工程地質(zhì)課件

Chapter2Theformationofsoil

anditsengineeringproperties

第二章土的形成和土的工程性質(zhì)1theimportanceSoilsaretheresultsofnaturalgeologicalhistory,atthesametimesoilsarealsothemostcommonmaterialsdistributedonthegroundsurfaceoftheearthcrust.Theengineeringpropertiesofsoilshavecloselyrelationswiththeengineeringactivitiesofhumanbeing.Becauseofcomplexitiesofsoils,manyengineershavebeenpaidmuchattentiontothestudyonsoils.Insomesense,thecomplexitiesofsoilsaremainlyfromthecomplexityofformationprocessofsoilsandthecomplexitiesofsoilsconstitution.Inthischapter,Wearemainlyconcernedwiththeformation,constitutionofsoils,theclassificationofsoilsbasedonthedifferentformation,sinceothersaspectsaboutsoilswillbediscussedinsoilsmechanics§2-1

Soilformation2thesoilsdefinition

Soilsareporousnaturalmaterialscomposedofinorganicandorganicmatter,soilsaretheendproductfromweatheringrocks.(Alsowecanmerelytakeitasastageinthegiganticcycleofmineralrecyclingbythemovementoftectonicplates)3theinfluencingfactorsofsoilsformationparentmaterial

time

climate

atmosphericcomposition

topography

organisms§4-2Themaintypesofsoils

basedontheformationprocess

Generallyspeaking,theengineeringpropertiesofsoilsaremuchinfluencedbythevarietiesofformationprocess.Sointhisaspect,itisimportantforacivilengineertoknowthesoilstypesbasedonformationprocess.1Eluvialsoils(殘積土)

Theeluvialsoils（residualsoils）arethedirectproductsof

weathering,theyareformedintheplacewheretheirmotherrocksarelocated.Features:

●solublematerialshavebeencarriedaway

●thecompositionhastherelationwiththemotherrock●differentparticlesize

●obviousedgeandcorner

●thicknesschangegreatlylowerpsephicity[si’fisiti]motherrockeluvialsoils2Slopedeposits(坡積物)Qdl

Theslopedepositsareformedfromerosionofsurfaceflowalongthemountainslopesurface.afterbeingcarriedtothefootofhillbysurfaceflow(面流),wherethespeedofflow（流速）

willslowdownandtheslacksedimentswilldepositthere.沖溝形成過程圖Features:

●slackcondition

●thecompositionhasnorelationwiththebadrock●

fineparticlesize

●obviousedgeandcorner

●thinthickness

●lowerpsephicity[si’fisiti]

Thepluvialdepositsaremorecommonlydistributedalongtheconnectionzonesbetweenthemountainousareasandplainareas.Thefloodwatercausedbyheavyrainorsnowdissolvedwhentemperatureriseupisthedynamicresource.3Pluvialdeposits(洪積物)QplABCAthezoneforgroundwaterleveldeeplyburied

◆largegrainsize

◆lowercompressivefactor

◆Higherbearingcapacity

◆

lowerpsephicityBZoneforgroundwateroverflowing

◆

sandysoilsandclayaredepositedalternatively

◆thegroundwatershallowlyburiedCZoneforperiodicdryanddampcondition◆clay◆engineeringpropertiesdependsondampcondition洪積扇地形4.Alluvialsoil沖積物

(Qal)（1）thedefinitionofAlluvialsoilAlluvialsoilsaretheresultsofrivergeologicalAction.(includingrivererosion;carrying;sedimentation)

CuterosionV字型河谷（上游）SideerosionandsedimentationU字型河谷（中游）Sedimentation成形型河谷地上河（下游）（2）rivergeologicalaction河流側(cè)蝕作用牛軛湖的形成Theresultofsideerosion侵蝕階地階座基地（侵蝕堆積）堆積階地（內(nèi)迭階地）Theformationofriverterrace階地的形成河床河漫灘河谷斜坡一級階地二級階地三級階地（3）FacesofRiverdeposits

?riverbedfaces（河床相）:

coarsesand,gravel,boulderwellpsephicity

?

terracefaces（階地相）:

upperpart→finesand

lowerpart→riverbedfaces?oxbowlakefaces（牛軛湖相）:

swampd<0.005mm

ooze:highwatercontenthighporosity,lowerstrength,highcompressive5.Lakedeposits(QL)6

