石屑改良膨胀土的剪切特性试验研究

Test Study on Shear Characteristics of Expansive Soil Improved by Aggregate Chip

为了研究石屑作为膨胀土物理改良材料的可行性,通过直剪试验研究了石屑掺量、初始干密度对石屑改良膨胀土的抗剪强度及其指标的影响。结果表明:石屑可显著改善膨胀土的抗剪切性能,但石屑掺量、初始干密度对膨胀土的抗剪强度参数和抗剪强度的影响各异。过大的石屑掺量会降低膨胀土的黏聚力,提高膨胀土的内摩擦角,但降低膨胀土的抗剪强度。提高初始干密度可提高膨胀土的黏聚力、内摩擦角和抗剪强度。在石屑改良膨胀土路基施工中,适宜的石屑掺量和较高的压实度,对提高石屑改良膨胀土路基施工质量有利。

In order to research the feasibility of aggregate chip to improve physical properties of expansive soil, the effect of aggregate chip content and initial dry density on the shear strength and other index of aggregate chip improved expansive soil was studied by indoor direct shear test, respectively. The result shows that aggregate chip may greatly improve the shearing resistance performance of expansive soil, while the effects of chip content and initial dry density on the shear strngth with the respective influencing mechanism are different. When the chip mixed, the expansive soil’s cohesion decreases, the internal friction angle increases, and the shear strength reduced. The initial dry density may increase the cohesion, internal friction angle and shear strength. For the subgrade construction in chip-improved expansive soil, proper chip content and relatively high compaction degree are good to enhance the quality of the construction therein.