Thesis
Numerical simulation of the performance of sand columns
Washington State University
Master of Science (MS), Washington State University
2004
Handle:
https://hdl.handle.net/2376/286
Abstract
Sand columns have been widely used to improve a range of soils less suitable for other techniques. The installation of sand columns results in the improvement of engineering properties. Current design and performance analysis of sand columns are limited and are mostly empirical. Most analytical methods consider the sand column and the surrounding ground as an elastic composite model and develop equivalent properties. The effectiveness of compaction and increase in density is dependent on the initial state of soil. Therefore, a state parameter that combines void ratio and mean stress is used here to better characterize the behavior of improved ground. This state parameter is incorporated into a numerical model and used to study the performance of improved ground. Numerical simulation of the deformation characteristics of an embankment on weak clay reinforced with stone columns was carried out using FLAC 3D. The problem was also analyzed by using equivalent critical state parameters of the composite ground. The results of the equivalent parameter model were found to correlate well with the analysis of the original configuration. The numerical analyses show that the improvement in vertical as well as lateral displacement of the embankment is dependent very much on the location and the extent of the placement of sand columns. The displacement patterns of an unimproved ground provide guidance towards the economical placement of the sand columns. The numerical results also show that beyond 40% improved area ratio very little improvement in displacement is achieved. The study conducted quantified the influence of the initial state of the ground on improved performance. It was found that for a given modular and improved ratios, improvement in vertical displacement ratio could vary significantly depending on the initial state parameter value.
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Details
- Title
- Numerical simulation of the performance of sand columns
- Creators
- Sathishbalamurugan Murugaiah
- Contributors
- Balasingam Muhunthan (Degree Supervisor)
- Awarding Institution
- Washington State University
- Academic Unit
- Civil and Environmental Engineering, Department of
- Theses and Dissertations
- Master of Science (MS), Washington State University
- Publisher
- Washington State University; [Pullman, Washington] :
- Identifiers
- 99900525370901842
- Language
- English
- Resource Type
- Thesis