This study discusses the results of numerical modeling aspect of aggregate pier foundations (aggregate piers) in soft, compressible soils. FLAC 2D (Fast Lagrangian Analysis of
Continua), a finite difference code is utilized in the analyses. Use of axisymmetry enabled to visualize a three dimensional model throughout this research.
The primary objective of this research is to make comparisons for stress concentration ratio &lsquo / n&rsquo / , and settlement reduction ratio b for given variables consisting of length, diameter,
elastic modulus of the aggregate piers, and foundation pressures.
Analyses have been carried out with 1, 1.5, 2, and 3 m long piers with diameters of 60 cm, and 80 cm, placed under a circular footing in 1.30 m diameter. Two values for elastic
modulus of the piers have been used to reflect the effect of pier stiffness on settlement behavior. Analysis and design methodology have been carried out in three stages. The first stage consists of modeling the matrix soil with an elastic constitutive model and exerting foundation pressures to first check the accuracy of the mesh by comparing the effective
vertical stress and settlement values by analytical methods. Once satisfactory results are achieved, modeling of a rigid foundation is carried out. Consequently, aggregate piers are
modeled and loaded. For foundation pressures, a range of values consisting of 25, 50, 75, and 100 kPa have been chosen to see the behavior of piers under variable foundation
pressures.
There are solid outcomes of this study. It concludes by stating that the settlement behavior of piers having L/d ratios greater than 3.75, are alike. Thus, there is almost no additional settlement improvement achieved with piers longer than 3 m with 60 cm pier diameter.
| Identifer | oai:union.ndltd.org:METU/oai:etd.lib.metu.edu.tr:http://etd.lib.metu.edu.tr/upload/12605190/index.pdf |
| Date | 01 April 2004 |
| Creators | Kemaloglu, Sarp |
| Contributors | Erol, Orhan Ahmet |
| Publisher | METU |
| Source Sets | Middle East Technical Univ. |
| Language | English |
| Detected Language | English |
| Type | M.S. Thesis |
| Format | text/pdf |
| Rights | To liberate the content for public access |
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