Kukuvadzwa kwevhu nekuda kwechando
Pakuitika kwechando, mvura yakasununguka isina kufamba inooma pa0°C uye panguva iyoyo inowedzera ne9% yevhoriyamu yayo. Zvisinei, mvura iri mumachubhu madiki ecapillary haiome pa0°C, asi pa tembiricha dzakaderera, dziri pakati pe-1°C ne-78°C. Tembiricha iyi yekupedzisira yekuoma yakasimbiswa nemiedzo yerabhoritari muAmerica. Kana chubhu yecapillary iri nhete, tembiricha yekuoma inowedzera kuderera.
Muvhu mune maporesi akabatana pakati pawo munzira dzose uye anoita machubhu emakapilari. Mujecha maporesi makuru uye anoita machubhu akafara emakapilari, umo mvura inooma nechando pa0°C kana patembiricha yakaderera zvishoma. Mvura inooma zvakaenzana, uye mumaporesi mune makristaro echando anoumbwa, kuwedzera kwawo kwevhoriyamu ne9% hakukonzere kukanganisika kukuru kwevhu. Muvhu rine zvimedu zviduku maporesi maduku uye anoita machubhu akatetepa emakapilari umo mvura inooma nechando patembiricha yakaderera kupfuura 0°C. Zvisinei, muchikamu chepamusoro chepasi ivhu rinogara rakasununguka zvikuru riine maporesi makuru, umo mvura inooma nechando pa0°C uye ichigadzira makristaro echando. Makristaro aya anokwezva mvura inotonhora kubva mumaporesi matete nesimba guru, rinonzi kristalizaciona sila. Kana mvura yakadaro yakakwezvwa yasvika pakubatana nemakristaro echando uye yacho yakatonhora zvakare ichiwedzera vhoriyamu yamakristaro echando, anova maiced lens, ukobvu hwawo hunogona kuva angangoita 0,1 kusvika 10 mm. Maiced lens aya anokonzera kukanganisika kukuru kwevhu panguva yechando, uko pasi pemamiriro akaipa zvikuru kunogona kusvika ku30 ne50 cm.
Kuitika uye ukuru hwekushanduka kwevhu nekuda kwechando zvinonyanya kuenderana nezvinhu 3 zvinotevera:
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Mwero wemvura yepasi pevhu
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Nguva yekugara kwechando.
Ad 1) Panyaya yekuumbwa kwezviyo, mhedzisiro huru yechando inowanikwa muvhu rinezvimedu zvidiki, rine maburi anokwana kuumba makapilari akatetepa, uye panguva imwe chete rine kukwanisa kupinza mvura kwakakwana, kunobvumira kutenderera kwemvura nekukurumidza panguva yekushanda kwechando. Ivhu rakadaro ndirwo runonyanya kunetseka nechando, zvose panyaya yekukurumidza kuoneka uye panyaya yehukuru hwekukanganisika. Aya ndiwo ivhu rine guruva, rinoumbwa zvikuru nezviyo zvine saizi 0,02-0,002 mm. Zviyo zvine saizi >0,02 mm zvine kukwirira kuduku kwekukwira kwekapilari, nepo zviyo zvine saizi < 0,002 mm zvichikwira zvishoma nekapilari, zvichiita kuti muzviitiko zviviri izvi panguva yechando huwandu huduku chete hwemvura hugone kusvika munzvimbo inobatwa nechando. Kana ivhu revhu rine kupfuura 25% zvimedu zvine saizi < 0,002 mm, kupinza kwemvura muvhu kunenge kushoma zvikuru uye kutenderera kwemvura mumaburi kunononoka zvekuti mvura iri mumaburi inotanga kuita chando isati yatorwa nemaziso echando.
Ad 2) Kunze kwechikonzero chine chekuita nekugadzirwa kwehukuru hwezvimedu zvevhu, panofanira kuzadzikiswa chimwe chimiro kuti pave nekuchinja kwevhu pakunaya chando. Ndicho kuti pave nemukana wekupihwa mvura kunzvimbo inobatwa nechando. Kana chimiro ichi chisina kuzadzikiswa, kureva kuti kana macapillary evhu asina kubatana nemvura inenge ichigara ichiyerera maari panguva yekuita kwechando, hapazovi nekuchinja kwevhu pakunaya chando, zvisinei nekuti kugadzirwa kwehukuru hwezvimedu zvevhu kwakadini.
Kana mwero wemvura yepasi pevhu wakakwirira, ndipo panowedzera mukana wekukanganisika kwevhu nekuda kwechiito chechando. Kana mwero wemvura yepasi pevhu uri pakadzika kupfuura kukwira kwecapillary kwemvura yevhu iroro, kukanganisika kunokonzerwa nechando kunenge kushoma.
