Zomwe zili muakatswiri wazakale: zolemba ndi mafomu osakanizidwa zimasunga mbiri yakale, koma si kafukufuku wa geotechnical, pulojekiti yosunga khoma, kuwerengetsa kukhazikika, kuwunika kwa khoma lomwe lilipo, mapulani okumba kapena malangizo a momwe angagwiritsire ntchito. Kupanikizika kwa dziko lapansi ndi madzi kumadalira pa nthaka yeniyeni, stratification, compaction, ngalande, madzi apansi, geometry, kayendedwe ka khoma, katundu wowonjezera, chisanu ndi zivomezi. Pazochitika zenizeni zilizonse, ntchito yofufuza, deta ya labotale, miyezo yovomerezeka ndi cheke chogwirizana ndi mainjiniya wovomerezeka wa geotechnical ndi zomangamanga ndizofunikira.

Masiku ano, Savo Kusić amayang’ana kwambiri mazenera amatabwa, mazenera a matabwa a aluminiyamu, mazenera amwambo, khomo ndi zopempha za mawu. Nkhaniyi idakali mbiri yakale ndipo siyikuyimira kuperekedwa kwa mapangidwe a geotechnical, kuwerengera kapena kumanga makoma otsekereza.

Kupsinjika kwapadziko pamakoma osungira

Kuchuluka kwa dziko lapansi mothandizidwa ndi khoma lomangirira kumapangitsa kuti pakhale zovuta, kumakonda kukankhira patsogolo motanthauzira (mku. 1a) kapena kukankhira (mkuyu 1b). Kuchuluka kwa mphamvu ya dziko lapansi E kumadalira zinthu zingapo, zomwe zili zofunika kwambiri zakuthupi za nthaka, mapindikidwe a khoma, chinyezi cha nthaka ndi madzi apansi, kutalika kwa khoma, katundu wakunja ndi kukhwima kwa mkati mwa khoma.

Mapulani omasulira ndi kugubuduza khoma lomangirira pansi chifukwa cha kupsyinjika kwa dziko

Chithunzi1- Kusuntha komasulira ndi kuzungulira kwa khoma lothandizira.

Kupanikizika kwapadziko lapansi pakupuma

Ngati khoma losungirako lili lolimba komanso losasunthika, kukakamiza komwe kumachitikapo kumatchedwa earth pressure at rest ndipo kumatanthauzidwa ndi E.0. Uku ndiye kupanikizika komwe kumakhalapo munthaka yosasokonezedwa ndi kuya kwake, motengera kulemera kwa nthakayo komanso mwinanso kudzaza zigawo zomwe zidakokoloka. Kupanikizika kwapadziko lapansi pakupuma sikochitika ndipo kumachitika nthawi zina, monga kusungitsa makoma okhazikitsidwa mumwala wolimba, kenako ndi mbiri yotsekedwa ya tunnel ndi mapaipi, komanso ndi ma docks akulu, omwe samayenda (mkuyu.2).

Scheme of earth pressure at rest on the side makoma a doko lalikulu

Chithunzi2- kupumula kupanikizika kwa dziko lapansi pa doko lalikulu.

Kuthamanga kwapadziko lapansi

Ngati khoma lothandizira pansi pa mphamvu ya E likupita patsogolo kapena kuyendayenda pamtunda wa phazi A, kapena mfundo ina yotsika, yomwe imakhala yokhazikika m’nthaka yosakanizika, kupatula zomwe tazitchulazo zotsekedwa ndi zazikulu, ndiye kuti dziko lapansi likukula kumbuyo kwa khoma. Ngati kusuntha kwa khoma kuli kwakukulu mokwanira, gawo la dothi kuseri kwa khoma, prism ABCA, imathyoledwa ndikutsika pansi AC (mkuyu.2). Kupanikizika komwe kumapangidwa ndi prism yotsetsereka pakhoma losungirako kumatchedwa kuthamanga kwa dziko lapansi ndipo kumatanthauzidwa ndi Ea. Kupanikizika kumeneku ndikotsika kwambiri kuposa kupanikizika pakupuma, pafupifupi0,5ku0,7_E0_. Chifukwa cha kutsetsereka kwa prism yapadziko lapansi ABCA, kumeta ubweya τ kumayendetsedwa motsatira AC, zomwe zimatsutsana ndi kutsetsereka ndikuchepetsa kupanikizika kwa dziko lapansi. Panthawi yomwe prism ABCA iyamba kutsetsereka, kukameta ubweya wa ubweya τ kufika pamtengo wake wapamwamba kwambiri, zomwe zikutanthauza kuti panthawiyo mtengo wa mphamvu ya dziko lapansi E ndiyochepa kwambiri. Chifukwa chake, Ea ndiye mtengo wotsika wapadziko lapansi.

