Rashin Kogin

Rashin nasarar banki kogi na iya haifar da lokacin da dakarun da ke aiki a kan banki suka wuce dakarun wanda ke riƙe da laka tare. Rashin ya dogara da nau'in laka, shimfidawa, da abun ciki na danshi.

YDukkanin koguna suna fuskantar satar-linkid="11" href="./Erosion" id="mwFA" rel="mw:WikiLink" title="Erosion">rushewa, amma gazawar ya dogara da wurin da kuma yawan abin da rushewa ke faruwa. Rashin bankin kogi na iya haifar da sanya gida, cikawar ruwa, nauyi a bakin kogi, ciyayi, da / ko aikin tectonic. Lokacin da aka gina gine-gine kusa da bakin kogin, nauyin su na iya wuce nauyin da bankin zai iya riƙewa kuma ya haifar da raguwa, ko hanzarta raguwa wanda zai iya kasancewa mai aiki. Ƙara ga waɗannan damuwa na iya ƙara saturation wanda ya haifar da ban ruwa da septics, wanda ke rage ƙarfin ƙasa. Duk da yake tsire-tsire masu zurfi na iya kara ƙarfin kogin kogin, maye gurbin da ciyawa da tsire-shire masu zurfin zai iya raunana ƙasa. Kasancewar ciyawa da Hanyoyin motsa jiki na kankare suna mai da hankali kan kogin, suna kara raunana shi. Tushen da tsarin suna kara kara damuwa. Kodayake kowane yanayin gazawar an bayyana shi a sarari, bincike kan nau'ikan ƙasa, abun da ke cikin banki, da muhalli dole ne a bayyana shi a fili don kafa yanayin gazawar, wanda nau'ikan da yawa zasu iya kasancewa a wannan yanki a lokuta daban-daban. Da zarar an rarraba gazawar, ana iya ɗaukar matakai don hana ci gaba da rushewa. Idan gazawar tectonic ta kasance a cikin kuskure, bincike game da tasirinsa na iya taimakawa wajen fahimtar tsarin alluvial da martani ga damuwa daban-daban.

## Bayyanawa
Ana iya raba bakin kogi zuwa yankuna uku: Yankin yatsan hannu, Yankin banki, da Yankin kan iyaka. Yankin yatsan hannu shine yankin da ya fi saukin lalacewa. Saboda yana tsakanin matakin ruwa na yau da kullun da matakin ruwa mai ƙarancin ruwa, yana da tasiri sosai ta hanyar raƙuman ruwa da abubuwan da suka faru. Yankin banki yana sama da matakin ruwa mai girma na yau da kullun, amma har yanzu ana iya yin sa'a ta hanyar ruwa, kuma yana samun mafi yawan zirga-zirgar mutane da dabbobi. Yankin overbank yana cikin ƙasa na duka yatsunsu da yankunan banki, kuma ana iya rarraba shi a matsayin ko dai ambaliyar ruwa ko bluff, dangane da gangarensa. Bankin kogi zai amsa ga aikin rushewa bisa ga halaye na kayan banki. Mafi yawan nau'in banki shine banki mai sassauci ko sassauci, wanda ya ƙunshi yadudduka marasa haɗin kai da aka haɗa da yadudduka masu haɗin kai. Idan ƙasa mai haɗin kai tana kan yatsun bankin, zai sarrafa yawan koma baya na Layer ɗin da ke sama. Idan ƙasa marar haɗin kai tana kan yatsun banki, waɗannan yadudduka ba a kare su da yadudduka na ƙasa mai haɗin kai. Bankin Bedrock yawanci yana da kwanciyar hankali sosai kuma zai fuskanci lalacewa a hankali. Bankin da ke da haɗin kai yana da saukin kamuwa da rushewa a lokutan rage matakan ruwa saboda ƙarancin ƙarancin ruwa. Rashin nasara a cikin ƙasa mai haɗin kai zai kasance a cikin juyawa ko faɗin gazawar ƙasa, yayin da a cikin ƙasa marar haɗin kai gazawar zai kasance a hanyar avalanche.

## Hanyoyin gazawar

### Rashin nasarar da aka haifar da ruwa
Hanyoyin hydraulic a ko a ƙasa da saman ruwa na iya haifar da turɓaya kuma kai tsaye ya haifar da rushewa. Bankunan da ba su da haɗin kai musamman suna da rauni ga irin wannan gazawar, saboda raguwar banki, lalacewar gado, da tsabtace basal.

