Abstract:

The main structures, working principles and construction procedures of open shields are presented. In case open shields are used, the stability of the soil mass of the excavation face can be guaranteed. Open shields have such features as good economical efficiency, good construction progress rate, good special situation coping functions and good risk controlling capability. Analysis is made on the applicability of open shields in the geological conditions in Beijing area. The study shows that open shields can meet the requirements of the tunnel construction in Beijing area and are worth to be popularized.

Key words: open shield, Beijing area, applicability analysis