Mayesero a Terzaghi a kuthamanga kwa nthaka ndi zinthu zamchenga pakhoma la kutalika h=1,50 madawonetsa kuti kufikira malire otsika amphamvu yapadziko lapansi Ea, kusuntha kopingasa kwa khoma Δl wa5/10.000kutalika kwa khoma kapena kuzungulira kwa pamwamba pa khoma Δl wa1/5.000_h_ kuzungulira mwendo A.

Kupanikizika kwapadziko lapansi

Ngati tikakamiza khoma kuchokera kunja kupita mkati mwa nthaka (mkuyu.3), khomalo lidzabwerera mmbuyo ndipo nthaka idzagwirizana. Kusuntha kwa khoma kukafika pamtengo wina Δl, prism yadothi ABCA idzalekanitsidwa ndi nthaka, yomwe idzakankhidwira mmwamba ndi malo otsetsereka AC pansi pa zochitika zina za mphamvu yakunja. Kukaniza komwe nthaka imapereka motsutsana ndi mphamvu yakunja panthawi yolekanitsa prism ABCA ndi passive earth pressure Ep. Ndilo mtengo wapamwamba kwambiri womwe mphamvu ya dziko lapansi imatha kufika.

Kupanikizika kwapadziko lapansi pakupuma kumatsimikiziridwa moyeserera, pomwe kupanikizika kwapadziko lapansi kumatha kuzindikirika mokhazikika, pogwiritsa ntchito njira zowunikira kapena zojambula, potengera chidziwitso cha mawonekedwe a nthaka, nthawi zambiri amatsimikiziridwa ndi labotale.

Dongosolo la kupanikizika kwa nthaka ndi kukwera kwa prism yotsetsereka kuseri kwa khoma lomangirira

Chithunzi3- Kupanikizika kwapadziko lapansi komanso prism yotsetsereka.

**Zofunikira pakukhazikitsa: ** zogwira ntchito, zongokhala, komanso zopanda pake sizimasankhidwa ndi dzina lokha lokha. Kusuntha kwakhoma kololedwa, kupanikizika kogwira mtima, kutayidwa kapena kutsekedwa, mlingo wa madzi apansi ndi kusintha, katundu wowonjezera ndi kuthekera kwa kutayika kwa nthaka kutsogolo kwa khoma ziyenera kuwonetsedwa. Kusankha kolakwika kwa mikhalidwe yopanikizika kumatha kusokoneza kukhazikika kotsetsereka, kugwedezeka, kunyamula mphamvu ya nthaka ndi mphamvu ya khoma.

Kutsimikiza kwa coefficient of rest pressure K0

Ngati khoma lothandizira likuwonekera chifukwa cha kuthamanga kwa static, kuthamanga kwa static E kuyenera kutengedwa kuti kukhale kukula kwa khoma lothandizira.0, yomwe ndi yayikulu kuposa kuthamanga kwapadziko lapansi. Kukula kwake kuli pakati pa mphamvu ya nthaka yogwira ntchito ndi yosasunthika, kutengera mtundu wa dothi ndi kuphatikizika kwake.

Pa kuya t pansi pa nthaka, mphamvu yoyima yochokera pa kulemera kwa nthakayo ndi σt = γ·t. Ngati palibe kuthekera kokulitsa nthaka, kuthamanga kopingasa σh = γ·t·K0, komwe K0 = σh/σt.

K0 ndikupumira. Coefficient of rest pressure ikhoza kuzindikiridwa ndi kuyesa kwa triaxial motere.

Chitsanzo cha dothi losasokonezedwa lomwe latengedwa kuchokera kukuya kwa kukanikiza kopumula kumayikidwa mu zida za triaxial, pomwe kuthamanga kwapambuyo σ3 pakagwiritsidwa ntchito mowongoka σ1 kumasinthidwa kuti mapindikidwe am’mbali asachitike, kutanthauza kuti mawonekedwe a zero ndi ofanana ndi zero. Miyezo ya ma voltages ogwira mtima σ’1 ndi σ’3 amayikidwa pa chithunzi σ’1 – σ’3 (mku. 4), ndi mzere wowongoka wa tange zimatsimikizira mtengo K0 = σ’3/σ’1.