Rugujewar yatsan ruwa tana faruwa ne lokacin da kwarara ke cikin jagorancin banki a karkatar kogi kuma mafi girman saurin yana a gefen waje da zurfin tsakiyar ruwa. Sojojin centrifugal suna ɗaga tsawo na ruwa don ya zama mafi girma a kan karkatar waje, kuma yayin da nauyi ke jan ruwa zuwa ƙasa, juyawa, juzu'i mai juyawa yana faruwa, tare da saurin saurin ƙasa akan bankin (ƙarfin rushewa).  Zai zama mafi girma a cikin ƙuƙwalwa mai ƙarfi. Mafi munin rushewa zai kasance nan da nan a cikin ruwa daga ma'anar matsakaicin curvature. A lokuta tare da yadudduka marasa haɗin kai, raƙuman ruwa suna cire kayan kuma suna ƙirƙirar cantilever overhang na kayan haɗin kai. Shear ya wuce mahimmancin shear a yatsan banki, kuma barbashi suna lalacewa. Wannan ya haifar da raguwa wanda ya haifar da koma baya da gazawar banki.

### Rashin nasarar geotechnical
Rashin nasarar geotechnical yawanci yana faruwa ne saboda damuwa a kan bankin wanda ya wuce ƙarfin da bankin zai iya karɓa. Ɗaya daga cikin misalai shine wuce gona da iri na bankin bayan saukar da matakin ruwa daga ambaliyar ruwa zuwa matakan banki na yau da kullun. Matsin ruwa mai tsabta a cikin bankin da ya cika yana rage Ƙarfin shear na ƙasa kuma yana ƙara ƙarfin zamewa. Irin wannan gazawar ya fi yawa a cikin ƙasa mai kyau saboda ba za su iya zubar da ruwa da sauri kamar ƙasa mai laushi ba. Ana iya jaddada wannan idan bankunan sun riga sun lalace saboda lalacewar yashi mara haɗin kai, wanda ke lalata kayan banki kuma yana haifar da rushewar banki. Idan bankin ya fallasa daskarewa, fashewar tashin hankali na iya haifar da gazawar banki. Rashin ruwa na ƙasa yana raunana shear na ciki. Ayyukan capillary na iya rage kusurwar hutawa na bankin zuwa ƙasa da gangaren banki na yanzu. Wannan yana ƙara gangaren kuma yana iya haifar da rushewa lokacin da ƙasa ta bushe.

Rashin fashewar bututu na iya faruwa lokacin da matsin ruwa mai zurfi ya karu, da kuma yawan kwarara. Wannan yana haifar da rushewar wani ɓangare na bankin. Rashin nasara yawanci saboda zaɓaɓɓen ruwan ƙasa ne tare da yadudduka masu cike da juna a cikin kogin kogin da aka shimfiɗa, tare da ruwan tabarau na yashi da kayan aiki mai laushi a tsakanin yadudduka na kayan haɗin kai.

### Rashin nasarar tectonic
Canje-canje a cikin gangaren kwarin na iya rinjayar koguna, wanda zai iya faruwa saboda tectonics. Wannan na iya haifar da gazawar bakin kogi, wanda ke haifar da haɗari ga mutanen da ke zaune kusa da kogi da kuma tsarin kamar gadoji, bututun mai, da ƙetare wutar lantarki. Duk da yake manyan koguna masu saurin gudana ya kamata su kula da hanyoyin su na asali, ƙananan gradients suna haifar da tasirin da canje-canjen gangara suka fi girma. Rashin nasarar banki sakamakon tectonics na iya haifar da avulsion, inda kogi ya watsar da tashar kogi don neman sabon. Avulsion saboda tectonics ya fi yawa a cikin koguna da ke fuskantar matsayi mai girma, wanda gazawar banki ya haifar da asarar raƙuman ruwa saboda liquefication da karyewa daga girgizar ƙasa.

