Title:
A Simple Method to Analyse Time-Dependent Forces Developed in Continuous Concrete Structures
Author(s):
W. H. Dilger
Publication:
Symposium Paper
Volume:
76
Issue:
Appears on pages(s):
325-340
Keywords:
continuity (structural); creep properties; frames;
loads (forces); reinforced concrete;shrinkage; strains; stresses;
structural analysis.
DOI:
10.14359/6794
Date:
10/1/1982
Abstract:
In any concrete frame structure in which the support conditions are changed during or after construction, or in which shrinkage strains are developed, time-dependent forces occur. These forces may be substantial in structures in which continuity is provided at a later stage of construction, or when it is built in stages. A simple method is presented in which the elastic equations (Muller-Breslau) are expanded to include the time-dependent displacements due to (a) the constant statically determinate and in-determinate forces which are present at the beginning of the continuous action and (b) the time-varying forces introduced by creep and shrinkage. Use is made of the relaxation (aging) coefficient which allows to include in a simple way the effects of aging of the concrete in a structural member subjected to varying forces. A number of different practical examples are given to explain the procedure.