Risk Assessment In Tunnel Portal Landslide Based On Fuzzy AHP Comprehensive Evaluation

Tunnel portal play an important role in the construction of the tunnel,is also a section of the construction accident-prone.The most common landslide is also easy to accident,if processes improper,slight into the tunnel is difficulties,while large difficulty to collapse,to cause great difficulty in construction.Therefore it is necessary to risk assessment before construction for the smooth construction project provide basis.According to build a tunnel for the landslide risk assessment model is studied,the main contents include following aspects:1.Summarize the domestic and overseas research of tunnel engineering risk, and the problems existing in the researc.2.Defining risk of tunnel portal, this paper expounds the connotation of risk and risk identification, risk estimation,risk evaluation, simple introduction and comment on some common risk identification risk estimation methods, risk acdeptance criteria and strategies.3.Collect and organize the domestic 62 seat for the tunnel protal landslide material, according to the survey result analyses on the tunnel protal landslide period of seven's most influential factors:Rock classification,Excavation width,Buried deep,Unsymmetrical pressure, Adverse geological,Groundwater effect,Construction technology and management level.4.Establish a tunnel portal landslide fuzzy AHP comprehensive evaluation model:by using fuzzy theory quantitative risk factors, using fuzzy method and experience all risk factors for method to establish the tunnel portal landslide probability and for the consequences of membership functions, using AHP to each factor of influence of landslide.5.Using the model to estimate the Maanshan tunnel,evaluate conclusion is high-risk(Ⅲ). In the process of construction, collapse occurs during construction in the right hole of tunnel, produced a pit collapse about 12.5×3m2.depths 2.8m.We can see calculation and practical results are basically same,verify the model is practicability and accuracy.6. This paper based on the engineering survey,establish a model have certain engineering application value,for the similar projects in future risk assessment has reference significance.