Namhlanje, i-Savo Kusić igxile kwi ifestile zomthi, iifestile zomthi-aluminiyam, iifestile zesiko, umnyango kunye nezicelo zekoteyishini. Esi sicatshulwa sihlala siyindawo yogcino lwe-geotechnical kwaye ayisosithembiso sovavanyo lwelabhoratri, uyilo lwe-geotechnical okanye imisebenzi yomhlaba.
Kukho iindlela ezininzi zokumisela izakhi zokumelana nomhlaba wangaphakathi, ukuhlangana kunye ne-engile yokukhuhlana kwangaphakathi kusetyenziswa iimvavanyo zaselabhoratri, phakathi kwazo uvavanyo direct shear kunye novavanyo triaxial compression zezona zidumileyo.
Ukucheba ngokuthe ngqo amava
Uvavanyo lwenziwa kwisixhobo esinecandelo loxande lohlobo A. Casagrandea okanye kwisixhobo sesetyhula sohlobo lwe Hvorsleva. Siza kuchaza umfuniselo ngesixhobo secandelo loxande, elona lisetyenziswa kakhulu. Kuzo zombini iimeko, uvavanyo lwenziwa ngesampuli engaphazamisekiyo, okanye ngesampulu ephazamisayo kwinqanaba lesivuno, apho uvavanyo lunexabiso lokuthelekisa.
Isixhobo sokucheba ngokuthe ngqo kwecandelo loxande (umzobo 1)
Fig. 1_Icandelo elinqamlezileyo lesixhobo sokucheba esithe ngqo seCasagrande_
Isixhobo sinamacandelo amabini, ifreyim ephezulu nesezantsi, apho elisezantsi limile, ngelixa elingaphezulu lishukuma kwaye linokushukunyiswa kwelisezantsi phantsi kwempembelelo yomandla othe tye Z, osebenza kwinqwelomoya yoqhagamshelwano lwesakhelo esiphezulu nesisezantsi.
Isampuli yomhlaba ifakwe kwintsimbi ye-rectangular ring, ngokuqhelekileyo ubukhulu be-100 × 100 × 30 mm, okanye loo milinganiselo xa ikhutshiwe ngokuchanekileyo. Amatye okucoca abekwe ngaphezulu nangaphantsi kwesampulu, emva koko yonke into ifakwe kwindandatho yesixhobo, ethi izaliswe ngamanzi. Isixhobo sokulayisha ngokuthe nkqo sibekwe kwisampulu. Ilitye lokucoca eliphezulu lixhunywe kwinkqubo yokulayishwa ngokuthe nkqo kwesampuli, ngelixa elisezantsi lixhunywe kumzila wamanzi, ngendlela apho isampuli ingagcinwa kwindawo egcweleyo ngexesha lovavanyo, ukwenzela ukuba ingabandakanyi ukuhambelana okubonakalayo.
Ukuze ungabandakanyi ukukhuhlana kwimigangatho yoqhagamshelwano phakathi kwesakhelo esiphezulu nesisezantsi, kukho izixhobo ezinesakhelo esiphezulu esijijekileyo, apho isakhelo esingaphezulu sihamba phantsi kwempembelelo yokucheba okuthe tye. Ukongezelela, iindawo zoqhagamshelwano zesakhelo esiphezulu nasezantsi zifakwe nge-petroleum jelly. Enye 2 isithelekisi sokubhalisa ukuguqulwa okuthe nkqo nokuthe tye kuqukiwe kwisixhobo.
