| Summary: | 碩士 === 國立臺灣科技大學 === 營建工程系 === 95 === During Chi-Chi earthquake, many short columns close to window sills in old school buildings were failed by pure shear, and the reinforced concrete (RC) short columns with insufficient stirrups were especially vulnerable. Furthermore, so far international research on columns of pure shear failure is few; therefore, this study discusses the short columns with pure shear failure subjected to earthquake force.
This study discusses the structure behavior of RC short columns with pure shear failure and member buckled under the low axial load. Short columns (ductile and non-ductile detailing) with span-to-depth ratio including three and four were connected to one frame with three columns and three frames with two columns to simulate shear frames subjected to earthquake force and double-curvature deformation. Based on the system of dynamic collapse experiment, local and global failure can be observed. Load redistribution of frame with three columns and the comparison with results of cyclic load tests of single column study the relationship between cyclic and dynamic tests. Also, the degradation of shear strength of columns and the change of cracks can be observed during experiments. The shear strength and displacement capacity can be evaluated using seismic assessment models for shear type buildings.
Test results show that after the non-ductile column of frame with three columns damages a lot, the axial load of this column will be distributed into outer ductile columns, but the frame with two columns collapse immediately after one of columns fails, without any redistribution of axial loads, which is similar to the cyclic test of single column. The shear strength of columns in dynamic tests is higher than that in cyclic tests. The predictions of shear strength models adopted in this study underestimates the shear strength of columns, especially for columns with non-ductile detailing, which represents that the shear strength of short column would be stronger than we expect. On the other hand, the accuracy of predictions of displacement is not enough and modification of models must be made. Test results in this study can be helpful in simulating the dynamic collapse behavior.
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