摘要
应用突变理论建立了超长桩在竖向静荷载作用下的尖点突变模型,推导得到了超长桩的竖向极限承载力预测公式。在静荷载分析的基础上,引入动荷载,建立了超长桩在动静组合荷载作用下的双尖点突变模型,并对其动力稳定性进行了分析。动力分析表明:动静组合荷载作用下超长桩的振幅H、频率关系q与结构非线性系数α三者之间符合双尖点突变模型;超长桩失稳时动载频率的变化值与桩顶预变形值及系统非线性系数有一定的关系;动载作用"路径"对超长桩的响应特征有很大的影响。工程算例表明:应用尖点突变理论对超长桩的竖向极限承载力进行预测具有较好的适用性。
Based on the catastrophe theory,a cusp catastrophe model of super-long pile under vertical sta￣tic load was established,and the predictor formula was derived.Based on the above analysis,dynamic load was tested,the double cusps catastrophe model of super-long pile under combined load was proposed and used in the analysis of the dynamic stability.Dynamic analysis showed that： The relationship among the amplitude H,the Frequency q and the nonlinear coefficient α was conformed to the double cusps catastrophe model when combined load was applied on super-long pile;there was a certain relationship among the change value of dynamic loading frequency,the previous deformation value of pile and the nonlinear coefficient of systems in the process of destabilization of super-long pile;important influence on the response characteristics of super-long pile was obtained under the different dynamic loading path.Project example results show that： the cusp catastrophe model is applicable in predicting vertical ultimate bearing capacity of super-long pile.
出处
《力学季刊》
CSCD
北大核心
2011年第4期531-538,共8页
Chinese Quarterly of Mechanics
关键词
突变理论
超长桩
竖向极限承载力
动力稳定性
非线性
catastrophe theory
super-long pile
vertical ultimate bearing capacity
dynamic stability
nonlinear
