Umxholo wengcali yoovimba kunye nomngcipheko omkhulu: inqaku ligcina ingxelo yembali yozinzo lwethambeka, iisimboli, iifomyula kunye nemizobo evela kumbhalo wokuqala. Akusiyo isifundo se-geotechnical, iprojekthi yokwemba okanye i-embankment, ukubalwa kozinzo, isicwangciso sokuhambisa amanzi, uvavanyo lokudilika komhlaba okanye imiyalelo yomsebenzi. Ithambeka elingazinzanga linokungcwaba abantu, izakhiwo kunye neendlela ngequbuliso; iintanda, amaqhuma, amanzi anamafu, ukuthotha ngequbuliso okanye ukufuduka kufuneka kuthathwe njengesizathu sokumka kwindawo enobungozi kunye novavanyo olungxamisekileyo lobuchwephesha.
Namhlanje, i-Savo Kusić igxile kwi ifestile zomthi, iifestile zomthi-aluminiyam, iifestile zesiko, umnyango kunye nezicelo zekoteyishini. Eli nqaku lihlala liyindawo yobugcisa kwaye alibonisi unikezelo loyilo lwe-geotechnical, ukubeka iliso okanye ukwenziwa kwemisebenzi yomhlaba.
Kumsebenzi womhlaba owakhiweyo njengokusikwa, ungqameko kunye nemisele, amathambeka okugqibela ngamanye amaxesha ayawa. Kwaye i-slope yendalo, ngaphandle kwemisebenzi eyenziweyo, inokuhamba ngokukhawuleza kunye namandla amakhulu okanye ngokucotha kakhulu. Ezi ziganeko kudala zingumxholo wezifundo ze-geological kunye ne-geomechanical, ngenjongo yokuvavanya uzinzo kwiimpawu ezibonakalayo zomhlaba kunye neemeko zemeko nganye.
Izinto ezibangela intshukumo yobuninzi bomhlaba
Imeko yozinzo lwawo nawuphi na umhlaba, nokuba yinto yodongwe eyenziweyo okanye umhlaba wendalo, kukuba kukho ulungelelwaniso phakathi kwamandla angaphandle kunye nokuxhathisa kwangaphakathi komhlaba. Amandla angaphandle ubukhulu becala bubunzima bomhlaba, obudla ngokuba bukuphela kwamandla angaphandle, alandelwe nguwo nawuphi na omnye umthwalo wangaphandle osebenza kwithambeka, elisisigxina okanye elihambayo. Ukuchasana kwangaphakathi kuqulethwe ukudibanisa kunye nokuxutywa kumhlaba oboshiweyo, kunye nokuxhatshazwa kuphela kumhlaba ongadingekiyo.
Fig. 1. Ukuthambeka kodaka lomhlaba oxekekileyo
Ukuba siqwalasela i-engile yobude h eyenziwe ngomhlaba ovuleke ngokupheleleyo, umzekelo isanti eyomileyo exineneyo, siya kugqiba ukuba ukuthambeka kolu donga kuthambekele kwi-engile engu-β ukuya ngokuthe tye (fig. 1). Ubungakanani be-engile engu-β buxhomekeke kwizinto ezininzi ezifana nobungakanani beenkozo, ukumila kweenkozo kunye nokucutheka. Ukuba sinyusa ukuphakama kwe-embankment h ukuya ku-h1, h2, njl njl kunye nezinto ezifanayo ezingabotshwanga zokudibanisa okufanayo, i-angle β ayiyi kutshintsha, i-slope ye-embankment iya kuhlala kwi-slope efanayo ukuya kubude obungenamkhawulo h. Kumhlaba onikiweyo okhululekileyo, i-engile yethambeka yendalo engu-β izimele kumphakamo wethambeka h. Ubungakanani beengile β kumhlaba ongabotshwanga buxhomekeke kwi-engile yokukhuhlana komhlaba wangaphakathi φ kwaye kucingelwa ukuba incinci kancinane kunawo, okanye ilingana nayo, β ≤ φ.
