循環(huán)交通荷載作用下鄭東新區(qū)飽和粉質(zhì)黏土的動(dòng)力特性研究

循環(huán)交通荷載作用下鄭東新區(qū)飽和粉質(zhì)黏土的動(dòng)力特性研究循環(huán)交通荷載作用下鄭東新區(qū)飽和粉質(zhì)黏土的動(dòng)力特性研究

摘要：

循環(huán)交通荷載作用下的飽和粉質(zhì)黏土動(dòng)力特性是影響地基穩(wěn)定性和基本工程設(shè)計(jì)的重要因素。本論文通過(guò)室內(nèi)試驗(yàn)和數(shù)值模擬的方法，探究了循環(huán)交通荷載作用下鄭東新區(qū)飽和粉質(zhì)黏土的動(dòng)力特性變化，并分析了其對(duì)于地基穩(wěn)定性和基礎(chǔ)設(shè)計(jì)的影響。試驗(yàn)結(jié)果表明，循環(huán)荷載的作用下，黏土的動(dòng)力特性表現(xiàn)出了顯著的非線性變化，重復(fù)荷載的次數(shù)越多，黏土的峰值剪應(yīng)力和剪應(yīng)變會(huì)逐漸下降，動(dòng)力彈性模量及阻尼比、動(dòng)態(tài)剪切模量也隨之降低，且地震波傳播速度隨著循環(huán)荷載次數(shù)的增加而增加。同時(shí)，本文還針對(duì)黏土孔隙流變參數(shù)的挖掘和分析，探究導(dǎo)致黏土動(dòng)力特性變化的本質(zhì)機(jī)理，尋找優(yōu)化黏土動(dòng)力特性的途徑。

關(guān)鍵詞：循環(huán)交通荷載、飽和粉質(zhì)黏土、動(dòng)力特性、地基穩(wěn)定性、基礎(chǔ)設(shè)計(jì)

Abstract：

Thedynamicpropertiesofsaturatedsiltyclayundertheactionofrepeatedtrafficloadsareimportantfactorsaffectingthestabilityofthefoundationandbasicengineeringdesign.Inthispaper,thedynamiccharacteristicsofsaturatedsiltyclayinZhengdongNewAreaundertheactionofrepeatedtrafficloadswereinvestigatedthroughindoorexperimentsandnumericalsimulations,andtheireffectsonthefoundationstabilityandbasicdesignwereanalyzed.Theresultsshowthatundertheactionofrepeatedtrafficloads,thedynamicpropertiesoftheclayshowobviousnonlinearchanges.Thepeakshearstressandshearstrainoftheclaywillgraduallydecreaseasthenumberofrepeatedloadsincreases,andthedynamicelasticmodulus,dampingratio,anddynamicshearmoduluswillalsodecrease.Meanwhile,thepropagationvelocityofseismicwaveswillincreasewiththeincreaseofthenumberofrepeatedloads.Inaddition,basedontheexcavationandanalysisoftherheologicalparametersofclaypores,thispaperexplorestheessentialmechanismcausingthedynamicpropertiesofclaytochangeandseeksawaytooptimizethedynamicpropertiesofclay.

Keywords:repeatedtrafficloads,saturatedsiltyclay,dynamicproperties,foundationstability,basicdesigRepeatedtrafficloadshaveasignificantimpactonthedynamicpropertiesofsaturatedsiltyclay,whichinturnaffectsthestabilityofthefoundation.Thedynamicmodulusanddampingratioofthesoildecreasewiththeincreaseofthenumberofrepeatedloads.Thisphenomenonisattributedtothedamagecausedbytherepeatedloadstothesoilstructure.Asthesoilstructureisdamaged,thesoilparticlesbecomemorelooselypacked,reducingthesoil'sstiffnessanddampingcapacity.

Furthermore,thepropagationvelocityofseismicwavesinthesoilincreaseswiththeincreaseofthenumberofrepeatedloads.Thisisbecausethepropagationvelocityofseismicwavesisinverselyproportionaltothesoil'sstiffness,andthestiffnessofthesoildecreaseswithrepeatedloading.Hence,seismicwavestravelfasterinsoilsthathaveundergonerepeatedloading,whichmayhavesignificantimplicationsforthedesignofearthquake-resistantstructures.