### Rashin ƙarfin maganaɗiso
**Rashin nasara** nauyi ya haɗa da zane-zane masu zurfi da juyawa, gazawar slab da cantilever, da kuma yaduwar ƙasa da yaduwar bushe. Shirin cire turɓaya ne da farko daga banki mai haɗin kai da jigilar shi ta hanyar kogi. Rashin daidaituwa yana faruwa inda wani nau'i na kayan ke motsawa tare da jiragen sama a layi daya da saman banki. Rashin nasara ya dace da ƙasa tare da ƙananan haɗin kai, kuma yana faruwa lokacin da kusurwar bankin ta wuce kusurwar rikice-rikice na ciki. Ana tilasta ƙananan tubalan matsakaici a ko kusa da tushe na bakin kogi saboda matsin ruwa mai yawa da overburden. Gilashin kayan da ke cikin rabin bankin zai fadi, yana barin rami mai kama da alcove. Rashin nasara yawanci yana da alaƙa da bankunan da ke da tsayi da kayan banki masu tsayi waɗanda ke ba da damar haɓaka matsin ruwa mai kyau da tsinkaye mai ƙarfi a cikin tsari. Rashin nasarar Popout shine lokacin da aka tilasta ƙananan tubalan matsakaici a ko kusa da tushe na bakin kogi saboda matsin ruwa mai yawa da overburden. Gilashin kayan da ke cikin rabin bankin zai fadi, yana barin rami mai kama da alcove. Rashin nasara yawanci yana da alaƙa da bankunan da ke da tsayi da kayan banki masu tsayi waɗanda ke ba da damar haɓaka matsin ruwa mai kyau da tsinkaye mai ƙarfi a cikin tsari. Ana tilasta ƙananan tubalan matsakaici a, ko kusa da tushe na bakin kogi saboda matsin ruwa mai yawa da overburden.

Rashin nasarar Slab shine zamewa da gaba da rushewar taro mai zurfi a cikin kogin. Rashin nasara yana da alaƙa da tsawo, ƙananan tsawo, bankunan da ke da alaƙa kuma suna faruwa a lokacin yanayin ƙarancin ruwa. Su ne sakamakon haɗuwa da ƙura a yatsan banki, matsin ruwa mai ƙarfi a cikin kayan banki, da tsagewa a saman bankin.

Rashin nasarar Cantilever yana faruwa ne lokacin da tubalan da ke kan tudu suka rushe cikin tashar. Rashin nasara sau da yawa yana faruwa bayan bankin ya sami raguwa. Rashin nasara yawanci yana cikin abun da ke tattare da kayan hatsi mai kyau da mai laushi, kuma yana aiki a lokacin yanayin low flow.

Rashin nasarar da aka haifar ta hanyar bushewar granular yawanci yana faruwa a kan bankunan da ba su da haɗin kai a, ko kusa da, kusurwar hutawa, waɗanda aka yanke su. Wannan yana ƙara kusurwar banki na gida sama da kusurwar friction, kuma hatsi na mutum yana juyawa, zamewa, kuma ya sauka a bankin a cikin Layer. Tattara yawanci yana faruwa a yatsan hannu.

Rashin ruwa yana faruwa inda asarar ƙarfin wani sashi na banki saboda saturating yana ƙara nauyin bankin kuma yana rage ƙarfin kayan banki don ƙasa ta gudana a matsayin ruwa mai tsami. Irin wannan gazawar yawanci yana faruwa a kan bankunan ƙananan kusurwa kuma kayan da abin ya shafa yana gudana a bankin don samar da lobes na kayan a yatsan hannu.

Rashin fashewar fashewa yana faruwa ne sakamakon fashewar tashin hankali a cikin overhang, kuma yana faruwa ne kawai lokacin da ƙananan ɓangaren toshewar overhang ya kasa tare da kusan farfajiyar gazawar kwance.

## Misalan

### 1811-1812 Girgizar kasa ta New Madrid
Girgizar ƙasa ta 1811-12 ta New Madrid ta haifar da girgizar ƙasa a kan Kogin Mississippi, kuma tana wakiltar gazawar banki da aikin tectonic ya haifar a cikin New Madrid Seismic Zone (NMSZ).  NMSZ shine sakamakon tsarin rift da ya gaza wanda ya kasance mai rauni a yau, kuma saboda haka yana da saurin lalacewa da aikin girgizar ƙasa. Girgizar ƙasa ta haifar da gazawar banki nan take, inda bankunan saman suka fadi sama da ƙasa da saman ruwa, suna haifar da kumbura mai girma don nutse jirgin ruwa. Wasu kumbura sun samo asali ne daga turɓaya da ke fadawa cikin kogi, amma a wasu lokuta kumbura da kansu suna buga bankunan sun sa manyan yankuna na bankunan Mississippi su faɗi a lokaci guda. An ga ruwan Mississippi yana gudana baya, saboda girgizar kasa ta haifar. An gabatar da adadi mai yawa na laka a cikin kogi. An ga kogon banki har zuwa Memphis, Tennessee. Kayan aiki na tsaye na iya zama tushen farko na rikici, kodayake ɗan gajeren lokaci.

