泥浆悬浮砂粒能力分层测定试验研究

Slice Measurement Test of Sand Carrying Capacity of Slurry

为实现泥浆悬浮砂粒能力的量化分析,提出一种分层测定方法,选取12%、15%和18%3种质量分数的试验泥浆,通过自行设计的分层取样装置进行试验研究,获取不同泥浆质量分数、沉降时间和砂粒粒径条件下的10个深度分段的砂粒质量分布,分析各参数影响下的砂粒沉降变化规律。结果表明:1)该分层测定方法可较好地获取不同深度分段的砂粒质量,弥补现有测定方法只能获取底层砂粒沉降质量的不足;2)试验所采用的3种质量分数的泥浆对0.1 mm以上粒径的砂粒悬浮能力均较差。根据砂粒沉降曲线分布特征,提出一种用于判别泥浆悬浮砂粒能力的方法,即砂粒沉降曲线越平缓,各层质量差异性越小,底层质量无明显拐点,不同沉降时间曲线越紧密,则泥浆悬浮砂粒能力越强。

A slice measurement method is proposed to quantitatively analyze the sand carrying capacity of slurry. The slurries with concentrations of 12%, 15% and 18% are selected to conduct the tests using self-made slice sampling device. The sand mass distributions of ten depth intervals are obtained, considering the effects of slurry concentrations, sedimentation times and sand diameters. The sand sedimentation variations affected by every parameter are analyzed. The results show that： 1 ） The sand mass of different depth intervals can be easily obtained by adopting the slice measurement method. The disadvantage of the existing method which can only obtain the bottom sand mass has been overcome. 2） The sand carrying capacities of those three concentrations of slurry are weak to suspend 0.1 mm sand or sand with a larger particle size. Based on the distribution characteristics of sand sedimentation curves, a method to determine the sand carrying capacity of slurry is put forward. The slurry will possess a better performance on sand carrying capacity in case the following conditions are satisfied： the sedimentation curve is more flat, the mass difference of adjacent layers is smaller, no obvious inflection point exists in the curve at the bottom, and the curves of different sedimentation times are closer.