Appraisal and Reconstruction-Strengthening Design of Reinforced Concrete Frame Structure After an Earthquake

Abstract

This chapter reviews an investigation of 198 R.C. frame buildings after the 1976 Tangshan earthquake and the application of the Code for Seismic Design of Buildings. Appraising methods and foundations for R. C. frame structures after an earthquake are discussed as well. A series of recovery reinforcement methods with suitable conditions and a three-level, three-stage antiseismic method for R.C. frame structure design and reinforcement are also presented. The methods of calculating earthquake resistance for repair and reinforcement of R. C. frame structure include response spectrum method of decomposing vibrating pattern, analysis method of time history, choice of cad software, and estimate of effects of repair and reinforcement of R. C. frame. As per an investigation of 198 R.C. frames in the areas of magnitude 6–11 during Tangshan earthquake in China, less than 10% of them collapsed and 40% suffered little or no damage. This shows that R.C. frame has a good capacity for earthquake resistance. In addition, more than 90% of frame structures, including some badly damaged, were used after repair and reinforcement with good economic and social benefits. This indicates that proper repair and reinforcement patterns should be identified to avoid creating a new weak section after repaired and reinforcement.