ABSTRACT
Despite advances in applications of limit analysis and despite recognition of the effects on stiffness of time-dependent variables, determination of moment demands for continuous beams is driven by two criteria that date from the time of working stress design: (1) moments in a reinforced concrete structure can be determined accurately on the basis of linear response, and (2) moments so determined must not be exceeded. Successful use of a design procedure based on those criteria provides another example of a design method that dees observed behavior but leads to acceptable results. Referring to a beam restrained at both ends, we develop a perspective of how this contradiction in concept leads to tolerable results.
