节理广泛存在于黄土地区,是分割黄土的结构弱面和水流入渗优势通道,目前对其工程特性尤其是水流入渗规律的研究较少。首先通过模型试验分析典型含单节理黄土的水流入渗分布及范围,然后采用SEEP/W数值模拟软件,根据模型试验结果,利用非饱和渗流理论结合数值分析的方法得到典型节理宽度为0.41,0.8,1.24 mm的黄土体的等效饱和渗透系数分别为1.5×10-4,1.67×10-4,1.83×10-4 cm/s,最后研究了节理对水分场分布的影响及节理数量、节理间距等对入渗范围的影响规律。结果表明,节理对黄土水分场有较大影响,湿润区深度随节理数量的增加而大幅增加;随节理间距的增大,节理对水流入渗深度的影响逐渐消失,而湿润区宽度受节理间距的影响较小。研究成果对黄土节理渗流规律研究、含节理隧道及地下工程稳定性评价、控制水土流失等具有重要意义。
Abstract
Distributed widely in loess area, joints are the weak channel of loess and the dominant channel of water infiltration. At present, studies on the engineering characteristics, especially on the law of seepage through joints are inadequate. In this paper, the distribution and range of water infiltration in typical loess with single joint are analyzed by model test. According to the model test results, the equivalent saturated permeability coefficient of loess with typical joint width of 0.41 mm, 0.80 mm and 1.24 mm are obtained as 1.5×10-4 cm/s, 1.67×10-4 cm/s and 1.83×10-4 cm/s, respectively, by combining unsaturated seepage theory and numerical analysis using SEEP/W. In addition, the influence of joints on the distribution of moisture field and the influence of the number and spacing of joints on the infiltration range are studied. Results revealed that joint has a great influence on the moisture field of loess site. The depth of humid zone increases remarkably with the growth of the number of joints. With the augment of joint spacing, the effect of joint spacing on humid zone depth gradually disappears. The width of humid zone is less affected by the spacing of joints.
关键词
黄土节理 /
水流入渗 /
湿润区 /
模型试验 /
数值模拟
Key words
loess joint /
seepage /
humid zone /
model test /
numerical simulation
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