中日规范中关于液化和侧向扩流场地桥梁桩基抗震设计考虑之比较

Comparison of Seismic Design Considerations Between Chinese and Japanese Seismic Design Codes for Bridge Pile Foundations in Liquefying Ground and Lateral Spreading Ground

评述了我国液化场地和侧向扩流场地桥梁桩基抗震设计规范。总结了中日两国液化场地和侧向扩流场地桥梁桩基的抗震设计方法与技术细节,阐述了日本规范中液化场地和侧向扩流场地桥梁桩基抗震设计中的液化地基土反力折减系数的确定方法,以及土体液化侧向扩流对桩作用力的计算模式。指出我国规范中在液化和侧向扩流场地桩的抗震分析方法、不同土层分界处桩的抗震措施、桩的竖向承载力及桩的屈曲稳定性分析等方面存在的主要问题,据此给出了亟待改进的初步建议。这对我国桥梁工程的抗震安全性具有重要意义,可供我国工程技术人员参考借鉴。

Firstly,this study briefly explains the current situation of Chinese seismic design codes for bridge pile foundations in liquefying and lateral spreading ground.The Chinese and the Japanese seismic design method and technical detail for bridge pile foundations in liquefying and lateral spreading ground are described and compared systematically and comprehensively,and the methods to determine the reduction factor of subgrade reaction as well as the computing mode of the applied force on piles due to liquefaction-induced lateral spreading of soil in Japanese design codes are especially introduced.Finally,some key problems of current Chinese design codes including seismic design method,vertical bearing capacity,buckling stability analysis and seismic measures near the soil dividing boundary for piles in liquefying and lateral spreading ground are generalized and the corresponding improvement suggestions are proposed.These will tend to improve the seismic safety of bridge engineering and provide certain reference values for our country＇s engineering talents.