Insitu test of steel-nailing reinforcement for cut slope with alternating sandstone and mudstone

In order to clearly understand the behavior of the nailed steel bar, an insitu test had been carried out for about two years at Nichinan in southern part of Kyushu, Japan. After analysis of the monitoring strain data of the steel bar, the tendency of distributions of bending and axial strain in the steel bar would become clear and the sliding surface of the slope with alternating sandstone and mudstone could be estimated. About two years after inserting the steel bars in the slope, some were picked up from the slope to compare the deformed shape of the steel bar with the distribution of bending strain and to identify the sliding surface of a slope. Considering these test results, many types of deformation of the steel bars including the shearing and creeping types were gotten. Furthermore the effect of bending strain for resisting the sliding of slope becomes important in some sliding cases.