Study On Reasonable Span Range Of RC Arch Bridge With Cantilever Casting Construction & Design Optimization

With the development of bridge construction technology,the construction method of arch bridge is gradually developing.At present,RC arch bridge is mainly use rigid frame method and and cantilever erection method,and the cantilever casting method has just been applied in the last few years.In the construction which use the cantilever cast-ing method,when the span of the arch bridge reaches a certain value,the tension of the temporary buckle cable near its midspan will be very large,lead the construction of the cables,temporary tower and anchorage becomes very difficult,resulting a substantial increase in the cost,so this method exists a suitable range span.This paper focuses on RC arch bridge constructed by cantilever casting method.On the basis of commonly used materials and structure of the current time,discuss reasonable span of RC arch bridge by Cantilever casting Method,and explore its design optimization.The main contents are as follows:(1)Study on reasonable span of RC arch bridge by cantilever casting methodFristly,investigate the RC arch bridge constructed by Cantilever casting Method,statistics and analysis the distribution of its span;Secondly,under the common existing material conditions,through the calculation and analysis of the force condition of 220 m,260m,300 m,350m and 400 m Span RC arch bridge,study use this method build RC arch bridge's theory span range;Thirdly,within the theoretical range span,compare the material consumption of two methods for temporary cables,temporary tower and anchorage with 220 m,260m and 300 m span of the cantilever and the rigid frame combination method,and determine a more economical span range.From the three aspects of the statistical span distribution,the theoretical span range and the economic span range,obtain the reasonable span range of the RC arch bridge by cantilever casting method.(2)Design optimization of RC arch bridge by cantilever casting method,based on the background projectBased on the background project.Firstly,let the arch ring remains unchanged,turn the concrete columns which near the arch foot and high into steel reinforced concrete column,then the simply supported concrete girders changed to continuous girder or the form of the columns and the girders consolidated,research on the entire structure's stress situation improved or not.Compare the force before and after the changes in the arch structure,discuss the feasibility of the arch structure optimization,compare the advan-tages and disadvantages of each program,and choose the best program.Secondly,let the colu-mns and girders remains unchanged,changed the box arch ring to double ribs arch.Compare the force before and after the changes in the arch structure,compare the advantages and disadvantages of the two programs,and select the better program.