西南石油大学学报(自然科学版)

• 本期导读 • 上一篇    

南阳膨胀土裂隙扩展及室内降雨入渗实验研究

汪为巍1 *,孔令伟2,臧濛2,张传成1   

  1. 1. 武汉轻工大学土木工程与建筑学院,湖北武汉430023
    2. 中国科学院武汉岩土力学研究所,湖北武汉430071
  • 出版日期:2015-06-01 发布日期:2015-06-01
  • 通讯作者: 汪为巍,E-mail:1464427693@qq.com
  • 基金资助:

    国家自然科学基金(51474168);湖北省自然科学基金(2014CFB889)。

Experimental Research on Crack Extension and Indoor Rainfall
Infiltration of Nanyang Expansive Soil

Wang Weiwei1*, Kong Lingwei2, Zang Meng2, Zhang Chuancheng1   

  1. 1. School of Civil Engineering and Architecture,Wuhan Polytechnic University,Wuhan,Hubei 430023,China
    2. Institute of Rock and Soil Mechanics,Chinese Academy of Sciences,Wuhan,Hubei 430071,China
  • Online:2015-06-01 Published:2015-06-01

摘要:

膨胀土在含水量降低时发生干缩开裂,给工程带来了极大的危害,其中降雨条件下裂隙膨胀土渗流问题是一
个典型的膨胀土工程问题。制备6 个相同的南阳重塑膨胀土样,在相同的环境下分别脱湿96,79,63,48,39,30 h,通
过数码拍照得到不同时刻试样表面裂隙图片,通过分析得到试样表面裂隙率;为了衡量裂隙在深部方向的发育情况,
使用煤油进行渗透实验,得到煤油入渗系数与脱湿时间、平均含水率、表面裂隙率的关系曲线;在油渗实验结束后进行
室内模拟降雨入渗实验,得到裂隙膨胀土入渗率的变化规律。通过对实验数据整理分析发现试样脱湿时间、试样平均
含水率、试样表面裂隙率、煤油入渗系数、降雨入渗实验径流开始时间、试样入渗率之间有良好的相互关系,降雨入渗
实验初期入渗率较大,入渗率随时间衰减很快,在15 min 内降低了两个数量级,脱湿时间越长的样初期入渗率越高,
衰减的也越快;入渗率在较短的时间内就开始趋于稳定,稳定后的入渗率随试样表面裂隙率线性增长,增长到一个峰
值后迅速降低。

关键词: 膨胀土, 裂隙, 降雨入渗, 径流, 入渗率

Abstract:

The crack of expansive soil occurs when the moisture content reduces,which brings great harm to the project.
Fissured expansive soil seepage under rainfall is a typical engineering problem. In this paper,6 identical remolded Nanyang
expansive soil samples were prepared,which were dried for 96,79,63,48,39 and 30 h in the same environment,respectively.
Surface crack images at different times were obtained with digital camera,and surface fracture rate was obtained through
images analysis. To measure crack development in the deep direction,the kerosene is used for infiltration experiments,and get
the curves of oil seepage coefficient and desorption time,average moisture content,surface crack rate were secured through
experiments;the law of fissured expansive soil permeability coefficient variation was got by the indoor simulated rainfall
experiments. Through analysis of the experimental data,we find out that there exist good relationship among sample desorption
time,surface cracks rate,average moisture content,oil seepage coefficient,the starting time of rainfall runoff and infiltration
rate. In the initial infiltration,infiltration rate decay with time soon,reduces two orders of magnitude within 15 min;the initial
infiltration rate of longer dewetting samples was higher and was with faster decay;infiltration rate stabilizes in a short time;
the stabilized infiltration rate increases linearly with the surface crack rate to a peak and then decreases rapidly.

Key words: expansive soil, crack, rainfall infiltration, runoff, infiltration rate