Masiku ano, Savo Kusić amayang’ana kwambiri mazenera amatabwa, mazenera a matabwa a aluminiyamu, mazenera amwambo, khomo ndi zopempha za mawu. Mawuwa amakhalabe ngati malo osungiramo zinthu zakale ndipo siwopereka mamangidwe a geotechnical, kuyesa kwa labotale kapena ntchito zapadziko lapansi.

Magawo azinthu m’nthaka

Nthaka imakhala ndi magawo atatu: olimba, madzi ndi mpweya. Gawo lolimba limayimiridwa ndi tinthu tating’onoting’ono, madzi amadzimadzi, ndi gawo la mpweya ndi mpweya wotsekedwa kapena nthunzi yamadzi mu pores. Mitundu ina ya dothi imatha kukhala ndi gawo limodzi, awiri kapena atatu, zomwe zikutanthauza kuti nthaka imatha kukhala gawo limodzi, magawo awiri kapena atatu. The thupi katundu wa nthaka zimadalira magawo payekha. Dothi losakhazikika, monga mchenga wouma kapena miyala, imakhala ndi gawo limodzi lokha - tinthu tolimba. Mpweya umene umakhala mu pores wa dothi limenelo sutsekedwa ndipo sutsutsana ndi kuyenda kwa tinthu tating’onoting’ono, choncho sungakhoze kuonedwa ngati gawo. Dothi lonyowa pamwamba pa madzi apansi, lomwe lili ndi tinthu tating’onoting’ono tating’onoting’ono tating’ono tating’ono tating’ono tating’ono tating’ono tating’ono tating’ono tating’ono tating’ono tating’ono tambiri timene timadzaza ndi madzi ndipo mwina ndi mpweya kapena nthunzi yamadzi, ndi dothi la magawo atatu. Pankhani yosuntha zolimba, madzi ndi mpweya m’nthaka pores amatsutsidwa nthawi yomweyo. Nthaka yomwe ili pansi pa madzi apansi, omwe pores ake amadzaza ndi madzi, kotero kuti mulibe mpweya kapena mpweya wa madzi mkati mwake, ndi dongosolo la magawo awiri. Nthaka m’zigawo zakuya imaganiziridwa kuti ndi gawo la magawo awiri, chifukwa mpweya wotsekedwa m’mabowo a nthaka pamtunda waukulu sumakhala ndi mphamvu yaikulu pa zinthu zake zakuthupi, zomwe zimatsimikiziridwa ndi zomwe zimakhala zolimba komanso zamadzimadzi.

Granulometric kapangidwe

Zosakaniza zolimba m’nthaka ndi mchere kapena zinthu zamitundu yosiyanasiyana, kuyambira miyala yayikulu ndi midadada, kukula kwa mazana ndi masauzande a mamilimita mpaka kukula kwa molekyulu imodzi. Monga mukudziwira, molekyulu ndi miliyoni imodzi ya millimeter, millimicron imodzi. Kukula kochepa kwambiri kwa zolimba zadothi kumatengedwa kuti ndi 20 mor microns.
Kukula kwa tinthu tating’onoting’ono tanthaka kumakhudza kwambiri mawonekedwe ake. Kukokoloka kumeneku kumawonetsedwa ndi kapangidwe ka granulometric, komwe kumayimira chiŵerengero cha miyeso yambewu iliyonse malinga ndi kulemera kwake ndi kulemera kwa nthaka. Kugawidwa kwa nthaka molingana ndi kapangidwe kake ka granulometric ndi kosiyana m’maiko osiyanasiyana. Gawo lathu lili motere:

Magawidwe akale a nthaka yokhuthala ndi yopyapyala molingana ndi kukula kwa tinthu

Malire a kukula kwa tinthu

Kukula2 mm- malire apakati pa dothi louma ndi losalala bwino. Zolimba particles mpaka2mmkuwonetsa kuchuluka kwa madzi m’nthaka. Dothi la coarse-grained alibe capillarity. Kukula0,2 mm- malire pakati pa mchenga wobiriwira (wokuthwa) ndi mchenga (wofewa). Kukula0,02 mm- malire omwe mbewu zamtundu umodzi zitha kuzindikirika ndi maso. Kukula0,002 mm- malire pakati pa dothi lotayirira ndi dongo Kukula0,0002 mm- malire pakati pa dongo ndi dongo la colloidal. Zosakaniza zolimba zomwe zili pansipa0,002 mmamakhudza kwambiri zinthu zakuthupi za nthaka. Zosakaniza izi zimapereka mgwirizano kunthaka, ndipo ngati zili zazing’ono komanso zambiri m’nthaka, nthaka imakhala yogwirizana kwambiri. Komabe, kugwirizana nthaka kumadaliranso mchere zikuchokera olimba particles ang’onoang’ono kuposa0,002 mm. Ngati tinthu tating’ono timene timapangidwa ndi kuwonongeka kwa mchere wovuta kwambiri monga quartz, ndiye kuti kugwirizana kwawo kumakhala kochepa kwambiri kapena kulibe, ndipo kuyamwa kwawo kwamadzi kumakhala kochepa. Ngati particles ali pansipa0,002 mmkupangidwa ndi kuwonongeka kwa zinthu zadongo, ndiye kuti ali ndi katundu womangiriza omwe ali amphamvu kwambiri ngati tinthu tating’onoting’ono tating’onoting’ono, pamene kuyamwa kwamadzi kwa tinthu tating’onoting’ono timeneti ndi kwakukulu kwambiri. Mapangidwe a granulometric a nthaka amapereka chidziwitso chofunikira komanso chodalirika pazinthu zina zakuthupi. Ngati dothi likulamulidwa ndi dongo particles kukula m’munsimu0,002 mm, ndiye kuti zimachokera kale kuti zikhoza kutsimikiziridwa kuti nthaka yotereyi ndi pulasitiki, yogwirizana, ya hygroscopic, imakhala ndi capillarity yapamwamba, yotsika kwambiri komanso imakhala ndi phokoso lochepa la mkati. Kupangidwa kwa granulometric dothi kumayimiridwa ndi mizere ya granulometric (mkuyu.1).

