Risk recognition of construction of large-span and shallow buried-highway tunnels based on analytic hierarchy process

In order to identify risk factors during the process of tunnel construction effectively, expert investigation method and analytic hierarchy process are combined to identify the risk in construction of large-span and shallow-buried highway tunnels based on the review of disadvantages of traditional risk recognition methods. The risk hierarchical structure for construction of Maoshan Mountain tunnel is established by using the analytic hierarchy process, and six basic risk events including surrounding rock instability, landslide of tunnel portal, overbreak, lining damage and leaking, tunnel top surface subsidence and influence of waste residue site on environment are obtained. The synthetic weight of each basic risk event is calculated, and the weight of surrounding rock instability related to the construction risk is close to 0.5. Therefore effective risk control measures are advised. It is concluded that analytic hierarchy process can act as a risk recognition model for construction of large-span and shallow-buried highway tunnels.