Tunnels and underground openings in hard rock are often constructed with arch-shaped ceilings and complicated 3D geometries arise at intersections with cross tunnels and other openings. This is further complicated due to the often irregular shape of the rock surface and the uneven shotcrete thickness, making it difficult to analyse the interaction between rock and support systems. A study of the interaction in 3D between an irregular, rough rock surface and supporting rock bolts and shotcrete has begun, through finite element modelling using non-linear material models and formulations capable of describing large deformations. Various cases that may cause failure are to be studied, such as falling blocks or heavily jointed rock, bolt failure and drumminess between rock and shotcrete. An important conclusion from the preliminary results is that rock bolts should be placed at points where the shotcreted surface is locally convex, i.e. at peaks.