Effects of cementation on pore water pressure response during normal faulting in clay

Abstract

Although pore water pressure was of significance to understand soil behaviour, limited efforts have been devoted to explore and understand pore water pressure responses due to fault propagation. This paper introduces and discusses measured pore water pressures in uncemented and cemented clay bed subjected to normal faulting in a geotechnical centrifuge. Different ground deformation mechanisms and pore water pressure responses in two soil strata are compared and discussed. For uncemented clay stratum, the soil deformed with a shearing mechanism. The uncemented clay tended to dilate during shearing and pore water pressure decreased. For cemented clay, the soil deformed with a bending mechanism. The pore water pressure at the early stage of faulting increased when subjected to shearing and decreased when subjected to tension. The excess pore water pressures in cemented clay dissipated faster as compared with that observed in uncemented clay attributed to shorter drainage path created by fault ruptures in cemented clay.