Study On The Application Of Safety Risk Assessment In The Preliminary Design Stage

The highway bridge construction has the characteristics of high construction difficulty, construction environment is complex, large investment projects, makes it faces more security risks in the design, construction and operation in the late. If the project preliminary design stage inconsiderate, it may cause major accidents and economic losses and bad social influence. Therefore, in the preliminary design stage of bridge engineering on a certain scale of safety risk assessment is very necessary.Relying on a typical Shangri La to Lijiang highway bridge of paper, according to the actual situation and engineering characteristics of the construction of the bridge, from risk identification, estimation, evaluation and control four aspects by comparison of two different types of bridges in the preliminary design of the program, the security risks exist in the design, construction and operation of the late stage of detailed and systematic analysis, it is concluded that the two different bridge preliminary design scheme of risk level, for the next phase of deepen design support. The main contents include the following aspects:1. In this paper, the definition of risk, risk identification and risk evaluation and other related concepts, study the domestic and international risk management situation and risk management in the project management of use, according to the Ministry of transport document "on in the preliminary design stage, implementation of highway bridges and tunnel engineering safety risk assessment system notice" requirements, detailed introduces the security risk assessment process, train of thought and the specific method of preliminary design of bridge engineering.2. Shangri la to Lijiang, a highway bridge based on, for the bridge preliminary design stage of the proposed two kinds of design scheme, combined with the actual situation of the bridge construction site and former engineering construction experience, adopts the method of risk sources census form, on the design, construction and operation stages possible security risks one by one identification, in risk sources census form based and does not pose a safety risk factors excluded screened main risk sources and the formation of the main risk source list.3. Using the "based on the weight of expert investigation method" on the list of the major sources of risk probability level and risk of loss grade quantitative investigation and evaluation, the establishment of a risk assessment matrix determined each kind of design scheme of bridge type in the construction conditions, structure scheme, construction technology, operation and management of various stages of the risk source risk rank size, through risk more preferred design scheme selection, at the same time, it puts forward the specific direction of the evaluation model.