Chithunzi cha kupsinjika kwakukulu kothandiza kudziwa kuchuluka kwa mphamvu yakupumula ndi mayeso a triaxial

Figure 4 — kutsimikiza kwa coefficient K__0 of resting pressure by triaxial test.

Malinga ndi Petermann, kuyerekezedwa kwa mphamvu yopumira ndi

kwa mchenga wothira K0 = 0,40 - 0,45

kwa mchenga wotakasuka       K0 = 0,45 – 0,50

kwa dongo K0 = 0,60 - 0,75

Ziwerengero za mu labotale: Chifupikitso cha m’munsimu chikukhalabe mbali ya malemba oyambirira, koma salowa m’malo mwa kuyesa kwachitsanzo, chitsanzo cha nthaka ndi mapangidwe ake. Zolemba za OCR za mafomula, zolembetsa ndi apostrophe ziyenera kuyang’aniridwa ndi gwero lovomerezeka musanawerengere.

Njira zodziwira kuthamanga kwa dziko lapansi - Lingaliro la Coulomb

Coulomb adafalitsa koyamba chiphunzitso cha kuthamanga kwa dziko (1770. chaka), kutengera zomwe zachitika m’munda. Anayang’ana khoma lomangira lomwe linali ndi dothi lotayirira. Panthawi ina adachotsa khomalo, pomwe misa ya dziko lapansi idatsetsereka pamalo otsetsereka AC, yokhotakhota pamakona a ndi yopingasa (mkuyu.5). Kulemera kwa W kwa prism yapadziko lapansi ABC, yomangidwa ndi mtunda wamtunda BC, malo otsetsereka AC ndi khoma losungira AB, limagwira ntchito imodzi pakhoma losungira komanso pamtunda wotsetsereka. Kukula kwamphamvu yapadziko lapansi Ea idatsimikiziridwa ndi Coulomb pansi pamalingaliro awiri awa:

  1. kuti malo otsetsereka ndi malo enieni;

  2. kuti atatu akuchita mphamvu: kulemera kwa kutsetsereka prism W, kukana kwa khoma kuthandiza Ea ndi kukaniza frictional Q pamodzi kutsetsereka pamwamba AC kudutsa pa mfundo imodzi, kutanthauza kuti ndege ya mphamvu yatsekedwa. Malingana ndi lingaliro ili, mu chikhalidwe cha malire kulemera kwake W kuthetsedwa nthawi imodzi ndi kukana kwa khoma lothandizira Ea ndi kukana kwa frictional Q pamodzi ndi kutsetsereka pamwamba.

Mtsinje wotsetsereka wa Coulomb kuseri kwa khoma ndi dongosolo la mphamvu zolemera, kukangana ndi kuthamanga kwa dziko lapansi

Chithunzi5- kutsimikiza kwa kuthamanga kwa dziko lapansi molingana ndi chiphunzitso cha Coulomb.

Malingaliro am’mbuyomu samagwirizana ndi zenizeni. Malo otsetsereka si malo owongoka koma opindika. Kuphatikizika kwa mphamvu zitatu zomwe zimagwira ntchito kumakhalapo nthawi imodzi, pamene pamwamba pa mtunda kumbuyo kwa khoma ndi yopingasa, mkati mwa khoma ndi ofukula ndipo njira ya mphamvu Ea ndi yopingasa, pamene kulibe zina. Komabe, ngakhale izi ndizopatuka, kutsimikiza kwamphamvu yapadziko lapansi kumakhazikikabe pamalingaliro a Coulomb, popeza zatsimikizira kuti ndizogwiritsidwa ntchito nthawi zambiri.

