Research On Long-term Creep Effect Of Long-span Continuous Rigid Frame Bridge With Corrugated Steel Webs

Continuous rigid frame bridge with corrugated steel webs has obvious advantages compared with box girder with concrete webs,so the application in the engineering practice of our country is gradually increases.Because this structure is composed of concrete and corrugated steel web,its creep characteristics may be different from traditional concrete box girder.it is necessary to analyze further on creep characteristics of this kind of bridge.In this dissertation,the long-term creep effect of long-span continuous rigid frame bridge with corrugated steel webs is carried out on the background project of Lidu Bridge(a long-span continuous rigid frame bridge with corrugated steel webs,190m main span)by using finite element analysis softwares Midas and Ansys.The main research works are as follows:(1)The development and structural characteristics of PC composite box girder with corrugated steel webs has been briefly introduced.The research at present about creep at home and abroad has been summarized,and the main contents of this dissertation was established.(2)The concept of creep,the mechanism of creep and the theory of creep were described,and the advantages and disadvantages of different creep calculation theories werebriefly discussed.(3)The finite element analysis software Midas was used to establish the beam element model of Lidu Bridge.The influence of creep on the vertical deflection,internal force,stress and prestress loss of the structure was analyzed.(4)The influencing factors of creep was briefly described,and the current creep prediction models were collected,and the sensitivity of some factors was analyzed.(5)Based on the finite element analysis software Ansys,the three-dimensional solid model of Lidu Bridge was established.Using the explicit creep and the effective modulus method adjusted by age,the mid-span deflection and the stress of corrugated steel webs under the effect of creep were analyzed.