Abstract
We had construct a railway tunnel at the site where the occurance of landslides was feared and in addition there were some private houses. We concerned ourself about bad influences on landslide behaviors and the houses due to shocks caused by blastings used for the construction. The maximum blasting shock occurs during a center cut explosion, which is the first explosion in a borehole among many ones filled with dynamite. First, we designed a criterion to evaluate the risk of landslides on the basis of vibration velocities of the blasting shocks. Next, by the survey of blasting-induced vibrations before and during the construction. we examinedthe permissible volume of center cut dynamite in comparison with the criterion. As a result, the tunnel was successfully excavated with no influence on the houses and landsliding due to blast shock. This report describes the method of investigation and analysis, and the results of observation of landslides during the actual construction.
