论文部分内容阅读
研究了掺煤矸石的非饱和压实膨胀土的工程性质。通过击实实验确定混合料的最佳含水率和最大干容重;在最佳含水率、不同的煤矸石掺量和控制压实度条件下,通过加州承载比实验测得CBR值和膨胀率;由直剪实验测定混合料的黏聚力(c)和内摩擦角(φ);利用滤纸法在3种控制压实度、5种控制含水率、不同煤矸石掺量组合条件下测定混合料的吸力。实验结果表明:随着煤矸石掺量的增加,膨胀土的最佳含水率随之降低,最大干容重逐渐增大;当煤矸石掺量在25%~35%之间,混合料的c、φ值得到明显提高;当煤矸石掺量大于35%时可较大地提高CBR值和降低膨胀率,可取得较好的压实效果,满足各级公路全厚式填筑路堤的强度要求;掺入煤矸石后,同一压实度条件下,随着煤矸石掺量的增加,混合料的吸力随之降低,利于降低膨胀土的膨胀率,减少吸水膨胀变形破坏。
The engineering properties of unsaturated compacted expansive soil with coal gangue were studied. Through compaction experiment, the optimum moisture content and the maximum dry bulk density of the mixture were determined. CBR value and expansion rate were measured by California bearing ratio experiment under the optimal moisture content, different gangue content and controlled compaction degree. The cohesion force (c) and internal friction angle (φ) of the mixture were measured by direct shear test. The mixture was measured under the conditions of three control compaction degrees, five kinds of controlled water cut rates and different combinations of coal gangue The suction. The experimental results show that with the increase of coal gangue content, the optimum moisture content of expansive soil decreases and the maximum dry bulk density increases gradually. When the gangue content is between 25% and 35% φ value can be significantly improved; when the content of coal gangue is greater than 35% can greatly increase the value of CBR and reduce the expansion rate, can achieve better compaction effect, to meet the full thickness of highway embankment filling requirements; Into the coal gangue, the same degree of compaction conditions, with the increase of gangue content, the mixture suction decreases, which will help reduce the expansion of expansive soil, reducing water swelling deformation and destruction.