RELIABILITY AND LOAD MODELING FOR BRIDGE MANAGEMENT

Managing the nation's bridge infrastructure requires major decisions on design and construction of new bridges, replacement, strengthening or posting of deficient bridges, issuing permits for truck overloads, and the implementation of truck weight regulations. These decisions have to be made after a careful review of the safety of the affected bridges. This paper illustrates how structural reliability theory can be used to provide tools for bridge management decisions. Using a reliability index as safety criteria, this paper describes reliability-based methods for the development of: a) Criteria for selection of load and resistance factors for a new LRFD bridge design code; b) Flexible load capacity evaluation or rating techniques for existing bridges; c) Fatigue evaluation procedures for steel bridges; and d) New bridge formulas for establishing truck weight regulations.