全风化花岗岩路基填料物理改良强度特性研究

以皖南山区G318青阳段改建工程的全风化花岗岩物理改良路基填料为研究对象，通过大型直剪试验研究其抗剪强度指标，探讨该改良填料的强度特性。研究结果表明：改良料具有较好的抗剪强度指标，表现为黏聚力较小，内摩擦角较大；抗剪强度随着含水率的增大呈减小趋势，在最佳含水率±3%的变化程度较小，施工时可以放宽填料含水率3个百分点进行填筑；在饱和时，抗剪强度降低约1/4，施工时应严防路基受水浸泡；压实系数的增大可以提高改良料的抗剪强度，增强其水稳定性；最大粒径对改良料的强度指标影响与粗颗粒含量有关，不可单独作为评价改良料强度的影响因素。

Intensity Character of Physically Modified Completely Weathered Granite

Taking the physically modified completely weathered granite subgrade filler of G318 recon-struction project in Qingyang County as the research object, its shear strength indexes and intensity char-acters are discussed through large direct shear test. The results prove that： the modified filler has good shear strength indexes, the cohesion is small and internal friction angle is large;the shear strength shows a trend of decrease with the increase of moisture content, the change of shear strength is small with 3%near the best moisture content of the improved filler, the moisture content of improved filler can be in-creased or decreased by 3%during construction;when the filler is saturate, the shear strength decreases nearly 25%, the subgrade cannot be soaked by water;the shear strength can be advanced and the water stability can be enhanced with compaction coefficient increase;the impact of max particle size on shear strength indexes relates to the coarse particle content, which cannot be used to evaluate the intensity of the improved filler separately.