Ground behavior evaluation for tunnels in blocky rock masses

Ground characterization and ground behavior evaluation are introductory steps in tunnel design. For a realistic evaluation reflecting specific ground and site conditions, reasonable ground models and evaluation tools are essential. At design stage simulations with discrete element method enables to model the reaction of blocky rock masses during excavation. At construction stage the predicted model is updated according to the absolute displacement monitoring data. In this paper a parametric study is performed with distinct element program UDEC for different joint characteristics and in situ stresses to evaluate the ground behavior in blocky rock masses. The classification of the ground behaviors are carried out according to the established delimiting criteria. Characteristics of various ground behaviors and conditions leading to the specified behavior are defined.