This paper describes the application of time-dependent analyses for developing progressively erected hybrid structures that combine precast/prestressed concrete with other structural building materials. Several examples of time-dependent analysis through the use of a specialized computer software program are discussed. These structures demonstrate how modern methods of design and construction can be applied to enhance the design of moderate to long span bridges. The featured structures combine the inherent advantages of precast/p restressed concrete with steel and cast-in-place concrete. The designs demonstrate how the strength and durability qualities of concrete can be integrated to produce structures that are light, elegant and economical while also having a minimum impact on the environment.
