钢筋混凝土桥墩有效刚度  

Effective stiffness of reinforced concrete bridge piers

作　　者：郑罡[1] 李贵乾[1,2] 

机构地区：[1]招商局重庆交通科研设计院有限公司桥梁结构动力学国家重点实验室,重庆400067 [2]广西壮族自治区交通规划勘察设计研究院,广西南宁530011

出　　处：《土木工程学报》2013年第6期44-52,共9页China Civil Engineering Journal

基　　金：重庆市杰出青年科技基金(CSTC;2008BA6039);国家国际科技合作专项项目(2011DFA83300)

摘　　要：基于桥墩屈服位移三分量模型,从弯曲、剪切和纵筋滑移变形三方面分析桥墩有效刚度的主要影响参数,提出桥墩有效刚度计算的五参数模型及三参数模型;通过75个钢筋混凝土桥墩模型拟静力试验数据的回归分析,标定桥墩有效刚度公式参数。结果表明:钢筋混凝土桥墩有效刚度随轴压比、纵筋率和剪跨比的增大而增大,随材料几何参数的增大而减小;钢筋混凝土墩柱有效刚度的既有公式在平均意义上均严重高估了桥墩有效刚度;与钢筋混凝土墩柱有效刚度的既有公式相比,建议公式的计算结果与桥墩试验结果的吻合程度远高于其他公式,可大幅降低高估桥墩有效刚度的程度和可能性,提高计算的准确度。Based on the three-component yield displacement model, and principal influence factors are analyzed considering the bending, shear and bar-slip deformations. New formulae with five coefficients and three coefficients are respectively proposed for the effective stiffness computation of bridge piers. The coefficients of the new formulae were calibrated with the pseudo-static test results of 75 model columns through regression analysis. The results show that the effective stiffness of bridge piers increases most consistently with axial-load ratio, longitudinal reinforcement ratio and h aspect ratio, while decreases with an increase in t efyd6/L √fc^tFrom the point of the average statistical meaning, existing formulae severely overestimate the effective stiffness of piers. Compared with the existing formulas for calculating the effective stiffness of piers, the proposed formulas agree well the test results and can provide higher accuracy and greatly reduce the degree and possibility of possible overestimation.

关 键 词：钢筋混凝土桥墩 有效刚度 弯曲变形 剪切变形 纵筋滑移变形 回归分析 

分 类 号：P315.9[天文地球—地震学] U442.55[天文地球—固体地球物理学]