Abstract: The collapse phenomenon of tunnel in construction process is closely related with the quality of shotcrete,so high strength and toughness on the shotcrete of good performance is one of the research contents of need in the construction of the underground engineering. The experiments of single steel fiber,polypropylene fiber,macrosynthetic fiber reinforced shotcrete on the compressive strength and flexural strength are researched in this paper,which are compared with the mechanical properties of common shotcrete,which shows that the compressive strength,flexural strength,flexural compression ratio of fiber shotcrete with appropriate dosage are obviously improved than common shotcrete; strength and flexural compression ratio of macro-synthetic fibers reinforced shotcrete are the best,whose content is 0. 3%. So steel fiberss and polypropylene fiber can be completely replaced by the macro-synthetic fibers in project application with its excellent price-lim,good dispersion and weak corrosion etc.

Key words: shotcrete, macro-synthetic fiber, polypropylene fiber, steel fiber, compressive strength, flexural strength, flexural compression ratio