基于π定理推导的桩基最大地震附加弯矩计算公式

A Formula for Estimating Maximum Additional Seismic Bending Moment of Pile Foundation Deduced by the π Theorem

基于对地震作用下黏性土中桩基与土动力相互作用机理的认识,从工程应用角度出发,采用量纲分析方法(π定理),在考虑影响桩基弯矩最广泛因素的基础上,提出了6个无量纲π式,并以此分析确定的半解析公式,它能对均质土体中的桩基(桩头固结)在地震作用下产生的最大弯矩进行较为准确地计算预测.结果表明,该结果与文献提供的设计图表相符,这可为实际桩基工程抗震设计提供参考.

Based on the realization of pile-soil dynamic interaction mechanism in clayey soil during earthquakes, this paper, from angle of engineering application,by using dimensional analysis principle （Buckingham-πs theorem） and considering comprehensive factors associated with pile seismic bending moment,deduced 6 dimensionless π parameter groups to reflect the mechanism of study problem,and finally acquired a semi-analytical formula to calculate maximum seismic bending moment developed in a head-fixed pile embedded in a uniform clay bed.This resulting semi-analytical solution was shown both correct and reasonable by conducting parametric sensitivity studies involving pile length, pile diameter, pile modulus, and among others, and can give good agreements with the design charts made by other researchers. This study presented an idea for calculating maximum seismic bending moments of pile foundation,and can be served as a reference for pile seismic designs.