Surface Settlement of Column-Supported Embankments: Results of Laboratory Tests
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Authors
Sloan, Joel A.
McGuire, Michael
Filz, George M.
Issue Date
2015-02
Type
Article
Language
en_US
Keywords
Alternative Title
Abstract
There is little published guidance describing how to relate settlement at the surface of a column-support embankment to settlement at the base. One method proposed by Russell et al. (2003) assumes that settlement at the base of the embankment produces zero volume change within the embankment. This paper describes results of extensive bench-scale experiments that indicate that the embankment material dilates in response to internal deformation caused by base settlement. Laboratory scale experiments performed by Demerdash (1996) are also considered. The effect of dilation leads to surface settlement that is less than what is predicted using the zero volume change assumption. A modification to the method by Russell et al. (2003) is described to account for the effect of volume change within the embankment. 1. INTRODUCTION A primary function of column-supported embankments is to reduce post-construction settlement that would otherwise occur due to the weight of the embankment and surface loads. A large part of this function is achieved by transferring imposed loads to an array of stiff columns, which reduces the change in load experienced by the compressible foundation soils. Load transfer to the columns above the foundation level occurs due to soil arching within the embankment and tension developed in the reinforcement, if included. Both mechanisms are activated by settlement of the subgrade between the columns that exceeds the settlement at the top of the columns. When an embankment is above the critical height, as that term is used in this paper, the differential settlement that occurs at the base of the embankment produces essentially uniform settlement at the surface of the embankment. The magnitude of uniform settlement at the surface of the embankment is less than the magnitude of the average differential base settlement. This paper uses the results of bench scale and laboratory scale experiments to investigate the reduction in settlement that occurs within the embankment. The method proposed by Russell et al. (2003), which relates the surface settlement to the average base settlement assuming no volume change within the embankment, serves as the starting point for comparisons to the experimental data. The aim is to provide guidance for estimating the magnitude of uniform settlement at the surface of the embankment from the magnitude of base settlement calculated using procedures such as the load-displacement compatibility method described by Filz et al.
Description
Citation
Mcguire, Michael & Filz, George & Sloan, Joel. (2015). Surface Settlement of Column-Supported Embankments: Results of Laboratory Tests.
Publisher
Geosynthetics 2015