Abstract: The key points of the application of and economical analysis on tunnel excavation by hydraulic rock drilling jumbos are discussed. The causes for the overbreak induced by hydraulic rock drilling jumbos and the collection of the basic data needed for economic analysis are presented and analyzed. The analysis results show that hydraulic rock drilling jumbos are suitable, rational and economical for the excavation of long railway tunnels.

Key words: long railway tunnel, hydraulic rock drilling jumbo, excavation technology, economical analysis