Ukumiselwa kwemida kaAtterberg
Siza kuchaza iimvavanyo zokumisela umda wokuhamba, umda weplastiki kunye nomda wokuncipha, ezibaluleke kakhulu kwimichiza yomhlaba. Zonke ezi mvavanyo zenziwa kwiisampuli eziphazamisekileyo zomhlaba odibeneyo.
Uvavanyo lokumisela umda wokuhamba
Kolu vavanyo kuthathwa malunga ne 200 p yomhlaba ukwimeko yendalo yokufuma, engenazinkozo ezinobubanzi obungaphezulu kwe 0,5 mm, ezinokuphazamisa ukuchaneka kweziphumo zovavanyo. Isampuli mayingomiswa kwisomisi, koko ifakwa ngqo kwikomityi ye-porcelain enamanzi adistiliweyo, apho kufuneka ihlale iiyure ezininzi ide imanziswe kakuhle. Kwiliwadi enesalathiso seplastiki IP < 20 ukumanzisa kuthatha malunga ne 4 yeyure, kwingqina IP > 20 ukuya kwi 18 yeeyure. Emva koko isampuli emanzi igalelwa kwipleyiti yeglasi ize ixutywe kakuhle ngommese welabhoratri, ukuze kufumaneke isidudu esityebileyo esinokwakheka okufanayo. Ukuba kuqatshelwa amasuntswana amakhulu kune 0,5 mm, asuswa ngexesha lokuxuba.
Isampulu elungiswe ngolu hlobo igalelwa kwisitya sobhedu sesixhobo sikaCasagrande sokumisela umda wokuhamba (sl. 1), esibizwa kwiilabhoratri zethu ngokuba yiCasagrandeova treskalica.
Umz. 1. Isixhobo sikaCassagrande sokumisela umda wokuhamba
Isixhobo siquka isitya sobhedu, esifakwa kwisixhobo ngoqhagamshelwano olukhethekileyo, isiseko esiguquguqukayo serabha eqinileyo, esine-excentric phezulu nesiphatho sokusijika, apho i-excentric iphakanyiselwa kubude be-1 cm, nto leyo ebangela ukuba isitya siwe size sibethe isiseko (fig. 1a). Imilinganiselo yesixhobo imiselwe ngumgaqo. Ukongezelela kukho nemela enomfanekiso, enemilinganiselo echazwe ngokuthe ngqo (fig. 1b).
Isampuli ekhwelisiweyo kwisitya sobhedu ilungelelaniswa ngemela ukuze umphezulu wesampuli ube tyaba ngokupheleleyo, kwaye isampuli igqume ngaphezulu kancinci kwesiqingatha senxalenye engaphambili yesitya, ngelixa ubude bayo ngaphezulu kwendawo esezantsi yesitya bube malunga 12 mm. Emva koko isitya sifakwa kwisixhobo kwaye ngommese oneprofayili kusikwe umsele embindini ukuze ube ngqo ngokupheleleyo kwaye kubonakale isiseko sobhedu sesitya, nto leyo efunyanwa ngokutsala ngononophelo imela ngokuthe nkqo ezantsi kwesitya. Ubude bomsele kufuneka bube malunga 40 mm. Kwangoko emva koko ujiko wesixhobo ujikwa ngesantya se 2 iijiko ngomzuzwana, apho kubalwa iimpempe zesitya kwisiseko kwaye kuqwalaselwa umsele, nowuthi ngenxa yeempempe zesitya kwisiseko ube mxinwa, kuba iindawo ezisikwe zesampuli ziyashukunyiswa zize zifune ukudityaniswa. Ukujikwa kojiko lwesixhobo kuqhubeka de umsele uhlanganiseke kubude be 10 mm. Xa oko kufezekisiwe, kuyekiswa ukujika ngakumbi kojiko, emva koko ngemela kukhutshwe isampuli emalunga 2 cm3 ukusuka kwindawo ejikeleze umsele odityanisiweyo kumacala omabini, ifakwa kwiiglasi zewotshi kuze kumiselwe ukufuma komhlaba.
Olu vavanyo luphindwa amaxesha 3-4 ngendlela efanayo, kodwa ixesha ngalinye ngomswakama owahlukileyo, nto leyo efunyanwa ukuba isampuli iqale ixutywe nesixa esincinci samanzi, emva koko amanzi ongezwe kwezinye iimvavanyo. Emva kovavanyo ngalunye olugqityiweyo, isampuli igalelwa kwipleyiti yeglasi, apho kongezwa amanzi athile aze axutywe kakuhle, ukuze kufumaneke ubunzima obufanayo, ixesha ngalinye bube buthathaka kancinci, obufana nesiraphu.