Kudziwa yogwira lapansi kuthamanga Ea Coulomb ankaganiza kuti chifukwa cha mphamvu ya kulemera kwa dziko lapansi misa W panali kuyenda kwa khoma lothandizira ndi mapangidwe a prism ABC ya kuthamanga kwa dziko lapansi. Poganiza kuti kutsutsa kwamkati kwa nthaka kumangokhalira kukangana. Coulomb amawola kulemera kwake W m’zigawo ziwiri, imodzi molunjika ku mphamvu yamphamvu yapadziko lapansi Ea, ina motsata kukana kwamphamvu Q pamtunda wotsetsereka (mkuyu.5b). Pochita izi, Coulomb amalingaliranso kuti chigawocho chimagwira ntchito pakona ya mikangano yamkati ndi yachibadwa mpaka pamtunda wotsetsereka AC, ndi kuti chigawo Ea chimachita pa ngodya yopatuka δ ndi yachibadwa mpaka mkati mwa khoma AB. Mphamvu W imatsimikiziridwa ndi chitsogozo, ukulu, ndi malangizo.

Pamalo otsetsereka pamakona α ndi yopingasa, mphamvu W imapezeka kuchokera pamwamba pa prism yapansi ABC kwa kutalika.1,0 mperpendicular ku pulani ndi volumetric nthaka kulemera γ, W=AΔABC x1,00x γ. Mphamvu Ea ndi Q zimadziwika ndi njira. Kutengera dongosolo la mphamvu (Chith.5b) ndi sine theorem yomwe tili nayo:

Foni yojambulidwa yopezedwa pogwiritsira ntchito sine theorem ku ndege ya mphamvu

Dongosolo lapadera lotsekera khoma lokhala ndi malo opingasa ndi ndege yamphamvu

Chithunzi6- nkhani ya mphambano ya mphamvu zochitira nthawi imodzi.

Njira iyi ndi yolondola pokhapokha ngati malo ali opingasa (v=0), mkati mwa khoma ndi woyima (θ=0) ndi mayendedwe a mphamvu Ea yopingasa (δ=0) i.e. pamene khoma lili bwino (mkuyu.6).

Pankhani yapaderayi yotchedwa Rankine tili ndi:

Anajambulapo mawonekedwe amphamvu yapadziko lapansi yankhani yapadera ya Rankine

Kulemera W kuli mu nkhani iyi W =0.5·γ·h_2/tg_α, pomwe γ ndi kulemera kwa dothi.

Ngati tiwonetsa mtengo wakutsogolo mu equation ya Ea, timapeza:

Zochokera ku sikenidwe za chilinganizo cha kuthamanga kwa dziko lapansi ngati ntchito ya ngodya yotsetsereka

Equation yapitayi ikunena za malo otsetsereka AC. Komabe, ndikofunikira kudziwa mphamvu Ea pa malo ovuta kwambiri otsetsereka, mwachitsanzo, pomwe kutsetsereka kungachitike. Idzakhala pamwamba yomwe imapereka mtengo wapamwamba kwambiri wa kuthamanga kwa dziko lapansi Ea.

Kwa kutalika kwake kwa khoma H ndi kutengera kosalekeza kosalekeza kwa mikangano yamkati ϕ, mtengo wa kuthamanga kwa dziko lapansi umasiyanasiyana malinga ndi mbali ya α ya malo otsetsereka kupita kumtunda. Mtengo wopambana Ea upezeka ngati tisiyanitsa Ea ndi α ndikuyika kusiyanitsa kofanana ndi ziro:

Masamu ofufuzidwa kuti adziwe mbali yofunika kwambiri ya mphamvu ya dziko

Fomula si chowerengetsera: ma equation oscan akhoza kukhala ndi ma exponent, ma indices, ngodya ndi zizindikiro zosawerengeka. Sanakopedwe mu polojekiti popanda kufananizidwa ndi gwero lodalirika la akatswiri, kufufuza mayunitsi, kulingalira kwachitsanzo ndi kulamulira kodziimira pazotsatira. Kuwerengeraku kuphatikizepo madzi, ngalande, katundu m’mphepete mwa khoma, zivomezi ndi malire onse oyenera.

Kutsimikiza kwa ngodya ϕ ndi δ

Kona ya kukangana kwamkati ϕ kumatsimikiziridwa mu labotale. Kukula kwake kumadalira mtundu wa dothi, chinyezi ndi compaction. Pamitundu ina ya dothi, mtengo wa ngodya ϕ nthawi zambiri umakhala mkati mwa malire operekedwa patebulo 1.

