Effect of Design Parameters on Piled Rafts in Sand under Eccentric Triangular Loads
Publication: International Journal of Geomechanics
Volume 22, Issue 6
Abstract
Piled raft foundations (PRFs) below stepped high-rise towers are often subjected to nonuniform triangular-shaped loads with eccentricities. In this study, 20 rectangular piled rafts with different pile configurations and orientations, embedded in medium-dense sandy soil, are analyzed using three-dimensional nonlinear finite-element (FE) analysis in which the critical state–based Clay and Sand Model (CASM) is used as the soil constitutive model. Different triangularly distributed loads with and without eccentricities are considered in addition to uniformly distributed loads. A systematic parametric study is performed by varying the different design parameters based on which the PRF behavior is systematically investigated in terms of multiple performance parameters such as maximum settlement, differential settlement, angular distortion, tilt, and load distribution between the raft and the piles and between the individual piles. It is observed that the pile diameter, number of piles, and raft plan area control the differential settlement, angular distortion, and tilt the most. Based on the insights gained from the parametric study, a design optimization exercise is performed, in which the most optimal pile configuration is selected based on the criteria of allowable settlement and angular distortion with additional considerations for tilt, load distribution, and the volume of concrete required.
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Published In
International Journal of Geomechanics
Volume 22 • Issue 6 • June 2022
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© 2022 American Society of Civil Engineers.
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Received: Aug 16, 2021
Accepted: Jan 3, 2022
Published online: Mar 24, 2022
Published in print: Jun 1, 2022
Discussion open until: Aug 24, 2022
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