Design of Main Bridge of Yunshi Hanjiang River Bridge

The main bridge of Yunshi Hanjiang River Bridge is a prestressed concrete extra- dosed bridge with double pylons,a single cable plane and with span arrangement(128+238+ 128)m.The main girder of the bridge is the concrete continuous triple-cell single box girder of long cantilevers and variable sections.The pylons,each being 39.9mhigh,are the single-column concrete structures and are designed into the structural form of rigid fixity of the pylons,girder and piers.The stay cables are arranged in fan shape and the piers of the pylons are supported on the group bored pile foundations.In the design,the software MIDAS Civil was used to establish the finite element model for the whole bridge and to carry out the global calculation of the bridge, the stress analysis of the stay cables and the dynamic behavior of the whole bridge.The software ANSYS was used as well to establish the finite element model for the segments of the main girder and to carry out the local stress analysis of the bridge.The results of the calculation and analysis indicate that the global structure of the bridge is safe and reliable and the structure can meet the requirements for highway vehicle riding safety and comfort.No significant local stress concentra- tion appears in the main girder,the stress amplitude values of the stay cables are within 30MPa and the structure can meet the requirements for durability in the service process of the bridge.