A Research on Limited Value of Axial Compression Ratio of Arbitrarily Shaped RC Columns

The information concerning the research on limited value for axial compression ratio of arbitrarily shaped RC columns in the case of high seismic fortification grade hasn't been found yet so far. Considering the fact that the related National Design Codes have been changed, the limited value for axial compression ratio of arbitrarily shaped RC columns in the case of 2~(nd) and 3~(rd) seismic fortification grades also needs changing. Therefore, it is necessary to make a systematical study on the limited value for axial compression ratio of arbitrarily shaped RC columns in the case of every seismic fortification grade. The theoretical analyses show that 12,10,8 and 6 are taken as the values of curvature ductility ratio of arbitrarily shaped RC columns respectively in the case of 1~(st) , 2~(nd), 3~(rd) and 4~(th) seismic fortification grades, which assures that the arbitrarily shaped RC columns meet the displacement ductility requirements for seismic structures. Then the limited value for axial compression ratio of the arbitrarily shaped RC columns in the case of every seismic fortification grade is determined on the basis of its nonlinear analysis of curvature ductility, and the requirements for the ratio of stirrup spacing to the diameter of longitudinal bar, s/d, and the diameter of stirrup, d_v are met.