Basal reinforcement failure

Basal reinforcement mainly (1) increases the stability of the embankment by mobilizing the force in the reinforcement, (2) confines the fill material and forms a flexible foundation (ductile failure in contrast to rapid failure of unreinforced embankment), (3) handles infiltration and separation of the subgrade into fill material, and (4) makes the settlement of embankments more uniform. 

For cases in which the available construction time is limited or serviceabiUty criteria are high, methods other than basal-reinforced embankments need to be chosen. Most commonly, ground improvement using stone or gravel columns is chosen. However if the foundation soil is extremely soft, the use of conventional stone columns can lead to unacceptable deformation or even failure. This is because the soft soil... 

The embankment was to be constructed of quarried chalk, with a basal layer of reinforcement. Computer analysis concentrated on the embankment and its reinforcement. Midway through construction, the embankment slipped sideways, remaining relatively intact, somewhat in the manner shown by the finite element analysis in Figure 4, which indicates a combined sliding and bearing failure. Analysis of this mode had not been considered, perhaps because it is quite complex and the significance of the extremely low strength of the muds was not understood, but mainly because of reliance on software that did not include this type of failure. 

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