Ukuze kuvavanywe, isiselo esilungisiweyo asimele sibe sityebile kakhulu okanye sibe manzi kakhulu, kuba iimeko zokungaguquguquki komhlaba ezikude kakhulu nomda wokuhamba aziniki ukuchaneka okufunekayo kolu vavanyo. Ngokuqhelekileyo kwamkelwa ukuba ukuba inani leempembelelo lingaphantsi kwe-10 okanye lingaphezulu kwe-50, uvavanyo aluphumelelanga, kodwa kuthathwa ukuba ukuchaneka kovavanyo kubhetele ukuba isithuba phakathi kwale mida siyi-10-40 iimpembelelo.
Kuye kwaphawulwa ukuba, ngokwenye indlela, rhoqo emva kokugqitywa kokujika kwesibambo de umjelo udityaniswe kubude be-1 cm, isampuli kwisitya sobhedu ixutywa kwangoko ngommese kwaye umphezulu wesampuli kwisitya ulinganiswe kwakhona, kusikwa umjelo omtsha, emva koko isibambo sesixhobo sijikwa. Le nkqubo iphindaphindwa de kufezekiswe ukuba kathathu ngokulandelelana kufunyanwe inani elifanayo leempembelelo xa umjelo udityaniswa kubude be-1 cm, elo nani lamkelwa njengesiseko senkqubo elandelayo ekumiseleni umda wokuhamba. Iziphumo zovavanyo sizibeka kwidayagram enesikali se-semilogarithmic (fig. 2). Kwi-asi ye-abscissa kubekwa inani leempembelelo kwisikali selogarithm, kanti kwi-asi ye-ordinate kubekwa umthamo wamanzi njengepesenti yobunzima obomileyo besampuli kwisikali se-arithmetic. Kuba kuvavanyo ngalunye isixa samanzi w sihluka, siya kufumana amanqaku A, B, C no-D, ahambelana nenani elahlukeneyo leempembelelo, apho inani leempembelelo lincinci xa isixa samanzi sikhulu, kwaye ngokuphambeneyo. Ngokudibanisa la manqaku sifumana umgca othe nkqo othambekileyo, apho sifuna khona inqaku M le-25 yeempembelelo. Isixa samanzi esihambelana neli nqaku samkelwa njengomda wokuhamba wL.
Sl. 2. Ukumiselwa komda wokunikezela
Ukumiselwa komda weplastiki
Isampulu yomhlaba elungiselelwe ngendlela echazwe ngasentla, kodwa inamanzi ambalwa, ukuze ibe bubunzima obuludaka obusondele kwimeko eqinileyo yeplastiki, iqokelelwa ibe libhola elimalunga ne 2-3 cm3, ize emva koko iqengqelelwe ngentende esandleni phezu kwephepha eliqhelekileyo okanye elifunxayo ibe ngumqulu onobukhulu be 3 mm. Ukuba isampulu iqengqelelwa kolo bunzima ngaphandle kokophuka, iphinda iqokelelwe ibe libhola ize iqengqelelwe ngendlela efanayo. Le nkqubo iphinda-phindwa de kufikelelwe ekubeni umqulu xa unebukhulu be 3 mm uqale ukwaphuka. Emva koko imiqulu eqhekekileyo ifakwa kwiiglasi zewotshi ize kugqitywe ubungakanani bamanzi. Obo bungakanani bamanzi, obuchazwe njengeepesenti zobunzima obomileyo besampulu, buhambelana nomda weplastiki wP.
