Numerical analysis of circular footings on natural clay stabilized with a granular fill

Murat Ornek (Author), Mustafa Laman (Author), Ahmet Demir (Author), Abdulazim Yildiz (Author)

Abstract

In this study, numerical predictions of the scale effect for circular footings supported by partially replaced, compacted, layers on natural clay deposits are presented. The scale- effect phenomenon was analyzed according to the footing sizes. Numerical analyses were carried out using an axisymmetric, two-dimensional, finite-element program. Before conducting the analysis, the validity of the constitutive model was validated using field tests performed by authors with seven different footing diameters up to 0.90 m and with three different partial replacement thicknesses. It is shown that the behavior of the circular footings on natural clay soil and the partial replacement system can be reasonably well represented by the Mohr Coulomb model. The Mohr-Coulomb model parameters were derived from the results of conventional laboratory and field tests. After achieving a good consistency between the results of the test and the numerical analysis, the numerical analyses were continued by increasing the footing diameter up to 25 m, considering the partial replacement thickness up to two times the footing diameter. The results of this parametric study showed that the stabilization had a considerable effect on the bearing capacity of the circular footings and for a given value of H/D the magnitude of the ultimate bearing capacity increases in a nonlinear manner with the footing diameter. The Bearing Capacity Ratio (BCR) was defined to evaluate the improved performance of the reinforced system. It was found, based on numerical and field-test results that the BCR of the partially replaced, natural clay deposits increased with an increase in the footing diameter and there was no significant scale effect of the circular footing resting on natural clay deposits.

Keywords

scale effect;circular footing;field test;finite-element analysis;natural clay;granular fill;

Data

Language:	English
Year of publishing:	2012
Typology:	1.01 - Original Scientific Article
Organization:	UM FGPA - Faculty of Civil Engineering, Transportation Engineering and Architecture
UDC:	550.3:624.15
COBISS:	270587904
ISSN:	1854-0171
Parent publication:	Acta geotechnica Slovenica
Views:	695
Downloads:	85
Average score:	0 (0 votes)
Metadata:

Other data

Secondary language:	Slovenian
Secondary title:	Numerična analiza okroglega temelja na naravni glini, stabilizirani z zrnatim polnilom
Secondary abstract:	V tej študiji so predstavljene numerične napovedi obsega učinka na okrogle temelje, podprtih z delno zamenjanimi in zgoščenimi plastmi na usedlinah naravne gline. Pojav obsega učinka je analiziran glede na velikost temelja. Numerične analize so bile izvedene z uporabo osno simetričnega, dvodimenzionalnega programa s končnimi elementi. Pred izvedbo analize je bila potrjena veljavnost osnovnega modela z uporabo terenskih testov s sedmimi različnimi premeri temeljev do 0,90 m in s tremi različnimi delno zamenjanimi debelinami. Izkazalo se je, da lahko obnašanje okroglih temeljev na tleh iz naravne gline in delno zamenjanim sistemom dovolj primerno prikažemo z Mohr-Coulombovim modelom. Parametri Mohr Coulombovega modela so izpeljani iz rezultatov z običajnimi laboratorijskimi in s terenskimi testi. Z doseženo dobro složnostjo med rezultati testa in numeričnimi analizami, so bile nadaljevane numerične analize s povečevanjem premera temeljev do 25m in upoštevanjem z delno zamenjavo debeline do dvakratnega premera temeljev. Rezultati te parametrične študije so pokazale, da ima stabilizacija precejšen učinek na nosilno kapaciteto okroglih temeljev in da se pri dani vrednosti H/D magnituda mejne nosilne kapacitete poveča s premerom temelja na nelinearni način. Določen je količnik nosilne kapacitete (BCR) za določitev izboljšanega učinka ojačenega sistema. Na podlagi rezultatov numeričnih in terenskih testov je ugotovljeno, da se BCR delno zamenjanih odloženih naravnih glin poveča s povečanjem premera temeljev in da ni pomembnega obsega učinka okroglega temelja ležečega na usedlini z naravno glino.
Secondary keywords:	geofizika;temelji;glina;analiza končnih elementov;Mohr-Columbov model;
URN:	URN:SI:UM:
Type (COBISS):	Scientific work
Pages:	str. 61-75
Volume:	ǂVol. ǂ9
Issue:	ǂ[no.] ǂ1
Chronology:	2012
ID:	10941024