Study On The Shear Lag Effect Of Large Span Composite Box Girder Bridge With Corrugated Steel Webs

Composite box girder bridge with corrugated steel webs is a new type of composite structure, which uses the corrugated steel webs instead of the concrete webs. It has many advantages, such as a clear stress path, high material utilization, light, beautiful, efficient, durable, and avoiding the cracks of the concrete webs. It effectively improves some defect of traditional concrete bridge. It’s a better selection for bridge type in city and scenic. It has spread and applied in our country. In recent years, a upsurge in construction of this type bridge is making.In order to study the shear lag effect of large span composite box girder bridge with corrugated steel webs,In this paper, Based on the ordinary box beam shear lag theory, Referring to corrugated steel box girder structure characteristics and two cantilever construction of large span box girder bridges with corrugated steel webs are adopted. Some finite element models are established. Studying on the rules of distribution about shear lag effect of large span composite box girder bridge with corrugated steel webs in different stages of construction and different load cases. While the associated geometry parameters that affect shear lag effect are analyzed. The paper includes the following aspects:(1)In first part, The plane and space finite element models are established by professional software. The construction processes are simulated and some critical sections are selected. Studying on the rules of distribution about shear lag effect of large span composite box girder bridge with corrugated steel webs in different stages of construction.(2)In second part, The bar simulation method of shear-lag effect in the composite box girder with corrugated steel webs were deduced, and combined with the finite element models to study the shear lag effect of large span composite box girder bridge with corrugated steel webs.(3)In third part, By ANSYS finite element software to study the shear lag effect of large span composite box girder bridge with corrugated steel webs in a different width-span ratio of beam(B/L) and depth-span ratio of beam(H/L), and different thickness of the roof(D), Which summarizes the main geometric parameters how to affect the shear lag effect of large span composite box girder bridge with corrugated steel webs.The results show that: large span box girder bridge with corrugated steel webs of shear lag effect goes along with the construction phase is a dynamic process. During the construction phase of cantilever construction, rapid changes in shear lag effect, in the latter, shear lag effect change slowly throughout the construction processes. The maximum shear lag effect occurs at critical sections of the cantilever bridge under the largest state. The bar simulation method of shear-lag effect in the composite box girder with corrugated steel webs is reliable and effective. The results also shows that width-span ratio of beam and different thickness of the roof are the key factors to shear lag effect. The engineering design. should pay more attention to these factors. In this paper, the shear lag effect of large span composite box girder bridge with corrugated steel webs in different stages of construction is made a detailed analysis, the results can provide a reference for related engineering design.