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为研究黄土结构性变化对其持水特性的影响规律,以兰州和平镇非饱和Q3原状黄土及其重塑土为研究对象,利用非饱和四联固结仪和压力板仪,对28个环刀试样进行了施加竖向应力和吸力的固结排水试验,以获取原状黄土和重塑黄土的土—水特征曲线。研究结果表明:固结试验中,竖向应力对黄土的持水特性有着明显影响。在同一竖向应力和吸力作用下,重塑土的固结排水要大于原状土;原状黄土的进气值和残余含水率均要略高于重塑土;吸力在20~80k Pa范围内,随着吸力的增大,原状土饱和度的减小趋势要强于重塑土;在吸力80~1000k Pa范围内,在同一吸力条件下,原状土饱和度要大于重塑土。低吸力作用下,原状黄土特殊结构有利于其排水;而高吸力作用下,对于原状黄土,其大孔隙和竖向孔洞中气体抑制水分排出,使得原状土排水减小,重塑土的排水增大。通过分析原状黄土和重塑黄土持水特性的差异,可为黄土结构性的研究提供一种新思路。
In order to study the influence of structural change of loess on its water holding capacity, taking unsaturated Q3 undisturbed loess and its remolded soil in Heping Town of Lanzhou as the research object, using unsaturated quadruple consolidator and pressure plate instrument, The knife samples were subjected to consolidated drainage tests applying vertical stress and suction to obtain soil-water characteristic curves of undisturbed loess and remolded loess. The results show that in the consolidation test, the vertical stress has a significant effect on the water holding capacity of loess. Under the same vertical stress and suction, the consolidated drainage of remolded soil is greater than that of undisturbed soil; the intakes and remnant moisture of intact loess are slightly higher than that of remolded soil; with the suction in the range of 20 ~ 80kPa, With the increase of suction, the decreasing tendency of undisturbed soil saturation is stronger than that of remolded soil. Under the same suction condition, the undisturbed soil saturation is greater than remolded soil under the suction of 80 ~ 1000k Pa. Under the action of low suction, the special structure of undisturbed loess facilitates its drainage; while under the action of high suction, the gas in the macropores and vertical holes of the undisturbed loess inhibits the discharge of water, so that the drainage of undisturbed soil decreases and the drainage of remodeled soil increases Big. By analyzing the difference of water-holding characteristics between undisturbed loess and remolded loess, it can provide a new idea for the study of loess structure.