Dynamic And Seismic Response Analysis Of Wide Deck And Dwarf-Tower Double Cable-Stayed Bridge

The main component parts of dwarf tower cable-stayed bridge are the main tower, beam,cable and pier.This bridge is a new bridge structure,rise in recent years,the general characteristics of it are dwarf tower and cable layout,belonging to the ultra-high fixed structure.Wide deck and dwarf-tower double cable-stayed bridge has the form of a cable-stayed bridge,but in layout of cable,structure size and the characteristics of force have clear difference from real cable-stayed bridge.Wide deck and dwarf-tower double cable-stayed bridge is an over-bridge which is between cable-stayed bridge and the rigid frame bridge,which not only have changefully structure system,but also the structural have rigid and flexible characteristics.By now, the static performance of this new style bridge system was studied deeply and widely, but dynamic behaviors were seldom studied.When it comes to system dynamic analysis of Double dwarf-tower wide cable-stayed bridge,it was none,therefore,studying on dynamic characteristics and seismic response performances for wide deck and dwarf-tower double cable-stayed bridge,and making proposition and reference to the earthquake resistance design are a important and significative work.The study of this paper is a domestic wide deck and dwarf-tower double cable-stayed bridge.Data about dwarf-tower cable-stayed bridge are collected and analyzed firstly,and the range of every parameter's value is decided.Then,seven parameters are selected for dynamic analysis.These parameters include the coupling mode between girder and pier,the space between adjoin stay cables,the ratio between height of tower and length of main span,section rigidity of tower,side to main span ratio, the ratio between height of girder and length of main span,and the total section area of cables.After dynamic analysis,use influence degree of pylons and cables to reflect the influence of cables and pylons on the dynamic behaviors.The study results indicated that dynamic characteristics of wide deck and dwarf-tower double cable-stayed bridge with girder fixing with the towers and the piers are more like characteristics of continuous beam bridge than ordinary cable-stayed bridge.Pylons and cables less influence main beam's dynamic characteristics,the coupling mode between girder and pier,the ratio between height of tower and length of main span,side to main span ratio, the ratio between height of girder and length of main span more influence main beam's dynamic characteristics.Based on dynamic analysis,parameters include the ratio between girder and pier,side to main span ratio and the ratio between height of pylon and length of main span were analyzed to find out the characteristics of seismic response. The study results indicated that seismic response of wide deck and dwarf-tower double cable-stayed bridge is very sensitive to parameters.The conclusions of this paper are valuable reference for further understanding of the dynamic properties of wide deck and dwarf-tower double cable-stayed bridge.Some conclusions and suggestions for anti-seismic design are presented in this paper.