THE RESEARCH FOR DAMAGE BEHAVIOR OF REINFORCED CONCRETE COLUMN UNDER BI-DERECTION LATERAL LOAD REVERSALS

采用悬臂式柱试件模拟某中高层钢筋混凝土框架首层中心柱，研究了钢筋混凝土柱在单向和双向输入作用下的抗震性能。试验采用10根普通钢筋混凝土柱和14根预制薄壳钢筋混凝土柱。常见的类型是那些现浇的，被称为RC柱和预制壳是那些有一个预制的外壳，只有核心混凝土浇筑到位。最后一种类型命名为PCa列。总共测试了24个样本。此外，还使用了普通和高强度混凝土。普通混凝土柱截面尺寸为40 cm × 40 cm，剪跨比为2.5;高强混凝土柱截面尺寸为35 cm × 35 cm，剪跨比为3.0。普通混凝土柱主筋采用12-D16规格的SD 35钢筋，混凝土名义强度为240 kg/cm ~ 2。对于高 关于我们 强度混凝土柱，12-D19条SD 50钢被用作主钢筋，混凝土的标称强度为600 kg/cm 2。在PCa混凝土的情况下，预制壳体的混凝土标称强度为600 kg/cm 2（当核心混凝土为正常强度时）和800 kg/cm 2（当核心混凝土为高强度混凝土时）。在这项研究中考虑的参数是加载路径（单向和双向）、横向配筋率（pw= 0.29，0.57，0.6，0.97，1.2%），横向配筋（单轴和双轴，螺旋），轴力比（N/BDFc= 0.25，0.4，0.5）和材料强度，并将实验测得的应变分布与用纤维模型分析得到的应变分布进行了比较，两者吻合较好。试验结果表明，对于较小的横向钢筋，双向荷载作用下的柱的最大承载力或最大荷载均小于单向荷载作用下的柱的最大承载力或最大荷载。对于大量的横向钢筋，最大荷载的差异并不明显。但是，在所有情况下，当试件受到双向载荷时，应变分布显示出比单轴载荷时更大的应变。这表明双向加载比单向加载产生更严重的破坏。通过与试验结果的对比分析，可以看出纤维模型可以用来模拟钢筋混凝土柱的抗震性能。少

Using cantilever type column specimen to model a central column of the first floor of RC frames for medium rise buildings, the seismic behavior of RC columns subjected to one direction and two direction input motions was investigated. 10 specimens of common type RC column and 14 specimens of precast-shell RC columns were used. The common type are those cast in-situ and are called RC-columns and the precast-shell are those which have a prefabricated external shell with only the core concrete cast in place. This last type are denominated PCa columns. In total 24 specimens were tested. Also, normal and high strength concrete was used. In the case of normal concrete the cross section of the specimens was 40cm*40cm with a shear span ratio of 2.5 and for high strength concrete the cross section was of 35cm*35cm with a shear span ratio of 3.0.For normal concrete columns, 12-D16 bars of SD35 steel were used as main reinforcement and the nominal strength of the concrete was 240kg/cm2. For high … More strength concrete column, 12-D19 bars of SD50 steel were used as main reinforcement with a nominal strength for concrete of 600kg/cm2. In the case of PCa specimes, the nominal strength of the concrete for the prefabricated shell was of 600kg/cm2 when concrete for core was of normal strength and 800kg/cm2 when concrete for core was high strength concrete. The parameters taken into account in this research were the loading path (one direction and two direction), transverse reinforcement ratio (pw=0.29,0.57,0.6,0.97,1.2%), transverse reinforcement arrangement (simple stirrup and double stirrup, spiral), axial force ratio (N/BDFc=0.25,0.4,0.5), and material strength.The strain distribution measured experimentally was compared with that obtained analytically using the fiber model analysis and shown good agreement. As conclusion, was observed that for small transverse reinforcement the maximum strength of the column or the maximum load is smaller when the specimen were subjected to two directional loal that when were subjected to one directional load. For large amount of transverse reinforcement that difference in the maximum load in not appreciable. However, in all cases, when the specimens were subjected to two directional loads the strain distribution shown a lager strain that when the specimens are under uniaxial loads. This shows that the two direction loading gives more serious damage than the one direction loading. Comparing the analytical results with experimental results it can be stated that the fiber model can be used to simulate the seismic behavior of the RC column. Less