Ukuqhuba uvavanyo oluthe ngqo lokucheba
Kukho ubukhulu becala2iintlobo zovavanyo oluthe ngqo lokucheba: fast kunye slow uvavanyo. Uvavanyo olu- quick luquka ukulayisha isampuli ngoxinzelelo oluthile oluthe nkqo, oludla ngokuba ngumlinganiselo0,50;1,0;2,0;3,0kwaye4,0kp/cm2, linda ukudibanisa, ekucingelwa ukuba kuphunyeziwe ukuba ukuthotywa ngexesha24iiyure Δh ≤0,02 mm, kwaye ke i-horizontal shear force Z, yobukhulu, iyasetyenziswa1/20okanye1/40inxalenye yamandla athe nkqo P, anyuka ngomzuzu ngamnye ngexabiso elifanayo de kuphuke umhlaba. Ngethuba lokusetyenziswa kwamandla okucheba okuthe tye, ukuhamba kwesakhelo esiphezulu sihlala sibekwe esweni ngokufunda kwi-comarator kunye ne-deformations ethe tye irekhodwa kwilogi ngokukhawuleza phambi komthwalo omtsha ngamnye. Umzuzu, apho umqhathanisi ubonisa ukunyakaza ngokukhawuleza, wamkelwa njengokuphulwa komhlaba.
Uvavanyo olukhawulezayo lusetyenziswa kwimihlaba yodongwe, ukuhlanganiswa kwayo kwendalo phantsi komthwalo omtsha kucotha kwaye kuhambelana nale ndlela yokwenza uvavanyo.
Slow uvavanyo lwenziwa ngendlela efanayo nangaphambili kunye nomahluko kuphela wokuba amandla okucheba othe tyaba anyuke kwixesha elide, elinokuba 2, 5 kunye 15 mimizuzu okanye de kube ukudityaniswa, okt ideificant deficant deficant deficant deficant deficient. Ikhosi yokudibanisa phantsi kwempembelelo yamandla anqamlekileyo ibekwe esweni kumthelekisi 9 (umzobo 1).
Uvavanyo olucothayo lusetyenziswa kumhlaba onesanti okanye onothuli, apho kwimeko yokwanda kwamandla ocheba othe tye ngexesha elifutshane, ukucheba kwesampulu kwisixhobo kuya kukhawulezisa ngenxa yesiphumo soxinzelelo lwamanzi kwiipores, ezingayi kuhambelana nenkqubo yendalo. Ngoko ke, ixesha lokuphumla linyuka ngokucokiseka kwamasuntswana omhlaba angabotshwanga, ukwenzela ukuba kube nokulingana koxinzelelo lwamanzi kwimibhobho yomhlaba kunye noxinzelelo lwangaphandle lwamanzi. Oku kulinganisa kuphunyezwa ngokushiya ixesha elaneleyo phantsi kwempembelelo yenqanaba ngalinye lomthwalo othe tye, ukwenzela ukuba amanzi angaphezulu kwi-pores akhutshwe ngelitye lokucoca.
Ukongezelela kwiimvavanyo ezikhankanyiweyo, kwiimeko ezithile uvavanyo olukhawulezayo ngaphandle kokuhlanganiswa phantsi komthwalo othe nkqo luyenziwa, oko kukuthi i-horizontal shear force isetyenziswe ngokukhawuleza emva kokuzisa isampuli kwi-apparatus kwaye ilayishwe ngomthwalo othe nkqo. Nangona kunjalo, le ndlela yokubulawa isetyenziswa phantsi kweemeko ezikhethekileyo, ezinje ngemeko yongqameko olusanda kufakwa olwenziwe ngomhlaba wodongwe, olulayishwa ngoko nangoko emva kodonga ngaphandle kokuxinzelelwa kwangaphambili.
Ukumiselwa kwe-angle yengxabano yangaphakathi kunye nokudibanisa
Ngokusekelwe kwiziphumo zovavanyo, uxinzelelo lwe-chear
τ=Z/A kwi-kp/cm²,
efunyenwe kumkhosi wokucheba Z kwi-kp ngexesha lokusilela kunye nommandla onqamlezileyo wesampulu A kwi-cm². Uvavanyo lwenziwa nge-3 ukuya 4 isixhobo esilayishwe ngoxinzelelo oluqhelekileyo olwahlukileyo σ=P/A kwi-kp/cm² apho P ingumthwalo othe nkqo wesampulu kwi-kp. Ezi xabiso zilandelayo zoxinzelelo oluqhelekileyo zidla ngokuthathwa: 1,0; 2,0; 3,0 kunye 4,0 kp/cm².