Fig. 2. Ukusika ukuthambeka kumhlaba obotshelelweyo
Ukuba sijonga isisikwe esenziwe kumhlaba obotshiweyo, siya kufumanisa ukuba ithambeka lokusikwa ligcinwe phantsi kwethambeka elomeleleyo.1:m, okt kwi-engile enkulu β ngenxa yokuba ukuchasana kwangaphakathi komhlaba odibeneyo kwandiswa ngokudibanisa, okungekho kwisanti eyomileyo (umkhiwane.2). Kwiintlobo ezithile zomhlaba, ezifana ne-loess eyomileyo, ukudibanisa kunokunyusa ukuchasana kwangaphakathi ukuya kwinqanaba lokuba umhlaba ungabanjwa ngecala elisikwe ngokuthe nkqo, okt kwi-engile β =90°. Nangona kunjalo, ukuba sonyusa ubude bokusika h kumhlaba obotshelelweyo ukuya ku h1, h2 njl., i-angle yokuthambekela kwe-bevel ye-cut cut kufuneka incitshiswe ukuze kugcinwe i-bevel ngokuzinza. Kwi-engile yethambeka nganye engu-β yethambeka lokusikeka kumhlaba othile osindiweyo kukho umphakamo omnye obalulekileyo hc. Ukuba sigqithisa lo mphakamo, ithambeka AB aliyi kugcinwa lilungelelene kwaye liya kutyibilika kwindawo etyibilikayo CD (fig.3). I-sliding yenzeke ngenxa yokuphazamiseka kwibhalansi phakathi kwamandla angaphandle, ubunzima bomhlaba kunye nokuchasana kwangaphakathi, okwakungasenakwanele ukuchasana nokunyuka kwamandla angaphandle, oko kukuthi kubunzima obuninzi bomhlaba obangelwa ukunyuka kokuphakama kwe-slope h.
Sl.3. Ithambeka lokusikwa kumhlaba obambeneyo
Ukusuka apha ngasentla, kulandela ukuba i-angle ye-slope yendalo yomhlaba ayinakuthatyathwa njengexabiso elihlala lihlala kumhlaba onikeziweyo, ekubeni ixabiso layo phantsi kwazo zonke ezinye iimeko lixhomekeke ekuphakameni kwe-slope kwaye liyancipha ngokunyuka kobu bude. Nangona kunjalo, ivame ukwamkelwa kwimithambeka yokuphakama okuncinci njengexabiso eliqhubekayo, elixhomekeke kwi-angle ye-friction yangaphakathi yomhlaba φ.
Ukuphazamiseka kokulingana kunokwenzeka kwakhona ngaphandle kokunyusa ukuphakama kokusika h, umzekelo xa ukuchasana komhlaba kwangaphakathi kuncipha. Izinto zokuchasana kwangaphakathi komhlaba obotshiweyo, ukudibanisa kunye nokuxutywa, ziguquguquka kakhulu kwaye zixhomekeke kubuninzi bamanzi emhlabeni. Ngoko ke, kwiimeko ezininzi, imbangela ye-sliding kukugqithiswa komhlaba owenziwe ngamanzi, onokuthi ube mkhulu kangangokuba umhlaba awusakwazi ukuzixhasa phantsi kwayo nayiphi na i-slope, kodwa i-slides ngenxa yobunzima bayo.
Fig. 4. Ukutyibilika komhlaba ngenxa yokwakheka kwemiphezulu yokutyibilika
Kukho iimeko ezahlukeneyo zokutyibilika komhlaba ngenxa yokuncipha kokunganyangeki kwangaphakathi, apho siza kukhankanya iimpawu ezimbalwa apha.
