Fig. 1 Frame calculation model 1 mm Table 1 Joints displacement mm

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似蝉桂
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1 ol. 33 No. 2 Apr GB TU A Study on Single-span RC Frame Reinforced with Steel Truss System Yuan Xing-ren 1 Zhang Peng-cheng 1 Lin Shu-zhi 1 2 Liao Wen-bin 3 1. School of Architecture & Civil Engineering Xiamen University Xiamen China 2. Xiamen Construction and Administration Bureau Xiamen China 3. Xiamen Zhongfuyuan Architecture Design and Research Institute Xiamen China Abstract Single-span frame are used in a general way in school buildings. After Wenchuan earthquake all school buildings are raised to B fortification. According to national seismic appraisal criteria GB frame structure is not appropriate for single-span frame B fortification should not be single-span frame structure. With lack of redundant constraints single-span frame structure is a weak seismic system and easily to collapse. Existing buildings need to be strengthened to improve seismic performance. Generally strengthening components is costly and complexly yet ineffectively comparing with other structural methods. Adding brace is a way to change frame system to brace-frame system. In this paper based on a practical engineering the building seismic performance after strengthened with steel braces and some concomitant problems which should arouse engineer s attention are discussed. The research shows that using braces to change structural system can improve seismic performance of buildings practically and cost-effectively. Keywords seismic design single-span frame steel brace seismic strengthening yxr @ sina. com GB April 2011

2 Fig. 1 Frame calculation model 1 mm Table 1 Joints displacement mm mm 2. 04mm 87% K α 2 Fig. 2 Internal force of initial frames ol. 33 No

3 Fig. 3 Interal force of braced frame 4 T T g 5T g 4 4 Fig. 4 Stiffness distribution of frames 3 u = 4K α K = 6K + 2αK 3 4 = α + α K = 2K 3 + α α = 2K 3 + α K = α η 1 = 1 + α α / 6-1 = 2α 3 + α η 2 = α / 6 = 4 5 η 1 η 2 α 3 + α α = 1 η 1 = 0. 5 η 2 = T 1s X 5 Fig. 5 Seismic coefficient curve α April 2011

4 ~ Fig. 6 6 The constitution of frame joint and column reinforcement 7 N φ 5mm 75mm GB50010 α a α a = 40mm 4mm 20r r 1. 0 α a = 0. 9 f a 500mm GB A a r 7mm Ⅱ T g = 0. 35s N 0. 9φ f c0 A c0 + f y0 A s0 + α a f a A a 6 3 ol. 33 No

5 Fig 7 7 The arrangement plan of the structure g 13. 6m 3. 6m C30 C25 HRB g 0. 15g 8 Y Pushover Fig. 8 The plastic hinge location under the Y direction earthquake mm 96mm 5. 3mm 9 a Y 0. 15g b 1 /808 1 / / PKPM 2 April 2011

6 Table 2 The comparison of reinforcement of the first floor beams and columns KJL KJL KJL KJL KJL KJL KJL KJL cm 2 Asx-Asy Asx-x Asy-y GA-B A B As1-As2-As3 As1 As2 As3 GA-B A B kN kN kN % mm 1 2 ol. 33 No

7 Fig. 9 9 The arrangement of steel braces 10 Y Fig. 10 The story drift in Y-direction 11 Y Fig. 11 The story shear force in Y-direction Fig Y The floor displacement in Y-direction 3. 80mm 5. 6mm % April 2011

8 Fig Flowchart of reinforcement References 1. J ~ 87 Lin Shu-zhi. Some Suggestions for Building Strengthening & Building Design after the Wenchuan Earthquake J. Earthquake Resistant Engineering and Retrofitting ~ 87 in Chinese 2 GB S GB Standard for Building Seismic Appraisal S in Chinese 3. M Song Tian-qi. Structural Design of Tall Buildings M. Chongqing Chongqing University Press 2006 in Chinese 4. M Shang Shou-ping Zhou Fu-lin. Seismic Design of Building Structures M. Beijing Higher Education Press 2003 in Chinese 5. J ~ 96 Fu Jian-ping Zhang Chuan Bai Shao-liang. Quantitative Evaluation of two Shear Transfer Mechanisms in Earthquake-resistant Beam-column Joints J. Journal of Building Structures ~ 96 in Chinese 6. J ~ 45 Bai Yu-fei Liu Chang. Shear Performance Analysis of the Wrapped Steel Joint J. Journal of Harbin University of C. E. & Architecture in Chinese 7 GB S GB Design Code for Strengthening Concrete Structure S in Chinese 1986 ~ ol. 33 No

38 2013 1 1972 280mm 110mm 14 7-8 BRBF 4 HRB400 14mm 9-13 60mm 37. 44MPa 38. 80MPa 15-16 2 BRBF BRBF BRB BRBF Fig. 1 1 Dormitory building before and a

38 2013 1 1972 280mm 110mm 14 7-8 BRBF 4 HRB400 14mm 9-13 60mm 37. 44MPa 38. 80MPa 15-16 2 BRBF BRBF BRB BRBF Fig. 1 1 Dormitory building before and a 46 7 2 0 1 3 7 CHINA CIVIL ENGINEERING JOURNAL Vol. 46 Jul. No. 7 2013 BJJQ-2010-169-01 2012-10-25 RC 100044 20 70 8 RC 1 2. 5 RC RC RC 66. 9% FEMA356 Perform-3D RC TU375. 4 A 1000-131X 2013 07-0037-10