Mizere ya granulometric ya mchenga wa miyala, mchenga wafumbi, fumbi lamchenga, dothi ladongo ndi dongo

Sl.1- Mizere ya dothi la granulometric:1- mchenga wamtengo wapatali;2- mchenga wafumbi;3- mchenga fumbi;4- dothi dongo;5-dongo

Ma ordinatere a mizere yopangidwa ndi granulometric akuwonetsa gawo la kulemera kwa tinthu tating’ono tolimba kuposa m’mimba mwake woimiridwa ndi abscissa ya mfundo yomwe wapatsidwa. Mwachitsanzo, pa mfundo A ya mzere4ogwirizanitsa akuwonetsa kuti alipo92%kukula kwa tinthu kochepa kuposa2 mm, ndi kuti otsalawo8%kukula kupitirira2 mm.

Gulu la dothi molingana ndi kapangidwe ka granulometric

Nthaka yokhala ndi tinthu zolimba pamwamba2 mmamagawidwa molingana ndi kugawanika kwa nthaka ndi mapangidwe a granulometric, akuwonetsedwa mkuyu.1. Pochita izi, yomwe imayimiridwa kwambiri m’nthaka imatengedwa ngati kachigawo kakang’ono, pamene ena ndi owonjezera. Mwachitsanzo, ngati kung’ambika kwa nthaka nthawi zambiri kumakhala mchenga wokhala ndi miyala yaying’ono, ndiye kuti nthaka yotereyi imayikidwa ngati mchenga wamiyala, pomwe mosiyana ndi mchenga wamchenga. M’magulu, magawo a tizigawo tating’ono m’nthaka atha kuwonetsedwanso. Ngati, mwachitsanzo, dothi lili ndi15%dongo,45%fumbi,30%mchenga ndi10%miyala, imatha kugawidwa ngati dothi ladongo ndi15%dongo ndi10%miyala. Komabe, zabwino-grained dothi munali olimba particles zosakwana2 mm, gulu lotengera kapangidwe kawo ka granulometric nthawi zambiri limapangidwa molingana ndi chithunzi cha katatu. Pali zithunzi zingapo zotere, zomwe tidzalemba zoyambira kwambiri kuchokera ku U.S. Bureau of Soils, mkuyu.2.

chithunzi cha katatu cha gulu la nthaka molingana ndi kuchuluka kwa mchenga, fumbi ndi dongo

Sl.2- Chithunzi cha Triangular Bureau cha U.S

Chithunzichi chimakhala ndi nkhwangwa zitatu zogwirizanitsa zomwe zimayikidwa mu makona atatu ofanana, momwe olamulira aliyense amaimira kachigawo kamodzi, komwe ndi mchenga, fumbi ndi dongo mu % ndi kulemera kwa nthaka yonse. Dera lachithunzi limagawidwa kukhala10zone, iliyonse yomwe imayimira mtundu wosiyana wa dothi. Mbali iliyonse ya makona atatu imayimira abscissa yomwe imayendera limodzi ndi ma abscissas ena awiri. Mfundo iliyonse pachithunzichi ili nayo3kugwirizana kuimira maperesenti otchulidwa3ting’onoting’ono m’nthaka yomwe mwapatsidwa ndikudziwitsa mtundu wa nthaka. Kotero, mwachitsanzo, mfundo M pa chithunzicho ikuyimira dongo. Imapezedwa mwanjira yomwe kuchokera pazithunzi za granulometric zikuchokera mkuyu.1dziwani magulu osiyanasiyana, omwe mu nkhani iyi angakhale (mzere4mu fig.1):35%dongo,25%fumbi,40%mchenga, kumene kuchuluka kwa8%miyala yonyalanyazidwa chifukwa imakhala yochepa kuposa10%. Gululi limatanthawuza tizigawo ta mchenga, fumbi ndi miyala malinga ndi magawo aku America, koma amatengedwa motere chifukwa cha kufananiza komanso zomwe akumana nazo ndi gulu lotere.

