Ukuguquka komhlaba ngenxa yesithwathwa
Lapho kunomakhaza, amanzi amahhala angagelezi aqina ku-0°C futhi ngesikhathi esifanayo ande ngo-9% womthamo wawo. Nokho, amanzi emapayipini amancane e-capillary awaqini ku-0°C, kodwa aqina emazingeni okushisa aphansi, aphakathi kuka -1°C no -78°C. Leli zinga lokugcina lokuqanda latholakala ngokuhlolwa kwaselabhorethri eMelika. Uma ipayipi le-capillary lincane kakhulu, izinga lokuqanda liba phansi nakakhulu.
Enhlabathini kukhona ama-pores axhumene omunye nomunye kuzo zonke izinkomba futhi akha amapayipi e-capillary. Esihlabathini ama-pores makhulu futhi akha amapayipi e-capillary abanzi, lapho amanzi eqandeka khona ku-0°C noma ezingeni lokushisa eliphansi kancane. Amanzi aqandeka ngokulinganayo, lapho kuma-pores kwakheka amakristalu eqhwa, ukukhula kwawo komthamo ngo-9% kungabangeli noma yiziphi izinguquko ezinkulu enhlabathini. Enhlabathini enokwakheka kwezinhlayiya ezincane ama-pores mancane futhi akha amapayipi e-capillary amancane lapho amanzi eqandeka khona emazingeni okushisa angaphansi kuka-0°C. Nokho, kungqimba olungaphezulu inhlabathi ihlale ixegisiwe kakhulu inama-pores amakhulu, lapho amanzi eqandeka khona ku-0°C futhi akhe amakristalu eqhwa. Lawa makristalu adonsela amanzi apholile asuka kuma-pores amancane ngamandla amakhulu, okuthiwa amandla e-crystallization. Uma amanzi adonsiwe ngaleyo ndlela efika ekuthintaneni namakristalu eqhwa futhi nawo aqandeka, andisa umthamo wamakristalu eqhwa, abe amalensi eqhwa, ubukhulu bawo bungaba cishe 0,1 kuya ku-10 mm. Amalensi eqhwa akhiwe anobangela ukuguquka okukhulu kwenhlabathi ngesikhathi sokusebenza kweqhwa, okuthi ezimeni ezimbi kakhulu kungafinyelela ku-30 no-50 cm.
Ukwenzeka nobukhulu bokukhubazeka komhlabathi ngenxa yesenzo seqhwa kuncike ikakhulukazi kulezi 3 zinto ezilandelayo:
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Izinga lamanzi angaphansi komhlaba
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Isikhathi sokuhlala kwesithwathwa.
Ad 1) Mayelana nokwakheka kosayizi bezinhlayiya, umthelela omkhulu wesithwathwa ubonakala emhlabathini onezinhlayiya ezincane, lapho izimbobo zawo zincane ngokwanele ukuba zakhe amashubhu e-capillary amancane, kanti ngesikhathi esifanayo unokudlula kwamanzi okwanele, okuvumela ukujikeleza kwamanzi ngokushesha ngesikhathi sokusebenza kwesithwathwa. Umhlabathi onjalo usengozini kakhulu esithwathwaneni, kokubili mayelana nesivinini sokuvela kanye nobukhulu bokuguquka komumo. Lezi yizindawo ezinohlobo lwempuphu, ezakhiwa ikakhulukazi izinhlamvu ezinobukhulu 0,02-0,002 mm. Izinhlamvu ezinobukhulu >0,02 mm zinokuphakama okuncane kokukhuphuka nge-capillary, kanti izinhlamvu ezinobukhulu < 0,002 mm zinokukhuphuka kwe-capillary okuhamba kancane, ukuze kuzo zombili izimo ngesikhathi sokuhlala kwesithwathwa kungafinyelela kuphela inani elincane lamanzi endaweni ethintekayo isithwathwa. Uma umhlabathi wobumba uqukethe ngaphezu kuka-25% izinhlayiya ezinobukhulu < 0,002 mm, ukudlula kwamanzi emhlabathini kuba kuncane kakhulu futhi ukujikeleza kwamanzi ezimbotsheni kuba kancane kangangokuthi emigodini kubanda kuqala amanzi ngaphambi kokuba izingqimba zeqhwa zikhone ukuheha.
Ad 2) Ngaphezu kwemibandela mayelana nokwakheka kwe-granulometric yomhlabathi kufanele kuhlangatshezwane nenye imibandela ukuze kuvele ukukhubazeka komhlaba ngenxa yesithwathwa. Lokho ukuthi kube khona amathuba okulethwa kwamanzi endaweni yokusebenza kwesithwathwa. Uma le mibandela ibingahlangatshezwa, okungukuthi uma ama-capillari omhlabathi ebengaxhumene namanzi ayozungeza njalo kuwo ngesikhathi sokusebenza kwesithwathwa, ngeke kube khona ukukhubazeka ngenxa yesithwathwa, kungakhathaliseki ukuthi ukwakheka kwe-granulometric yomhlabathi kunjani.
