Date of Award

2014

Degree Type

Thesis

Degree Name

Master of Science (MS)

Department

Civil and Environmental Engineering

First Advisor

Aaron S. Bradshaw

Abstract

This thesis presents a comparison between measured breakout capacity and a range of theoretical capacity solutions (i.e. limit equilibrium, limit analysis, finite element and cavity expansion) for shallow embedded anchors in sand. Evaluation and reviews are performed using a database of measured vertical breakout capacity results from largescale, shallow embedded, single-helix anchors collected by the author. Understanding the soil-anchor interaction and predicting the capacity of shallow circular plate and helical anchors in sands has been a major focus among geotechnical engineering researchers since the 1950’s. A number of models have been developed which range from purely theoretical to semi-empircal and empirical formulations. There is uncertainty in the current models due to limitations in theory and experimental data used for validation. Attention in most models is focused on the shape and size of the failure surface and lateral earth pressures established during anchor uplift; the components affect shear stresses and the weight of soil being displaced, thus the total breakout capacity. The identified theoretical models were evaluated using the soil properties measured and estimated from the large-scale test results that were performed. Results suggest an over-prediction in capacity among many of the limit equilibrium models, with the exception of a re-derived limit equilibrium model that considers non-associated flow. Furthermore, good agreement is seen between the finite element and cavity expansion models as well as some limit analysis methods.

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