خصوصیات ورقه ارتباطی کامپوزیت بتن-فولاد در پل با تیر دو سرمفصل
Abstract
1- Introduction
2- Failure Mechanism of Link Slab
3- Theoretical Analysis of Stress Characteristics of the Bridge Link Slab
4- Introduction and FE Analysis of Steel-concrete Composite Flat Link Slab
5- Field Test of SCC-FLS
6- Conclusions
References
Abstract
Based on linear elastic theory, the concrete cracking problem of link slab on simply supported beam bridge was explored and theoretical analysis of bridge link slabs were carried out. Meanwhile, the formulas for calculating the stress of link slab were deduced and the cause for continuous damage of bridge deck was quantitatively analyzed. On the base of analysis of its failure mechanism, a new type of steel-concrete composite flat link slab was proposed. The results of full-scale model tests and finite element (FE) analysis indicated that it can alter the transfer path of internal forced inside the link slab and then concrete cracking can be prevented effectively. It was found that the main factors to link slab failure were influentially descending from girder end upturning, longitudinal tensile action and girder end rotation. Furthermore, the unbonded region between girder and link slab can effectively decrease the continuous stress and then alleviate the damage to bridge deck. All those results in this paper can be used as a reference and guidance for further research and development of new type of bridge link slab and jointless bridge.
Introduction
The simply supported beam bridges with link slab have the advantages of simple structure, definite stress and convenient construction, and the link slab can lead to the jointless bridge deck in the simply supported beam bridge, which can avoid the bridge diseases and high maintenance costs caused by the bridge expansion joints. Therefore, the link slab has been widely used in small and medium span bridges. The concept of the link slab of simply-supported beam bridges was first proposed in the late 1970s (Loveall, 1985), which connecting the bridge deck as a whole instead of setting up special telescopic devices between two girders. This simply-supported beam bridge with link slab not only has the mechanical characteristics of simply-supported beam bridge, but also has good driving stability and driving comfort. However, in the process of bridge operation, there are many cracks in the bridge slab-deck, which not only affected the ride comfort, but also caused a series of diseases, such as bridge corrosion (Badie et al., 2001; Oesterle et al., 2004; Okeil and Elsafty, 2005; Attanayake et al., 2008; El-Safty, 2008). In 1998, Alampalli and Yannotti (1998) investigated the deck of 105 bridges (including the concrete girder bridge and the 33 steel girder bridges) in the United States of America, and found that almost all of the bridge decks continuously cracked, these diseases significantly increased the cost of bridge maintenance. In order to reduce the continuous deck damage, many scholars have explored the damage reasons and proposed improvements. Okeil and Elsafty (2005) compared the data from the experimental and FE analysis with the existing data in the literature, and explored the effect of the bridge deck pavement material stiffness on the angle of the continuous slab-deck (link slab), the angle formula of the continuous slab-deck (link slab) section under the static load was also derived. Kendall et al.