Research On Construction Risk Assessment And Control Of Steel Pipe Concrete Tied Arch Bridge In Plateau Mountain Area

With the basic formation of the expressway network along the southeast coast of China,and in order to meet the transportation needs and open up the connecting hubs of Southeast Asia and South Asia,the basic transportation construction in China began to shift to plateau and mountainous areas on a large scale.However,the complex terrain,numerous mountains and rivers,strong ultraviolet rays,large temperature difference between day and night,and large humidity change are unfavorable to the construction.There are many uncertain risk factors in the construction of bridges in plateau mountainous areas compared with those in inland areas.The number of concrete-filled steel tubular tied arch bridges studied in this paper is small in China,and the number of arch bridges built in plateau mountainous areas is very small,and there is a great risk in the construction process in plateau mountainous areas,so it is necessary to evaluate and control the risk of concrete-filled steel tubular tied arch bridges in plateau mountainous areas.Taking the construction process of a concrete-filled steel tubular tied arch bridge in plateau mountainous area as the research object,the risk evaluation index system is constructed.According to the original data collected by expert scoring method,the weights are calculated by combining analytic hierarchy process and entropy weight method,and the mathematical model is established by using fuzzy comprehensive evaluation method.The risk evaluation of a concrete-filled steel tubular tied arch bridge in plateau mountainous area is carried out and the control measures are put forward.The main contents are as follows:(1)The research background and significance are analyzed.By studying the relevant literature at home and abroad,the research status and existing problems of bridge construction risk assessment in plateau and mountainous areas at home and abroad are analyzed.On this basis,the main research contents and technical routes of this paper are put forward.(2)According to the characteristics of plateau mountain area,this paper analyzes the characteristics of bridge construction in plateau mountain area,and combs the commonly used theories and methods of bridge risk assessment,including the definition of risk factors,risk identification methods,risk assessment methods and risk control contents,as well as the advantages,disadvantages and applicable scope of assessment methods.(3)Through expert investigation,field exploration,personnel visits and sorting out construction data,the construction process of concrete-filled steel tubular tied arch is divided.From the main sub-projects,various risk factors affecting the construction of tied arch bridge are identified,the tied arch construction risk evaluation index system is established,and the fuzzy hierarchical entropy weight comprehensive risk evaluation model is constructed.(4)Relying on the actual project,according to the original data collected by the expert scoring method,the weights are calculated by the combination of analytic hierarchy process and entropy weight method,the mathematical model is established by using fuzzy comprehensive evaluation method,and the GUI interface is established.With the help of MATLAB,the risk assessment of the main risk factors in the construction process of concrete-filled steel tubular tied arch bridge in plateau mountainous areas is carried out.(5)According to the calculated results of construction risk assessment,the overall risk level is obtained,and the construction risk control measures are put forward according to the risk level.