Nonlinear Time-Dependent Analysis of Segmentally Constructed Structures

Abstract

A general step-by-step model for the nonlinear and time-dependent analysis of reinforced concrete, prestressed concrete, and composite steel-concrete planar frame structures is presented. The model can simulate segmental construction processes such as changes in either the longitudinal and cross-sectional geometry or in the properties of the materials; the placement or removal of elements, prestressing tendons, and stays; and modifications in the internal and external boundary conditions. The nonlinear time-dependent materials properties, the structural effects of the delayed deformations, and the second-order effects are also considered in the structural analysis under loads and imposed deformations. The model can trace structural response during the construction of the structure and throughout its service life. Consideration of the geometric and material nonlinearities allows the structural response to be traced through the elastic, cracked, and ultimate load level, providing valuable information about the influence of the construction process on the short- and long-term carrying capacity of the structure. Complex phenomena such as delayed cracking, nonlinear creep, or creep buckling can also be captured by the model.