### Rashin bankin Arewa maso Yammacin Minnesota

Rashin nasarar banki ya kasance a kan Kogin Red da masu goyon bayansa. An haifar da shi ta hanyar rushewa kuma yana wakiltar raguwa. Rashin nasara yana faruwa a wannan yanki saboda kogin kogin sun hada da yumɓu, saboda lalacewar glacial da tafkin, sabanin mafi yawan tsaunuka masu tsayayya kamar yashi ko dutse. Mafi yawanci, raguwa ya wanzu a cikin Sherack Formation, wanda ke zaune a kan wani tsari mara ƙwarewa da ake kira Huot da Brenna Formations .  Sherack Formation ya ƙunshi yumbu da yumbu laminations, yayin da Brenna ajiyar yumbu ce. Wadannan ƙananan tsari sun bayyana lokacin da kwarin kogin ya rushe Sherack Formation. Har ila yau, fashewa na iya samuwa a cikin Sherack Formation, yana haifar da rauni a cikin yumɓu mai zurfi, da raguwa. Saduwar da aka fallasa tsakanin tsari (yawanci a yankin Red River), kuma ta haka ne raunin da ke tattare da wannan hulɗa, yana haifar da lalacewar kogin. Ayyukan ɗan adam kusa da bakin kogin suna ƙara haɗarin gazawar. Saboda wannan tsangwama ta mutum, mafi kyawun yanayin kogi shine guje wa ɗorawa mara amfani kusa da kogi da kuma inganta wayar da kan jama'a game da batutuwan da ke haifar da gazawar. Lokacin da gazawar ta faru, fahimtar sigogi na geotechnical na gangaren ya zama dole, kuma sune mafi yawan dogaro da su don fahimtar ainihin abubuwan da suka haifar. Ana iya cim ma wannan ta hanyar samun dabi'u don iyakar filastik da iyakar ruwa na ƙasa.

Har ila yau, abin sha'awa shine hulɗar tsakanin rafi da gudummawar sediment. Kogin Red da Minnesota suna karɓar gudummawa daga Kogin Pembina na arewa maso gabashin North Dakota .  Rashin lalacewa yana da yawa ga wannan kogi, kuma yana haifar da lalacewa mai yawa da tsayi na bakin kogi. Wannan karuwar runoff sannan ya samar da karuwar rafi kuma ta haka ne mafi girman abubuwan da suka faru a cikin ruwa, kamar a cikin Red River.

## Magani
Rashin bankin kogi ya dogara da mafita da yawa, mafi yawan su shine daidaitawar lemun tsami da riƙe ganuwar, riprap da takarda, kiyaye tsire-tsire masu zurfi, iska da rami, jaka da tubalan, gabions da mattresses, ƙasa-cement, da kuma guje wa gina gine-gine kusa da bankunan kogi.

### Rashin jituwa

Riprap da aka yi da duwatsu da sauran kayan, an shirya su ta hanyar hana hanyoyin rushewa a bakin kogi. Wannan hanyar tana da tsada kuma tana iya fuskantar gazawar, amma tana da ikon amfani da ita don manyan yankuna. Ana ganin gazawar lokacin da bankin ya fuskanci lalacewar barbashi, saboda duwatsu sun yi ƙanƙanta don tsayayya da damuwa, cire wasu duwatsu da ke raunana riprap gaba ɗaya, gangaren gefen bankin ya yi tsayi sosai don riprap don tsayayyar dakarun motsi, ko gradation na riprap ya zama daidai (babu abin da zai cika ƙananan sarari). Rashin nasara na iya faruwa ta hanyar raguwa, slide na fassara, ko raguwa mai canzawa.

### Jirgin ruwa da rami
Windrows sune tarin kayan da ke tsayayya da rushewa a bakin kogi, inda idan aka binne su, za a san su da rami. Lokacin da rushewa ya ci gaba da kasancewa a wani wuri da aka riga aka ƙaddara, ana yin waɗannan iska da ramuka don zamewa tare da bankin don kare shi daga ƙarin abubuwan da suka faru na rushewa. Wannan yana ba da damar buƙatar ƙaramin aikin ƙira, a cikin wannan shigarwa yana da sauƙi a kan manyan bankunan, kodayake wasu hanyoyin na iya haifar da gazawar. Rashin fa'idodi sun haɗa da windows da trenches da ke ci gaba da lalacewa har sai sun haɗu da kayan da ke tsayayya da lalacewa. Sakamakon wannan hanyar an ga ba daidai ba ne, kamar yadda gangaren bankin ke haifar da karuwar saurin kogin.

