEUSEDONTHESOILORROCKANDTHEAMOUNTOFTOTALSETTLEMENTANDDIFFERENTIALSETTLEMENTWHICHTHESTRUCTURECANWITHSTANDTHEINSTALLEDPARTSOFTHEFOUNDATIONSYSTEMMAYBEFOOTINGS,MATFOUNDATIONS,SLABFOUNDATIONS,ANDCAISSONSORPILES,ALLOFWHICHAREUSEDTOTRANSFERLOADFROMASUPERSTRUCTUREINTOTHEEARTHTHESEPARTS,WHICHTRANSMITLOADFROMTHESUPERSTRUCTURETOTHEEARTH,ARECALLEDTHESUBSTRUCTUREFOOTINGSFOOTINGSORSPREADFOUNDATIONSAREUSEDTOSPREADTHELOADSFROMCOLUMNSORWALLSTOTHEUNDERLYINGSOILORROCKNORMALLYFOOTINGSARECONSTRUCTEDOFREINFORCEDCONCRETEHOWEVER,UNDERSOMECIRCUMSTANCESTHEYMAYBECONSTRUCTEDOFPLAINCONCRETEORMASONARY,WHENEACHFOOTINGSUPPORTSONLYONECOLUMN,ITISSQUAREFOOTINGSSUPPORTINGTWOCOLUMNSARECALLEDCOMBINEDFOOTINGSANDMAYBEEITHERRECTANGULARORTRAPEZOIDALCANTILEVERFOOTINGSAREUSEDTOCARRYLOADSFROMTWOCOLUMNS,WITHONECOLUMNANDONEENDOFTHEFOOTINGPLACEDAGAINSTABUILDINGLINEOREXTERIORWALLFOOTINGSSUPPORTINGWALLARECONTINUOUSFOOTINGSTHESIZESOFFOOTINGSAREDETERMINEDBYDIVIDINGTHELOADSTOBEIMPOSEDATTHEBASEOFTHEFOOTINGSBYTHEALLOWABLEBEARINGPRESSUREWHICHCANBEIMPOSEDONTHESOILORROCKOFTHEEARTHMOSTBUILDINGCODESANDTEXTBOOKSONFOUNDATIONSCONTAINTABLESLISTINGALLOWABLEBEARINGPRESSURESFORVARIOUSTYPESOFSOILANDROCKHOWEVER,THERETABLESGIVEONLYGENERALCLASSIFICATIONSANDDESCRIPTIONSOFTHESOILORROCKANDMUSTBEUSEDWITHCAUTIONMORESPECIFICINFORMATIONABOUTTHESOILORROCKISNORMALLYOBTAINEDBYDRILLINGTESTBORINGS,EXTRACTINGSOILORROCKSAMPLES,PERFORMINGLABORATORYTESTSONTHESAMPLES,ANDMAKINGENGINEERINGANALYSISTODETERMINESUITABLEBEARINGPRESSURESINADDITIONTOBEARINGPRESSURE,CONSIDERATIONMUSTBEGIVENTOTHEAMOUNTOFSETTLEMENTWHICHMAYOCCURANDTHECAPABILITYOFTHESTRUCTURETOWITHSTANDSUCHSETTLEMENTIFSETTLEMENTISAPROBLEMITMAYBENECESSARYTOUSEANALTERNATEFOUNDATIONTYPERATHERTHANFOOTINGSORTOENLARGETHEFOOTINGSANDDECREASETHEBEARINGPRESSUREGRADEBEAMSMAYBEUSEDBETWEENEXTERIORCOLUMNFOOTINGSTOSUPPORTWALLS,WITHTHEBEAMSTRANSFERRINGTHEWEIGHTOFTHEWALLSTOTHECOLUMNFOOTINGSBEAMSAREALSOUSEDBETWEENINTERIORCOLUMNFOOTINGSTOACTASBRACESORTOSUPPORTINTERIORWALLSRETAININGWALLSARETHOSEWALLSSUBJECTTOHORIZONTALEARTHPRESSURESDUETOTHERETENTIONOFEARTHBEHINDTHEMTHEFOUNDATIONFORTHESEWALLSMUSTHAVESUFFICIENTFRICTIONALRESISTANCEWITHTHESOILORROCKONWHICHTHEYRESTSOTHATTHEYWILLNOTSLIDEWHENSUBJECTEDTOTHEHORIZONTALEARTHPRESSUREINADDITION,RETAININGWALLSMUSTBEDESIGNEDSOTHEYWILLNOTOVERTURNINFROSTSUSCEPTIBLEAREAS,FOOTINGSMUSTBEPLACEDBELOWTHEFROSTLINEMATFOUNDATIONSMATORRAFTFOUNDATIONSARELARGE,THICK,ANDUSUALLYHEAVILYREINFORCEDCONCRETEMATSWHICHTRANSFERLOADSFROMANUMBEROFCOLUMNSORCOLUMNSANDWALLSTOTHEUNDERLYINGSOILORROCKMATSAREALSOCOMBINEDFOOTINGS,BUTAREMUCHLARGERTHANAFOOTINGSUPPORTINGTWOCOLUMNSTHEYARECONTINUOUSFOOTINGSANDAREDESIGNEDTOTRANSFERARELATIVELYUNIFORMPRESSURETOTHEUNDERLYINGSOILORROCKMATSARERIGIDANDWILLACTASABRIDGEOVERDISCONTINUITIESINTHESOILORROCKONWHICHTHEYAREFOUNDEDMATSFOUNDEDSEVERALMETERSBELOWTHEGROUNDSURFACE,WHENCOMBINEDWITHEXTERNALWALLS,ARETERMEDFLOATINGFOUNDATIONSTHEWEIGHTOFTHESOILEXCAVATEDFROMTHEGROUNDSURFACETOTHEBOTTOMOFTHEMATMAYBEEQUALTOAPPROACHTHETOTALWEIGHTOFTHESTRUCTUREINTHISCASE,LITTLEORNONEWLOADISAPPLIEDTOTHEUNDERLYINGSUPPORTINGSOIL,ANDSETTLEMENTSOFASTRUCTUREMAYBEMINIMALAFTERCONSTRUCTIONSLABFOUNDATIONSSLABFOUNDATIONSAREUSEDFORLIGHTSTRUCTURESWHEREINTHECOLUMNSANDWALLSARESUPPORTEDDIRECTLYONTHEFLOORSLABTHEFLOORSLABISTHICKENEDANDMOREHEAVILYREINFORCEDATTHEPLACESWHERETHECOLUMNANDWALLLOADSAREIMPOSEDSPECIALPROBLEMSGROUNDWATERISAMAJORPROBLEMINCONNECTIONWITHTHEDESIGNANDINSTALLATIONOFFOUNDATIONSWHEREASUBSTRUCTUREISTOBEPLACESBELOWTHEGROUNDWATERLEVELWELLPOINTS,PUMPINGFROMDEEPWELLS,ORPUMPINGFROMSUMPSAREMETHODSUSEDTODEWATERCONSTRUCTIONSITESDURINGFOUNDATIONINSTALLATIONOTHERMETHODSWHICHARELESSOFTENUSEDAREFREEZINGOFTHEWATERINTHESOUL,REMOVALOFWATERBYELECTROOSMOSIS,ANDTHEINSTALLATIONOFCUTOFFWALLSMADEOFPILLINGORGROUTAROUNDTHEPERIPHERYFROMWITHINTHEEXCAVATIONIFDEWATERINGOPERATIONSAREPERFORMEDINANAREASURROUNDEDBYEXISTINGSTRUCTURES,PRECAUTIONSMUSTBETAKENTOPROJECTTHEM,ASTHELOWERINGOFTHEGROUNDWATERMAYCAUSETHESOILONWHICHTHEYARESUPPORTEDTOSUBSIDEIFABASEMENTISPARTIALLYORTOTALLYBELOWTHEGROUNDWATERLEVEL,ITSWALLSMUSTBEDESIGNEDTOWITHSTANDTHEHYDROSTATICPRESSURESOFTHEWATERONTHEOUTSIDEINADDITIONTOTHEPRESSUREFROMTHESOILBACKFILLANALTERNATEPROCEDUREISTOINSTALLAPERMANENTSYSTEMTOREMOVEWATEROUTSIDETHEWALLSSOMESUBSTRUCTURESBELOWGROUNDWATERLEVELMAYATTIMESBESUBJECTEDTOHYDROSTATICUPLIFTFORCESWHICHAREGREATERTHANTHEDOWNWARDFORCESIMPOSEDBYTHESTRUCTURESINTHESECASES,PROVISIONSMUSTBETOANCHORTHESTRUCTURESTOPREVENTTHEMFROMFLOATINGUPWARDGROUNDWATERALSOCAUSESPROBLEMSBYINFILTRATINGTHROUGHBASEMENTWALLS,SLABS,ANDJOINTSINTOTHEBASEMENTITSELFTHISCANBEPREVENTEDORREDUCEDBYPROVIDINGANEXTERNALPERMANENTDRAINAGESYSTEMTHATCARRIESWATERAWAYFROMTHEBASEMENT,BYENCASINGTHEWALLSANDSLABSINANIMPERMEABLEPLASTICMEMBRANE,ORBYCOATINGTHEEXTERNALWITHANASPHALTICMASTICTOLOWERTHEIRPERMEABILITYCOMBINATIONSOFTHEFOREGOINGAREALSOUSEDRETAININGWALLSANDABUTMENTSOFTENHAVEWEEPHOLESINTHELOWERSECTIONSTHROUGHWHICHWATERACCUMULATINGBEHINDTHEWALLSORABUTMENTSCANESCAPETHEWATERPRESSUREBEHINDTHEWALLSISRELIEVEDASTHEWATERFLOWSTHROUGHTHEWALLSINTOANOPENEXTERNALDRAINAGESYSTEMFOUNDATIONSPLACEDONEXPANSIVESOILSAREOFTENSUBJECTEDTODISTRESSINGMOVEMENTSUNLESSSPECIALPRECAUTIONSARETAKENEXPANSIVESOILSARETHOSEWHICHSWELLANDCONTRACTEXCESSIVELYWITHVARYINGAMOUNTSOFMOISTUREPROBLEMSCANBEOVERCOMEBYINSTALLINGFOUNDATIONSBELOWTHEZONEOFSIGNIFICANTCHANGEINMOISTURECONTENTANDBACKFILLINGWITHNONEXPANSIVEMATERIALS,BYALTERINGTHESOILWITHANADMIXTURESUCHASLIMEORCEMENTSOTHATVOLUMNCHANGESDONOTOCCUR,ORBYPROVIDINGFLEXIBILITYINTHESTRUCTURETOACCOMMODATEMOVEMENTSUNDERPINNINGOFFOUNDATIONISOFTENNECESSARY,ANDITMAYBEEITHERREMEDIALORPRECAUTIONARYREMEDIALUNDERPINNINGISUSEDTOCORRECTDEFECTINEXISTINGFOUNDATIONSWHICHMAYHAVESETTLEDEXCESSIVELYIFTHESTRUCTUREISTOBESAVEDORRETURNEDTOITSORIGINALSTATE,ADDITIONALFOUNDATIONSUPPORTMUSTBEPROVIDEDPRECAUTIONARYUNDERPINNINGISUSEDWHENNEWSTRUCTURESARETOBEINSTALLEDADJACENTTOORBENEATHEXISTINGSTRUCTURES,ASINTHECONSTRUCTIONOFCITYSUBWAYSUNDERPINNINGOFFOUNDATIONISASPECIALIZEDCONSTRUCTIONTECHNIQUETHEWORKISGENERALLYPERFORMEDINACONFINEDSPACE,SUCHASTHEBASEMENTOFABUILDING,ORINSMALLPITSEXCAVATEDOUTSIDEABUILDINGAREAITISNECESSARYTOPROVIDESUPPORTFORTHELOADSOFTHEEXISTINGSTRUCTUREWHILENEWFOUNDATIONSAREINSTALLEDTHENEWFOUNDATIONSMAYBEFOOTINGSWHICHAREPLACEDDEEPERINTHEGROUNDTHANTHEORIGINALFOUNDATIONS,ORTHEYMAYBEPILESORCAISSONSUNDERPINNINGOFAWALLFOOTINGMAYBEPERFORMEDBYEXCAVATINGPITSADJACENTTOANDBENEATHEXISTINGFOUNDATIONSTHEPITSARESMALL,SOME09MWIDEBY12MLONGHORIZONTALSHEETINGISPLACEDINTHEPITASEXCAVATIONPROCEEDSTOPREVENTCAVINGOFTHEWALLSANDUNDERMININGOFTHESTRUCTUREBEINGUNDERPINNEDWHENTHENEWBEARINGSTRATUMISREACHED,FORMSAREPLACEDINTHEPIT,ANDCONCRETEISPOUREDFROMTHENEWBEARINGSTRATUMUPTOWITHIN76MMOFTHEBOTTOMOFTHEOLDFOOTINGAFTERTHENEWCONCRETEHASHARDENED,THE76MMSPACEISPACKEDBYHANDWITHAMIXTUREOFSAND,CEMENT,ANDASMALLAMOUNTOFWATERCALLEDGROUT,THEMIXTUREISPACKEDVERYTIGHTLYINTOTHESPACEBETWEENTHETOPOFTHENEWFOOTINGANDTHEUNDERSIDEOFTHEOLDFOOTINGTHEPITUNDERPINNINGPROCESSISREPEATEDTHROUGHOUTTHEENTIRELENGTHOFTHEWALLFOOTINGTHERESULTINGNEWFOUNDATIONMAYBEACONTINUOUSWALLORINTERMITTENTPIERS基礎(chǔ)建筑物或已建成的工程是由基礎(chǔ)下的地基土支撐著的?！盎A(chǔ)”一詞意味著土本身或在土內(nèi)（或其上）布置的物體作為支撐體，或作為土和在它上面布置的構(gòu)件的聯(lián)合體。多層辦公建筑物的基礎(chǔ)一般是混凝土底板與土（或底板置于其上的巖石）的聯(lián)合體。土壩的基礎(chǔ)是天然的地基土或巖石?