M法及非线性法在桩基础抗震设计中的对比研究

我国桥梁桩基础设计常采用M法,在桩基础产生小位移的情况下,M法的计算结果较为准确,然而,当桩基础产生大位移时,尤其是地震作用下,其计算结果将产生较大误差.采用日本规范中计算土弹簧刚度的方法考虑地震作用下土体对桩基础的作用,对桥墩进行Pushover分析,并将计算结果与M法的计算结果进行比较,结果表明考虑土体的非线性作用时计算得到的墩顶位移将明显大于M法的计算结果,同时,采用日本提出的抗震指标对桥梁的抗震性能进行了评价.

Comparative Study of M and Nonlinear Method in Seismic Design of Pile Foundation

M method is often used in the design of bridge pile foundation in our country because in the case of small displacements of pile foundation, the calculation of M method is more accurate. However, when a large dis- placement of pile foundation occurs, especially under the circumstance of earthquake, it would produce greater errors in the calculation results. This paper discusses the role of soil on pile foundation in the case of earthquake with the Japanese calculation method for soil spring stiffness, carries out Pushover analysis on the bridge pier, and compares the results with the results of M method. It indicates that the pier top displacement considering the nonlinear interaction of the soil will ly, the seismic performance of the b be significantly greater ridge aere evaluated by than the calculation resuhs of M method. According- seismic indicators proposed by Japan.