Analiza utjecaja usisnih naprezanja na stabilnost djelomično zasićenog nasipa

master's thesis

• Title: Analiza utjecaja usisnih naprezanja na stabilnost djelomično zasićenog nasipa : diplomski rad
• Title (english): Numerical analysis of suction stress on the stability of partially saturated embankments : master’s thesis
• Author: Marina Bošković
• Mentor: Biljana Kovačević Zelić (mentor)
• Committee member: Biljana Kovačević Zelić
• Committee member: Predrag Kvasnička
• Committee member: Petar Hrženjak
• Granter: University of Zagreb; Faculty of Mining, Geology and Petroleum Engineering; (Department of Mining and Geotechnical Engineering); Zagreb
• Defense date and country: 2013-09-26, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Mining, Petroleum and Geology Engineering; Mining

Abstract

Nesaturirana tla mogu uzrokovati različite geotehničke probleme koji se javljaju kod
zemljanih brana ili nasipa zbog raspodjele pornog tlaka vode i zraka što može dovesti do
njihove nestabilnosti. Numerički model nasipa od nesaturiranog tla obuhvaća analizu
procjeđivanja i stabilnosti nasipa provedenu kroz pojedinačne faze s porastima razine vode
na uzvodnoj strani do maksimalne visine od 7 m. Usporedbom rezultata analize dvaju
modela, saturiranog i nesaturiranog, pokazalo se da djelovanje privlačnih sila, usisa,
između molekula vode i čestica tla, koji uzrokuje ulazak vode u porni prostor i njeno
zadržavanje, dolazi do povećanja posmične čvrstoće a samim time i povećanjem stabilnosti
nasipa. Rezultati analize stabilnosti pokazuju veće faktore sigurnosti za model od
nesaturiranog tla u odnosu na model od saturiranog tla. Osim toga prikazan je i utjecaj
dreniranja nožice nasipa na stabilnost nasipa. Dren „navlači“ vodu uzrokujući smanjenje
pornih pritisaka čime se onemogućava erozija nasipa te sprječava pojava hidrauličkog
sloma tla a posljedično i gubitka stabilnosti pokosa.

Abstract (english)

Abstract: Unsaturated soil can cause a variety of geotechnical problems that occur in earth dams or
embankments for the distribution of pore water pressure and air which can lead to
instability of the embankment. The numerical model of unsaturated soil embankment
includes an analysis of seepage and stability of embankments carried out through a single
phase with the rise in water level on the upstream side to a maximum height of 7 m.
Results of analysis, comparing the two models, saturated and unsaturated, show that the
action of the forces of attraction, suction, between water molecules and soil particles,
which causes the suction of water in the empty cavity and its retention, increase shear
strength and thus increasing the stability of the embankment. Results of the analysis show
greater factor of safety of unsaturated model unlike saturated models. Additionally, the
impact of drainage dike base on the stability of embankments is shown. Dren "pulls" water
and thus a decrease in pore pressure and reducing erosion of embankments which could
lead to hydraulic fracturing and the development of the sliding surface.

• Keywords: nesaturirano tlo; usis; faktor sigurnosti; stabilnost kosina; procjeđivanje
• Keywords (english): unsaturated soil; suction; safety factor; slope stability; seepage
• Language: croatian
• URN:NBN: urn:nbn:hr:169:365719
• Study programme: Title: Mining; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra inženjer/inženjerka rudarstva (magistar/magistra inženjer/inženjerka rudarstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Access restricted to students and staff of home institution
• Created on: 2016-01-21 13:34:02