【摘要】 根据已有试验结果,得到适用于铁路低配筋混凝土桥墩的荷载位移双折线模型。选取4类场地的320条实际地震记录,利用该双折线模型研究4类场地的强度折减系数谱值随桥墩屈服后刚度折减系数变化的规律。结果表明:在考虑桥墩屈服后刚度退化的情况下,强度折减系数谱值随桥墩屈服后刚度折减系数的增大而降低,说明低配筋混凝土桥墩屈服后的刚度退化越大,桥墩对地震的强度需求越大。通过对4类场地强度折减系数谱的统计分析,给出考虑刚度退化的三折线型强度折减系数谱以及据此的铁路低配筋混凝土桥墩抗震评估方法。更多还原

【Abstract】 From the existing experimental results,it can be found that the P-Δ load displacement curve of RC railway piers with low steel ratios can be described as a double-broken-line model.Then the total of 320 earthquake records for 4 types of soil conditions were selected,and the rule that the strength reduction factor spectra for 4 types of soil conditions varying with the stiffness reduction factors was studied by the proposed double-broken-line model.It can be seen that under the condition of considering stiffness degradation,the values of the strength reduction factor spectra will decrease with the increasing of the stiffness reduction factors.It indicates that the seismic strength demands will increase if the stiffness degradation of RC railway piers with low steel ratios becomes distinctive.From the statistical analysis of the strength reduction factor spectra for 4 types of soil conditions,the trilinear strength reduction factor spectra considering stiffness degradation were given and the seismic evaluation method of RC railway piers with low steel ratios was proposed.更多还原