不同脏污质对格栅加筋道砟性能的影响

加筋格栅广泛应用于有砟轨道中以提高道床承载及侧向抗变形性能.?由于受到来自行进列车落下的煤渣或底砟及地基层翻冒的泥浆等的污染,格栅加筋道砟集料的力学性能会受到严重影响.?选用黏土、煤渣两种有砟铁路常见脏污杂质,对格栅加筋道砟开展了不同法向压力、不同脏污程度下的大型直剪试验,对比研究了不同脏污质对格栅加筋道砟的抗剪强度、...

Influence of Various Fouling Materials on Geogrid-Reinforced Ballast Performance

Geogrid has been widely adopted in ballasted railways to improve the bearing capacity of ballast and its resistance to lateral deformation. The mechanical properties of geogrid-reinforced ballast aggregate are seriously affected by contaminants of coals falling from the moving hauls or clay fines from ballast layer and subgrade. A series of large-scale direct shear tests of geogrid-reinforced ballast under different normal pressures and various fouling levels were performed using the two common fouling substances of ballasted railway, i.e., clays and coals. The effects of the two fouling materials on the shear strength, peak friction angle, vertical dilatant displacement, and peak dilatant angle of the geogrid-reinforced ballast were compared and analyzed, and the mechanical mechanism that contributes to the different performances was also explored. The results showed that the presence of fouling materials decreases the shear strength and peak friction angle of geogrid-reinforced ballast, but reduces its vertical dilatant displacement and peak dilatant angle. Compared with that fouled by clay fines, the ballast fouled by coals exhibits a lower shear strength and peak friction angle, and a larger vertical dilatant displacement and peak dilatant angle, indicating increasingly adverse impacts on the mechanical performances of geogrid-reinforced ballast.