Abstract: This article describes the overview of technical progress of shotcrete before and after construction of highspeed railway tunnel. The technical specifications of tunnel shotcrete has not been appropriately used in the latest tunnel improvement project of No.9 highway in Taiwan. It needs to review and revise the existing inappropriate specifications to meet the international trend. The preliminary suggestions for the amendment of the existing specifications has been included in this article. It is expected that the suggestions described in this paper would provide a reference basis for the next specification revision of shotcrete construction.

Key words: Tunnel shotcrete, shotcrete admixtures, steel fibers, early strength, flexural toughness and test methods