Digiri ya kusalingana kwa nthaka

Malinga ndi Allen Hazen, kuchuluka kwa kusagwirizana kwa nthaka ndi chiŵerengero (mkuyu.3)

U=d60/d10

ku d60m’mimba mwake molingana ndi dongosolo60%,ndi d10 m’mimba mwake wa tirigu wofanana ndi ordinatere10%. Za U< 5 tlo je ravnomernog sastava,
za U =5-15dothi silimafanana m’mapangidwe ake, za U >15nthaka ndi yosafanana. Pamene mzere wa mapangidwe a granulometric ndi otsetsereka, mtengo wa kusagwirizana U ndi wawung’ono, pamene mzere wapansi ndi waukulu. Mtengo wocheperako wa U ndi1. Ngati mzere wopangidwa ndi granulometric uli wosalala kwambiri, mtengo wa U ndi wapamwamba. Kwa mchenga nthawi zambiri ndi U=1-15, kwa dothi ladothi U=10-90, koma ngati dothi lopangidwa mosagwirizana kwambiri, U likhoza kukhala lamtengo wapatali kwambiri.

Kutsimikiza kwa ma diameter a njere pa mzere wa granulometric

Sl.3- Kutsimikiza kwa kukula kwa mbewu d60ndi d10

Lamulo losefera

Lamuloli limachokera ku kapangidwe ka granulometric kwa fyuluta, yomwe ntchito yake ndikuchepetsa ma hydraulic gradient pakulumikizana pakati pa nthaka ndi ngalande yamadzi yamwala ndi kukula kwake kwambewu, kuti aletse kutsuka kwa tinthu tating’ono tadothi ndi madzi apansi. Zofunikira zomwe gawo la fyuluta liyenera kukumana nalo ndikuti likhale lotha kulowa m’madzi komanso lokhazikika. Pali malamulo angapo opangira zosefera, zomwe ndi malamulo a Terzaghi okha omwe atchulidwa pano ngati odziwika kwambiri.

Lamulo la Terzaghi

Lamulo la Terzaghi likuti: Granulation ya fyuluta iyenera kukhala kuti mbewu zake pa kuchuluka kwake.15%magawo potengera kulemera kwa sefa yonse (F15) kukhala osachepera4nthawi zambiri kuposa tinthu tating’ono ta dothi tomwe fyulutayo imakhazikika (zoyambira) pa kuchuluka kwake15%Zigawo potengera kulemera kwa maziko (B15), popanda kukhala wamkulu kuposa4nthawi B85, ndiko kukula kwa tinthu tating’ono kwambiri85%zigawo potengera kulemera kwa maziko. Lamuloli likhoza kuwonetsedwa ndi maubwenzi: F15/B15 >4ndi f15/B85< 4.
Chiŵerengero choyamba chimatsimikizira kutsekemera kwa madzi kwa fyuluta, pamene chachiwiri chimatsimikizira kukhazikika kwake. Mizere ya granulometric yoyambira pansi ndi fyuluta molingana ndi lamulo la Terzaghi

Sl.4- Lamulo losefera la Terzaghia

Zing’onozing’ono komanso zazikulu kwambiri za m’munsi zimaperekedwa mkuyu.4mizere yamalire1ndi2. Mizere yamalire ya fyulutayo ndi3ndi4. Chikhalidwe F15 >4_B15_ imayimiridwa ndi mfundo A pamzere wamalire3, chikhalidwe F15< 4_B85_ tačkom b na liniji 4.
Ndikofunikira kuti mzere wa mawonekedwe a granulometric wa fyulutayo ukhale wofanana ndi mzere wa granulometric wa maziko. M’malo mwa mizere iwiri yowopsya ya granulometric yochokera kumunsi monga mkuyu.4, ukhoza kukhala mzere umodzi wa tirigu wamba. Zikatero, mfundo B15_ndi b85 ali pamzere womwewo (monga mkuyu.5). Nthawi zambiri, kusiyana kwa granulation pakati pa maziko ndi ngalande ndi ngalande kuti zone fyuluta imodzi sikokwanira kusintha pakati pa maziko ndi wosanjikiza. Pankhaniyi, fyuluta imakhala ndi magawo angapo a fyuluta, omwe amatsimikiziridwa molingana ndi lamulo lomwelo, mpaka kukula kwakukulu kwa phala la ngalande kufikire.

Chitsanzo chofotokozera zigawo zingapo zosefera pakati pa nthaka ndi ngalande

Sl.5- Chitsanzo cha kuwerengera zigawo zosefera

Magawo omwe ali pamwambapa, kukula kwake ndi malamulo amasamutsidwa kuchokera ku mbiri yakale ndipo salowa m’malo mwa gulu lamakono la geotechnical, lipoti la labotale, kapangidwe kazosefera kapena dongosolo la magwiridwe antchito. Dothi lenileni ndi ngalande zimafuna zitsanzo zoyimira, kuyezetsa koyenera, kuyang’ana madzi apansi ndi pansi, kukokoloka kwa nthaka ndi kukhazikika kwamkati, komanso kuunika kwa katswiri wovomerezeka malinga ndi malamulo ndi zikhalidwe za polojekitiyi.