Ad 3) Kana nguva inoenderera mberi yechando yakareba, deformasions dzinokonzerwa nechando dzinova huru, nekuda kwekuumbwa kwemalens makuru uye mazhinji. Chando chakanyanya uye chipfupi chinokonzeresa deformasions shoma, nokuti mumamiriro akadaro mvura iri mumapores inotonhora nokukurumidza uye kuyerera kwecapillary kwemvura kunomira. Kusiyana nazvo, chando chepakati uye chinogara kwenguva refu chinokonzeresa deformasions huru nekuda kwekuumbwa kusina kuvharidzirwa kwemalens echando.
Mhedzisiro yekusunungura kubva kubviro
Pakunyunguduka kwechando, kutanga macores echando ari pamusoro pevhu repamusoro anonyunguduka, asi ipapo pazasi paro panoramba paine rukoko rwakaoma nechando, saka harupfuuri mvura. Sezvo macores echando anonyunguduka achiburitsa huwandu hukuru hwemvura, husingakwanisi kupinda nepamurukoko rwepasi rwakaoma nechando, huwandu hwemvura uhu hunowedzera hunozadza vhu remusoro nemvura kusvika rawandisa uye rwogadzira ruremu rwemvura, rusingachina kusimba kupi nokupi, asi runosvinwa parutivi pasi pekumanikidzwa. Kukuvadzwa kwevhu nekuda kwekuita kwekunyunguduka kwechando kunogona kuve kukuru uye mune dzimwe nguva kune ngozi. Kukuvadzwa uku kunowanzoitika mumakomba ezvitima nemumigwagwa, uko muchirimo kunoitika kutsvedza kwechidimbu kwemateru nekuda kwekuzara kwevhu nemvura kubva kumacores echando akanyunguduka, pamwe nemumigwagwa, umo migwagwa inochinjika pasi pekufamba kwemotokari pavhu rakarasa kutakura mutoro nekuda kwekuzara nemvura.
Chiyero chekuyera kukanganisa kwechando pavhu
Kuburikidza nekudzidza kushanda kwechando pamhando dzakasiyana dzevhu, kwakawanikwa mhedziso yokuti maererano nemaitiro acho muchando panofanira kusiyaniswa mhando mbiri dzevhu: rakachengeteka uye rine ngozi muchando.
Ivhu risingakuvadzwi nechando ndiro rinenge risingaumbi mazaya echando, zvisinei nekuti nguva yechando yakareba sei. Muvhu remhando iyi kungovapo kwekuzara kwechando mumapores aro uye kuumbwa kwemakristasi echando, iine kushanduka kudiki pakuitika kwechando. Muboka iri munosanganisirwa matombo madiki, jecha uye ivhu rakafanana naro.
Ivhu rinokuvadza nechando ndiro iro mune rinoumbwa marinse echando, zvichikonzera kuti kuumbike kuremara kukuru. Mvura yakaunganidzwa muchikamu chepamusoro iri muchimiro chemarinse echando panguva yekuita kwechando inoburitsawo chiito chekunyungudutsa. Muboka iri munosanganisirwa mamwe mavhu ane guruva-nevhu, zvikurusei mavhu ane guruva.
Pane nzira dzakawanda dzekuongorora kusagadzikana kwevhu nechando, pakati padzo dzinonyanya kuzivikanwa nzira dzaArthur Casagrande naRukl, dzatichatsanangura pano.
Maitiro aA. Casagrande
Chimiro ichi chinobva pakuumbwa kwezviyo zvevhu uye chinoti:
a) Kana iri ivhu remhando yakafanana, rine mwero wekusaenzana U < 5, ivhu rinenjodzi nechando kana rine zvinopfuura 10% zviyo zvehukuru huri pasi pe0,02 mm.
b) Panyaya yevhu rine kusarongeka kwekuumbwa, iro dhigirii rekusarongeka U > 15, ivhu rine ngozi nechando kana rine kupfuura 3% kwezvimedu zvine saizi iri pasi pe0,02 mm.
Kunyange hazvo chiyero ichi chakashandiswa kwenguva refu uye chichigara chichipa mhedzisiro yakavimbika, kushomeka kwacho kuri pakuti chinotsamira chete pagranulation yevhu uye hachifungi nezvimwe zvinhu zvinokanganisa kuita kwechando muvhu. Nokuda kweizvozvo nhasi zvinofungidzirwa kuti chiyero ichi chakanyanya kuomarara uye hachibatsiri pakudzika kwemari.