Gome la mbiriyakale la pafupifupi makona a mkati mwa mwala wophwanyidwa, miyala, mchenga, loam, loess ndi dongo

Table 1 — mtengo woyerekeza wa ngodya ya friction yamkati ϕ pamitundu ina ya dothi.

Kona yapatuka δ ya mphamvu Ea kuchoka pamalo abwino mpaka mkati mwa khoma zimatengera kusinthika kwa khoma ndi dothi lakumbuyo kwake komanso kukhwimitsa kwa mkati mwa khoma. Ngati kukhazikika kwa nthaka kuli kwakukulu kuposa kukhazikika kwa khoma, komwe kumakhala kofala kwambiri, ndiye kuti ngodya δ ndi yabwino, kukangana pakati pa khoma ndi nthaka kumachita mmwamba. Ngati kukhazikika kwa khoma kuli kwakukulu kuposa kukhazikika kwa nthaka, zomwe ndizochitika zapadera, ndiye kuti ngodya δ ndi yolakwika, kukangana pakati pa khoma ndi pansi kumagwera pansi. Miyezo yochepetsera ya ngodya δ ndi yapakhoma yosalala kotheratu δ=0, panjira yovuta kwambiri δ=ϕ. Kawirikawiri, δ=2/3_ϕ_ imatengedwa, ndi mfundo yakuti nthaka ya khoma imatetezedwa kwamuyaya kuti isanyowe mwamphamvu. Ngati dothi kuseri kwa khomalo likukumana ndi zivomezi zamphamvu, δ=ϕ/2 imatengedwa, ndipo ngati ili yonyowa kwambiri δ=0.

Mapangidwe a ma angles: ma tabular ndi ofotokozera ϕ ndi δ sagwiritsidwa ntchito mwachindunji kumalo enaake. Kusankhidwa kwa magawo kuyenera kugwirizana ndi mtundu ndi momwe nthaka ilili, njira yokhazikitsira ndi kuphatikizika, ngalande, kayendedwe koyembekezeka kwa khoma, kukhwinyata kwa kukhudza ndi njira yoyenera yogwirira ntchito.

Kugawa kwapadziko lapansi kuseri kwa khoma ndi kukakamiza malo owukira Ea

Dongosolo la malo otsetsereka ndi kugawanika kwa mphamvu ya katatu pamene khoma lizungulira mwendo

Figure 7 - kugawa kwamphamvu kwa dziko lapansi pozungulira khoma lomangirira kuzungulira phazi A.

Kagawidwe ka mphamvu ya nthaka m’kati mwa khoma kumadalira kusinthika kwa khoma lomangirira, mawonekedwe a nthaka kuseri kwa khoma ndi mawonekedwe a mkati mwa khoma.

Malo owukira amphamvu yapadziko lapansi Ea amatengera kufalikira kwapakatikati pa khoma komanso mawonekedwe ake. Nthawi zonse zimakhala pamtunda wapakati pa mphamvu yokoka pamwamba pa chithunzi cha kuthamanga.

Coulomb adatengera kuti kuthamanga kwa dziko kuseri kwa khoma kumawonjezeka motsatana ndi kuya, monga ndi madzi, otchedwa. kugawa kwa hydrostatic ya kuthamanga kwa dziko lapansi (mkuyu 7). Komabe, kugawanika kwa hydrostatic pressure kumapezeka kokha pamene khoma lizungulira mwendo A kapena malo otsika, pamene nthawi zina zonse limapatuka.

Ngati khoma lomangira lizungulira pozungulira phazi A, kapena potsika, nthaka imasunthira pansi (mkuyu 7a), pomwe palibe kukankhira mkati mwa nthaka. Pamenepa, kutsetsereka kwa dothi kumawonekera pamalo otsetsereka pang’ono M1C1, M2C2…kufanana ndi malo otsetsereka AC, zomwe zimachitika pamene kuzungulira kwa khoma kumakhala kwakukulu kokwanira kupanga pride. ABCA.

Choncho, pamenepa, kupanikizika kumawonjezeka mofanana ndi kuya, mwachitsanzo, kugawa kwapadziko lapansi kumagwirizana ndi Coulomb hydrostatic. Chojambula chogwira ntchito chapadziko lapansi chidzapezedwa potengera chidziwitso cha mphamvu Ea ndi kutalika kwa khoma h, popeza mphamvu Ea ndi yofanana ndi gawo lachithunzithunzi abc (Mkuyu.7b):

Ea=x·h/2, kuchokera x=2Ine/h,

ndiye kuti, popeza Ea = ½ γh2Ka, x = γhKa.

