Author : Shobha Kanta Subedi
Publisher :
ISBN 13 :
Total Pages : 114 pages
Book Rating : 4.:/5 (969 download)
Book Synopsis Load Rating of Flat Slab Bridges Without Plans by : Shobha Kanta Subedi
Download or read book Load Rating of Flat Slab Bridges Without Plans written by Shobha Kanta Subedi and published by . This book was released on 2016 with total page 114 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the United States, there is a large number of reinforced concrete flat slab bridges, which were constructed during 1900's and are still in service. The state Departments of Transportation (DOT) do not have necessary information of design details, and properties of materials used during the construction of those old flat slab bridges. Those old bridges are not designed to support the current traffic. Therefore, they might have certain issues regarding durability, strength and safety. Nowadays, the visual inspection techniques followed by AASHTO guidelines are used for the evaluation of current load carrying capacity of concrete flat slab bridges. Such techniques or guidelines may overestimate or underestimate the load bearing capacity, and may not represent the actual capacity. The load bearing capacity of structures depends upon the physical dimensions and properties of materials from which they were built. In this research, the unknown parameters, such as clear cover, size, bar spacing and compressive strength of the concrete, were determined by using simple non-destructive tests on existing bridges. For a simple non-destructive test, Profoscope and Schmidt hammer were used to run the test in the field. By using the field data, three dimensional finite element analysis of a flat slab bridge was performed in ANSYS to determine deflection at the mid-point of a concrete flat slab bridge under a truck load. In the analysis, the truck load position which would results the maximum displacement at mid-point of bottom face was used as a critical load position. The load was increased up to a point that produces the deflection close to the maximum allowable value according to AASHTO Section 2.5.2.6.2 criteria. The load corresponding to the maximum allowable deflection on the existing bridge is used to calculate the rating factor of the bridge. The Ohio legal load vehicle of gross weight 30 kip having the truck load designation of OH-2F1 is considered for this research. The rating factor is determined as the ratio of truckload that produce the maximum allowable midpoint deflection to the original designated truck load. The research outcome will provide guidelines to evaluate the load rating factor of existing flat slab bridges without plans.
