旋挖切削土阻力的理论分析与试验研究

Theoretic analysis and experimental study of soil rotary cutting resistance

在传统土的平面切削理论基础上,提出了土的旋挖切削模型,推导出旋挖切削土阻力公式,公式考虑了孔壁内侧剪切破坏和实际切削角减小等问题。采用多种刀具对砂土进行大量旋挖试验,以测得不同刀具在改变切削角时的旋挖切削阻力。通过试验与理论分析结果比较,证明了理论公式的正确性。研究发现,切削阻力与切削角呈非线性关系,并且不同土质有不同的最佳切削角;不带刀齿的刀具切削阻力大于有齿刀具,而且受切削角影响较大。

A three-dimensional model to predict soil rotary cutting resistance is established besed on the traditional straight soil cutting theory; and the formula is given to calculate the resistance. The model considered the lateral shear failure; and true cutting angle is smaller than tool angle. In order to check the model, test were conducted using different tools in sandy soil; the torque during the expressional test has been gained. The calculated values value fit well with the observed values. The result showed that the nonlinear relationship between the cutting angle and resistance varies for different soil, which optimized cutting angle is existent for different soil. The toothless tool have larger cutting resistance and more sensitive to the cutting angle than the ones with teeth.