Performance Improvement of Overpass Bridge by Weight Reduction

Abstract

In this study, structural safety capacity analysis of the overpass railway bridge between Konkuk Univ. and Guui station railroad has been performed. The overpass is expected to have suffered durability reduction by deterioration. The weight reduction of the overpass has been implemented to prevent further durability reduction and to improve performance capacity. To reduce the weight, 3 procedures of replacing concrete soundproofing wall to light-weight soundproofing wall, replacing gravel ballast to concrete ballast, and reducing the weight of trough have been performed. The analysis of static/dynamic behaviors and improved capacity of the light-weighted overpass bridge has been performed. The structural safety verification of the improved structure has been implemented by using rating factors of load carrying capacity of PSC I girder. The results have shown that the deflection has been reduced by 2.6mm and tensile strength has been improved by 1.07MPa, which indicate that the structural capacity has effectively been improved. Also, the natural frequency has improved by approximately 30% where vibration reduction and dynamic behavior improvement have been achieved. Moreover, in the rating factor evaluation based on analysis and test results, an improvement from 1.82 to 1.93 has been observed. Therefore, weight reduction method for the overpass is effective considering overall results.

Ethics in International Trade

“…In fact, studies have estimated that for every job lost as a result of free trade, two or three or more jobs are created, or that the cost of saving a job exceeds the salary of the worker whose job is saved (Boorstein 1987;Bryan & Humpage 1984;Collyns & Dunaway 1987;Crandall 1984Crandall , 1987deMelo & Tarr 1990;Dinopoulos & Kreinin 1988;Feenstra 1992;Hickok 1985;Hopkins 1991;Hufbauer, Berliner & Elliott 1986;Lindsey 2004;Luttrell 1989;Smith & Venables 1991;Tarr & Morkre 1984). The Institute for International Economics sponsored major studies to measure the costs of protectionism in Europe (Messerlin 2001), the United States (Hufbauer & Elliott 1994), China (Shuguang, Yansheng & Zhongxin 1998) and Korea (Kim 1996). More recent studies have also concluded, mostly on utilitarian grounds, that free trade is the best policy (Bhagwati 2004;Griswold 2007;Ikenson 2009Ikenson , 2010Ikenson , 2011James 2009;Sally 2008;Wolf 2004).…”