Ulwakhiwo lomhlaba

Ngaphantsi kwesakhiwo somhlaba kuqondwa ulungelelwaniso lwesigaba esiqinileyo kubunzima bomhlaba. Njengoko kusaziwa, umhlaba uqulunqwa ngamasuntswana aqinileyo kunye neepore ezizaliswe ngamanzi, ngumoya okanye ngumphunga wamanzi, amaxesha amaninzi ngokuyinxenye ngumoya ngokuyinxenye ngamanzi. Ngokutsho kolungelelwaniso lwamasuntswana aqinileyo emhlabeni kusetyenziswa ukumiselwa kwesakhiwo sawo. Izakhiwo zomhlaba ongabotshelelwanga kunye nomhlaba obotshelelweyo zahluke kakhulu omnye komnye.

Ulwakhiwo lomhlaba ongabotshelelwanga

Isakhiwo somhlaba ongabophelelwanga sithatha ubume phantsi kwesenzo samandla omxhuzulane. Amasuntswana aqinileyo alo mhlaba makhulu aze ehlele ezantsi, azinze phantsi kwesenzo samandla omxhuzulane, logama amandla okutsalana phakathi kweemolekyuli ala masuntswana engabikho okanye emancinci kakhulu aze oyiswe ngumxhuzulane. Ngenxa yoko, kumhlaba ongabophelelwanga amasuntswana aqinileyo abekwa ecaleni kwelinye, ezalisa indawo ekhululekileyo phakathi kwamasuntswana abekiweyo (sl. 1_a_). Ukuba amasuntswana omhlaba ongabophelelwanga aphantse abe ngqukuva kwaye anobukhulu obufanayo, njengoko kunokuba njalo kwisanti enesakhiwo esifanayo, ngoko isakhiwo sinokuba sesona sishinyeneyo (sl. 1_b_) okanye sesona sixineneyo kancinane (sl. 1_c_), kuxhomekeka kulungelelwaniso lwamasuntswana aqinileyo emhlabeni. Isakhiwo sesona sishinyeneyo sihambelana nowona mlinganiselo mkhulu wokuxinana komhlaba ongabophelelwanga yaye isithuba sawo esingenanto ngu nmin=26%. Isakhiwo esona sixineneyo kancinane sihambelana nowona mlinganiselo mncinane wokuxinana okunokwenzeka komhlaba ongabophelelwanga yaye isithuba sawo esingenanto ngu nmax=48%. Ngokomzekelo, isanti ekhululekileyo yeendunduma ine n=47%.

Ukuzinza kweentlobo zomhlaba ezingenakubotshwa phantsi kwesenzo somxhuzulane

Esona sakhiwo sixineneyo nesona sikhululekileyo somhlaba ongabophelelwanga

Sl. 1 Ubume bomhlaba ongabotshelelwanga

Ukuba umhlaba ongabotshelelwanga unobukhulu beenkozo obuhlukahlukeneyo, ukuze amasuntswana amancinci azalise izikhewu phakathi kwezo zinkulu (umz. 2), iporosity yomhlaba iba sezantsi kakhulu (n=20% nangaphantsi).

Ubume bomhlaba ongabophelelwanga obunobukhulu obahlukeneyo beenkozo

Sl. 2. Isakhiwo somhlaba ongabophelelwanga onobukhulu beenkozo obahlukeneyo

Ulwakhiwo lomhlaba odibeneyo

Kwimihlaba enomdibaniso, ulwakhiwo luhlukile kunolwemihlaba engabotshelelwanga. Kulo mhlaba unodibaniso kuvela amandla odibaniso, anamandla ngakumbi kunamandla omxhuzulane wamasuntswana amancinci kwaye awancamathisele kwiindawo zothintelo. Ngenxa yoko la masuntswana awa ngolandelelwano asezantsi, koko ahlala encamathele omnye komnye nakufuphi komnye komnye (umz. 3_a_), ngaloo ndlela enza ulwakhiwo olufana nothungelwano lwetyathanga (umz. 3_b_), olunjengamaqhwa athambileyo (umz. 3_c_) njl. njl., olubizwa ngokuba lulwakhiwo lwamanqanaba aphezulu. Ezi zakhiwo zinendawo enkulu yeeporosity, enokufikelela ku 60-80% yobunzima bubonke, nto leyo engenzeki kumhlaba ongabotshelelwanga.

Ulwakhiwo lomhlaba odibeneyo

Sl. 3. Ubume bomhlaba obudityanisiweyo

Iporozithi kunye ne-coefficient ye-porozithi

Ubunorho bomhlaba buchazwa ngumlinganiselo womthamo wemingxuma kumthamo opheleleyo womhlaba (umz. 4).

Ubunyangwa kunye nekhoyefishini yobunyangwa bomhlaba

Umz. 4. Ububobo kunye ne-coefficient yobubobo bomhlaba

Ukuba sichaza ngo

  • Vp = umthamo weepore emhlabeni
  • Vm = umthamo wamasuntswana aqinileyo
  • V = umthamo opheleleyo womhlaba,

i-porosity yomhlaba n ngokwenkcazo

n = VP / V = VP / (VP + Vm),

oko kukuthi kwi-% yomthamo opheleleyo womhlaba

n = 100 * VP / (VP + Vm) %.

