this report describes studies in the oxford area of the settlement of three road embankments founded on the compressible alluvium commonly occurring in the region. the construction loading and subsoil conditions were similar at the three locations. at one site vertical sand drains had been installed to accelerate the process of consolidation and a study was made of the effectiveness of the drains. the settlements at all three sites occurred considerably more rapidly than was estimated on the basis of the data from conventional laboratory consolidation tests. the magnitudes of the calculated and measured settlements were, however, in reasonably close agreement and, by using in-situ measurements of permeability, close agreement was also obtained between the measured and calculated rates of settlement. the sand drains were found to be ineffective at accelerating the process of consolidation. as the primary consolidation was largely completed at all three sites within the construction period, the studies showed that the use of special foundation treatments such as sand drains and excavation of the alluvium was unnecessary. estimations of the rate of secondary consolidation using the soil parameters from long-term consolidation tests did not give a very reliable assessment of the actual rate of movement. (a)

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