；炷恋装寤驑都捌錁睹背１豢醋龌A(chǔ)，而不包括他們所涉及的地基土或巖石。所建立的構(gòu)件和天然的土或巖石形成了基礎(chǔ)系統(tǒng)；土和巖石為這一系統(tǒng)提供了基本支撐。已建立的基礎(chǔ)不是由地基土支撐就是由巖石支撐。土和巖石對(duì)于增加給他們荷載的反應(yīng)，一般決定了基礎(chǔ)系統(tǒng)功能的好壞程度。在設(shè)計(jì)安裝的基礎(chǔ)部分中，設(shè)計(jì)者必須確定安全壓力即在土或巖石上可能受到的壓力以及建筑物可能承受的總沉降或沉降差?；A(chǔ)系統(tǒng)以建的部分是底板、閥板、板基礎(chǔ)和沉箱或柱，所以這些形式把上部結(jié)構(gòu)荷載傳遞給地基上。把上部結(jié)構(gòu)荷載傳遞給地基土的部分叫下部結(jié)構(gòu)。底板底板或伸展性基礎(chǔ)是通過(guò)柱或墻把上部荷載傳給下面的土或巖石。一般來(lái)說(shuō)底板由預(yù)應(yīng)力混凝土構(gòu)成。然而在一些環(huán)境下，地板也可由素混凝土和磚石構(gòu)成，當(dāng)每個(gè)底板僅支撐一根柱時(shí)，地板是方形。底板支撐兩個(gè)柱稱組合底板，它可能是矩形或不規(guī)則四邊形。懸臂底板承受兩根柱子的荷載，其中一根柱子和底板的末端對(duì)著建筑物輪廓線或外墻。底板支撐墻是連續(xù)底板。底板的尺寸由底板地基受的荷載除以土或巖土允許承載壓強(qiáng)而得到。對(duì)于基礎(chǔ)來(lái)說(shuō)大部分規(guī)范或教科書上都有表格列出了不同類型土和巖石的允許承載力值；然而，這些表格僅給出了土和巖石一般性分類和描述，使用時(shí)要謹(jǐn)慎。關(guān)于土和巖石更詳細(xì)的信息一般可通過(guò)鉆探試驗(yàn)孔、取土和巖石試件、在實(shí)驗(yàn)室測(cè)試試件得到，并做工程分析來(lái)確定適當(dāng)?shù)某休d力值。除承載力外要考慮到總的沉降以及結(jié)構(gòu)承受這樣沉降的可能性。如果沉降是一個(gè)問(wèn)題，采用置換基礎(chǔ)是必要的而不是用底板或擴(kuò)大底板和減少承載力。梯級(jí)梁可在外柱底板和支撐墻之間使用，用梁把墻的重量傳給柱底板。梁也在內(nèi)柱底板之間使用，其作用作為支柱（拉桿）或支撐內(nèi)墻。擋土墻是承受墻后土體引起的水平土壓力的墻體。對(duì)于墻基礎(chǔ)來(lái)說(shuō)，當(dāng)其受水平壓力時(shí)在墻與土（或巖石）之間要有足夠的抗滑力，以至于墻不會(huì)滑動(dòng)。另外，為了防止墻傾覆也應(yīng)該做擋土墻設(shè)計(jì)。在凍融敏感區(qū)，底板必須放置在凍融線以下。筏板基礎(chǔ)筏板基礎(chǔ)是大的、厚的，常常是預(yù)應(yīng)力混泥土板，通過(guò)數(shù)根柱基或柱與墻聯(lián)合體把荷載傳給下部的土或巖石。筏板也可是相連的底板，但筏板要比支撐兩個(gè)柱的底板大些。筏板可謂是連續(xù)底板，它們被設(shè)計(jì)用來(lái)把相對(duì)均一的壓力傳給下面的土或巖石。筏板是剛性的，當(dāng)支撐其的土或巖石不連續(xù)時(shí)，其作用類似橋。筏板可建在地表以下幾米處，當(dāng)與外墻連接時(shí)，則稱為浮動(dòng)基礎(chǔ)。從地表到筏板底部所開(kāi)挖土的重量可接近于建筑物的總重量。在這一情況下，很少或沒(méi)有新的荷載施加于下部的支撐上，在建筑物建成后，建筑物沉降為最小。板基礎(chǔ)板基礎(chǔ)用于輕型建筑物，把柱和墻直接支撐在底板上。在柱和墻施加荷載的位置，底板是厚重的預(yù)應(yīng)力混凝土板。一些特殊問(wèn)題在設(shè)計(jì)和建設(shè)下部結(jié)構(gòu)應(yīng)布置在地下水位以下的基礎(chǔ)時(shí)，地下水是一個(gè)主要的問(wèn)題。在基礎(chǔ)安裝期間，從深井中抽取基坑中的水或從貯水槽中抽取基坑中的水，都可以用以降低地下水位。其他一些不常