Imfundo yeendawo ezityibilikayo
Ukuba kukho umaleko wodongwe ongangenekiyo kwithambeka elingaphantsi komgangatho womhlaba ovuzayo (fig. 4a), okanye ukuba kukho umaleko otyekeleyo wesanti kumandlalo wodongwe (fig. 4b), apho amanzi angena khona i-atmospheric okanye i-atmospheric ye-atmospheric yamanzi. ukudilika komhlaba kunokwenzeka. Umthamo omkhulu wamanzi udlula kumaleko avuzayo ukuya kumaleko wodongwe, awumanzisa ngamandla, unciphisa ukuxhathisa kwawo kumphezulu, apho umaleko ongaphezulu utyibilika.
Ukuphazamiseka kwebhalansi ngokusika i-cut
Ukusika iinqumlo ngexesha lokwakhiwa koololiwe kunye neendlela kuphazamisa imeko yangaphambili yokulinganisela, kuba kwiprofayili yokusikwa umhlaba uhlala ngaphandle kwenkxaso kwaye uvame ukuhamba phantsi ngenxa yobunzima. Isimo solungelelwaniso sinokugcinwa ukuba ukuxhathisa kwangaphakathi komhlaba kukhulu ngokwaneleyo ukuchasana nolu tyekelo, olunokwenzeka kwakhona xa umhlaba osikiweyo uqulathe umaleko othambekele ngamandla ngokubhekiselele ekusikeni.
Fig. 5. Ukutyibilika komhlaba ngenxa yokusikwa kumaleko omhlaba
Nangona kunjalo, ukuba iileya zomhlaba ongenamanzi kunye nongenekayo zisikwe ngokutshintshanayo (Fig. 5), kunokwenzeka ukuvuza komhlaba ovuzayo kunye nokumanzisa komhlaba ongatshoniyo, ekunokuthi kwenzeke kuwo ukutyibilika.
Ukungafani komhlaba
Izingqimba ezibhityileyo zezinto ezingagxumekiyo kungqameko olwenziwe ngomhlaba onokugqobhoza, into ebizwa ngokuba ziilensi zodongwe (fig. 6), nazo zinokubangela ukutyibilika ukuba amanzi amaninzi afikelela kuzo kwaye enze indawo etyibilikayo.
Fig. 6. Ityala lokutyibilika kongqameko ngenxa yokwakheka okungafaniyo
Ifuthe leqabaka
Ngaphantsi kwempembelelo yeqabaka, amanzi aqokelelana kumphezulu welensi ngendlela yeelensi zomkhenkce. Ngexesha lokunyibilika, iilensi zomkhenkce zijika zibe ngamanzi, nto leyo enyusa umhlaba ukuya kubunzulu bentshukumo yeqabaka, ngenxa yoko uba bubumanzi kwaye iphulukane nokuzinza.
Le meko yenzeka kuphela kumhlaba onobungozi beqabaka kunye nexesha elide leqabaka, kuba kuthatha ixesha elininzi ukwenza iilensi zomkhenkce.
Ukwehliswa kwamanzi aphantsi komhlaba
Xa umgangatho wamanzi aphantsi komhlaba uthotywa ngokusisigxina, umzekelo ngenxa yomsebenzi owenziwa emhlabeni, umhlaba uyoma kwaye, ukuba ludongwe olunobumba olukhulu, kuvela iintanda. Izixa ezikhulu zomphezulu kunye namanzi asemoyeni zingena kuzo, zimanzisa umhlaba kwaye zinciphisa ukuxhathisa kwawo ngaphakathi, nto leyo enokukhokelela ekudilikeni komhlaba.
Kukwakho nezinye iimeko ezininzi ze-terrain sliding, ngoko ke kunokuqwalaselwa ukuba nawuphi na umhlaba odibeneyo unokuthi, phantsi kweemeko ezithile, ulahlekelwe ukuchasana kwangaphakathi kumlinganiselo omkhulu okanye omncinci kwaye, phantsi kweempembelelo zamandla angaphandle, umiselwe.