Dongosolo la kagawidwe ka mphamvu yogwira ntchito ndi yokhazikika pozungulira khoma pozungulira pamwamba kapena pamwamba

Chithunzi8- kugawa kwamphamvu kwa dziko lapansi pamene khoma limazungulira pamwamba pa B kapena malo ena apamwamba L.

Ngati khoma lothandizira lizungulira pamwamba pa khoma B kapena malo ena apamwamba L (mkuyu.8a), pali kukankhira kumtunda kulowera mkati mwa nthaka, komwe kumakankhidwira mmwamba motsatira malo osakanizidwa pang’ono M1C1, M2C2…

Pakazungulira kokwanira kwa khoma, malo otsetsereka AC amapangidwa, pomwe prism yotsetsereka imatsikira pansi pakutulutsa. Chifukwa cha kukankhira kwa dothi kumtunda, kuthamanga kwa dziko lapansi kumawonekera, komwe kumakhala kokwera kwambiri kuposa komwe kumagwira ntchito, ndipo m’gawo limenelo chithunzi cha bd chimagwirizana ndi Ep (mkuyu 8b). Monga kuthamanga kwa dziko lonse Ea kumadalira kukula kwa dziko lapansi prism ABCA ndipo ndi wofanana ndi katatu pamwamba pa chithunzithunzi chopanikizika abe, chithunzichi chidzachepa mu njira yake yowonjezera, mpaka pamwamba pake ikhale yofanana ndi katatu pamwamba abe. Chojambula chenichenicho pankhaniyi ndi curvilinear bc, chomwe sichingadziwike masamu. Komabe, pakati pa mphamvu yokoka S ya pamwamba pa chithunzi ac ili pamwamba pa mphamvu yokoka pamwamba pa chithunzi cha triangular, chomwe sichimakondweretsa kukhazikika kwa khoma losungirako, chifukwa malo owukira a mphamvu Ea ndi apamwamba. Malinga ndi Terzaghi, ili pa theka la kutalika kwa khoma lothandizira.

Ngati khoma lothandizira likusunthira patsogolo pomasulira (mku. 9a), kupanikizika komwe kusanachitike kusuntha kumayenderana ndi kupanikizika kwa dziko lapansi mu mpumulo E0 kumachepa, kumene malo otsika kwambiri samawoneka, koma pamene khomalo likuyenda mokwanira, _AC _A prim BC amatsetserekera pansi. Popeza kupanikizika kwathunthu ndi kofanana ndi gawo la katatu lachithunzi choponderezedwa abe (mkuyu 9b), chojambula choponderezedwa chidzacheperachepera. Chojambula chenichenicho ndi mzere wokhotakhota ac, womwe sungadziwike masamu. Malinga ndi Terzaghi, pakati pa mphamvu yokoka S ili pamtunda 0,40 - 0,45_h.

Scheme of curvilinear pressure distributions during translational forward of the retaining wall

Figure 9 — kugawa kwapadziko lapansi panthawi yomasulira kwa khoma lomangirira kutsogolo.

Poganizira njira yodziwira kupanikizika kwa dziko lapansi ngati mtengo wokwera kwambiri, waukulu kwambiri wogwira ntchito komanso wocheperako, chiphunzitso cha Coulomb chimawonedwa ngati njira yowopsa kwambiri yodziwira kuthamanga kwa dziko.

Chidziwitso chomaliza cha uinjiniya: kugawa ndi kuukira kwapanikizidwe kumadalira momwe dongosololi limapunthira. Kuphatikiza pa kuthamanga kwa dziko lapansi, kuthamanga kwa madzi ndi hydrostatic, kukhazikika kwapadziko lonse ndi mkati, kutsetsereka, kusamuka, kunyamula nthaka ndi kukhazikika, mphamvu za khoma ndi maziko, kukokoloka, leaching, magawo ofukula ndi kukhazikika kwakanthawi ziyenera kuyang’aniridwa. Mkhalidwe wa khoma lomwe lilipo lomwe likuwonetsa kusuntha, ming’alu, kuphulika kapena kutayikira kwamadzi kosalamulirika kumafuna kuunika mwachangu kwa akatswiri.