Preconsolidation of Sovind Marl-A Highly Fissured Eocene Clay

摘要

Determination of the preconsolidation stresses is a key tool in geotechnical engineering used to evaluate and estimate the behavior of soils. However, it has proven difficult to accurately estimate these stresses in highly fissured, overconsolidated clays, due to the influence of the fissured structure. In the current study, oedometer tests were performed on Sovind Marl, a plastic Eocene clay containing a large number of fissures and slickensides. Four incremental loading oedometer tests and four continuous loading oedometer tests were performed in order to determine the preconsolidation stresses. Multiple assessment methods were used to assess preconsolidation stresses based on the oedometer test data, results of which are presented and discussed on this paper. All of the test and interpretation methods yielded very similar results, with two possible values calculated as the preconsolidation stresses. However, only the upper stress bound is actually identified as being associated with preconsolidation; the lower bound is generated as a result of the collapse of the fissured structure in response to increasing stresses that were applied during testing. The upper bounds of the preconsolidation stresses of Sovind Marl were between 6300 and 8900 kPa, whereas the lower were between of 600 and 800 kPa.