Optimum design of RC continuous beams considering unfavourable live-load distributions

• Published in: KSCE journal of civil engineering Vol. 21; no. 4; pp. 1410 - 1416
• Main Authors: Nigdeli, Sinan Melih, Bekdaş, Gebrail
• Format: Journal Article
• Language: English
• Published: Seoul Korean Society of Civil Engineers 01-05-2017; Springer Nature B.V; 대한토목학회
• Subjects: Bars; Building codes; Civil Engineering; Concrete; Continuous beams; Cross sections; Design; Design analysis; Design engineering; Design optimization; Engineering; Equations; Geotechnical Engineering & Applied Earth Sciences; Industrial Pollution Prevention; Live loads; Load distribution; Load distribution (forces); Minimum cost; Optimization; Preliminary designs; Reinforced concrete; Reinforcement; Structural Engineering; 토목공학; RC continuous beam; Three moment equations; live load distribution patterns; random search technique; optimization; ACI-318
• ISSN: 1226-7988; 1976-3808
• DOI: 10.1007/s12205-016-2045-5

The cross-sections of Reinforced Concrete (RC) members are assumed in the preliminary design. With optimization, optimum dimensions of cross-sections providing required security measures can be obtained. Although, the area of the reinforcement bars is a computable value according to the cross-section, the amount and size of bars are also design variables in order to ensure the placement of bars providing adherence and other physical conditions. In this paper, the optimum design of RC continuous beams is presented by considering design constraints given in ACI-318 (Building Code Requirements for Structural Concrete). The most critical stress resultants of continuous beams are computed for all live load distribution patterns using three moment equations and were used in the analysis of continuous beam. A Random Search Technique (RST) is developed in order to minimize the material cost of the continuous beam. The RST is employed in different stages of optimization process such as cross-section and reinforcement bar optimization. The approach is effective to find the detailed optimum design of RC continuous beams with minimum cost.