高吸力下广西重塑红黏土吸力与含水率关系试验研究

发布时间：2018-03-15 07:24

本文选题：蒸汽平衡法　切入点：红黏土　出处：《岩土工程学报》2015年S2期 　论文类型：期刊论文

【摘要】：吸力对非饱和土的性质有着重要的影响,探讨吸力与非饱和红黏土含水率之间的关系可以有效地服务地方经济。用蒸汽平衡法研究了高吸力段(3~368 MPa)广西贺州红黏土持水特性。研究表明,质量含水率或者饱和度随着控制吸力的增加而减小,随着吸力的降低而增大;本组试验在控制吸力值为21.82 MPa时,曲线存在突变点,此时试样吸排水速率发生比较大的变化;脱湿曲线与吸湿曲线间存在滞回效应,吸力值小于突变点的时候,滞回现象明显。不同初始含水率的土样对应的吸力与含水率间关系曲线基本重合,而吸力与饱和度间关系曲线则不重合,主要与含水率的变化和土体的胀缩变形不成正比有关,孔隙比和吸力间的关系曲线也进一步说明了这一点,因此分析红黏土土水特征时要根据实际情况选用坐标变量。所获结果为当地边坡土体持水特性分析提供了基础数据,有助于该地区工程实践的防灾减灾。
[Abstract]:Suction has an important effect on the properties of unsaturated soils. The relationship between suction and moisture content of unsaturated red clay can serve the local economy effectively. The water holding capacity of red clay in Hezhou, Guangxi, is studied by steam equilibrium method. The mass water content or saturation decreases with the increase of the controlled suction and increases with the decrease of the suction. When the controlled suction is 21.82 MPa, the curve has a catastrophe point, and the suction and drainage rate of the sample changes greatly. There is hysteretic effect between desiccant curve and moisture absorption curve. When the suction value is smaller than the catastrophe point, the hysteresis phenomenon is obvious. The relation curve between suction and moisture content of soil samples with different initial moisture content basically coincides with each other. However, the curve of relationship between suction and saturation does not coincide, and it is mainly related to the change of water content and the expansion and shrinkage of soil, which is further illustrated by the curve of relationship between void ratio and suction. Therefore, the coordinate variables should be selected according to the actual situation when analyzing the water characteristics of red clay soil. The obtained results provide the basic data for the analysis of the water retention characteristics of the local slope soil, and are helpful to the disaster prevention and mitigation in engineering practice in this area.
【作者单位】：桂林理工大学土木与建筑工程学院;桂林理工大学广西建筑新能源与节能重点实验室;
【基金】：国家自然科学基金项目(11372078,51309055) 广西自然科学基金创新研究团队项目(2012GXNSFGA060001,2014GXNSFBA118236)
【分类号】：TU411

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