土木專業(yè)英語課件lesson 3

1、Lesson3Newwds1.col`loidal膠狀的，膠體的，`colloid膠體2.sievenv.篩，過篩，過濾3.samplen.vt.樣品，取樣specimen4.meshn.v網(wǎng)孔，網(wǎng)格，分網(wǎng)格5.`cumulativea.積累的；cumulatecumulation6.gradingn.級配，等級；grade7.sedimentationn.沉淀sediment8.suspensionn.懸??；suspend~bridg

2、ecablestayedbridge9.agitatev.攪動，混合；disturb10.hydrometern.（液體）比重計11.viscosityn.黏性；viscoidal12.flakyn.薄片狀的，offlake13.pipetten.吸液管14.irrecoverablea.不可恢復(fù)的irretrievable15.concavea.凹的；convex凸的16.permeabilityn.滲透性permeatepermea

3、bleseepseepagePhrasesexpressions1.frostsusceptibility霜凍敏感性2.sievingmethod篩分法3.semilogarithmiccurve半對數(shù)曲線4.gradingcurve級配曲線5.wetsieving濕法篩分6.dispersingagent分散劑7.Stoke’slaw斯托克定律8.unitweight重度9.coefficientofgrading級配系數(shù)10.sed

4、imentationmethod沉降法11.particlesizedistribution粒徑分布TextParticleSizeAnalysis粒徑分析粒徑分析Therangeofparticlesizesencounteredinsoilsisverywide:fromaround200mmdownto由重量差確定粘粒粉粒的總重，并將其表示為子土樣總重的百分?jǐn)?shù)。最粗的部分（即粒徑20mm的部分）也可被過篩，并用其結(jié)果完成級配曲線的

5、繪制。Afurthersubdivisionofparticlesizedistributioninthefinegrainedfractionisnotpossiblebythesievingmethod.不能用篩分法對細(xì)粒部分的粒徑分布作進(jìn)一步分組。Aprocessofsedimentationisnmallycarriedoutfthispurpose.通常必須用沉降法實現(xiàn)此目的。Asmallsubsampleofsoilisfi

6、rsttreatedwithadispersingagentthenwashedthrougha63?msieve.首先將一小子土樣用分散劑進(jìn)行處理，然后洗過63的篩子。Thesoilwatersuspensionisthenmadeupto500mlagitatedvigouslyfashtwhilethenallowedtosettle.再從中取出500ml的土水懸浮液，充分?jǐn)嚢枰粫笞屍涑两?。Theprocedureisbased

7、onStoke’slawwhichstatesthatthevelocityatwhichasphericalparticlewillsinkduetogravityinasuspensionisgivenby:此方法是基于斯托克思定律，即在重力作用下球形顆粒在某一懸浮液中下降的速度為Whered=diameterofparticle顆粒直徑?s=unitweightofthegrainofparticle顆粒重度?w=unitweig

8、htofthesuspensionfluid(usuallywater)懸浮液的重度（通過為水的重度）?=vescosityofthesuspensionfluid（懸浮液的黏度）Thediameterofthoseparticlesthatwillhavesettledagivendistanceinagiventime(t)maybeobtainedbyrearrangingEq.3.1:將式3.1變形得在給定時間t內(nèi)，沉降一給定距

9、離的那些顆粒的直徑為Usuallyh=100mm通常h=100mmgiving由此給出Samplestakenatadepthof100mmatanelapsedtimeoftwillnottherefeincludeparticlesofgreatersizethanthediameterdgivenbyEq.3.2因此在，在深度100mm處，t時間后所取的懸浮液中將不會有粒徑大于式3.2所給出的土粒buttheproptionsof

10、particlessmallerthandinthesuspensionwillremainunchanged.但懸浮液中小于d的顆粒所占的比例仍保持不變。Theprocedureusingahydrometerconsistsofmeasuringthesuspensiondensityatadepthof100mmataseriesofelapsedtimeintervals.用液體比重計的方法包括以一系列時間間隔在深度100mm處

11、測定懸浮液的比重。Thepercentagefinervaluescrespondingtoparticulardiameter(i.e.particlesizes)areobtainedfromthedensityreadingsthusagradingcurvefthefinegrainedfractionmaybedrawn.通過比重讀數(shù)得到小于某一特定粒徑的顆粒的百分?jǐn)?shù)，從而可畫出細(xì)粒部分的級配曲線。Gradingacteris

12、ticsThegradingcurveisagraphicalrepresentationoftheparticlesizedistributionistherefeusefulinitselfasameansofdescribingthesoil.級配曲線是粒徑分布的一種圖形表達(dá)，因而可用來作為描述土的手段。Fthisreasonitisalwaysagoodideatoincludecopiesofgradingcurvesinla

13、batyothersimilarrepts.因此，人們總是認(rèn)為在實驗室報告或其它報告里附上幾份級配曲線是一種好做法。Itshouldalsoberememberedthattheprimaryobjectistoprovideadeivetermfthetypeofsoil.還應(yīng)牢記的是我們的主要目的是提供對土的類型的描述性術(shù)語。Thisiseasilydoneusingthetypeoftbyestimatingtherangeofs