推力桩桩间土拱几何力学特性及桩间距的确定

Geometrically mechanical characters of soil arch between two adjacent laterally loaded piles and determination of suitable pile spacing

从推力桩桩间土拱形成的机理和力学特性入手,根据桩间土拱的静力平衡以及拱脚处土体本身的强度条件,建立了相应的计算模型。得到了工程设计中的桩间距、拱厚与土拱拱高之间的方程组。在该方程组之中只要确定其一,其余二者便可相应求解。如假定的是土拱厚与土拱拱高中的一个,则得出桩间距与桩间土体的抗剪强度参数成递增的关系。就基坑工程土压力分布的特点,对其处理方法提出了建议。以工程实例对推导的桩间距计算公式进行了验证,结果表明:实际设计值与计算结果基本一致。

Starting from the principle and the mechanic characteristic of forming soil arch of laterally loaded piles, and based on static equilibrium of the soil arch between two piles and soil resistance on its two end sections near two Piles, the computation model is put forward. The equations involved space between two adjacent piles, thickness and height of soil arch are provided. One of the three parameters assumed, the other two could be solved. If one of thickness and height of soil arch is assumed, space between two adjacent piles will increase with shear strength parameters of the soil between two adjacent piles. Based on the characteristics of excavation engineering＇s earth pressure, suggestions are given to deal with it. Landslide was cited to verify the formulae. The computed result is 1.85 m; and the anti-slide piles spacing which was used in the field is 1.8 m. The computed results are consistent with the evidence in the field.