Seadeposits(Qm)海積物7

Winddeposits(Qeol)風(fēng)積物windsand（風(fēng)積砂）wind-loess（風(fēng)積黃土）

collapsiblesoil

uniform,homogeneous

porous,scatteredstructure8

Glacialdeposits(Qgl)冰積物河谷橫斷面及各部位名稱§4-3Mineralcompositioninsoils1Primaryminerals（原生礦物）

2Secondaryminerals(unsolvablewithwater)

次生礦物

3Solublesaltanddecomposedminerals

可溶鹽類

4Organicmaterials（有機(jī)物質(zhì)）階地的類型1Primaryminerals（原生礦物）

?Primarymineralsarefrommagmarock,theyaremainlyquartz,feldspar,ice,amphibole

?

generalfeatureofPrimaryminerals:

--Stableinchemicalproperties--weatheringresistance--GoodperformanceofengineeringProperties河谷的形態(tài)階地的類型2secondaryminerals

（次生礦物）

?Primarymineralsarefromtheprocessofsoilsformation,theyare

①

clayminerals（黏土礦物）

Kaolinite，montomorillonite，watermica

②SiO2,Al2O3,Fe2O3:colloidalstate

③

Oxidizedmaterial（）

Themineraldescribedaboveisveryimportanttotheengineeringpropertiesofsoil.Reasonare：

mineralparticlesurface→surfacepowerabsorbingwateraffinity(親和力)

3Solublesaltanddecomposedminerals

可溶鹽類

solublesalt:NaCl,Caso4.2H2O(石膏),

CaCO3(calciumcarbonate)

salinizedsoil(鹽

土)

Usually,solublesaltinsoildon’thavemuchinfluencetosoilengineeringproperties,becauseitslittlecontent(indroughtarea,saltcanbeaccumulatedintheupperpartsofgroundsurface),Butifsoilcontainingmuchsaltreactwithwater,theconnectionbetweensoilgrainwilldisappear,sothesoil’sstrengthandstabilitywillbedecreased.4Organicmaterials（有機(jī)物質(zhì)）

Whichusuallyexitsintheooze.Whencontentofoozeismorethan5%.Theinfluencewillbeobvious.§4-4Thestructureandtectonicsofsoils

(土的結(jié)構(gòu)與構(gòu)造)一、soilsstructuretype(土的結(jié)構(gòu)類型)Whichmeanthecharacteristicsofsoilgrainandtherelationshipsamonggrains.

thesizeofgrain

Shapeandroughnessofgrain

arrangementofgrainand

connectionbetweendifferentgrain

1.

SingleParticleStructure(SPS)(crushedstone,gravel,sand)

--d>0.074mm

--nocohesion,nocapillarywater

--permeabilityisobvious

--highstrengthandlowdeformatio

2honeycombstructure

d<0.075mm

--siltgrain(粉粒

d=0.075-0.005mm)

--claygrain(粘粒

d<0.005mm)

--sandgrain(砂粒

d=2-0.074mm)

3cottonstructure

whichinsomesenselikehoneycombstructureTheclayusuallyhavethehoneycombandcottonstructureandhavetheengineeringpropertiesasbelow：

d<0.005mm

bigporosity(50%-98%)

easytobedeformed

watercontent(w)>75%

unstablewhenencounterwater二.Thetectonicsofsoil（土的構(gòu)造）

soil’stectonicsmeanthespaceshapeofsoillayer.?Innorth-westarealoess—verticalcracks

?Incoastarea,softclayhaveusuallydistributed,stratifiedstructure,isotropicsoil§4-5Theindexofphysicalpropertiesofsoils(土的物理性質(zhì)指標(biāo))soils’sthree-phasecomposition

liquidsolidairV：

totalvolumeofsoilsW:totalweight(KN)Vs:solidvolume

Ws:solidweightVw:watervolumeWw:waterweightVa:airvolumeVv:porevolumeVWV=Vs+Vw+Va=Vv+VsW=Ws+Ww(1)

relativeunitweight(G)土的相對密度unitweightofsolidmineralparticleunitweightofwater(10KN/m3)

