Study On Key Design Issues Of Long Span Hybrid Single-tower Rotational Cable-stayed Bridge

With the rapid development of modern transportation industry in our country,a large number of new passenger dedicated lines,intercity railways and urban expressways are accompanied by the rapid expansion of the main urban areas of large and medium-sized cities,which is bound to lead to the emergence of more and more bridges above the railways.If we consider from economic angle,the hybrid beam as the main girder of swivel cable-stayed bridge will improve spanning capacity and also create great economic benefits at the same time.Therefore,the hybrid rotational cable-stayed bridge is proposed.Based on a bridge which is a long span hybrid single-tower rotational cable-stayed bridge some key issues of designing are studied in this paper of which the main contents are listed as follows: selecting the position of steel-concrete connection,determining the reasonable completion state,design optimization,designing steel-concrete connection and swivel system.The research work is carried out mainly from the following aspects:(1)Derive a reasonable range of side-span ratio and the steel-concrete connection position.(2)Study on the determination of the reasonable completion state for long span single-tower hybrid rotational cable-stayed bridge.(3)The design optimization is carried out from the steel-concrete connection position selecting,auxiliary pier design and cable tower anchorage form and put forward optimized design scheme.(4)Derive the formula of shear strength of multi-row shear connectors based on the Goodman elastic sandwich method and elastic deformation theory and compared with the numerical simulation results.(5)Building simulation models of steel-concrete connection segment and rotional system to analyze its mechanical property.And the conclusion is drawn as follows:(1)The location of the steel-concrete connection of this project is more suitable for reaching the main span of 11.5m.(2)Dividing the optimization process into two stages makes the design idea clearer.(3)Putting forward optimized design scheme.(4)The overall force of the steel-concrete connection meets the requirements of the design specification and the transmission of force is smooth.(5)The overall force of the swivel system meets the requirements of the design specification.In conclusion,some key problems in the design process were solved through studying on key design issues of long span single-tower hybrid rotational cable-stayed bridge and will provide reference for the design of similar projects in the future.