Study On The Application Of The Static Cutting Technology On The Demolition Of Overpasses Within Urban Core Areas

At present,the originally designed maximum bridge load,the traffic flow,the safety,the applicability and the durability of the overpasses within the core areas of China's cities are difficult to meet the new demands of the current urban municipal transport development.Hence,the situation of demolition and new construction are coming.Since the 1980 s,the demolition technology applied in urban overpasses has developed over the past 40 years and gradually formed a relatively completed demolition technology system based on controlled blasting,static crushing,mechanical crushing and static cutting.In recent years,in order to adapt to the national development strategy of “high quality and high development”,the speed and convenience of the construction,the smooth passage of the lower roads,the safety and reliability of the demolition,environmental protection and smart construction have been added to the requirement of the demolition of the overpasses within the core areas of China's cities.A large number of engineering practice of the overpasses demolition show that the existing demolition technology has been difficult to meet the new requirements for the current demolition of the overpasses within urban core areas.It needs to be improved and optimized and further research as well as innovation are needed in terms of speed,greenness and wisdom.Firstly,through literature review and analysis,it is clear that the current demolition technology system of urban overpasses is mainly composed of controlled blasting,static crushing,mechanical crushing and static cutting technology.At the same time,the development process,essence,core technology and application methods of smart building technology are summarized as well.Secondly,starting from the self characteristics of the overpasses within the urban core areas and the characteristics of the demolition of urban overpasses,the characteristics of the demolition of the overpasses within the core urban areas of China are analyzed in depth.The structural form,mechanical characteristics,distribution characteristics of the urban overpasses,as well as the principles,key points and difficult problems of the demolition of the overpasses are described profoundly.Thirdly,based on the existing demolition technology system of the current urban overpasses,combined with the characteristics of the demolition construction ofoverpasses,the comprehensive comparison and selection study on the technical plan of the demolition within the urban core areas is carried out.On the basis of expounding the concept,principle and process flow of four types of overpasses demolition technology,the paper analyzes and selects the best technical plan of the demolition of the overpasses from five dimensions such as technology,construction period,cost,safety and environmental protection.Fourth,the improvement and optimization study is carried out based on the selected best technical plan of the demolition.Based on the analysis and summary of the shortcomings of the selected demolition technology applied in overpasses,an optimization model based on the new support and transportation system,sewage collection and treatment system as well as BIM technology is proposed.And the optimization content is analyzed in more detailed.Finally,a demolition project of a pre-stressed concrete overpass in front of the 1#terminal building of the Huanghua International Airport in Huanghua County of Changsha City is taken as an actual case.Based on the research results of the optimization of the demolition technology applied in the overpasses within urban core areas,the demolition effect of the improved and optimized static cutting technology has been analyzed and demonstrated.Practice shows that the research results basically meet the new engineering requirements for the demolition of the T1 overpass,which can provide some references for similar demolition projects of the urban overpasses in the future.