水电站机组检修,需要关闸抽水,闸门反复启闭,导致落闸后经常漏水,影响检修工期.以传统堵漏材料煤渣为基础,提出膨润土包裹煤渣造粒,形成煤渣-膨润土团粒,以提升封堵效果.研究表明:以闸门最大漏水孔缝约 15mm 为例,适量的膨润土掺入率(31%～36.3%),优化级配的煤渣-膨润土团粒,即质量比 61%的 2～5 mm 团粒、22.3%的>5～10 mm 团粒、16.7%的>10～15mm团粒,可显著降低渗透系数,煤渣-膨润土团粒饱和渗透系数为 4.87×10-9 m/s,较纯煤渣减少 99.55%;显著提升抗剪性能,较纯煤渣,内摩擦角由 45.57°提高到 77.25°,黏聚力由 24.72 kPa提高到 174.61 kPa.膨润土-煤渣团粒中,煤渣颗粒表面粗糙,有利于团粒间嵌合形成骨架;膨润土吸水膨胀,可充填煤渣颗粒之间的孔隙;而且,膨润土水化后黏附性较强,能把煤渣颗粒黏合成整体,不受水流的波动影响,封堵效果更佳.
Preparation Method and Hydro-Mechanical Properties of Cinder-Bentonite Aggregates
It is necessary to close the sluice for the maintenance of hydropower station units,but the repeated open and close of the sluice gate will leads to the aging of the sealing rubber strip and then causes leakage,which affects the maintenance schedule.Traditional leakage plugging materials,such as cinder,have limitations.This paper proposes a granulation formation method using bentonite-wrapped cinder for agglomerates,aiming to enhance sealing efficiency.The study reveals that for a maximum leakage aperture of approximately 15 mm,an appropriate bentonite incorporation rate(31%to 36.3%)and optimized grading of cinder-bentonite agglomerates(61%mass ratio of 2～5 mm agglomerates,22.3%of 5～10 mm agglomerates,16.7%of 10～15 mm agglomerates)significantly reduce the material's saturated permeability coefficient.The saturated permeability coefficient of cinder-bentonite agglomerates is 4.87×10-9 m/s,which is 99.55%less than that of cinder alone.Additionally,this composition improves shear performance,increasing the internal friction angle from 45.57°to 77.25°and cohesion from 24.72 kPa to 174.61 kPa compared to cinder.In the bentonite-cinder agglomerate,the rough surface of cinder particles facilitates the formation of embedded skeletons.Bentonite expands upon absorbing water,filling the pores between cinder particles.Moreover,bentonite has strong adhesion after hydration and can bond cinder particles into a whole,which is not affected by water flow fluctuations,thus enhancing the prevention effect.
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