Key Techniques for Demolition of Multi-Span Continuous Arch Bridge with Concrete-Filled Steel Tubes
Taking the demolition project of Jianhu Bridge as the research background,the demolition of arch bridges with concrete-filled steel tubes under complex conditions was studied.First,the current bridge demolition methods and application status were introduced,and three bridge demolition schemes were put forward according to the difficulties of the bridge demolition.The appropriate demolition scheme for the bridge was selected after comparison,and the sequence of arch bridge demolition was explained.Then,the stress characteristics of the bridge at each construction stage were analyzed,and the theoretical and measured displacement and stress at the most unfavorable stage during demolition were compared.Finally,the influence of material strength and temperature on structural displacement and stress was studied.The results show that the gantry crane method for steel trestle bridges is best suited to the demolition of bridges with navigable requirements and limited space.After the flange is cut,the working space on both sides can be increased,and the self-weight of the beam can be reduced.During the demolition of the web,the stress and displacement of the structure are proportional to the cantilever length of the beam body,and the theoretical stress and displacement are smaller than measured values.The change of material strength and temperature does not affect the force law of the structure,and the structural stress and displacement are inversely proportional to the material strength and proportional to the temperature.