Risk Management And System Development Of City Tunnel Construction Underpassing Existing Facilities

The risk of city tunnel project construction has the characteristics of diversity and multi levels, long time span, wide dynamic change, and many difficulties in management. The risk, which has influence on the third-party's existing facilities, is an important component of the city tunnel project risk. Being lack of scientific risk assessment tools and scientific risk management system, the safety accidents occur occasionally in the process of city runnel construction. With more city buildings and denser underground pipeline network are constructed, the risk of engineering construction is also becoming increasingly high and attracts more and more attention. Its research can be mainly divided into risk identification methods, risk assessment methods, risk management theory and application of research, while the systematic study of which is particularly scarce. At present, the research results achieved are far from meeting the city tunnel project construction requirements. According to the characteristics of the whole process risk in city tunnel project, based on existing research results, by means of theoretical analysis, field investigation and numerical simulation, this thesis has made a comprehensive, systematic and deeply research on the entire process of city tunnel project risk integration dynamic management theory, risk comprehensive assessment methods, and risk management information systems, and has got some innovative results.1. Based on system theory, the thesis puts forward tunnel project integrated risk management framework, which has integrated the expert knowledge, experience and process, centralized risk management organization, risk management method, risk management environment and risk management objectives. The risk management integrated model can make risk management activities as an organic whole and overcome some weaknesses, such as randomness and dispersion of the past risk management activities.2. Aiming to the weakness of imperfect and unreasonable risk management organizations, based on the Bell's live system model control principle, the thesis has set up the owners' layer and the contractor integrated risk management organization structure models, which will meet the requirement of fundamental principles in cybernetics, and provide the risk integrated management with an organization foundation.3. A composite risk index assess model is proposed. City runnel project construction is a complex open system. In the disaster system of the existing facilities damage inducing by tunnel construction, the construction sub-system and geological hazard environment sub-system make up the disaster-causing subsystem and the hazard bearing body sub-system consists of the adjacent facilities. The dangerousness and vulnerability assessment has been done separately, then the composite risk index assess model has been set up.4. According to existing research results and numerical calculation, four dangerous factors such as the tunnel span, the tunnel depth, surrounding rock grades and construction method is considered as the impact index. Through the use of combination of the orthogonal hierarchy process and numerical simulation, the sensitivity analysis of the four risk factors has been done and the dangerousness assessment model has been get. Summarized and summed up the vulnerability factor of the impact of the nearby facilities, a vulnerability assessment model has been set up.5. Fuzzy fault tree risk assessment model is set up based on fuzzy math, interval calculation methods and fault tree analysis method. "Interchange GuangZhou-FoShan deformation failure" is chosen as the top event to set up fault-tree model. Through analyzing and calculating the model, the fuzzy probability of the top event and fuzzy importance of affecting factors have been obtained and Qualitative analysis and quantitative analysis could be done for the bottom events.6. The fuzzy comprehensive evaluation method and the Analytic Hierarchy Process have been integrated into FAHP methods and successfully applied to the risk assessment of the "Interchange GuangZhou-FoShan deformation failure" Event, and has gained the fuzzy interval from this accident.7. The risk management information system has been developed. In the system, many new technologies have been adopted, such as the B/S structure, J2EE technology, JW Framework development platform, Hibernate technology and Oracle database technology, which have provided powerful technical support to enhance the comprehensive level of risk management and the emergency reaction ability.