（2）unitweight土的重度（3）dryunitweight土的干重度

whichindicatethedensityofsoilsgrain（4）saturatedunitweight飽和重度

（5）effectveunitweight土的有效重度（6）watercontent(w)土的含水量

Thewatercontentinsoils,especiallyincohesivesoils,hasmuchinfluenceontheengineeringpropertiesofsoils.Sothedeterminationofwatercontentisnecessary(7)saturationdegree飽和度（8）porosity(n)空隙度(9)relativeporosity(voidratio)孔隙比Chapter2Rock第二章巖石Sincemineralsarethebuildingblocksofrocks,itisimportantthatyoulearntoidentifythemostcommonvarieties.Mineralscanbedistinguishedusingvariousphysicaland/orchemicalcharacteristics,but,sincechemistrycannotbedeterminedreadilyinthefield,thephysicalpropertiesofmineralsareusedtoidentifythem.§2-1:Themainmineralsintherock(造巖礦物)?

Crystalform（晶形）

?

Hardness（硬度）

(relativetoasteelbladeoryoufingernail),?

colour(真色，假色，它色)

?

Luster（光澤）

?

Streak(條痕)

(thecolourwhenamineralisgroundtoapowder).

?cleavage（解理）Physicalpropertiesofmineralsincludefeaturessuchas：Quartzishard-itcaneasilyscratchasteelknifeblade.Inmanyrocks,quartzgrainsareirregularinshapebecausecrystalfacesarerareandquartzdoesnothaveacleavage(ie,itdoesnotbreakonregularflatfaces).1Quartz(石英):Quartzisaglassylooking,transparentortranslucentmineralwhichvariesincolourfromwhiteandgreytosmoky.Whenthereareindividualcrystalstheyaregenerallyclear,whileinlargermassesquartzlooksmoremilkywhite.油脂光澤

Feldsparisalsohardbutcanbescratchedbyquartz.Feldsparinigneousrocks（火成巖）formswelldevelopedcrystalswhichareroughlyrectangularinshape,andtheycleaveorbreakalongflatfaces.Thegrains,incontrasttoquartz,oftenhavestraightedgesandflatrectangularfaces,someofwhichmeetatrightangles.2Feldspar（長石）:Feldsparistheothercommon,light-colouredrock-formingmineral.Insteadofbeingglassylikequartz,itisgenerallydulltoopaque（不透明）

withaporcelain-likeappearance.Colourvariesfromred,pink(orthoclase正長石),andwhitetogreen,grey(plagioclase斜長石).Plagioclase斜長石Orthoclase正長石Themostcommonamphiboleishornblende（角閃石）.Hornblendeisquitesimilartoaugite（普通輝石）

inthatbotharedarkminerals,howeverhornblendecrystalsaregenerallylonger,thinnerandshinierthanaugiteandthemineralcross-sectionsarediamond-shaped.hornblende（角閃石）3Amphibole（閃石）Themostcommonpyroxenemineralisaugite.Augiteisgenerallydarkgreentoblackincolourandformsshort,stubby（短而粗）

crystalswhich,ifyoulookatanend-onsection,havesquareorrectangularcross-sections.Pyroxene（輝石）4Pyroxene輝石Talcoccursingranular（粒狀的）

orfoliated（片狀的）

massessometimesknownassoapstone（皂石）.Itiswhitetogreen,sometimesgreyorbrownish.Itisverysoftandwillbescratchedbyafingernail.Ithasagreasyfeel（滑感）5Talc（滑石）Olivineinthejewellerytrade,isyellow-green,translucent（半透明的）

andglassylooking.Crystalsarenotcommon;itusuallyoccursasroundedgrainsinigneous（火成的）

rocksorasgranularmasses.Olivineisalmostashardasquartz;itdoesnothaveawell-developedcleavage.6Olivine橄欖石Micaiseasilydistinguishedbyitscharacteristicofpeelingintomanythinflatsmoothsheetsorflakes（薄片）.Thisissimilartothecleavageinfeldsparexceptthatinthecaseofmicathecleavageplanesareinonlyonedirectionandnorightanglefacejoinsoccur.Micamaybewhiteandpearlyordarkandshiny.7Mica云母8Gypsum(plasterstone,石膏)9Kaolinite(高嶺石)10Montmorillonite（蒙脫石）11Watermica（伊利石）§2-2:Rock(巖石)(一種或多種礦物組成的集合體)

一、Theclassificationofrockaccordingto

thecauseofformation

igneousrock（巖漿巖）

(magmarock)

sedimentaryrock（沉積巖）

metamophicrock（變質(zhì)巖）

巖石二、

Igneousrock1theformationofigneousrock:DeepwithintheEarth,rockiskeptinamolten（融熔的）

stateduetoextremetemperatureandpressure.