Uma izinga lamanzi angaphansi komhlaba liphakeme, kuba mkhulu nethuba lokuguquka komhlabathi ngenxa yomphumela wesithwathwa. Uma izinga lamanzi angaphansi komhlaba likujula okukhulu kunokuphakama kokukhuphuka kwekapilari kwamanzi alolo hlobo lomhlabathi, ukuguquka ngenxa yomphumela wesithwathwa kuba kuncane kakhulu.
Ad 3) Uma isikhathi sokuhlala okuqhubekayo kwesithwathwa side, kuba mkhulu ukuguquka okubangelwa isithwathwa, ngenxa yokwakheka kwama-lens amakhulu amaningi. Isithwathwa esinamandla nesesikhashana sibangela ukuguquka okuncane, ngoba kuleso simo kwenzeka ukuqhwa ngokushesha kwamanzi ezikhala kanye nokuphazamiseka kokugeleza kwamanzi nge-capillary. Ngokuphambene nalokho, isithwathwa esimaphakathi nesesikhathi eside sibangela ukuguquka okukhulu ngenxa yokwakheka okungavinjelwe kwama-lens eqhwa.
Umthelela wokukhipha ubisi lwenkomo
Ngesikhathi sokuncibilika kwenhlabathi eqandisiwe, kuqala kuncibilika ama-lens eqhwa engxenyeni engenhla yomhlabathi ongaphezulu, kanti ngaphansi kwayo kusala ungqimba oluqandisiwe, ngakho-ke olungangenisi amanzi. Njengoba ama-lens eqhwa ancibilikile ekhipha inani elikhulu lamanzi, angakwazi ukungena ngesendlalelo esingezansi esiqandisiwe, lesi samba esandisiwe samanzi engxenyeni engaphezulu sigcwalisa umhlaba ngokweqile futhi sibe isisindo esiwuketshezi, esingenawo nhlobo amandla, kodwa esikhishwa eceleni ngaphansi kwengcindezi. Ukuguquka komhlabathi ngenxa yokuncibilika kungaba kukhulu futhi kwezinye izimo kube yingozi. Lokhu kuguquka kuvamile emigedeni emathafeni ezitimela nasezindleleni, lapho entwasahlobo kuba nokushelela kancane kwemithambeka ngenxa yokugcwala komhlabathi ngamanzi avela ema-lens eqhwa ancibilikile, kanye nasezindleleni, lapho imigwaqo yakhona iguquka ngaphansi kwethrafikhi emhlabathini olahlekelwe amandla okuthwala ngenxa yokugcwala ngamanzi.
Indlela yokuhlola umphumela wesithwathwa emhlabathini
Ngokucwaninga umthelela wesithwathwa ezinhlotsheni ezahlukene zenhlabathi kwafinyelelwa esiphethweni sokuthi mayelana nokuziphatha esithwathweni kufanele kuhlukaniswe izinhlobo ezimbili zenhlabathi: eziphephile nezisengozini esithwathweni.
Inhlabathi ephephile emakhazeni yilezo lapho kungakhiwa khona izinsika zeqhwa, noma ngabe isikhathi seqhwa side kangakanani. Kule hlobo lomhlabathi kuba kuphela ukubanda kwamanzi emaqandeni ayo nokwakheka kwamakristalu eqhwa, ngokuguquka okuncane lapho kuhlasela iqhwa. Kuleli qembu kungena amatshe amancane, isihlabathi kanye nenhlabathi efana naleyo.
Inhlabathi eyingozi ngenxa yesithwathwa yilena lapho kwakheka khona izindilinga zeqhwa, ngenxa yalokho okungavela ukukhubazeka okukhulu. Amanzi anqwabelene ungqimbeni olungaphezulu ngendlela yezindilinga zeqhwa ngesikhathi sokusebenza kwesithwathwa aphinde adale nomphumela wokuncibilikisa isithwathwa. Kuleli qembu kungena inhlabathi ethile enothuli nobumba, ikakhulukazi inhlabathi enothuli.
Kukhona imibandela eminingana yokuhlola ukumelana komhlabathi eqhweni, kanti eyaziwa kakhulu yileyo ka-Arthur Casagrande noRukli, esizoyichaza lapha.
Umgomo ka-A. Casagrande
Lo mbandela usekelwe ekwakhekeni kwe-granulometric komhlabathi futhi uthi:
a) Ezweni elinesakhiwo esifana, elinezinga lokungalingani U < 5, inhlabathi iba sengozini yesithwathwa uma iqukethe ngaphezu kuka-10% wezihlabathi ezinobukhulu obungaphansi kuka-0,02 mm.
b) Emhlabathini onezingxenye ezingalingani, lapho izinga lokungalingani U > 15, umhlabathi uyingozi eqhweni uma uqukethe ngaphezu kuka-3% kwezinhlamvu ezinosayizi ongaphansi kuka-0,02 mm.
Nakuba le nqubo yasetshenziswa isikhathi eside futhi yahlale inikeza imiphumela ethembekile, ukushoda kwayo ukuthi isekelwe kuphela ku-granulometry yenhlabathi futhi ayicabangi nezinye izici ezinethonya ekusebenzeni kwesithwathwa enhlabathini. Ngenxa yalokho namuhla kubhekwa ukuthi le nqubo iqine kakhulu futhi ayinawo umnotho.