### Sacks / Block
Ana iya amfani da jaka da tubalan a lokacin ambaliyar ruwa, inda aka cika jaka da kayan aiki, yana ba da damar tubalan don ƙarfafa ruwa da ci gaban ciyayi. Wannan hanyar tana buƙatar ƙarin aikin mutum da adadi mai yawa na kayan cikawa, kamar yadda duk jaka da tubalan ya kamata su kasance daidai.

### Gabions da mattresses
Gabions suna tarawa, akwatunan waya na rectangular cike da duwatsu. Suna da amfani a kan gangaren da ke da tsawo lokacin da ruwa ya yi sauri sosai don amfani da fasahar riprap. Suna da tsada kuma suna da ma'aikata masu yawa, kuma suna buƙatar dubawa na lokaci-lokaci don lalacewa da kulawa ta gaba, kodayake an ga su suna nuna kyakkyawan aiki.

Mattress gabions manyan kwando ne masu zurfi, masu amfani a kan koguna masu santsi don ci gaban ciyayi. An ɗaure su gefe da gefe kuma an shimfiɗa su kusa da juna a kan ƙananan wurare, suna haifar da bargo na kariya daga rushewa.

Ana amfani da matattarar kankare a cikin manyan koguna kamar Mississippi, kuma sun ƙunshi tubalan kankare da sandunan ƙarfe ke riƙewa. Da sauri don amfani tare da kyakkyawan suna, suna ba da damar cikakken ɗaukar bakin kogi lokacin da aka sanya shi yadda ya kamata. Wannan kuma yana haifar da rikodin sabis mai kyau. Koyaya, sarari masu buɗewa (8%) suna ba da damar kayan aiki masu kyau su wuce, kuma sarari tsakanin tubalan na iya haifar da cire bankin. Abin takaici, mattresses da kansu ba su dace da kyau a cikin tsaunuka masu kaifi ba, kuma yana iya zama mai tsada don cire ciyayi a bankin, wanda ake buƙata don sanyawa.

### Ƙasa
Daidaitaccen wurin da aka sanya siminti na ƙasa na iya zama daban dangane da gangaren bankin. A cikin koguna tare da babban aikin raƙuman ruwa, ana iya buƙatar tsarin matakala don kawar da makamashi da ke fitowa daga raƙuman. A cikin yanayin da ke da ƙananan ƙarfin raƙuman ruwa, ana iya 'flated' siminti a cikin takalma a layi daya da gangaren. Ba za a iya amfani da wannan dabarar ba duk da haka a kan tudu mai tsawo. Ciminti na ƙasa na iya samun mummunar tasiri a yanayin daskarewa / bushewa, amma sakamako mai kyau a bankunan da yashi da ciyayi, saboda ƙarancin ƙarfi da impermeability na iya haifar da gazawar.

### Shuke-shuke
Akwai manyan nau'ikan ciyayi guda uku don hana gazawar banki: itatuwa, shrubs, da ciyawa. Bishiyoyi za su samar da tsarin tushe mai zurfi da yawa, yana ƙara damuwa da kogin zai iya ɗauka. Ana sanya shrubs a cikin kogin don samar da kariya daga rushewa, samar da kyakkyawan shuke-shuke da kwanciyar hankali. Ana iya ɗaure yankan tare a cikin abubuwan ban sha'awa, kuma a sanya su cikin rami mai zurfi daidai da bakin kogin. Yawanci, willows da sandunan auduga sune kayan da suka fi amfani, duk da haka, ana iya amfani da samfuran fiber  sannan a binne su kuma a sanya su a wurin. Wadannan tarin yankan suna haifar da tsarin katako wanda zai samo asali, girma, kuma ya haifar da kyakkyawan shuke-shuke. Tsarin yana riƙe da ƙasa a wurin kuma yana kare bankin rafi daga rushewa. Amfani da ciyayi don magance hanyoyin rushewa shine hanyar da ta fi dacewa da aiki, yayin da kuma mafi tsada. Har ila yau, yana inganta mazaunin kuma yana da kyau sosai. A kan bankunan da ke da tsawo, duk da haka, itatuwa bazai iya daidaita yatsan bankin ba, kuma nauyin itacen da kansa na iya haifar da gazawar. Har ila yau, yana da wahala a shuka shuke-shuke a cikin yanayi kamar daskarewa. Idan ba a kare shi yadda ya kamata ba, dabbobin daji da dabbobi na iya lalata shuke-shuke.

## Manazarta