Effect of compaction history on the shearing behaviour of a silty sand under constant water content conditions
Compaction conditions govern the shear strength behaviour of a compacted soil. The shear strength parameters are usually evaluated for specimens compacted at a given state and then tested for different post-compaction loading conditions. While this approach enables the prediction of the behaviour in service, the impact of compaction history is usually ignored. This is an important aspect as the shearing behaviour of compacted soil is strongly influenced by soil structure and suction, and thus the soil's compaction/loading history. In this paper, the aspects related to the effect of compaction history of a silty sand soil subjected to direct shearing under constant water content conditions are described. To investigate the role of compaction history, specimens were prepared at different compaction energy levels and subsequently tested under the same vertical stress. The results confirm the importance of the initial stress state of the soil in relation to its compaction history in governing the mechanical response during direct shearing.