Umgomo kaRukliev
Ngale ndlela inhlabathi ihlukaniswa ibe izingxenye ezimbili ngokokuqina kwezinhlayiya eziqinile, okungukuthi ingxenye enezinhlayiya ezinkulu, ezinobubanzi d > 2 mm kanye nengxenye enezinhlayiya ezincane, ezinobubanzi d < 2 mm. Ukuze kuhlolwe ukuzinza kwenhlabathi ekubandeni, kusungulwa ubudlelwano phakathi kwenani lengxenye enezinhlayiya ezincane nenani lengxenye enezinhlayiya ezinkulu futhi lobu budlelwano bunikezwa ngomngcele ongezansi kanye nowaphezulu (sl. 1).
Umkhawulo ophansi umele iphesenti eliphezulu elivunyelwe lezinhlayiya eziqinile ezinobubanzi d < 0,02 mm lwesisindo esomile sokugcwaliswa, okungukuthi ingxenye 0-2 mm, lapho ngokuyisisekelo zingaveli khona nhlobo umonakalo ngenxa yesithwathwa ngaphansi kwezimo ezingezinhle, njengamazinga aphezulu amanzi angaphansi komhlaba, izimo zezulu ezingezinhle (isithwathwa esihlala isikhathi eside) kanye nomswakama omkhulu wemvelo womhlabathi.
Umkhawulo ongaphezulu umelela iphesenti elikhulu elivumelekile lezinhlayiya d < 0,02 mm ngokwesisindo esomile sengxenye enohlamvu oluhle, lapho kungenzeki khona, cishe, noma yimuphi umonakalo ngenxa yesithwathwa ngaphansi kwezimo ezivumayo, njengokuthi izinga eliphansi lamanzi angaphansi komhlaba, izimo zezulu ezivumayo (izithwathwa zesikhashana) kanye nomswakama omncane wemvelo womhlabathi.
Umfan. 1 Umngcele ophansi nowaphezulu wokuhlola ingozi yomhlabathi eqhweni ngokwenqubo kaRukl
Ukuvikelwa emandleni esithwathwa emhlabathini
Ukujula komthelela wesithwathwa emhlabathini kuncike ezimweni zezulu zendawo. Ezweni lakithi kuvame ukuba 0,8 kuya ku 1,0 m ngaphansi kobuso bomhlaba. Ngakho-ke, izakhiwo ezisungulwe ekujuleni okulingana noma okukhulu kune 1,0 m ngeke zithonywe isithwathwa.
Izakhiwo ezinesisekelo esingashoni njengamaphasi emigwaqweni, zibhekene nomthelela wesithwathwa, ongabangela ukuguquka okukhulu nokonakala emgwaqweni, kokubili ngesikhathi sokubanda nangesikhathi sokuncibilika. Ngakho-ke lapho kwakhiwa amaphasi emigwaqweni nasemizileni yokundiza ezikhumulweni zezindiza, kudingeka kuhlolwe inhlabathi mayelana nomthelela wesithwathwa futhi uma inhlabathi yesisekelo iyingozi ekuqandeni, kufanele kuthathwe izinyathelo zokuzivikela. Emaphasini emigwaqo nasezikhumulweni zezindiza isinyathelo esisebenza kakhulu ukwakha ungqimba lwe-buffer, ubukhulu balo obunqunywa ngendlela yokuthi ubukhulu obuphelele bephasi kanye nongqimba lwe-buffer bube 0,80 m kuthrafikhi enzima kuya ku 0,60 m kuthrafikhi elula. Imvamisa ubukhulu bongqimba lwe-buffer 0,30 m ngaphansi kwephasi buyisivikelo esanele emandleni esithwathwa.
Impahla yokwenza ungqimba lwe-tampon obujwayelekile iwubhuqu noma amatshe amancane anesihlabathi, okufanele ahlangabezane nale mibandela elandelayo:
Inkomba yepulasitiki IP < 5
Okuqukethwe kwengxenye d < 0,02 mm kungaphansi kuka 3%
Ileveli yokungalingani U > 7.
Ingxenye engaphezulu yongqimba lwe-buffer enobukhulu obungu-20 cm akumele ibe yisihlabathi esifana ngokufanayo nesincane kakhulu ngenxa yokungacindezeleki kahle nokuthwala okulinganiselwe. Kule ngxenye, ungqimba lwe-buffer kufanele lube yitshe elincane elinesihlabathi elino-30-70% wosayizi wezicucu 2-30 mm. Izicucu ezinkulu kuno-30 mm azinconywa.
Izindonga zocingo ezisungulwe zingajulile nazo zithonywa isithwathwa emhlabathini, ngenxa yalokho zithambekele, okuthi lapho isithwathwa siphindaphinda ngokuhamba kwesikhathi kuholele ekugingqikeni nasekudilikeni kwazo. Ngakho-ke lezi zidonga kufanele zisungulwe ekujuleni kwe-1,0 m, uma inhlabathi isengozini yesithwathwa.