深层搅拌桩机的小直径多钻头间偏移分析

Skewing Analysis between Blades of Small Diameter Multi-bit Deep Mixing Pile Driver

深层搅拌桩作为一种有效的堤防截渗技术,但多头小直径深层搅拌桩机随着施工深度的增加,相邻钻头之间的叶片会产生碰撞问题。针对叶片碰撞问题,本文假设钻头叶片两侧分别受土体所施加的被动土压力和主动土压力,以正南淮堤截渗工程为例,分析了桩机钻头的变形特征,推导了钻头受力和变形公式,以及初始相位角公式,揭示了调节相邻钻头之间叶片的相位差为90°时,可最大程度地避免叶片间的碰撞,增加有效截渗的深度。

The deep mixing pile is an effective technology in dike seepage cutoff. But along with operation deepening, between the blades of multi-bit mixing pile driver will create collisions. In allusion to the issue, the paper has assumed the both sides of blade have borne soil mass applied passive and active earth pressures respectively. Taking the Zhengyangguan south Huai River dike seepage cutoff project as an example has analyzed deformation features of pile driver bit;derived bit stressing, deforming and initial phase angle formulae. The paper has revealed when to adjust the skewing between neighboring bit blades to 90°, can avoid collision between blades furthest and increase effective seepage cutoff depth.