Coupled shear strain-pore pressure responses of soil in shaking table tests

Shaking table tests on a saturated sand specimen in a laminar shear box were performed to measure the coupled shear strain-pore pressure response of sands subjected to horizontal shaking. Three methods of shear strain evaluation techniques, which use soil motions recorded by embedded sensors within the soil specimen and external sensors on frame, were utilized to evaluate the shear strain-time histories in one-dimensional shaking cases. Coupled shear strainpore pressure responses throughout the liquefaction process are presented based on evaluated shear strains and measured pore pressures at corresponding depths. More insights of the interactions between the induced shear strain and generated excess pore pressure are also given, including the temporal variations of induced shear strain prior and after the initial liquefaction, development of liquefied zone, and duration of liquefaction state. These spatial and temporal variations of coupled responses reveal that the induced shear strain amplitude is not only an important property in triggering soil liquefaction but also a better index in defining the time of initial liquefaction. Identifications of these coupled features will be beneficial for verifying and interpreting testing data in physical modelling for liquefaction studies.