Title:
Partial Factor Design for Reinforced Concrete Buildings During Construction
Author(s):
Ashram M. El-Shahhat, David V. Rosowsky, and Wai-Fah Chen
Publication:
Structural Journal
Volume:
91
Issue:
4
Appears on pages(s):
475-485
Keywords:
building codes; concrete construction; failure; loads (forces); multistory buildings; reliability; structural design; Design
DOI:
10.14359/4207
Date:
7/1/1994
Abstract:
A considerable number of building failures occur during construction. One of the more common causes of failure is the overloading of partially stiffened concrete members. This problem becomes more significant with increasing rates of construction. The current codes provide general guidelines for insuring the safety of members after the completion of construction; however, no tools exist for the designer to check the safety of partially stiffened slabs. In this paper, a safety-checking equation for multistory concrete buildings during construction is developed. The proposed equation takes into account the effect of both the construction rate and the construction procedure. Both the loads and resistance are treated as random variables, and an advanced first-order second-moment analysis is performed to compute the reliability index. A calibration of the proposed equation with existing code provisions shows a low reliability for buildings during construction. A partial factor-checking equation for multistory concrete buildings during construction is developed based on a Level-2 reliability analysis. The equation is calibrated to provide the same level of safety as provided for by current service-life design procedures.