The Bolu viaduct is a 2.3 km long seismically isolated structure whose construction was nearly complete when it was struck by the 1999 Duzce earthquake in Turkey. It suffered complete failure of the seismic isolation system and narrowly avoided total collapse due to excessive superstructure movement. This paper presents an evaluation of the design of the viaduct’s seismic isolation system and a...

A program for engineering wood bridges is described. The program performs the analysis, design, and/or rating of wood bridge superstructures in accordance with the 15th Edition of the AASHTO Specification or the AASHTO-LRFD Specification. Bridges may be analyzed for design review and/or rating. In review/rating mode, the superstructure is analyzed and checked against all applicable specificatio...

This study concerned a stretch of 17 km of a 94-km highway alignment in Southeastern Nigeria that has a high incidence of pavement failure arising from subgrade failure. The subgrade of this section of the roadway is composed of Ekenkpon shale, New Netim marl, and Nkporo shale. Under the Unified Soil Classification System, the shales classify as OH (organic clay) and the marl classifies as MH (...

This paper summarizes the test results of an extensive research program sponsored by the US Transportation Research Board of the National Research Council to examine the behavior of high-strength concrete rectangular columns subjected to concentric and eccentric loading conditions. The variables considered in this investigation were concrete strength ranging from 7.9 ksi (55 MPa) to 16.5 ksi (1...

This report deals with the evaluation of the ultimate behavior of AASHTO I-beams with concrete strengths up to 9000 psi. The relevant AASHTO and IDOH design specifications are thoroughly evaluated based on the results of this research. The findings of this study remark the many beneficial implications of the use of higher strength concrete in precast prestressed AASHTO I-beams. Higher strength ...

The National Cooperative Highway Research Program (NCHRP) is supported on a continuing basis by funds from participating member departments of the American Association of State Highway and Transportation Officials (AASHTO), with the cooperation and support of the Federal Highway Administration, U.S. Department of Transportation. The NCHRP is administered by the National Research Council’s Trans...

Recently, the use of high-strength concrete has become more popular due to the availability and significant variety of the admixtures. High-strength concrete increases the load carrying capacity of the columns, therefore, reduces their sizes in buildings and bridges. In bridges, high-strength concrete could result in reduction of number of girders as well as an increase in the span length which...