基于能量法的斜坡中楔形基桩屈曲稳定性分析

Buckling stability analysis for tapered pile in slopes based on energy method

考虑了桩侧摩阻力以及桩后土体滑坡推力的影响,采用非线性桩侧土水平弹性抗力分布形式,基于Rayleigh-Ritz法,对斜坡中楔形基桩的屈曲稳定性问题进行了研究,得出了斜坡中楔形基桩屈曲临界荷载的表达式.分析了坡角、桩后土体滑坡推力分布形式、桩身埋置率、桩侧摩阻力及桩身嵌固率对斜坡中楔形基桩屈曲稳定性的影响.研究结果表明:与等截面桩相比,桩端直径不变时,不同桩径变化率下的斜坡中楔形基桩的屈曲临界荷载均有了不同程度的增加;桩径变化率越大,斜坡中楔形基桩的屈曲临界荷载增加的幅度也随之增大.坡度、桩身埋置率以及桩身嵌固率对斜坡中楔形基桩的屈曲临界荷载影响较大;桩侧摩阻力能够提高斜坡中楔形基桩的屈曲临界荷载,但是提高的幅度有限.桩后土体滑坡推力的大小和分布形式对斜坡中楔形基桩屈曲临界荷载影响很小,以上两者均可以忽略不计.

Considering the side frictional force and the soil thrust behind pile,with nonlinear side horizontal elastic soil resistance distribution,the buckling stability analysis for tapered pile in slopes was discussed based on Rayleigh-Ritz method to obtain the formulation of critical buckling load for tapered pile in slopes.The effects of slope angle,distribution of soil thrust behind pile,pile embedded ratio,side frictional force and pile insertion ratio on buckling stability for tapered pile in slopes were analyzed.The results show that compared with equal diameter piles,the critical buckling loads for tapered piles in slopes are increased for different varying rates of pile diameter when pile tip diameter keeps constant.The critical pile buckling load is increased with the increasing of varying rate of pile diameter.Slope angle,pile embedded ratio and pile insertion ratio have significant effects on the buckling stability for tapered pile in slopes.The side frictional force is helpful to increase the critical pile buckling load,but the improvement extent is limited.The effects of the value and distribution of soil thrust behind pile on the critical pile buckling load is tiny.Both of them can be neglected.