I-coefficient ye-porosity yomhlaba ichazwa ngomlinganiselo womthamo wemingxuma ukuya kumthamo wamaqhekeza aqinileyo:

e = VP / Vm.

Kwifomula ye-porosity n sinayo:

nVP + nVm = VP, apho Vm = VP(1-n) / n.

Ngokufaka eli xabiso kwifomula ka e sifumana

e = n / (1-n).

Kule equation sifumana

e - ne = n; n = e / (1 + e).

I-coefficient ye-porosity ibonisa ubuninzi bomhlaba. Ukuba i-coefficient e inkulu ngakumbi, ubuninzi bomhlaba buba buncinci, yaye ngokuphambeneyo. Ukuba umhlaba othile ocinezelwayo uhlala phantsi komthwalo, ngokusebenzisa i-coefficient ye-porosity ngaphambi nasemva kokuhlala kunokumiselwa ubungakanani bokuhlala Δ_h_.

Masingqwalasele umaleko womhlaba ocinezelayo onobukhulu h (umz. 5_a_). Ukuba lo maleko uyathwaliswa umthwalo, uya kuhlala phantsi ngobude be Δ_h_, ukuze ubukhulu bawo ngenxa yomthwalo bunciphe bube h1. Ngoko ke

Δ_h_ = h – h1.

Ekubeni ukuhlala phantsi komhlaba ocinezelwayo kwenzeka ngeendleko zeepore, kuba amasuntswana aqinileyo phantse awacinezeleki, ngokunjalo namanzi, ukuba iipore zomhlaba zigcwele wona ngokuyinxenye okanye ngokupheleleyo, oku kuhlala phantsi kungamelwa ngokwesikimu kwi-sl. 5_b_.

Ukuhla Δh kwelayer yomhlaba ecinezelekayo enobukhulu h phantsi komthwalo

Sl. 5. Ukuhlala phantsi Δh komaleko womhlaba oxinzelekayo onobukhulu h phantsi komthwalo

Ukuba sibeka nge h0 ubude obucingelwayo boluhlu lwamasuntswana aqinileyo ngaphandle kweepore, olubizwa ngokuba lubude obuncitshisiweyo, ngoko sinokubonisa ukuhlala phantsi Δ_h_ ngokunxulumene nobude obuncitshisiweyo h0 ngolu lwalamano:

Ubudlelwane phakathi kokuzinza Δh nobude obuncitshisiweyo h₀

Ukuba sithatha umaleko womhlaba onobubanzi nobude obulingana neyunithi enye, ke ukuphakama h, h1 kunye no h0 kumela imithamo, ngoko ke

Ubudlelwane bee-coefficients zeporosity phambi nasemva kokuhlala phantsi

apho e isisiqu sobukhulu bemingxuma phambi, e1 emva kokuhlala. Koku kungentla kufunyanwa ukuhlalisa

Δ_h_ = h0 (e-e1).

Ukuzika kungachazwa ngokwawo ngokunxulumene nobude bomaleko h ngaphambi kokuzika ukuba sitshintsha ixabiso lobude obuncitshisiweyo h0:

h0 = h – nh = h (1-n) = h / (1+e),

kuba n = VP / V = VP / h_,_ apho ke VP = nh.

Ngoko ke kufumaneka

ukusuka ku 3

Iindidi ezithile zomhlaba zinezi xabiso ziphakathi zilandelayo ze-porosity n kunye ne-coefficient ye-porosity e:

Amaxabiso aphakathi eporosity kunye ne-coefficient ye-porosity ngokweentlobo zomhlaba

Ukufuma komhlaba

Iindidi zamanzi emhlabeni

Amanzi emhlabeni abonakala ngohlobo lwamanzi asezimbotsheni phakathi kweentwana eziqinileyo, oko kubizwa ngamanzi ephoro, emva koko njeng amanzi adsorbhweyithi kwiintwana eziqinileyo kunye njeng amanzi e-konstitutional.

Amanzi eepore aqulunqwa ngamanzi asimahla phakathi kwamasuntswana aqinileyo, intshukumo yawo eyenzeka ngokomthetho kaDarcy, emva koko ngamanzi omxhuzulane, ahamba phantsi kwesenzo somxhuzulane ukusuka phezulu aye ezantsi kuzo zonke iindlela, kodwa intshukumo yawo ayenziwa ngokomthetho kaDarcy, ngamanzi e-capillary ahamba phantsi kwesenzo samandla e-capillary kunye namanzi oxinzelelo lomphezulu, agcinwa ngoxinzelelo lomphezulu kwiikona phakathi kwamasuntswana omhlaba aqinileyo yaye abizwa kwakhona ngamanzi eepore asezimbombeni. Onke la manzi anokususwa ngokupheleleyo ngokomisa umhlaba kubushushu be 110oC.

