International Journal of Civil and Structural Engineering Research ISSN 2348-7607 (Online) Vol. 8, Issue 1, pp: (182-191), Month: April 2020 - September 2020, Available at: www.researchpublish.com
Seismic Performance of Multi-Simple Span Bridges with Link Slabs Nagi F. Hanna1, Ahmed A. Rashed2, Magdy M. Genedy3, Ahmed M. Bohout4 1
Professor, Civil Eng. Dept., Helwan University, Cairo, Egypt 2
Professor, Civil Eng. Dept., Cairo University, Cairo, Egypt
3
Assistant Professor, Civil Eng. Dept., Helwan University, Cairo, Egypt
4
Structural Engineer, M.Sc. of Structural Eng. Researcher, Helwan University, Cairo, Egypt
Abstract: Multi simple-span bridges form a majority of crossings used in the highway system. A typical span has a reinforced concrete deck over precast I-girders. Span lengths range from 15 to 35 meters. Expansion joints are introduced between each two adjacent spans to allow deck movements induced by temperature variation, creep and shrinkage. However, having expansion joints between adjacent spans develops costly maintenance problems. The main issues that generate the need for maintenance are: Water leakage through expansion joints; water leakage through the expansion joints can cause deterioration of bearings, decks, girder ends, and cap beams. Accumulation of debris in the joints; accumulated debris in the joints can restrain deck expansion and can cause undesirable damages to the structure. Damage and loss of function caused by impact of heavy trucks; impact induced by dynamic effects of heavy truck loads can delaminate the expansion joint concrete. Another disadvantage of the expansion joints is the noise emission. Residents next to highway and bridges suffer from noise caused by flow of traffic. Expansion joints placed across traffic direction can be subjected to constant intolerable impact between wheels of vehicles and steel parts of the joints, which creates noise. Therefore, elimination of expansion joints between adjacent spans would eliminate the noise emission, and can also more significantly reduce the cost for construction and maintenance of the bridges. Keywords: Multi simple-span bridges, highway system, Link Slabs, maintenance problems.
I. INTRODUCTION Current design philosophy in Egypt promotes to use expansion joints between continuous decks between adjacent simplespans as shown in Figure 1 [1]. Bridges with link slabs (with continuous decks) was observed that it performed very well & better than others with expansion joints as example in earthquakes, even if they were very close to the fault line as shown in Figure 2 [2].
Figure 1: New bridge with expansion joint.
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