Fig. 2. Umzobo woguqulo oluthe tye
Ngokusekelwe kumzobo wezinto zangaphakathi zokungqubuzana, iindidi ezimbini zemizobo 1 kunye nomzobo wokuguqulwa okuthe tye (umzobo 2) zifunyenwe.
Umzobo woluphelo oluthe tye ufunyanwa ngokusebenzisa ukufuduswa okuthe tye ΔL kwi-mm yesakhelo esiphezulu sesixhobo ukuya kwesezantsi kwi-abscissa axis, efunyanwa ngokufunda isithelekisi 9, nakwi-axis ehambelanayo i-kg² ehambelanayo i-kg² 2).
Kuxhomekeke ekudityaneni komhlaba, umzobo 1 wokucudiswa kunye nedayagram 2 yemathiriyeli eyobekileyo ifunyenwe.
Kwimathiriyeli exineneyo, uxinzelelo lwechear τ luyanda ekuqaleni kunokuba kabukhali ngokunxulumene nokususwa okuthe tye ΔL ukuya kumda wobume bobume be P, ngokucotha ngakumbi, ngelixa ijika lomzobo.1ukwanda kunye nokufikelela kubude obuphezulu B, emva koko umzobo uyancipha ubude obuthile, ekugqibeleni ufikelele kwi-horizontal flow. Ummandla wokunyuka okuthe tye kwedayagram ye-deformation ethe tyaba, apho ukonyuka koxinzelelo lwe-shear kuhambelana nokunyuka kwe-deformation, kucingelwa ukuba yindawo ye-elastic deformation. Ngaphaya komda P, ukonyuka koxinzelelo lokucheba kuncipha ngokonyuka kokonakala ΔL ukuya kweyona ndawo iphezulu B yomzobo. Kulo mmandla, izinto ziqala “ukuhamba” kwaye zamkelwa njengendawo yokuguqulwa kweplastiki. Eyona ndawo iphakamileyo yomzobo B1imele ubuninzi boxinzelelo lwe-chear max τ, kwaye kucingelwa ukuba ukuphuka komhlaba kwenzeka kweli nqanaba, oko kukuthi loo ndawo B yindawo yokuqhawula. Ngaphandle kwenqaku B, izinto eziphathekayo zikwimeko yolwelo, amandla okucheba ayancipha, kwaye kucingelwa ukuba kulo mmandla, apho uxhulumaniso phakathi kwamasuntswana aphukileyo, kukho ukuchasana kwe-sliding kuphela okuchasana ne-horizontal shear force. Inqaku G apho umzobo1idlula kwicala elithe tye yamkelwa njengomda wokutyibilika.
Uxinzelelo lokucheba kumda wokusilela u-B ubizwa ngokuba ngamandla okucheba okanye amandla okucheba asulungekileyo τf, ngelixa uxinzelelo lokucheba kumda wesivuno G kuthiwa ngamandla okucheba τg.
Kwimathiriyeli ekhululekileyo, umzobo othe tyaba wokufuduka nawo unommandla olulastiki kunye nomda wokulinganisa P, kodwa ezantsi ngummandla weplastiki ukuya kumda wokutyibilika G, o.k.t. ubuninzi boxinzelelo lokucheba bulingana namandla omda, ukutyibilika (τ=τg), ngaphaya apho imeko yolwelo yezinto.
Sl.3. Idayagram yokucheba, a) yemihlaba eyondeleleneyo, b) yemihlaba engahambelaniyo
Umzobo wokucheba ufunyanwa xa uxinzelelo oluqhelekileyo σ kwi kp/cm lusetyenziswa kwi-abscissa axis.2, kunye ne-axis ehambelanayo amandla okucheba ahambelanayo τf kwi kp/cm2, apho omabini la maxabiso asetyenziswa kwisikali esifanayo (Fig.3). Ukusukela oko amandla okucheba τf omhlaba enyuka ngoxinzelelo oluqhelekileyo σ, iya kuxinzelelo olwahlukileyo σ1 fumana amanqaku A, B, C, kunye no-D, amele amandla okucheba ahambelanayo.