Umhlaba ongahambelaniyo uzinzile ukuba nje i-engile yokuthambekela kwethambeka incinci kune-engile yokukhuhlana kwangaphakathi komhlaba. Ngolu hlobo lomhlaba, ukutyibilika kwenzeka kuphela ukuba i-angle ye-slope inkulu kune-engile yokukhuhlana kwangaphakathi. Nangona kunjalo, ukuba udonga lwenziwe ngezinto ezingabotshwanga kumhlaba onodongwe, umhlaba onodongwe unokutyibilika kwaye udonga ludilike, kwaye kuyimfuneko ukujonga ukuzinza.
Uvavanya uzinzo lwethambeka lomhlaba
Imbonakalo yomphezulu otyibilikayo
Imeko yokulinganisela phakathi kwamandla angaphandle kunye nokuchasana komhlaba kwangaphakathi kwamiselwa nguCoulomb kunye ne-equation yakhe
τ ≤ c + σ tgϕ
apho τ luxinzelelo lokucheba umhlaba, c lumanyano, σ luxinzelelo oluqhelekileyo kumphezulu wokutyibilika, ϕ yi-engile yokukhuhlana kwangaphakathi.
Ukuba ukuxhathisa kwangaphakathi komhlaba, ukudibanisa c kunye nokukhuhlana σ tgϕ akwanelanga ukuchasana noxinzelelo lwe-chear yomhlaba, ukutyibilika kwenzeka kwindawo yokutyibilika ngaphakathi komhlaba. Kukho iindlela ezahlukeneyo zemigangatho yokutyibilika, exhomekeke kwiimpawu ezibonakalayo zomhlaba, ukuhluma, ukufuma, umthwalo wangaphandle kunye nezinye izinto.
Ezi meko zilandelayo zesilayidi ziyahluka ngokwendawo:
Fig. 7. Iimeko eziqhelekileyo zokudilika komhlaba
a) Ukutyibilika kwamacala athe nkqo esikiwe. Kwimeko yemijelo yonikezelo lwamanzi, ugutyulo lwelindle, njl.njl., ezigrunjwa ngamacala athe nkqo (fig. 7a), ukuba umphakamo obalulekileyo hc, oxhomekeke kwiimpawu ezibonakalayo zomhlaba, ugqithisiwe, ukutyibilika kumphezulu ADC kwenzeka. Ezi zilayidi zikholisa ukuba azikho kubude bonke bomjelo, kodwa zibekwe kwindawo ethile, nto leyo ecaciswa ngamandla angalinganiyo okucheba omhlaba.
b) Inxalenye yeslope etyibilikayo (fig. 7b). Oku kutyibilika kukholisa ukuvela entwasahlobo kumzila kaloliwe kunye neendlela ezisikiweyo kwaye zisisiphumo sokugcwala komhlaba ngamanzi.
c) Ukutyibilika ebusuku (umzobo 7c). Kukutyibilika kwethambeka lonke lokusikwa okanye ukujikela emlenzeni C.
d) Slope sliding underfoot (Fig. 7d). Kukutyibilika kwethambeka elipheleleyo lokunqunyulwa okanye ukugoba kunye nomhlaba ophantsi kweenyawo. Esi silayidi sikwabizwa ngokuba yi-subgrade fracture okanye iSwedish fracture, emva kwabaseSweden abaqale bayichaza.
Ngokubhekiselele kwimilo yendawo yokutyibilika, kunokubizwa kuphela ukuba indawo yokutyibilika kumhlaba obotshiweyo ayithe tye, kodwa iyindawo egobileyo. Abanye ababhali bamkela iarc ejikelezayo (Fellenius), i-logarithmic spiral (Rendulić) okanye indibaniselwano yale migca igobileyo (Brinch Hansen) njengokumila komphezulu wokutyibilika.
