混凝土墩柱塑性铰区箍筋设计用量试验研究

建立塑性铰区箍筋用量与墩柱抗震性能目标的定量关系，通过延性指标计算箍筋设计用量，是当前延性抗震构造设计的重要研究内容。大批学者给出众多箍筋用量的计算公式，但其中大部分无法给出任意延性系数对应的设计配箍率，少量可定量公式的适用性和准确性有待提高。为此，基于课题组21个桥墩试验结果、PEER数据库中135个墩柱试件及相关学者的18个墩柱试件，在大量试验数据的基础上，分析实心及空心墩延性性能的主要影响因素，以轴压比、剪跨比、纵筋及混凝土强度、配筋率及位移延性系数等为参数，回归得到不同类墩柱塑性铰区约束箍筋用量的简化算式。关于试验墩柱的计算结果表明，回归公式比既有公式更适用于估算各类墩柱约束箍筋的设计用量。

Experimental study on design quantity of stirrup plastic#br# hinge region of concrete column

 The quantitative relationship between the stirrups in the plastic hinge region and the seismic performance objectives of columns, which means that the quantity of stirrups could be calculated by the ductility index, is an important issue of detail design in the current ductile seismic framework. Various calculation formulas of stirrups have been proposed by different scholars, however, most of them couldn’t satisfy the designed stirrups corresponding to arbitrary ductility coefficient. The applicability and accuracy of some existing quantifiable formulas need to be improved. The main influence factors on the ductility of solid and hollow piers are analyzed based on the analysis results from the 21 piers of research group, 135 piers of PEER, and 18 pseudo-static tests. The simplified calculation formula of confinement stirrups is regressed based on a large number of test results for columns with different sections, in which the axial compression ratio, shear span ratio, longitudinal reinforcement, concrete strength, transverse rebar ratio, and displacement ductility coefficient are chosen as the design parameters. The research results show that the proposed formula is much more suitable than those existing models to estimate the amount of confinement stirrups for various columns.