Research On Loading Features And Damage Characteristics Of Continuous Rigid-Frame Bridge With Corrugated Steel Webs

ABSTRACT:Continuous rigid-frame bridge with corrugated steel webs box gider integrated the advantages of rigid-frame bridge and box girder with corrugated steel webs. This new structure has larger span capacity,lighter self-weight,excellent seismic performance and higher effective prestressing system,etc,which is suitable for large span bridge in high seismic intensity. The loading features and damage characteristics of this structure are researched by experimental and FEA methods.With the experimental model,the loading features of continuous rigid-frame bridge with corrugated steel webs (have and none inner lining concrete) and continuous rigid-frame bridge with concrete webs are contrastively researched.The results show that the bending stiffness of box gider with corrugated steel webs is slightly less than box gider with concrete webs,but it’s torsion stiffness is lower. Adding the inner lining concrete can increce the bending stiffness and torsion stiffness of box gider with corrugated steel webs. The inner lining concrete can share the shear stress with corrugated steel webs, having the improve function on the stress state of corrugated steel webs.Combined with the test and the related literature, the difference of torsion and distortion of continuous rigid-frame bridge with corrugated steel webs and continuous rigid-frame bridge with concrete webs and simply supported box girder bridge with corrugated steel webs are contrastively researched.The research is from four aspects as deflection, longitudinal strain distribution along height of box gider, warping stress distribution and the shear stress of steel webs along height. The results show that the abilitity to resist torsion and distortion of continuous rigid-frame bridge with corrugated steel webs are worse than continuous rigid-frame bridge with concrete webs and better than simply supported box girder bridge with corrugated steel webs. The abilitity to resist torsion and distortion of continuous rigid-frame bridge with corrugated steel webs is related with the distance of the observation section to the pier beam junction, which is better with short distance and worse with long distance.With the experimental model, the damage characteristics of continuous rigid-frame bridge with corrugated steel webs and continuous rigid-frame bridge with concrete webs are contrastively researched. The results show that with the same loading condition and boundary conditions, the cracking load of continuous rigid-frame bridge with corrugated steel webs is lower than continuous rigid-frame bridge with concrete webs, the ultimate bearing capacity is higher than the latter. Continuous rigid-frame bridge with corrugated steel webs show significantly ductile damage characteristics.The effect of change corrugated steel web thickness, minimum thickness of inner lining concrete and number of diaphragm to the torsion and distortion of continuous rigid-frame bridge with corrugated steel webs is researched with FEA software. The results show that it’s will beneficially improve the performance of torsion and decrease the performance of distorsion to add the inner lining concrete and reasonably set the diaphragm.