Research On Structure Design Parameters. And Construction Process For Continuous Rigid Frame Bridges With Corrugated Steel Webs

Externally prestressed concrete composite box girder with corrugated steel webs is a structure which uses corrugated steel webs instead of the traditional concrete webs. This combined system consists of top and bottom concrete board, corrugated steel webs, externally prestressing cables. Composite box girders with corrugated steel webs take full advantages of compressive strength from concrete and high shear buckling from corrugated steel webs, and reduce the prestress loss of top and bottom concrete board effectively, eliminating the complex process of buring pipelines in addition. Compared with the traditional prestressed concrete bridges, the design of composite box girders with corrugated steel webs is more reasonable.However, through the relevant researches on structure design parameters and construction process from home and abroad, the key problems at the present stage for research were found out in continuous rigid frame bridges with corrugated steel webs,such as the uncertainty of setting parameters in the concrete lining of negative moment areas,various but inaccurate calculation formulas of ultimate stress and secondary effect in external prestressing cables, an increasing risk ofthe full scaffold construction method in the side span with large height differences.This paper used the combination of theoretical research and design of a real bridge to acquire the method of building equivalent models for ultimate bearing capacity calculation in practical composite continuous rigid frame bridges. At the same time, the paper has discussed the necessarity of different setting parameters in concrete lining and the ultimate strength in external prestressing cables. As a result, their contributions to the bending performances were analyzed. Besides, a new construction method--"Using stiffness of the corrugated steel webs instead of the stiff skeleton" has been taken into account.The main contents in this paper including:(1) The method of building equivalent models for ultimate bearing capacity calculation in practical composite continuous rigid frame bridges;(2) Research on the construction process of the side span closure segments which have a large elevation difference between the land and themselves;(3) The bending performances which consider the effect of different setting parameters in concrete lining, the ultimate stress and secondary effect in external prestressing cables;(4) Mechanical performance analysis on finite element models of combined with actual design example;(5) Design suggestions on continuous rigid frame bridges with corrugated steel webs. Therefore, this paper has established finite element modelsbased on the Xiao Shagoubridge with a span of (57+2 x 100+57)m under different conditions through Midas Civil 2012 software to research on structure design parameters and construction process for this kind of continuous rigid frame bridges with corrugated steel webs. Proposals to the design for this bridge type were validated by means of calculating the actual bridge finite element models. Hope to provide beneficial references for engineering design and application on continuous rigid frame bridges with corrugated steel webs.