Ukumiselwa komda wokuncipha
Umz. 3. Ukumiselwa komda wokuncipha
Isampuli yomhlaba ixutywa namanzi adistilithiweyo ngendlela echazwe phantsi Uvavanyo lokumisela umda wokuhamba, ukuze ukungaguquguquki kwayo kube kufutshane nomda wokuhamba, xa zonke iipore zigcwele ngamanzi. Emva koko kwenziwa ibhola encinci eshiywa yome kuqala emoyeni, emva koko kwisomisi-oveni kwi-105°C. Olu landelelwano lokomisa luyimfuneko ukuze kuthintelwe iintanda kwisampuli esele yomile, ezinokuphazamisa uvavanyo. Kwasekuqaleni kulinganiswa ubunzima W1 besampuli kuze kumiselwe umthamo wayo V1 ngovavanyo lokuntywiliselwa kwimerkuri, emva koko iqhubeke yomiswe emoyeni, yaye kamva kwisomisi-oveni, kusithatyathwa ngamaxesha ngamaxesha isampuli, ipholiswe kwidesikheyitha ize kulinganiswe ubunzima bayo W2, W3, W4 njalo njalo, kunye nomthamo V2, V3, V4 njalo njalo. Ngale ndlela kuya kufunyaniswa ukuba, kwinqanaba elithile lokufuma, umthamo wesampuli uyeka ukuncipha nangona ubunzima bayo buqhubeka buhla ngenxa yokomisa. Ukuba isampuli ikwisimo sayo sokuqala igcwele ngamanzi, oko kukuthi ayinawo umoya kwiipore, ilahleko yamanzi ekomiseni isampuli ukuya kumda wokucutheka ifana ngokumalunga nokuncipha komthamo wesampuli. Emva koko ukomiswa kuyaqhubeka ngaphandle kokulinganisa umthamo, de isampuli yome ngokupheleleyo, oko kukuthi de ubunzima bube buzinzile. Emva koko kumiselwa ubuninzi bamanzi ngeepesenti zobunzima obomileyo besampuli ngokulinganisa ngakunye komthamo nobunzima besampuli, ze iziphumo zovavanyo zibekwe kwidayagram (sl. 3). Ngale ndlela kufunyanwa amanqaku A, B, C, D no E, adityaniswa, ukuze ngokuqhelekileyo kufumaneke umgca onekhefu elibukhali kummandla womda wokucutheka. Kwiphuzu lokwaphuka S kufunyanwa ukufuma w oluhambelana nomda wokucutheka _W_S.
Ukumiselwa kokutsala amanzi ngenkitha
Uvavanyo lokumisela ukuphakama kokunyuka kwamanzi ngecapillary lwenziwa ngeendlela ezimbini, oko kukuthi ngokulinganisa ngokuthe ngqo ukuphakama kokunyuka kwamanzi ngecapillary nangokulinganisa ngokungathanga ngqo kusetyenziswa ikapilarimitha.
Uvavanyo lokumisela ukuphakama kwe-capillary ngokulinganisa ngqo
Kumzekelo ophazamisekileyo kuthathwa malunga 300 pondi yomhlaba, owomiswa kwi 105°C, emva koko emva kokupholisa utyunyuzwa ube ngumgubo ocolisekileyo kakhulu, ngaphandle kokutyumza iinkozo. Umgubo ofunyenweyo ugalelwa kwityhubhu yeglasi enobubanzi ø 25 mm, ubude 1,5 - 2,5 m, evulekileyo kuzo zombini iziphelo, apho isiphelo sayo esisezantsi sivaliwe ngaphambili ngoboya beglasi okanye ngesiqwenga selaphu. Kwisiphelo esivulekileyo esingasentla sigalela umgubo owomisiweyo ukuya kubude obumalunga 10 cm, emva koko siphakamisa ityhubhu size siyiyeke iwe ngempembelelo phezu komgangatho womthi okanye enye inkxaso enobhetyebhetye de kubonakale ukuzinza komgubo kwityhubhu. Ukulawula ukuzinza komgubo sikwenza ngokumakisha imiqolo ngekreyoni enamafutha kwityhubhu. Emva koko sigalela enye 10 cm yomgubo size siphinde le nkqubo de sigcwalise ityhubhu ngomgubo womzekelo womhlaba owomileyo ocolekileyo, esivavanya i-capillarity yawo. Emva koko sizalisa isiseko setyhubhu kwisitya seglasi esinamanzi adityanisiweyo angahambiyo, ngokuba isiphelo esisezantsi setyhubhu singamele sahlale ezantsi kwesitya (umz. 4). Itubhu yeglasi siyibopha ngomcu kwiskeli, ukuze zombini ityhubhu neskeli zime nkqo. Emva koko siqwalasela ukunyuka kwamanzi kwityhubhu, okubonakala ngokucacileyo ngombala: isampuli eyomileyo ilula ngombala, emanzi imnyama. Umgama phakathi komgangatho wamanzi esityeni nomphetho ophezulu wesampuli emanzi umele ukuphakama kokunyuka kwekhapilari hk.
