Research On Risk Assessment Of Long-span Cable-stayed Suspension Collaborative System Bridge

With the continuous development of social and economic sciences,there are more and more large-scale cross-sea,cross-river and cross-canyon bridge projects,making great contributions to the economic development of society and the construction of transportation projects.At the same time,with the increase of bridge holdings,the various negative effects of bridge accidents at home and abroad are also increasing,and the risk of bridges has become the focus of attention of the government and the public.It is of great significance and value to carry out bridge risk assessment in order to better play the various service functions of the bridge,reduce unnecessary losses and safeguard the public interest.As a new type of bridge system,there are few relevant studies on cable-stayed suspension cooperative system bridges,so it is of great theoretical value and practical significance to carry out risk evaluation research on cable-stayed suspension collaborative system bridges.Firstly,based on the basic theory of risk assessment,the process of bridge risk assessment is expounded,and secondly,according to the bridge accident case in recent years,the cause of the accident is divided into three categories: human factors,environmental factors and self-structure factors.Then,according to the literature and the structure and performance characteristics of the cable-stayed suspension cooperative system bridge,the bridge risk source of the cable-suspension collaboration system is analyzed and determined,and the bridge risk assessment index system of the cable-suspension collaboration system is constructed.On the basis of the analytic hierarchy process and combining the entropy value method,the weights of various security indicators are determined by combination empowerment.Then,according to the overall situation of the project,taking a main span 1488 m cable-stayed suspension cooperative system bridge as the object,the risk assessment and application are carried out.Based on the results,the corresponding risk countermeasures for the high-weight risk source are put forward,and the risk level is reduced to level II.Finally,the practical suggestions for the risk management method of the bridge project are put forward,which is of certain reference significance.