Amanzi adsorbhweyithi ngawo agubungela iintwana eziqinileyo, ezibotshelelwe kuwo ngamandla eemolekyuli. Le nto ibizwa ngokuba yifilimu yamanzi, ubukhulu bayo busuka 6-80 µµ (1µµ=10-6 mm, milimikron). Impembelelo yamanzi adsorbhweyithi kwiintwana ezinkulu incinci, kodwa ukuba iintwana zincinci ngakumbi impembelelo yawo iba nkulu, kuba indawo yonke yeentwana iyanda yaye ngaloo ndlela nenxalenye yamanzi adsorbhweyithi xa ithelekiswa neentwana eziqinileyo kwiyunithi yomthamo womhlaba iyanda. La manzi anokususwa kancinci kuphela ngokomisa ku 110oC.

Amanzi e-konstitutional adityaniswe ngokwemichiza kwiikristale zeeminerali zeentwana eziqinileyo zomhlaba. Eli manzi lincinci kakhulu kwaye alinakuye lisuswe ngokomisa umhlaba. Ngoko ke eli manzi linokuthathwa njengenxalenye eyakha intwana eqinileyo.

Ubuninzi bamanzi emhlabeni

Ngokwencazelo, ubungakanani bamanzi emhlabeni okanye ukufuma komhlaba bubudlelwane phakathi kobunzima bamanzi aqulethwe emhlabeni kunye nobunzima bezinto zawo eziqinileyo. Ngokweqondo lamanzi emhlabeni kuhlukaniswa iimeko ezintathu: umhlaba ogcwele ngokupheleleyo ngamanzi, umhlaba ogcwele ngamanzi ngokungaphelelanga kunye nomhlaba owomileyo ngokupheleleyo.

Umhlaba uzaliswe ngokupheleleyo ngamanzi

Ukuba simisela n njenge-porosity yomhlaba, γs ubunzima bomthamo wazo zonke iinqununu, γw ubunzima bomthamo wamanzi, ngoko umswakama womhlaba ozele ngokupheleleyo wZ ungabonakaliswa ngale equation ilandelayo

Umlinganiselo wokufuma womhlaba ogcwele ngokupheleleyo ngamanzi

Umhlaba ugcwele amanzi ngokuyinxenye

Ukuba sibonisa ngo Ww ubunzima bamanzi aqulethwe emhlabeni, ngo Wd  ubunzima bamasuntswana aqinileyo, oko kukuthi ubunzima obomileyo bomhlaba, ngoko ke ukufuma komhlaba w

w = Ww / Wd , oko kukuthi ngepesenti zobunzima bomile bomhlaba: w = 100 Ww / Wd.

Kule meko ukufuma komhlaba kunokubonakaliswa ngedegree yokufuma Sr emele umlinganiselo wobunzima bokwenene bamanzi emhlabeni xa kuthelekiswa naloo bunzima bamanzi akulo mhlaba mnye obunokubakho ukuba onke ama-poro ayegcwele ngamanzi, oko kukuthi, xa kuthelekiswa nobunzima bamanzi omhlaba ogcwele ngamanzi:

Inxaki yenqanaba lokufuma komhlaba ongazaliswanga ngokupheleleyo

oko kukuthi, ku _γ_w = 1,00  Sr = w*γs / e.

Imida esezantsi yenqanaba lokufuma yile:

  1. kumhlaba owomileyo ngokupheleleyo w = 0; Sr = 0
  2. kuba umhlaba ugcwaliswe ngokupheleleyo w = e/γs; Sr = e/γs * γs / e = 1,0.

Isampuli yomhlaba egcwele amanzi ngokuyinxenye

Sl. 6. Isampulu yomhlaba enamanzi agcwalise inxenye

Iqondo lokuzaliseka (elithi ngamanye amaxesha likwabizwe ngokuba kukuzala okanye iqondo lokufuma) libonakaliswa nangomlinganiselo womthamo wemingxuma ezaliswe ngamanzi xa kuthelekiswa nomthamo uphela wemingxuma (sl. 6):

Sr = V2 / V1

apho V2 ingumthamo wemingxuma ezaliswe ngamanzi, V1 umthamo opheleleyo wemingxuma ezaliswe ngamanzi, umoya neegesi. Ukuba w bubumanzi bomhlaba kwi-% yobunzima obomileyo bomhlaba Wd, ngoko sinakho

V2 * γW = w Wd, apho V2 = w Wd / γw.

Kwelinye icala, sinayo ukuba V1 = V – Vd, ngoko ke njengokuba Vd * γs = Wd, ke oko kuthetha ukuba

Vd = Wd / γs kunye V1 = V – Wd / γs.

Ngoko ke, iqondo lokuzaliseka komhlaba Sr liya kuba

Isibalo se-degree yokuzaliseka komhlaba Sr

oko kukuthi ngeepesenti zobunzima obomileyo bomhlaba

Iqondo lokugcwala komhlaba Sr ngepesenti yobunzima obomileyo bomhlaba

Umhlaba womile ngokupheleleyo

Kule meko w = 0. Onke amanzi asemingxunyeni asusiwe, logama amanzi adityaniswe kumphezulu asusiwe kuphela ngokuyinxenye, oko kukuthi ifilimu yamanzi isekhona, kodwa ubukhulu bayo buncitshisiwe.