Ukufumana amanqaku A, B, C kunye no-D kumzobo3kwimihlaba ehambelanayo (umkhiwane.3a), amandla okutyibilika _τ_g amkelwe. Nangona kunjalo, kwimeko yomhlaba wodongwe, izinto ziqala ukuhamba ixesha elide ngaphambi kokuba umda we-sliding G ufikeleleke, kwaye kukho ukuthambekela ukwamkela amandla okucheba kumda wokulinganisa P ukumisela ukudibanisa c kunye ne-angle yokungqubuzana kwangaphakathi komhlaba, kodwa ekubeni incinci kakhulu, amandla okucheba apho i-deformation idla ngokusetyenziswa kwidayagram _ΔL_2Iphindwe kabini kune-deformation kwinqanaba langaphambili lokulayisha kwi-apparatus. La mandla akwindawo ethile phakathi komda weP kunye no-B, oko kukuthi, uG (fig.2).
Ukudibanisa amanqaku A, B, C kunye no-D kwidayagram 76a inika umzobo we-shear, ongumgca othe ngqo kwiimvavanyo eziyimpumelelo. Ngokwandisa umzobo kwindawo ekudibanela kuyo i-axis elungelelanisiweyo, ye σ = 0, ifunyenwe ngokusekwe kwipatheni yeCoulomb τf = c+σ tgϕ ukuba τf = c = ukudityaniswa komhlaba, ngelixa ukuthambeka komzobo ukuya kwi-engile ethe tyaba inika i-engile. Ngokwandisa umzobo we-shear kwelinye icala le-axis elungelelanisiweyo, uxinzelelo ngenxa yokubambisana pk ifunyenwe kwi-abscissa axis, xa ubukhulu bokubambisana c bubonakaliswa njengokulingana nokuchasana kwefrictional:
c = pk tgϕ, ivela phi pk = c/tgϕ
Kumhlaba ongahambelaniyo, onjengesanti, umzobo wekhiwane. 3b, edlula kwimvelaphi yolungelelwaniso, kuba kwi σ = 0 sifumana τ = 0. Nangona kunjalo, ukuba isanti ilungile kwaye imanzi, i-diagram efana neyomkhiwane. 3a, kunye nomanyano oluncinci c, olumele umanyano olubonakalayo. Kwimeko apho, uxinzelelo pk kwi-abscissa eyandisiweyo ye-axis kwelinye icala lemvelaphi yolungelelaniso imele uxinzelelo lwe-capillary.
Kufuneka kuqatshelwe ukuba ukumiselwa kokubambisana komhlaba kunye nokukhuhlana ngovavanyo oluthe ngqo lwe-chear lunezinto ezininzi ezingalunganga, eyona nto ibaluleke kakhulu kukuba ukusilela komhlaba kwenzeka kumphezulu omiselweyo wokucheba kwaye kungekhona kumphezulu wobuncinci ukuchasana kwe-chear, ukuba ngexesha lokucheba isampuli kwi-apparatus, umphezulu we-shear uyancitshiswa ngenxa yesampulu esisezantsi, emva koko kwisampulu ephantsi. ukucheba kunokujongwa kuphela kubude obufutshane, ukwenzela ukuba ukuxhathisa ukutyibilika ngaphaya komda akukwazi ukulawula ukwaphuka ukusa kwinqanaba elaneleyo, ngakumbi kwimeko yomhlaba othambileyo xa iziphene ngexesha lokucheba zinkulu, njl. njl.
Uvavanyo loxinzelelo lweTriaxial
Uvavanyo lwenziwa kwi-triaxial apparatus, enezakhiwo ezahlukeneyo, kodwa zonke zisekelwe kumgaqo ofanayo, ololu hlobo lulandelayo. Isampulu engaphazamisekiyo ngendlela ye-roller ibekwe ngokuthe nkqo kwi-stand kwaye ibonakaliswe kuxinzelelo lwecala lobunzima bolwelo oluvela kumacala onke kwaye emva koko kuxinzelelo oluthe nkqo, olunyuka ngokuthe ngcembe, de kube ukuphuka kwesampuli kubangelwa phezu kobuncinci be-shear resistance. Ngokusekelwe kumandla okucheba ngexesha lekhefu, umanyano kunye ne-engile yokukhuhlana kwangaphakathi komhlaba kubalwa.