Thismoltenrockiscalledmagma（巖漿）.

Themagmaisconstantlymovingandsometimesmovesitswaytothesurfacethroughthecracks（裂縫）inthesolidrock.

Onceitreachesthesurface,itiscalledlava（熔巖）.

Thelocationitpushesthroughtothesurfaceiscalledavolcano（火山）.

Theopeninginthevolcanothatthelavaeruptsoutofiscalledavent(出口).

Formanyvolcanos,thereismorethanonevent.

Oftenvolcanoshaveafunnel（漏斗）shapewithapitatthetop.

Thispitiscalledavolcaniccrater（火山口）.

Ifthiscraterbecomesverylarge,thewallsofthecratermightcollapsetoproduceafeaturecalledacaldera（噴火山口）HowIgneousrockrockIsFormedPyroclasticash(火山灰)Batholith巖基Captivemass俘虜體laccolith巖盤巖墻Rockwall巖株Volcanoneck火山頸Lavaflow巖流theformationstateofigneousrock（巖漿巖的產(chǎn)狀）Sill巖床3theclasscificationofigneousrock（巖漿巖的分類）

（1）Accordingtotheformationstate(按產(chǎn)狀)

?IntrusiveIgneousRocks（侵入巖）

-usuallymediumtocoarsegrainedtextureduetoslowcooling.

Typicallylightcoloured.

?

ExtrusiveIgneousRocks（噴出巖）

-glassyorfine-grainedduetorapidcooling.Mayhavevoidsduetodegassingofthemagma.Typicallydarkcoloured.

(2)AccordingtotheSilicaContentandMineralComposition(根據(jù)二氧化硅含量)

?

AcidIgneousRocks(酸性巖)-silicarich(>65%byweight)composedmainlyoflight

colouredminerals(eg.feldspars,quartz)

?IntermediateIgneousRocks（中性巖）

silica50-65%byweight,composedmainlyoffeldspars,

some

mafic（鐵鎂質(zhì)的

minerals,withsomequartz.

?BasicIgneousRocks（基性巖）

-silicapoor(<50%byweight)containsignificantamountsofmaficordarkcolouredferromagnesianminerals(eg.olivines,pyroxenes,

amphiboles,micas).Nofreequartz.thedescriptionofmainigneousrock

（巖漿巖描述）

?

granite（花崗巖）

Graniteisanigneousrockthatiscomposedoffourminerals.

Thesemineralsarequartz,feldspar,mica,andusuallyhornblende.Graniteformsasmagmacoolsfarundertheearth'ssurface.Becauseithardensdeepunderground，itcoolsveryslowly.Thisallowscrystalsofthefourmineralstogrowlargeenoughtobeeasilyseenbythenakedeye.Graniteisanexcellentmaterialforbuildingbridgesandbuildingsbecauseitcanwithstandthousandsofpoundsofpressure.Itisalsousedformonumentsbecauseitweathersslowly.Engravingsinthegranitecanbereadforhundredsofyears,makingtherockmorevaluable.GraniteisquarriedinmanyplacesintheworldincludingtheUnitedStates.TheStateofNewHampshirehasthenickname"GraniteState"becauseoftheamountofgraniteinthemountainsofthatbeautifulstate.TheCanadianShieldofNorthAmericacontainshugeoutcroppings(surfacerocks)ofgranite.

?

porphyriticgranite

(花崗斑巖)

shallowintrusiverock（淺成侵入巖）

moderatecrystallization（中等結(jié)晶）

porphyriticstructure斑狀結(jié)構(gòu)

quartz-feldspar-blackmica花崗斑巖

?

rhyolite（流紋巖）

Rhyoliteisverycloselyrelatedtogranite.Thedifferenceisrhyolitehasmuchfinercrystals.Thesecrystalsaresosmallthattheycannotbeseenbythenakedeye.Rhyoliteisanextrusiveigneousrockhavingcooledmuchmorerapidlythangranite,givingitaglassyappearance.Themineralsthatmakeuprhyolitearequartz,feldspar,mica,andhornblende.Rhyolite流紋巖

?

