Hartwall Arena ice hockey rink, the widest underground rock space in Helsinki

摘要

An ice rink intended for ice hockey training purposes was constructed in an urban area and in the rock below a street adjacent to the Hartwall multipurpose arena in Pasila, Helsinki, in 1998. The principal dimensions of the hall are: width 31 m (32 m at the rinks), length 75 m and roof height approximately 6 m. The design allows for a possible future lowering of the street level above the rink. Hence the average thickness of the rock roof is 10 m. The site investigations showed the rock to be of very good quality (Q'= 53). The two-dimensional finite element program UDEC-BB, version 3.0, was used for numerical simulation, enabling scrutiny of the rock mass for risks of shearing or block failure. The safety factor of the rock mass with respect to caving was found to be >4 according to the Hoek-Brown failure criterion. Rock quality was monitored during the excavation work. The rock quality conformed to expectations and the measured displacements were of the same order of magnitude as those which had been calculated.