关键词: 泥水盾构, 泥浆, 悬浮能力, 颗粒沉降, 分层测定

Abstract:

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.

Key words: slurry shield, slurry, suspension capacity, particle settlement, slice measurement