Diorite(閃長巖)

1abyssalintrusiverock2wellcrystallization3feldspar,quartz,amphibole?Dioriteporphyrite（閃長玢巖）1shallowintrusiverock,2mediancrystallization3feldspar,quartzamphiboleDaciteisanextrusiveigneousrock.Theprinciplemineralsthatmakeupdaciteareplagioclase,quartz,pyroxene,orhornblende.Dacite安山巖?Dacite（安山巖）Andesite

?

pyroxenire(輝巖)

1abyssalintrusiverock2wellcrystallization3amphibole,phyroxenefeldsparBasaltsaredarkcolored,fine-grainedextrusiverock.Themineralgrainsaresofinethattheyareimpossibletodistinguishwiththenakedeyeorevenamagnifyingglass（放大鏡）.Theyarethemostwidespreadofalltheigneousrocks.Mostbasaltsarevolcanicinoriginandwereformedbytherapidcoolingandhardeningofthelavaflows.SomebasaltsareintrusivehavingcooledinsidetheEarth'sinterior.?basalt玄武巖1ultrabasicrock（超基性巖石）(sio2<45%)2abyssalintrusiverock（深成巖）

3wellcrystallization（結(jié)晶好）

4olivine；pgroxene?

olivinerock(橄欖巖)?Obsidian黑耀巖Obsidianisaveryshinynaturalvolcanicglass.Whenobsidianbreaksitfractureswithadistinctconchoidal（貝殼狀的）fracture.Noticeinthephototothelefthowitfractures.Obsidianisproducedwhenlavacoolsveryquickly.Thelavacoolssoquicklythatnocrystalscanform.Whenpeoplemakeglasstheymeltsilicarockslikesandandquartzthencoolitrapidlybyplacingitinwater.Obsidianisproducedinnatureinasimilarway.Obsidianisusuallyblackoraverydarkgreen,butitcanalsobefoundinanalmostclearform.Pumiceisaverylightcolored,frothy（起泡的）volcanicrock.Pumiceisformedfromlavathatisfullofgas.Thelavaisejectedandshotthroughtheairduringaneruption.Asthelavahurtles（急飛）throughtheairitcoolsandthegasesescapeleavingtherockfullofholes.?Pumice（浮石）Pumiceissolightthatitactuallyfloatsonwater.Hugepumiceblockshavebeenseenfloatingontheoceanafterlargeeruptions.Somelavablocksarelargeenoughtocarrysmallanimals.三、sedimentaryrock（沉積巖）

1theformationofsedimentaryrock:

Forthousands,evenmillionsofyears,littlepiecesofourearthhavebeeneroded--brokendownandwornawaybywindandwater.Theselittlebitsofoureartharewasheddownstreamwheretheysettletothebottomoftherivers,lakes,andoceans.Layerafterlayeroferodedearthisdepositedontopofeach.Theselayersarepresseddownmoreandmorethroughtime,untilthebottomlayersslowlyturnintorock.HowSedimentaryRockIsFormedSedimentsaresubdividedintothreetypes:

?1Clasticordetritalsediments（碎屑巖）

Comprisingparticlesofvarioussizescarriedinsuspensionbywind,waterorice.Sand(砂巖)isanexampleofaclasticsediment.Silt（粉砂巖）andsand

sizeparticlesarecarriedinsuspensionbywind,waterandice.

2theclassificationofsedimentaryrock:

?2

Chemicalorprecipitatedsediments（化學(xué)巖）

whicharecarriedinaqueoussolution.Salt(halite)isanexampleofachemicalprecipitate.·

?3

Organicorbiogenicsediments（有機(jī)巖）

precipitatedoraccumulatedbybiologicalagents.Manyorganismspromotetheprecipitationofcalcitetoformbiogenicallyprecipitatedcalcareous（含鈣的）

muds.3Thetextureandstructureofsedimentaryrock

沉積巖的結(jié)構(gòu)和構(gòu)造沉積巖的層理構(gòu)造平行層理斜層理波狀層理印模粒序?qū)永斫徊鎸永沓练e巖的結(jié)構(gòu)特征砂?？紫赌z結(jié)物砂粒粘粒粉粒鐵餅形的Sphericity球形度[sfe’risiti]4thedescriptionofsedimentaryrockConglomeraterocksaresedimentaryrocks.Theyaremadeupoflargesedimentslikesandandpebbles（鵝卵石）.Thesedimentissolargethatpressurealonecannotholdtherocktogether;itisalsocementedtogetherwithdissolvedminerals.?gravelstone(conglomerate)礫巖(clasticrock)?

