膨胀土边坡模型的含水量与变形特征
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摘要
采用室内模型试验,研究降雨蒸发条件下边坡模型的含水量变化和变形特征,并分析两者之间的关系,揭示降雨、蒸发条件下膨胀土边坡遇水膨胀,失水收缩的变形机制。结果表明:含水量的变化是导致膨胀土边坡变形最直接的原因;降雨期间,雨水下渗缓慢,含水量的改变主要发生在浅层土体;边坡的膨胀变形在降雨的第一时间发生,膨胀速度由快变慢;蒸发阶段,雨水入渗使坡体较深处含水量增高,深层土体继续膨胀,而表面土层由于含水量的降低已经开始收缩,因此边坡的整体变形与坡体含水量分布紧密关联。
Indoor model tests were conducted to investigate the deformation mechanism of hydrophilic expansion and dehydration shrinkage,and the relation between them.Water content change and deformation characteristics of expansive soil slope under rainfall evaporation were analyzed.The results demonstrate that the direct reason of expansive soil slope deformation is the change of water content which occurs mainly in shallow soil.Slope expansion occurs at the beginning of rain tall,and its speed is fast and then slow.In evaporation stage,deep soil expands with the increase of water content by rain infiltration,whereas soil surface shrinks with the decrease of its water content.It can be concluded that slope defor-mation is closely related to its water content distribution.
Indoor model tests were conducted to investigate the deformation mechanism of hydrophilic expansion and dehydration shrinkage,and the relation between them.Water content change and deformation characteristics of expansive soil slope under rainfall evaporation were analyzed.The results demonstrate that the direct reason of expansive soil slope deformation is the change of water content which occurs mainly in shallow soil.Slope expansion occurs at the beginning of rain tall,and its speed is fast and then slow.In evaporation stage,deep soil expands with the increase of water content by rain infiltration,whereas soil surface shrinks with the decrease of its water content.It can be concluded that slope defor-mation is closely related to its water content distribution.
引文
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[6]Ng C W W,Zhan L T,Bao C G,et al.Performance of an unsatu-rated expansive soil slope subjected to artificial rainfall infiltration[J].Geotechnique,2003,53(2):143-157.
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[12]Fredlund D G,Xing A,Huang S Y.Predicting the permeabilityfunction for unsaturated soils using the soilwater characteristiccurve[J].Canadian Geotechnical Journal,1994,31:533-546.
[13]詹良通,吴宏伟,包承纲,等.降雨入渗条件下饱和膨胀土边坡原位监测[J].岩土力学,2003,24(2):151-158.
[14]徐光明,王国利,顾行文.雨水入渗与膨胀性土边坡稳定性试验研究[C]∥第二届全国非饱和土学术研讨会论文集.杭州:浙江大学,2005:606-613.
[2]李兆平,张弥.降雨入渗对基坑工程安全性影响的研究[J].中国安全科学学报,2000,10(3):16-22.
[3]刘鸣,刘军,谭峰屹,等.新乡膨胀岩试验段渠坡处理现场监测研究[J].长江科学院院报,2011,28(10):148-155.
[4]田仕明,董羽蕙.边坡在降雨条件下的稳定性分析[J].科学技术与工程,2010,10(24):6079-6083.
[5]周东,孙义刚,乐观永,等.环境因素对膨胀土边坡温度场影响的模型试验[J].广西大学学报:自然科学版,2011,36(4):653-658.
[6]Ng C W W,Zhan L T,Bao C G,et al.Performance of an unsatu-rated expansive soil slope subjected to artificial rainfall infiltration[J].Geotechnique,2003,53(2):143-157.
[7]丁加明,王永和.雨水冲刷及地表径流对膨胀土路基边坡稳定的影响分析[J].路基工程,2005(6):16-18.
[8]刘义虎,杨果林,黄向京.干湿循环作用下水对膨胀土路基破坏机理的试验研究[J].中外公路,2006,26(3):30-35.
[9]王国利,陈生水,徐光明.干湿循环下膨胀土边坡稳定性的离心模型试验[J].水利水运工程学报,2005,12(4):6-10.
[10]姚海林,郑少河,陈守义.考虑裂隙及雨水入渗影响的膨胀土边坡稳定性分析[J].岩土工程学报,2001,23(5):606-609.
[11]廖世文.膨胀土与铁路工程[M].北京:中国铁道出版社,1994.
[12]Fredlund D G,Xing A,Huang S Y.Predicting the permeabilityfunction for unsaturated soils using the soilwater characteristiccurve[J].Canadian Geotechnical Journal,1994,31:533-546.
[13]詹良通,吴宏伟,包承纲,等.降雨入渗条件下饱和膨胀土边坡原位监测[J].岩土力学,2003,24(2):151-158.
[14]徐光明,王国利,顾行文.雨水入渗与膨胀性土边坡稳定性试验研究[C]∥第二届全国非饱和土学术研讨会论文集.杭州:浙江大学,2005:606-613.