在高桥墩桩基屈曲能量法分析的基础上,提出兼顾结构稳定、强度和经济性的优化模型,并应用优化算法中非线性序列二次规划法,进行优化设计探讨,同时给出优化设计算法流程图,编制了相应的优化计算程序;为了解桥墩高度、轴向荷载、地基比例系数和混凝土弹性模量对于高桥墩桩基屈曲的影响,结合优化设计模型进行了因素分析,探讨了参数变量对目标函数最优值的影响规律和程度,比较结果说明,在进行高桥墩桩基的屈曲受力分析时,高桥墩的大变形影响不容忽视;而一般在工程设计中,可考虑将桩周土体和混凝土弹性模量的增强作用作为设计的安全储备。
Based on the buckling analysis on pile foundation with high bridge pier using energy method, a optimization model is set up according to the structural stability, strength and economy. Then optimization design is discussed by adopting nonlinear sequential quadratic programming algorithm. The Sketch of optimization algorithm is provided, and the corresponding program is developed also. In order to understand the factors, which include pier height, axial load, foundation coefficient and concrete elastic modulus, affect to buckling of pile foundation with high bridge pier, the factors analysis is put forward in connection with the optimization model. The law and degree of effect parameter or a variable on optimal value of target function is discussed. And the results show that the large deformation of pile foundation with high bridge pier affects its buckling property evidently and should be considered in analyzing buckling behavior. The strengthening of soil surrounding piles and concrete elastic modulus are considered to be safety storage in general engineering design.