sandstone(d=2-0.05mm)砂巖Sandstonerocksaresedimentaryrocksmadefromsmallgrainsofthemineralsquartzandfeldspar.Theyoftenforminlayersasseeninthispicture.Theyareoftenusedasbuildingstones.?siltstone(d=0.05-0.005mm)粉砂巖?mudstone(d<0.005mm)泥巖

kaolinite(高嶺石)

montorillonite（蒙脫石）

watermica（伊利石）MineralCompositionShalerockisatypeofsedimentaryrockformedfromclaythatiscompactedtogetherbypressure.Theyareusedtomakebricks?shalestone(d<0.005mm)頁巖Limestonerocksaresedimentaryrocksthataremadefromthemineralcalcitewhichcamefromthebedsofevaporatedseasandlakesandfromseaanimalshells.Thisrockisusedinconcreteandisanexcellentbuildingstoneforhumidregions.colorgrey?limestone石灰?guī)r?

dolomiterock白云巖color:white-greymineral:dolomit?

Gypsum石膏Gypsumrocksaresedimentaryrocksmadeupofsulfatemineralandformedastheresultofevaporatingseawaterinmassiveprehistoricbasins.ItisverysoftandisusedtomakePlasterofParis,casts,molds,andwallboards.四、Metamorphicrock（變質(zhì)巖）

Metamorphicrocksaregeneratedbyrecrystallizationofeitherigneousorsedimentaryrocksbytheactionofanyorallofthefollowing:Pressure,Temperature,PoreFluids.

Thetypeofmetamorphicrockisdeterminedbytheparentrock（母巖）

andtheP/Tconditions.Ingeneral,metamorphismcauses:

Growthofnewminerals

Deformationandrotationofmineralgrains

Recrystallizationofmineralsaslargergrains1theformationandclassificationofMetamorphicrocks變質(zhì)巖的形成接觸變質(zhì)巖的形成區(qū)域變質(zhì)巖的形成2thedescriptionofMetamorphicrocks

?Marble

（大理巖）Marbleismetamorphosedlimestoneordolomite.Bothlimestoneanddolomitehavealargeconcentrationofcalciumcarbonate(CaCO3).Marblehasmanydifferentsizesofcrystals.

Marblehasmanycolorvariancesduetotheimpurities(雜質(zhì))presentatformation.Someofthedifferentcolorsofmarblearewhite,red,black,mottledandbanded,gray,pink,andgreen.Marbleismuchharderthanitsparentrock.Thisallowsittotakeapolishwhichmakesitagoodmaterialforuseasabuildingmaterial,makingsinktops,bathtubs,andacarvingstoneforartists.Today,headstonesaremadefrommarbleandgranitebecausebothoftheserocksweatherveryslowlyandcarvewellwithsharpedges.?

Quartzite（石英巖）Quartziteiscomposedofsandstonethathasbeenmetamorphosed.Quartziteismuchharderthantheparentrock,sandstone.Itformsfromsandstonethathascomeintocontactwithdeeplyburiedmagmas.Quartzitelookssimilartoitsparentrock.Thebestwaytotellquartzitefromsandstoneistobreaktherocks.Sandstonewillshatterintomanyindividualgrainsofsandwhilequartzitewillbreakacrossthegrains.Chapter6

Themainengineeringgeology

problemsincivilengineering

第六章工程地質(zhì)問題分析Themaintopicsofchapter6:

§6-1Theerosionofriver(河流的侵蝕)§6-2landslide（滑坡）

§6-3Collapse（崩塌）

§6-4mudflow（泥石流）

§6-5KarstandEarthcave（巖溶和土洞）

§6-6Theengineeringproblemsinundergroundengineering

（地下工程地質(zhì)問題）§6-1Theerosionofriver(河流的侵蝕)

一、Whatisrivererosion

Whichmeanthedamagetotheriverbedorriverbank,therivererosionisthemostactive,vigorousfactortothechangeoftopography.Norivererosion,nocomplicatedsurface.二、Therivererosion’stype

Whichcanbedividedinto：

sideerosive（側(cè)蝕）

cuterosion（下蝕）cuterosion(下蝕)→meansthatthemovingwateranditsmaterialscarriedbywaterhavemotivepowerthatmakesriverbeddeepenedcontinuously.Cuterosionareusuallyobviousinupstreamofriver.

