Study On Safety Risk Of Adjacent Buildings During Metro Tunneling Construction

The recent China exerts increasing demands to go underground, particularly manifested in larger building scale and more construction items, which is however accompanied by severe safety issues.As an underground project, metro tunnel is obviously put into high-risk class due to its complicated surroundings and broad social implications. Thus during the working process, its impacts on adjacent buildings are both structural and social.Reinforcing the risk management for metro tunnel construction, as well as adopting reasonable risk reduction measure and appropriate construction technique based on relatively accurate analysis, are significant approaches of disaster prevention and mitigation. And realization of a smooth construction process under the condition of the neighbors'safety also is an important aspect of tunnel risk management study. This issue is getting wide attentions of engineers and scholars, while arousing high governmental concerns.The paper studied risk of buildings adjacent to metro tunnel from general procedures of risk management. Firstly, identifying factors that affect buildings'safety in metro construction environment, and analyzing the mechanism of surface subsidence. Both mechanical and risk indicators are being considered. Variable fuzzy set and relative theory are introduced next, including values of adjacent index relative importance method, fuzzy optimization model and fuzzy identification model. Then safety risk ranking model and risk evaluation model of buildings adjacent to metro tunnel are established. With these two models, safety risk degree of building can be evaluated. And by estimating the risk accurately, constructors are capable of taking protective measures to high-risk building.When the models are applied to some tunnel under construction, the results given correspond to the engineering practice. These consequences prove that the methods are exercisable and effective, which can provide valuable reference for risk decision-making and reduce the impact on the adjacent buildings, and ensure the smooth progress of construction as well as safety of adjacent buildings.