应用无限地基方法研究打桩振动对海堤的影响

海堤多建在软弱土地基上，在周围地区建设工程并打桩对海堤工程的安全性将有一定的影响。目前打桩动力分析是将原本无限的地基区域近似地取为有限区域界面来模拟，若能考虑地基的无限性，同时又采用较小的计算区域，一方面可以提高精度，另外计算量可大大降低，特别是对于动力分析时具有更重要的意义。采用阻尼溶剂抽取法来获得有限区域边界的刚度和阻尼，这样就可以采用较小计算区域模拟无限地基的方法来研究打桩对海堤的影响分析。此外，针对桩施工的特点，提出了阻尼溶剂抽取法的积分步长和激励频率。最后，给出了这种分析方法的一个工程计算实例。

Using infinite foundation method to study the influence of vibration produced by pile-construction to sea-dikes

Ambient construction engineering and pile-construction are certainly to influence partly on the safety of sea-dikes as they almost belong to soft-soil foundation. The presented dynamic analysis on pile-construction usually adopt the way of using finite-field to replace the original infinite-field to simulate, if the infinity of foundation is considered and a small calculation field is utilized, it certainly is favorable to calculation precision improvement and calculation effort reduction, specially to dynamic analysis. In the paper, for using infinite foundation method to study the influence of vibration produced by pile-construction to sea-dikes, the damping-solvent extraction is employed to get the area boundary stiffness and damping of finite region. Meanwhile, aimed at the characteristic of pile-construction, the integration-step and exciting frequency of the damping-solvent extraction are presented. In the last, an engineering example is used to demonstrate the feasibility of the proposed method.