基于三维土拱效应的预应力锚拉桩锚头间距确定

Determination of suitable anchorhead spacing of prestressed anchor pile based on three-dimensional soil arching

讨论了传统预应力锚拉桩支护结构荷载传递路径存在的不足,根据其受力特性,首次提出了基于三维土拱效应的力学计算模型,并对该模型的正确性进行了验证。分析了土拱的形状、土拱的拱高,进而提出了该模型的数学表达式。同时对三维土拱的形成条件进行了论证,建立了形成土拱的静力平衡条件及土的强度条件,在此基础上确立了锚头间距的控制方程,分析了抗剪强度参数c、φ及桩板后土压力q的对锚头间距的影响。最后,将上述分析成果应用于一工程案例,节约了工程造价效果。

The existing problem of load transmission path of traditional prestressed anchor piles is discussed;and a mechanical calculation model is first proposed based on three-dimensional soil arching effect by its mechanics property;and the correctness of the model is verified.Then the soil arch shape and arch rise are analyzed;and further the mathematical expression of the model is presented.Meanwhile,three-dimensional soil arch formation conditions are demonstrated;static equilibrium and the strength of the conditions are established.On this basis,anchorhead spacing control equation is deduced and the influences of shear strength parameters c and and soil pressure q on anchorhead spacing are analyzed.Finally,a project example is given so as to verify saving project cost.