浅圆仓散料侧压力计算探讨

CALCULATION OF BULK-SOLID PRESSURES IN SQUAT SILOS

浅圆仓散料侧压力一般采用Rankine或Coulomb土压力理论计算,而Rankine理论和Coulomb理论适合于直线形挡墙,对仓壁这样在平面上投影为圆形的墙不一定适用,况且,在应用上述理论时往往假设侧压力沿墙高是线性分布的,但众所周知,散体不同于流体,其侧压力沿高度的分布不可能是线性的。基于此,依据极限平衡理论,研究浅圆仓散料侧压力的实际分布规律及计算方法。首先得到散粒体作用在单位弧长的墙壁上的合压力,然后通过严格的数学推导,求得侧压力的曲线分布规律。将结果与实仓试验结果对比,说明公式不论对贮料平堆还是锥堆都比较适合,而上述两种理论用于浅圆仓均有缺陷。

There are several ways to calculate the lateral pressure of squat silos. The most popular are Rankine and Coulomb earth pressure theories which are based on the consideration that the soil behind the retaining wall is two-dimensional plane. So they may not be suitable for a silo wall whose projection is circular on the plane. Furthermore, it is almost acceptable that the wall pressures vary linearly with depth according to the above two theories. Nonetheless, the bulk-solid pressure may not distribute linearly with depth because a bulk-solid behaves very differently from a fluid. The real pressure distribution law and calculation methods are studied. Based on the limits equivalent theory and through rigorous mathematical deduction, the curvilinear lateral pressure distribution is acquired. The results are in good agreement with that of the full-size silo experiment for both the horizontal plane top and the conical pile top of the stored bulk material, while Rankine＇ s formula and Coulomb＇ s formula are not accurate for the two cases.