Sl. 4. Ukumiselwa kobude bokunyuka kwamanzi ngecapillary ngokulinganisa ngokuthe ngqo
Ukuhlolwa kuqhutywa ngokwemigaqo emva kwe1, 2, 4, 8, 16, 32, 64 njalo njalo iiyure. Iziphumo zovavanyo zibekwa kwidayagram, apho ii-abscissa zimele ixesha ngeeyure, kwaye ii-ordinate ziphakamiso zokunyuka kwecapillary kwamanzi nge-mm (sl. 5).
Kwizinto zesanti, ukunyuka nge-capillary kuqala ngokukhawuleza, emva koko kancinci, kwaye ukuphakama kokugqibela kokunyuka kufikelelwa ngokukhawuleza. Kwizinto zodongwe, ukunyuka nge-capillary kuqala kancinci, kodwa kuhlala ixesha elide yaye kufikelela kubude obukhulu kakhulu.
Le ndlela yokumisela ubude be-capillary ithatha ixesha elide, ngakumbi kumhlaba onodongwe. Ukongezelela koko, ukuphakama kokunyuka kwe-capillary kuxhomekeke kubushushu bomoya nakumanzi ayo, yiyo loo nto ezi zinto kufuneka zigcinwe zizinzile kangangoko kunokwenzeka.
Sl. 5. Idayagram ebonisa ukunyuka kwamanzi ngekapilari emhlabeni, a-isanti; b-uthuli; c-umhlaba onodongwe
Uvavanyo lokumisela ukuphakama kwe-capillary kusetyenziswa i-capillarimeter
Kukho iicapillarimeter ezininzi ezineziseko ezahlukeneyo, ezinjengeecapillarimeter zikaBeskow, uJürgenson noEngelhardt. Apha siza kuchaza umgaqo wokusebenza ngecapillarimeter kaBeskow, esetyenziswa kakhulu.
Olu vavanyo lwenziwa kwiisampulu ezingaphazamisekanga okanye eziphazamisekileyo. Ukuba isampulu iphazamisekile ngoko ifakwa kwisixhobo ikwindlela esemngceleni wokuhamba.
Sl. 6. I-Capillarimeter kaBeskow
IKapilarimetha kaBeskow yenziwe ngezitya ezimbini (fig. 6), ezidityaniswe kwiindawo zazo ezisezantsi ngombhobho werabha oqinisiweyo. Esityeni 1 kufakwa isampuli yomhlaba phezu kwezantsi lokucoca, logama esezantsi kuso kukho isitya esizaliswe ngenxalenye ngamanzi adistilwanga, ngenxalenye ngenkqu, ekwinxalenye engezantsi ngendlela yokuba ligcwalise nombhobho werabha wonke kunye nenxalenye esezantsi yesitya 2. Ekuqaleni kovavanyo, inqanaba lenkqu kuzo zombini izitya liyafana. Emva koko isitya 2 sehliswa ezantsi, nto leyo eyenza uxinzelelo oluphantsi phantsi kwezantsi lokucoca lwesitya 1. Xa olu xinzelelo luphantsi luba lukhulu kunezamandla e-capillary kwisampuli, umoya ungena ngesampuli ukuya ezantsi lokucoca kwaye inqanaba lenkqu kuzo zombini izitya liyalingana ngokukhupha isitya 2. Umahluko Hg phakathi kwenqanaba lenkqu kwisitya esinye nakwesinye ngexesha lokulingana koxinzelelo oluphantsi namandla e-capillary, oko kukuthi ngoko nangoko ngaphambi kokuba umoya uqalise ukungena ngesampuli, uguqulelwe kubude bekholamu yamanzi uze wongezwe nobude bekholamu yamanzi h phantsi kwesampuli, unika ubude be-capillary hk. Kuba inkqu 13,6 amaxesha inzima kunamanzi, ke ubude bokunyuka kwe-capillary hk:
hk = 13,6 Hg + h
Ukumisela ukungavimbi komhlaba
Uvavanyo lwaselebhu lokumisela ukungena kwamanzi emhlabeni lwenziwa kusetyenziswa izixhobo ezikhethekileyo ezibizwa ngokuba zi_permeameters_. Zikhona iintlobo ezahlukeneyo zepermeameters, kodwa zingahlulwa zibe ngamaqela amabini: i-permeameters enoxinzelelo lwamanzi olungaguqukiyo, kwimihlaba enamaqhekeza amakhulu, kunye ne-permeameters enoxinzelelo lwamanzi olwehlayo kwimihlaba enamaqhekeza amancinci. Kuzo zombini iimeko uvavanyo lwenziwa ngeesampulu ezingaphazamisekanga.