Tounderstandtheunderlyingmechanismofthechangeindynamicpropertiesofclay,thisstudyconductedresearchontherheologicalparametersofclaypores.Theresultsrevealedthatrepeatedloadingcausestheporesizestoincrease,increasingtheporewaterpressureandleadingtoadecreaseinthesoil'sshearstrength.Thereductioninshearstrengthfurtherresultsinadecreaseinthesoil'sstiffnessanddampingratio.Therefore,theoptimizationofthedynamicpropertiesofclayshouldfocusonreducingtheporesizesandimprovingthesoil'sshearstrength.

Inconclusion,repeatedtrafficloadshaveadetrimentaleffectonthedynamicpropertiesofsaturatedsiltyclay,whichcanhavesignificantimplicationsforthestabilityoffoundationstructures.Thereductioninstiffnessanddampingcapacityduetorepeatedloadingcanleadtosoilfailureandcompromisetheintegrityofthefoundation.Therefore,efficientdesignapproachesthatimprovethedynamicpropertiesofclaywhileconsideringtheeffectsofrepeatedloadsarenecessaryfortheconstructionofstablefoundationstructuresOneapproachtoimprovingthedynamicpropertiesofsaturatedsiltyclayisthroughtheincorporationofadditivesorstabilizers.Thesemayincludelime,cement,flyash,orothermaterialsthatcanincreasethesoil'sstrength,stiffness,andresistancetodeformation.Theselectionanddosageoftheseadditivesshouldconsiderthespecificcharacteristicsofthesoil,suchasitsmineralogyandparticlesizedistribution.

Anotherapproachisthroughtheuseofgroundimprovementtechniques,suchasdynamiccompaction,vibrocompaction,ordeepsoilmixing.Thesemethodscandensifythesoilandimproveitsload-bearingcapacity,aswellasincreaseitsresistancetoliquefactionandcyclicloading.

Itisalsoimportanttoconsidertheeffectofsoil-pileinteractiononthedynamicpropertiesofthefoundation.Thepresenceofpilescansignificantlyalterthesoilresponsetodynamicloads,andthedesignofthepilefoundationshouldaccountforthisinteraction.

Inaddition,theuseofadvancednumericalmodelingtechniques,suchasfiniteelementanalysis,canprovideinsightintothedynamicbehaviorofthesoilanditsinteractionswiththefoundationstructure.Thesemodelscanhelpoptimizethedesignofthefoundationsystemandmitigatepotentialfailuremechanisms.

Overall,thedynamicpropertiesofsaturatedsiltyclayplayacriticalroleinthestabilityoffoundationstructures,andcarefulattentionshouldbepaidtotheircharacterizationandimprovement.Byconsideringtheeffectsofrepeatedloading,incorporatingappropriateadditivesandstabilizationtechniques,accountingforsoil-pileinteraction,andutilizingadvancednumericalmodeling,stableanddurablefoundationstructurescanbeconstructedinchallengingsoilconditionsInordertoimprovethedynamicpropertiesofsaturatedsiltyclay,thereareseveraltechniquesthatcanbeemployed.Oneofthemostcommonistheuseofgeosynthetics,whichcanhelptoincreasethestrengthandstabilityofthesoil.Geotextiles,geogrids,andgeocellscanbeusedtoprovidereinforcementandpreventthesoilfromslumpingorsettling.Thesematerialscanbeinstalledbelowthefoundationorunderthesub-gradeinordertocontrolthedeformationofthesoil.

Anothertechniquethatcanbeusedtoimprovethedynamicpropertiesofsaturatedsiltyclayistoincorporateadditives.Lime,cement,andflyashcanallbeaddedtothesoilinordertoincreaseitsstrengthandstiffness.Theseadditivescanalsohelptoreducethemoisturecontentofthesoil,whichcanimproveitslong-termstability.Additionally,chemicalstabilizerssuchassodiumsilicateorpolymericstabilizerscanbeusedtoimprovethesoil'sload-bearingcapacityandreduceitssusceptibilitytoliquefaction.

Incaseswherethesoilconditionsareparticularlychallenging,advancednumericalmodelingtechniquessuchasfiniteelementanalysis(FEA)orboundaryelementanalysis(BEA)canbeusedtosimulatethebehaviorofthesoilandpredictitsresponsetoloading.Thiscanhelptooptimizethedesignofthefoundationandensureitslong-termstability.

Itisalsoimportanttoconsidertheinteractionbetweenthesoilandthefoundationstructureitself.Soil-pileinteractioncansignificantlyaffecttheperformanceofthefoundation,anditisimportanttotakethisintoaccountduringthedesignprocess.Techniquessuchaspiledrivingandpiletestingcanbeusedtomeasurethepropertiesofthesoilandoptimizethedesignofthefoundation.

Inconclusion,th