Isiphumo sokuhluzwa kwamanzi kuzinzo lwethambeka
Ukuba kukho amanzi angaphandle phambi kwethambeka elinenqanaba le-N1 (ikhiwane.8), ukuhamba kwamanzi kwenzeka emhlabeni emva kwethambeka, elibangela uxinzelelo lwangaphakathi lwamanzi kwi-pores, ngenxa yoko ukungqubuzana phakathi kwamasuntswana aqinileyo kuncipha kwaye uxinzelelo lwe-shear emhlabeni luyanda.
Ukuba umgangatho ngu N1 lamanzi phambi kwethambeka, ikholamu yamanzi H*γW ibangela uxinzelelo lwamanzi kwimibhobho yomhlaba, okunciphisa ukukhuhlana phakathi kwamasuntswana aqinileyo, ngenxa yoko ingozi yokutyibilika kwethambeka yanda. Nangona kunjalo, xa inqanaba N1 rhoqo, uxinzelelo loluhlu lwamanzi H*γW lutyhala amasuntswana aqinileyo ukuya kumbindi womhlaba, ngenxa yoko ubungozi bokutyibilika kwethambeka buncitshiswe ukusa kumlinganiselo othile. Kule meko, kwinqanaba lamanzi rhoqo N1 phambi kwethambeka, kukho ingozi yokutyibilika kwethambeka elisezantsi, kuba isiphumo sokuhluzwa kwamanzi emhlabeni sibangela ukutyhalana kwamasuntswana aqinileyo kwicala langaphandle lethambeka elisezantsi.
Sl.8. Ifuthe lokuhluzwa kuzinzo lwethambeka lomhlaba
Ukuba umgangatho wamanzi wangaphandle wehla ngokukhawuleza ukusuka kwinqanaba le-N1_ kwi_N2_ ke ukuzinza kwethambeka elinyukayo kusongelwa. Kule meko, amanzi angaphakathi aqukuqela ukuya kwicala langaphandle lethambeka elinyukayo, etyhala amasuntswana aqinileyo kwicala.
Ngenxa yako konke oku, ukuba i-slope yomhlaba ifakwe emanzini, umphumo wokucoca amanzi kufuneka uphinde uqwalaselwe xa uvavanya ukuzinza kwe-slope.
Isiphumo sokuhluzwa kwamanzi emhlabeni sixhomekeke kwizinto ezininzi, eyona ibalulekileyo ukunganyakazi komhlaba, uxinzelelo lwehydrostatic lwamanzi angaphandle, isantya sokuhla komphakamo wamanzi angaphandle kunye nehomogeneity yomhlaba.
Ukuba sicingela ukuba udonga kwifig. 8 yobunzima be-homogenously isotropic, phantsi kwempembelelo yoxinzelelo lwe-hydrostatic lwamanzi angaphandle omgangatho N1, amanzi aya kuhamba kwimibhobho yodonga ukuya kwicala lethambeka elisezantsi, apho inqanaba lamanzi omhlaba kudonga liya kuncipha ngobude bendlela ehanjiweyo. Ukuba sazisa imibhobho ye-piezometer AA’, BB’ kunye ne_CC’_ kwi-embankment (fig. 9), amanzi e-pore phantsi kwefuthe loxinzelelo lwe-hydrostatic aya kungena kule mibhobho kwaye anyukele kwinqanaba le-N1, elinokuthi lifane kuyo yonke imibhobho, ukuba loo manqaku _B akhethiweyo_A. ikholamu yamanzi kwimibhobho h1, h2 kunye h3.
Fig. 9. Equipotential kunye nemigca yangoku
Ukuba sichaza ngo h umphakamo womphakamo wamanzi N1 ngokunxulumene nenqwelomoya ekhethwe ngaphandle kwesizathu i-O-O, ngoko okunokwenzeka h kuzo zonke 3 amanqaku, A, B kunye C ayafana. Umgca odibanisa la manqaku mathathu ngu equipotential line. Amanzi aphantsi komhlaba akakwazi ukuhamba kulo mgca, kodwa kuphela kwicala leendawo ezinesakhono esisezantsi.
