Tailor Made Concrete Structures – Walraven & Stoelhorst (eds) © 2008Taylor & Francis Group, London, ISBN 978-0-415-47535-8 Rapid construction of long span precast concrete box girders for Incheon Bridge viaducts constructed with FSLM K.Y. Choi, D.O. Kang, K.L. Park, C.H. Lee, H.Y. Shin & M.G.Yoon Samsung Corporation, Seoul, Korea ABSTRACT: The FSLM (Full Span Launching Method) is being successfully applied to the viaducts of the Incheon Bridge. This method made it possible to construct the long marine viaducts over 8kilometers within 3 years. The integrated monitoring of a girder with 50 m span was conducted through the whole construction sequences. It verified the applicability and efficiency to the rapid construction of marine bridges with FSLM. 1 INTRODUCTION Incheon bridge is the longest causeway in Korea that is underway presently.The viaduct part of Incheon bridge is about 8 km and this comes to the 75% of the whole span. For the successful construction within the short period, around 3 years, the FSLM has been applied to the viaduct part(Shin et al, 2007). In this study, a brief introduction and several new concepts applied to the FSLM are presented for the whole sequences from fabrication to erection of a 50 m precast concrete box girder. Simple static loading test was conducted and the result verified the safety and stability of the girder with FSLM. 2 INCHEON BRIDGE PROJECT Incheon bridge is designed based on the AASHTO LRFD Bridge Design Specification (AASHTO, 1998). Table 1. General outline of Incheon bridge project. Span length Sub-structure Item (m) (Drilled Shaft) Super-structure West Viaduct 5,950 (1.8, 2.4 or 3.0) + -shaped bent FSLM Approach 889 (2.4) BCM Cable Stayed Bridge Side span 80 + 260 (3.0) Steel Deck Main span 800 (3.0) + Inversed Y shaped concrete Pylon Side span 260 + 80 (3.0) East Approach 889 (2.4) BCM Viaduct 2,450 (1.8, 2.4 or 3.0) + -shaped bent FSLM Sum 11,658 (on shore part is excluded ) It is composed of 3 types of bridges, cable stayed bridge, approach bridge and viaduct. General outline of this bridge project is presented in Table 1. The main span of the cable-stayed bridge is 800 m, but the viaduct is the longest as 8,400 m, which makes up around 75% of the whole spans. The superstructure of viaduct is designed to be a 5 span continuous pre-stressed concrete box girder, of which the length is 50 m for each span with the uniform height of 3 m and the design strength for 28 days of applied concrete is 45 MPa. The full viaduct is consisted of 336 units and the weight of each one is around 1350 tons. The simple dimension of each segment is shown in figure 1. In this project, several developed technologies are applied for rapid construction. Each 50 m-long con- crete box girder is fabricated by 2 day cycle using steam-curing system and pre-tension method. One production line is composed of a series of two sets, where one is for rebar work and the other is for 1189