Inkcazelo yesixhobo setriaxial
Fig. 4. Isixhobo seTriaxial
Isixhobo se-triaxial (umzobo 4) iqulethwe kwindawo ephantsi yeplate yesiseko yegumbi, apho isampuli ihleli khona, kunye nenxalenye ephezulu yepiston yokulayisha ngokuthe nkqo isampuli kunye neplate ephezulu evala igumbi. Ezona milinganiselo zixhaphakileyo zesampulu zidayamitha ϕ=36 mm, ubude h=2,2-2,5_ϕ_. Idayamitha yegumbi ngu D=135mm, ubude H = 180 mm. Ityhubhu emxinwa i-K1 yokukhupha isampuli ukusuka ezantsi iqala ukusuka kumbindi wesampulu yesampulu, efumana amanzi kwisampulu ngepleyiti ene-porous kwaye ikhuphe ngaphandle kwegumbi kwityhubhu yeglasi emileyo C1. Ukuba uvavanyo lwenziwa ngaphandle kokukhupha isampuli, lo mzila usebenza ukulinganisa uxinzelelo lwamanzi kwiipores. Kwisiseko sobhedu segumbi kukho umjelo we-K2 wokunikezelwa kobunzima be-liquid ukuze ugcwalise igumbi kwaye ufezekise uxinzelelo olusecaleni kwigumbi kwisampuli.
Ngokusebenzisa ipleyiti ephezulu yegumbi idlula i-piston handle yokulayisha isampuli. Isampuli kwigumbi lijikelezwe yi-membrane yerabha, eyandisiweyo kuzo zombini iziphelo kwaye ixhunywe kwipiston kunye nesiseko ngokusebenzisa iindandatho zerabha. Embindini wepiston kukho umjelo we-K3 wokukhupha isampuli ukusuka kwicala eliphezulu.
Amacala egumbi atywinwe ngokwe-hermetically ngePlexiglas cylinder edityaniswe kumacwecwe aphezulu nasezantsi egumbi ngamakhonkco erabha.
Igumbi libekwe kwisiseko esiqinileyo. Ukulayishwa okuqhelekileyo kwesampulu kwenziwa nge-lever enesisindo, umlinganiselo oqhelekileyo 1: 10. Inkqubo yokufezekisa uxinzelelo olusecaleni kwisampulu kwigumbi liquka ibhotile enobunzima obumanzi B, obungeniswa kwigumbi ngetyhubhu, i-manometer yokulinganisa uxinzelelo lomoya kunye nebhotile enomoya ocinezelweyo. Umlinganisi ubekwe ngaphezu kwepiston yokulayisha isampuli ukulinganisa ukuhlaliswa kwesampuli phantsi komthwalo.
Uxinzelelo lwecala lobunzima be-liquid kwigumbi linokulungelelaniswa ngokuthanda usebenzisa uxinzelelo lomoya kwibhotile B, ngee-valve V1 kunye ne-V2. Olu xinzelelo lubangela uxinzelelo oluthe tye kwisampulu σ2 kunye σ3, ethi ngenxa yecandelo lesetyhula yesampulu zilinganiswe σ2 = σ3.