Inbridgeengineering,thelocationoffoundationmustbeconsideredcarefully.Thatistheelevationofbottomsurfaceoffoundationmustwillbelowerthantheerosionbaseline(侵蝕基準(zhǔn)面).Erosionline1Erosionline2sideerosiveSideerosionarecausedbytraversecirculationofriver.Theresultsofsideerosionisthatrivervalleyisbroaden.Thesideerosionisobviousinmiddleordownstreamofriver.Preventingmethod:stonecage,changingofriverrouteDirectionofsideerosionDirectionofsideerosionBuildingisnotingoodpositiontraversecirculationofriver

§6-2landslide（滑坡）

一.Thedefinitionoflandslide

Thesoilorrockbodyslidedownalongthefixedslidingsurfaceontheactionofgravity.

Thehappeningoflandslidemaycausethedamageofbuilding,endangerhumanlife,alsocausetheartificalearthquake.

滑坡形態(tài)描述滑坡體Slidingbody滑坡床Slidingbed滑坡壁cliff滑坡面Slidingsurface扇形張裂縫Fan-hapedtensivecracks滑坡舌鼓脹裂縫Swellingcracks

剪裂縫Shearcracks

滑坡周界滑坡臺階二.ThefeatureofdifferentpartoflandslideTensioncracks三.Theclassificationoflandslide1.

Accordingtothematerialsdifferenceofslidingbody

■soillandsliding(土體滑坡)

■rocklandsliding(bedrocklandslide)巖層滑坡

■speciallandslides(frozenandthaw、collapeslide)

特殊滑坡■soillandsliding(土體滑坡)

cohesivesoilslandslides（黏土滑坡）

loesslandslides（黃土滑坡）eluvialsoilslandslides（殘積層滑坡）Eluvialsoillandslide

cohesivesoilslandslides■rocklandsliding(bedrocklandslide)巖層滑坡順層滑坡切層滑坡滑動面滑動面movementparalleltoplanesofeaknessandoccasionallyparalleltoslope.■speciallandslides(frozenandthaw、collapeslide)

特殊滑坡凍融層Flow:

viscoustofluid-likemotionofdebris.

2

Accordingtothemechanicscondition

RivererosionArtificialcuttingtractivestylePushingstyle3accordingtothelandslidescalesize四、thedevelopingprocessoflandslide

step1creepdeformationstagenofixedslidingplane

Softrock巖質(zhì)邊坡的破壞形式：松動蠕動剝落4滑坡5崩塌深層蠕動表層蠕動step2failurestage

Thepenetratingfailureplanehasformed;theslidingmassslowlyorquicklyslidesalongthecrackplane，

drunken-liketrees;sabre-liketreesdevelopsinthisstagestep3stablestage

Theslidingmasshasbeeninbalancedpositiondrunkentreeshavebecometogrowvertically五、Themechanicsanalysisandinfluencingfactor土層均勻時：Theanalysis

influencefactorsofsliding

Theinfluencefactorcanbeconsideredasthefactorswhichhavethecontributiontothechangeofsafetyfactor(K)

①

slopeappearance

slophigh;slopeangle,slopeshape②

rockandsoilsproperties

softrock(shale,sandrock)

soilwithmontmorillonitewhichiseasytoabsorb

waterandexpanding.③

structure

theconditionofstrataplane,joint,fault,(dipangle,dipdirection)

④

water

tosoftrockandsoil

⑤

earthquakes

tostimulatetheliquefaction(液化)

toproducetheinertiaforcetorockorsoilbody

⑥

artificialfactors

impropercuttingslope

puttingon(piling)(overlapping)soilorbuildingstructure六、thecontrol(harness)oflandslippingC