鉄骨鉄筋コンクリート柱脚部の力学性状に関する実験的研究 (その 1) : 軸力・曲げモーメント・せん断力を受ける柱脚の実験

抄録

This paper reports an experimental study on the stress distribution, strength and deformation characteristics of column base connections between steel reinforced concrete columns and their footings. Experimental results for 23 specimens are presented and discussed. Theoretical and experimental performance characteristics are compared, and suggestions for practical design are made. The main results derived from the analysis on these experiments are as follows : (1) A rotation angle R under the maximum load is about 0.020 rad. in the case of Type A and is from 0.012 to 0.034 rad. or so in the case of Type B. The rotation capacity is not influenced so much by increasing axial load for Type A, but it is gradually decreased by increasing axial load for Type B. (2) The co-operated interaction of stresses generated between the steel column base and reinforced concrete column may be preserved sufficiently to P/_<min>P_u=0.8 at N/bDF_c=0 and to P/_<min>P_u=1.0 at N/bDF_c=0.26〜0.54 in both Types A and B. (3) In the ratio of measured maximum loads to minimum values of the calculated ultimate strength, the difference in the safety region is nearly increased in proportion as the axial load increases. (4) Significant effects are observed on the strength and the rotation capacity of the connections at the ultimate loads by the strength of anchor bolts, haunch slope of concrete column, and anchorage length of longitudinal reinforcement. (5) The allowable design strength of S. R. C column bases may be calculated by the equation of the cumulative strength.