Ubunzima bolwelo bunokuba ngamanzi adibeneyo okanye i-oyile, ekhethwa ukutywinwa okungcono, kuba amanzi anokudlula kwizikrufu. Phantsi kweempembelelo zoxinzelelo lomoya kwibhotile B, ubunzima bolwelo buzalisa igumbi ukuya kuthi ga kwivalve V6, ethi emva koko ivale. Umthwalo othe nkqo wesampulu P, ekhutshelwe phantse ngokungakhubekiyo kwisampulu ngokusebenzisa isiphatho sepiston, esahlulwe yindawo enqamlezayo yesampulu A inika uxinzelelo oluthe nkqo σ1 = P/A
Ukwenza uvavanyo loxinzelelo lwetriaxial
Kwisampuli yokuvavanya, icutshungulwa kwi-apparatus eyahlukileyo, ukwenzela ukuba i-roller enobubanzi be-36 mm, ukuphakama kwe-78 mm okanye 90 mm kufunyenwe, apho amatye okucoca abekwe ukusuka phezulu nangaphantsi kwaye i-membrane yerabha ifakwe. Emva koko isampuli kunye namatye okucoca ibekwe kwindawo yokumisa kwigumbi, iziphelo, iimbumba zeerubha zitsalwa phezu kwesigxina kunye nepiston yokulayisha kwaye ikhuselekile ngamakhonkco erabha. Ngokwendlela yokwenza iilabhoratri ezithile, ezifana noProf Skempton eLondon, ukukhupha isampuli kwigumbi ngexesha lovavanyo kukhawuleziswa ngokufaka amacala esampuli ngephepha lokucoca, elibekwe phambi kokuba inwebu yerabha itsalwe. Xa isampuli ifakwe kwi-apparatus kunye ne-Plexiglas cylinder igxininiswe kwiiplate eziphezulu kunye nezisezantsi, kunokwenzeka ukwenza iimvavanyo, ezinokuthi zenziwe ngeendlela ezininzi, ezifana nezi zilandelayo:
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Iemvavanyo ezingapheliyo. Kule mvavanyo, ukuchithwa kwesampuli akuvumelekanga ngexesha lokusetyenziswa kovavanyo olusecaleni kunye noluthe nkqo, ngelixa ii-valve V4 kunye ne-V5 zivaliwe.
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Uvavanyo olungagonywanga ngokudibanisa. Ngethuba lokusetyenziswa koxinzelelo lwecala, isampuli ikhutshwe (ii-valve V4 kunye ne-V5 zivulekile), ngelixa ukusetyenziswa koxinzelelo oluthe tye, ukukhutshwa kwamanzi akuvumelekanga (V4 kunye ne-V5 ivaliwe).
3_) Iisampuli ezikhutshiweyo_. Isampuli ihlanjululwa kulo lonke ixesha lovavanyo (ii-valve V4 kunye ne-V5 zivulekile), ukwenzela ukuba ukuhlanganiswa okupheleleyo kwenzeke kwaye akukho manzi agxininisiweyo adalwe kwiipores ngexesha lokusetyenziswa koxinzelelo oluthe nkqo σ1. Olu vavanyo luthatha ixesha elide, ngakumbi ngomhlaba ongenakungena kakuhle, kuba ukulayisha ngokuthe nkqo σ1 kufuneka kuqhutywe kwinani elikhulu lezigaba ezincinci kwaye ukudibanisa kufuneka kulindwe kwinqanaba ngalinye. Ukongeza, uvavanyo olukhankanyiweyo lunokwenziwa ngeesampulu saturated kunye partially saturated._
Ngokwemeko ekhankanywe ngasentla, iimvavanyo zoxinzelelo lwetriaxial zinokwenziwa ngeendlela ezahlukeneyo kwaye zilungelelaniswe ngokohlobo lomhlaba phantsi kweemeko zomthwalo.
Izixhobo, iinkqubo, iiyunithi, amaxabiso kunye neepatheni ezichaziweyo zikhutshelwe ukusuka kumthombo wembali. Isicatshulwa ayisosifundo se-geotechnical, iprotocol yelabhoratri, iprojekthi yesiseko, ubungqina bozinzo lwe-slope okanye isicwangciso sokomba. Ukukhethwa kwesampulu kunye nendlela yokuvavanya, imeko yokukhupha amanzi kunye nokudityaniswa, amanzi aphantsi komhlaba, ulawulo lomthwalo, iimpembelelo zenyikima kunye nokhuseleko lokugrumba kufuneka kumiselwe umhlaba othile kunye nesakhiwo, ngokwemigaqo yangoku, kunye nebhubhoratri efanelekileyo kunye neengcali ze-geotechnical ezigunyazisiweyo.