【摘要】 探索影响桥梁高桩承台群桩基础抗震能力值的关键因素,在OpenSees平台下,对位于黏土中的高桩承台群桩基础建立非线性有限元模型,采用二阶中心差分法进行灵敏性分析.结果表明,群桩基础抗震能力值的各衡量指标,对混凝土抗压屈服强度的反应灵敏性较小,对钢筋抗拉屈服强度和土体黏聚力的反应灵敏性较大,对桩体核心混凝土截面积的反应灵敏性较平稳;差分步长取10-2倍均值是合理的.进一步的群桩基础动力可靠度分析要重点考虑钢筋抗拉屈服强度和土体黏聚力对系统失效概率的影响.更多还原

【Abstract】 To explore the key parameters controlling the antiseismic capacity(or supply)of the high-rise pile cap foundation,a finite element model for such foundation lay in the uniform clay was built in the OpenSees finite element framework,and elastic-plastic static analyses were performed on the model.Meanwhile sensitivity analysis was performed on the model using second-order central difference method.The results of these analyses indicate that among some indices of the anti-seismic capacity of the high-rise pile cap foundations,the response sensitivity for the compressive strength of concrete is small,the response sensitivity for the tensile strength of reinforcements and the soil cohesive force are large,the response sensitivity for the core concrete section area is stable,and the time inerval of the finite difference taken as 10-2 order is reasonable.For the further dynamic reliability analysis of pile cap foundation,the tensile strength of reinforcements and the soil cohesive force should be treated as the important parameters affecting the system failure probability.更多还原