Introduction

Column-supported embankments (CSEs) are a method of ground improvement commonly used when an embankment is required over soft, compressive soil that is likely to experience expansive settlements because of the added load in the absence of soil improvement. CSEs are an alternative to other methods to mitigate settlement in compressible soils such as the use of prefabricated vertical drains and surcharge fills. Because a CSE can greatly reduce the ultimate consolidation settlement, the embankment can be constructed immediately and there is less potential for damage to nearby facilities. CSEs are often constructed with a square, rectangular, or triangular column arrangement. In general, column-supported embankments should be designed and constructed with a total embankment height greater than the critical height. Embankments with a total height at least as tall as the critical height are expected to experience uniform surface settlement even though there will be differential settlement at the base.