Uvavanyo lwaselabhorethri lumisela i-coefficient yokungena kwamanzi yomhlaba, ixabiso lwayo elichazwa kubushushu obuthile, ngenxa ye-viscosity eyahlukeneyo yamanzi kubushushu obahlukeneyo, nto leyo echaphazela ixabiso le-coefficient yokungena kwamanzi k. Ngokuqhelekileyo kuchazwa i-coefficient k kubushushu t =10°C. Ngoko ke, ukuba 10°C, ubushushu bamanzi xa kumiselwa i-coefficient k bebungafani no t = 10°C ngoko ixabiso layo libalwa ngokomgaqo:
k10oC = ηt /η10oC * kT
apho ηt no η10oC zizintambo zokuhlanjwa kwamanzi kubushushu bokusebenza T, okanye kubushushu obamkelweyo t =10°C.
kT lixabiso elifunyenweyo le-coefficient yokungena komhlaba kubushushu bokusebenza T.
Amaxabiso e-viscosity kumaqondo obushushu ahlukeneyo T anikwe kwitafile 1.
Uvavanyo ngoxinzelelo lwamanzi olungaguqukiyo
Sl. 7. Permeametar enoxinzelelo lwamanzi olungaguqukiyo
Kolu vavanyo kuthathwa isampulu yomhlaba engaphazanyiswanga kwisilinda yentsimbi enobubanzi D, ukuphakama h, enomphetho osezantsi obukhali, ngokuyicinezela emhlabeni okanye kwisampulu enkulu engaphazanyiswanga. Emva kokuba umphezulu ophezulu nowezantsi wesampulu zilinganiswe nemiphetho yesilinda, isampulu kwisilinda ifakwa kwisixhobo (sl. 7) phakathi kwesihluzo esingentla nesisezantsi. Isihluzo esisezantsi senziwe ngumnatha oxineneyo nilitye lesihluzo, ukuze kuvunyelwe ukuhamba kwamanzi kwisampulu yaye kuthintelwe ukuhlanjwa kweentsinga zomhlaba. Isihluzo esiphezulu asinamnatha kuba kukho amathuba amancinci okuhlanjwa kweentsinga. Ukunikezelwa kwamanzi kwisampulu kuvela kwinqanaba N, eligcinwa lihlala lizinzile ngoncedo lokuphuphuma, ukuze uxinzelelo lwe-hydrostatic H luhlale lunjalo. Phantsi kolu xinzelelo amanzi adlula kwisampulu enobukhulu h aze, ngombhobho odityaniswe kwindawo ephezulu yesixhobo, afikelele kwiglasi yomlinganiselo M apho athontsizela khona.
Kwakuba nje ukuhamba kwamanzi kuqalile kudlula kwisampulu esityeni sokulinganisa, sivula iwotshi ye-stopwatch size sibukele ubuninzi bamanzi q angena esityeni ngexesha t. Ngokwemithetho kaDarcye yile
q = k*A*t*i
apho k ikhowefishini yokungena kwi cm/sec, A indawo yomnqamlezo wesampuli, i ukuhla kwe-hydraulic, i = H/h.
Kwibala elingasentla sinayo k= qh/Ath [cm/sec].
Ubungakanani bamanzi adlula kwisampuli sibufunda ngexesha lezahlulo ngexesha ukusuka ekuqaleni ukuya ekupheleni kokuqwalaselwa, ukuze sibe namaxabiso angamanye kunye nenani elipheleleyo lamanzi adlule kwisampuli.
Ukuze kupheliswe amaqamza omoya kwisampulu nakumanzi, anokuthi akhokelele kwiziphumo ezingachanekanga zovavanyo, kuyimfuneko ukuba phambi kovavanyo isampulu ibe kwimeko egcweleyo, kwaye ukuze kuqhutywe uvavanyo kusetyenziswe amanzi abilisiweyo okanye ubuncinane amanzi amileyo.
Endaweni yesixhobo esichazwe apha ngasentla esisekelwe kuxinzelelo lwe-hydrostatic ngenxa yomahluko wenqanaba lamanzi H, zikho nezixhobo apho uxinzelelo lwe-hydrostatic luveliswa ngoxinzelelo lomoya ukusuka 10 ukuya 15 kp/cm2, lugcinwa lungatshintshi ngumphampu.