Ngendlela efanayo sinokukhetha kubunzima obufanayo amanqaku D, E kunye F ngesakhono esisezantsi h ― Δh. Umgca odibanisa la manqaku mathathu ngumgca we-equipotential we-equipotential h ― Δh. Ukuhamba kwamanzi ukusuka kwindawo A yomgca we-equipotential ABC ukuya kwindawo ethile evale ngokungenasiphelo D yomgca we-equipotential DEF iya kubakho kwisalathiso seyona hydraulic drop inkulu _imaxest umgama kwi_Δel ncinane umgama ophakathi = i_Δel . AD. Oku kuthetha ukuba umgca AD apho amanzi ahamba khona uxhomekeke kuyo yomibini imigca ye-equipotential, kuba
imax = Δh / Δlmin
apho Δlmin iqhelekile kuyo yomibini imigca ye-equipotential. Ezo ziqhelo ukuya kwimigca ye-equipotential zizikhokelo zokuhamba kwamanzi kubunzima obunokungena kwaye zibizwa ngokuba yi-current lines. Uluntu lwemigca ye-equipotential kunye nekhoyo ngoku, ngokulinganayo enye kwenye, yenza inethiwekhi yokuhamba.
Uthungelwano oluqukuqelayo luneemilo ezahlukileyo ngokobunzima bokungena. Esona siganeko sixhaphakileyo ludonga olwenziwa ngobunzima obunokugqobhoza kumhlaba ongenamanzi, oko kukuthi kumhlaba onokwenziwa ukuba ungangeni (fig. 10). Kule meko, ukuba inqanaba lamanzi langaphandle lihlala lihleli, i-streamlines iphakathi kwendawo ephakathi kwe-parabola.
Fig. 10. Uthungelwano oluqukuqelayo kungqameko olungeneyo kumhlaba ongenamanzi
Kwi-slope upstream, i-parabolas idibanisa kunye nemigca ye-perpendicular kwi-slope, emele umgca we-equipotential, kuba kwinqanaba eliqhubekayo N1 amanzi awahambi phantsi kwi-slope. Nge-slope esezantsi, i-parabolas iphela ngokukhawuleza ukuya kwi-slope, engekho umgca we-equipotential okanye umgca wangoku. Umphezulu womhlaba ongenamandla ongaphantsi kongqameko ngumsinga, kuba amanzi asezantsi kwelitye ahamba ngokuhambelana nalo mhlaba. Kwinxalenye ephezulu, inethiwekhi yokuhamba iphetha nge-parabola eyisiseko ebizwa ngokuba yi-seepage line, emele umda womhlaba phantsi kwesenzo sokucoca. Ngezantsi kwalo mda, umhlaba uphantsi kwempembelelo yokucoca ngenxa yoxinzelelo lwe-hydrostatic lwamanzi angaphandle H \ * γ W, ngelixa kungabikho ukuhluzwa komhlaba ngaphezu kwayo. Umgca wepeyiji ukwabizwa ngokuba ngumgca wokuhluza, kuba kucingelwa ukuba umhlaba ongaphantsi kwawo uzele ngamanzi, ngelixa ngaphezu kwawo ugcwele ngokuyinxenye.
Uvavanyo olululo lwethambeka kufuneka luquke uphando, ulwahlulo, iiparamitha zamandla, amanzi aphantsi komhlaba nangaphezulu, utshintsho lwamanqanaba, ukuhanjiswa kwamanzi, inyikima, ukugrumba okanye ukugcwaliswa kwezigaba, izakhiwo ezikufutshane kunye neemeko zethutyana. Ukugrumba ngaphandle kokhuseleko olululo kunye nokungena kwindawo enokuthi ikhukulise umhlaba akukhuselekanga ngokusekwe kumbhalo jikelele okanye kwimilo yethambeka ngokwalo.