Utjecaj veličine inkrementa naprezanja na konsolidacijska svojstva tla

master's thesis

• Title: Utjecaj veličine inkrementa naprezanja na konsolidacijska svojstva tla : diplomski rad
• Title (english): Influence of load increment ratio on soil consolidation properties : master's thesis
• Author: Martina Gavrić
• Mentor: Biljana Kovačević Zelić (mentor)
• Mentor: Evelina Oršulić (pomoć pri izradi, neposredni voditelj)
• Committee member: Biljana Kovačević Zelić (predsjednik povjerenstva)
• Committee member: Helena Vučenović (član povjerenstva)
• Committee member: Dubravko Domitrović (član povjerenstva)
• Granter: University of Zagreb; Faculty of Mining, Geology and Petroleum Engineering; (Department of Mining and Geotechnical Engineering); Zagreb
• Defense date and country: 2023-09-14, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Mining, Petroleum and Geology Engineering; Mining

Abstract

Cilj ovog rada bio je ispitati utjecaj veličine inkrementa naprezanja na konsolidacijska svojstva tla. U tu svrhu provedeno je laboratorijsko ispitivanje jednodimenzionalne konsolidacije u klasičnom edometarskom uređaju. Prikazani su temeljni principi teorije jednodimenzionalne konsolidacije te interpretacija parametara koji se koriste u procjeni slijeganja. Ispitivanje tla je provedeno na dva uzorka s različitim rasporedom opterećenja. Jedan uzorak opterećen je u inkrementima koji su definirani u normi i uobičajeno se primjenjuju u praksi, a drugi je opterećen ciklusom s manjim inkrementima. Opažano je kakav će to utjecaj imati na parametre stišljivosti i konsolidacijska svojstva tla. Indeks kompresije i rekompresije, kao i naprezanje prethodne konsolidacije nisu se značajnije razlikovali. Međutim, kod analize dijagrama vremenskog tijeka slijeganja, za uzorak s malim inkrementima, krivulje konsolidacije su odstupale od teorijskih zbog čega interpretacija koeficijenta konsolidacije nije bila moguća. U nekoliko drugih studija o sličnoj problematici pokazalo se da veličina inkrementa naprezanja značajno utječe na komponente ukupnog slijeganja zbog čega krivulja gubi karakterističan oblik. Zaključeno je kako ispitivanje s malim inkrementima može biti praktično za preciznije određivanje naprezanja prethodne konsolidacije i parametara stišljivosti, ali može onemogućiti interpretaciju vremenskog tijeka slijeganja.

Abstract (english)

The aim of this study was to investigate the influence of the load increment ratio on the soil consolidation properties. For this purpose, a laboratory test of one-dimensional consolidation was carried out using a conventional oedometer. In this work, the fundamental principles of the one-dimensional consolidation theory were presented and the parameters used for the settlement calculation were defined. Two soil samples were subjected to a constant total axial stress with different load increment ratios. One test was carried out with the standard loading sequence commonly used in practise, the other with an alternative loading scheme consisting of small load increments. The effects on the consolidation behaviour of the soil were investigated by observing the compressibility parameters and the consolidation properties. The results for the compression index, swell index and pre-consolidation pressure showed no significant differences. However, in the tests with alternative loading sequence, the time–displacement curves show a different shape than the one based on the onedimensional consolidation theory. For this reason, it was not possible to correctly estimate the coefficient of consolidation. Several other studies have shown that the magnitude of the load increment ratio strongly influences the shape of the time–displacement curve, which can be explained by the change in the primary consolidation ratio of the total settlement. It was concluded that although small increments are desirable to determine the preconsolidation stress and compressibility parameters with greater accuracy, they may hinder the evaluation of the coefficient of consolidation and time settlement interpretation.

• Keywords: geotehničko inženjerstvo; slijeganje; konsolidacija; stišljivost; koeficijent konsolidacije; edometar
• Keywords (english): geotechnical engineering; settlement; consolidation; compressibility; consolidation coefficient; oedometer
• Language: croatian
• URN:NBN: urn:nbn:hr:169:318543
• Study programme: Title: Mining Engineering; specializations in: Mining engineering, Geotechnical engineering, Waste treatment and disposal; Course: Mining engineering; 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: Open access
• Created on: 2023-10-11 08:58:35