Rukliev kriteria
Maererano nenzira iyi, ivhu rinopatsanurwa kuva zvikamu zviviri maererano nekuoma kwezvimedu zvakasimba, kureva chikamu chezvimedu zvakakora, zvine dhayamita d > 2 mm uye chikamu chezvimedu zvakatetepa, zvine dhayamita d < 2 mm. Kuti kuongororwe kusimba kwevhu pakubatwa nechando, kuwirirana kuri pakati pehuwandu hwechikamu chezvimedu zvakatetepa nehuwandu hwechikamu chezvimedu zvakakora kunoiswa, uye kuwirirana uku kunopiwa nemuganhu wepasi nepamusoro (fig. 1).
Muganhu wepasi unomirira chikamu chikuru chinotenderwa chezvimedu zvakaoma zvine dhayamita d < 0,02 mm cheuremu hwakaoma hwekuzadza, kureva chikamu che0-2 mm, pakusina kukuvadza kunenge kusiri kuitika nekuda kwechando pasi pemamiriro akaipa, akadai semvura yepamusoro yepasi pevhu yakakwira, mamiriro ekunze asina kunaka (chando chinogara kwenguva refu) uye hunyoro hukuru hwepanyama hwevhu.
Muganhu wepamusoro unomirira chikamu chikuru chinotenderwa chezvimedu d < 0,02 mm chiri muuremu hwakaoma hwechikamu chezviyo zvakanaka, uko kusina kana kukuvadzwa kunooneka kunokonzerwa nechando pasi pemamiriro akanaka, akadai sekuderera kwemvura yepasi, mamiriro ekunze akanaka (chando chipfupi) uye hunyoro hwepanyama hwevhu hushoma.
Sl. 1 Muganho wepasi nepamusoro wekuongorora ngozi yevhu pachando maererano nechiyero chaRukliev
Kudzivirira kubva pakuita kwechando muvhu
Kudzika kwekuita kwemazaya muvhu kunoenderana nemamiriro ekunze enharaunda. Munyika yedu kazhinji kuri 0,8 kusvika 1,0 m pasi pechiso chepasi. Naizvozvo, zvivakwa zvakavambwa pakadzika inoenzana kana kupfuura 1,0 m hazvizokanganiswi nemazaya.
Zvivako zvine nheyo dzisina kudzika, zvakadai semigwagwa inofambwa nemotokari, zvinobatwa nechando, chinogona kukonzera kushanduka kukuru uye kukuvadzwa kwepavhimenti, zvose pakutonhora uye pakunyunguduka. Naizvozvo pakugadzira pavhimenti pamigwagwa uye pamapista ekusimuka nekumhara panhandare dzenhandare dzendege, zvinodiwa kuongorora ivhu maererano nekubata nechando uye kana ivhu renheyo richinetsa nechando, matanho ekudzivirira anofanira kutorwa. Panhengo dzemigwagwa nemanhandare, chiyero chinoshanda zvikuru kugadzirwa kwechikamu chebuffer, ukobvu hwacho hunotsanangurwa zvekuti ukobvu hwose hwepavhimenti pamwe nechikamu chebuffer huve 0,80 m yemutoro unorema kusvika 0,60 m yemutoro wakareruka. Kazhinji ukobvu hwechikamu chebuffer hwe 0,30 m pasi pepavhimenti hunokwana kudzivirira kubatwa nechando.
Zvinhu zvekugadzira rukoko rwetamponi kazhinji jecha kana matombo ane jecha, izvo zvinofanira kusangana nemitemo inotevera:
Indekisi yeplastisiti IP < 5
Zviri mukati mefrakisheni d < 0,02 mm zvishoma pane 3%
Chiyero chekusaenzana U > 7.
Chikamu chepamusoro chechikamu chepadding, chine ukobvu hwe 20 cm, hachifaniri kuva jecha rinenge rakafanana uye rakatsetseka nokuda kwekusakwana kwekusimbiswa uye kutakura mutoro kushoma. Muchikamu chino, padding inofanira kuva jecha rakasanganiswa nematombo madiki rine 30-70% yezviyo saizi 2-30 mm. Zviyo zvikuru kupfuura 30 mm hazvikurudzirwi.
Masvingo efenzi akavakirwa padiki zvakare anobatwa nechando chiri muvhu, zvichiita kuti avimbe, izvo pakudzokororwa kwechando nekufamba kwenguva zvinozoguma nekupidiguka nekudonha kwawo. Naizvozvo masvingo aya anofanira kuvakwazve pa1,0 m kudzika, kana ivhu richiva nenjodzi yechando.