Performance-Based Design Concepts for Japanese Severe Loading Conditions

摘要

Recently, some fatigue failures have been observed in the reinforced concrete slabs of Japanese bridges. These slabs were mainly designed according to the 1964 specifications for Japanese highway bridges. As the causes of the fatigue cracks was judged to be lack of slab depth and an inadequate specification for design moment, the minimum depth of the slab has been increased at every review of Japanese specifications and the allowable stress on the reinforced bars has been reduced. To construct high-performance, low-cost decks, we need to develop a new design concept for bridge decks. In this paper, we describe the newly developed Performance Based Design Concept. To judge performance requirements for bridge decks, we have chosen five criteria; serviceability for the user and local communities, static strength under heavy load, fatigue strength under repetitive load, durability of materials, and overall bridge manageability. This paper shows the results of comparisons between severely loaded decks designed according to the new concept and those designed to traditional specifications.