Static shear strength of silty soil exposed to cyclic loading

Dynamic and static experiments were performed on the dynamic three-axis pressure test system in silty sandy and clayey soils from Adapazarı. The indicative side of this study is to be performed at low cyclic stress ratio. The aim of this study is to determine the static shear strength of silty soils exposed to earthquake load during and after earthquake. In this respect, the study was carried out on the samples that been prepared from the slurry in the laboratory. The frequency, shearing speed and dynamic loading ratio were fixed in all experiments while the number of cycles was changed. The initial strengths of the samples were compared with the final strengths after the dynamic load. Thus, the effect of dynamic loads on the ground has been investigated. Six different mixtures were determined in the study. These mixtures were prepared according to the percentage of silt and clay they contain. According to the results of the experiments, after the dynamic loading of the grounds, the strengths determined by the static shear increased according to the initial state and thus the resistance gains on the soils have formed. Due to the low dynamic shear stress ratio, it is thought that low intensity repetitive loads on the ground change the grain sequences of the ground and cause the soil to harden. Another reason is that the clay does not have a tendency to liquefy because of the cohesion property of clay, since the lowest clay ratio in the test samples starts at 20%. At the same time, to be a more rigid form due to compression of the ground and some cases like settlement as a result of this cituation may happen. It should not be neglected that the settlements will cause negative effects on the superstructure.