剪切压实仪压实均匀性研究

Study on Compaction Uniformity of Shear Box Compactor

为研究剪切压实仪(SBC)成型试件的均匀性,开展了不同装料方式对SBC成型试件的均匀性影响研究,确定了标准的装料方法;采用CT扫描法和逐层切割法从微观和宏观两个角度研究了空隙空间分布规律,并对比落锤击实、旋转压实和剪切压实三种成型方式下试件的空隙分布特性。结果表明:分层装料插捣装料方式可作为SBC成型试件的标准方法;SBC成型试件的空隙空间分布规律为:沿高度方向两头大、中间小的类"U"形分布,沿高度方向30～150 mm内的空隙率与设计值偏差在±0.5%范围内;基于有效高度比和空隙率变异系数的评判结果表明SBC成型的试件最均匀、变异性最小,旋转压实居中,落锤击实最次。

In order to study the uniformity of Shear Box Compactor(SBC)formed specimen,the effect of different charging methods on the uniformity of SBC specimen was studied,and the standard charging method was determined.Using CT scanning method and layer by layer cutting method,the spatial distribution law of voids was studied in the micro and macro perspective.In addition,the void distribution characteristics of specimens under three molding methods of drop hammer compaction,rotary compaction and shear compaction were compared.The results show that the layered charging and ramming charging method can be used as the standard method for SBC forming specimens.The space distribution rule of SBC molded specimens is a U-shaped distribution with large ends and small middle along the height direction,and the deviation between the void ratio and the design value within 30~150mm along the height direction is within ±0.5%.The evaluation results based on the effective height ratio and the coefficient of variation of void fraction show that SBC formed specimens are the most uniform,with the least variability,the rotary compaction is in the middle,and the hammer is the worst.