非饱和Q3黄土渗气特性试验研究

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摘要为研究非饱和原状和重塑Q3黄土渗气系数的变化规律及其两者的差异，以改进的三轴渗气仪为手段，进行一系列考虑干密度、含水率和各向异性等因素影响的渗气试验。研究结果表明：根据Fick定律和Darcy定律推导的渗气系数计算公式，在较低压力下两者计算结果差别不大，而在较高压力下，Darcy定律计算结果要优于Fick定律；非饱和原状黄土中气体流动遵循Darcy定律，原状黄土渗气系数随着干密度和含水率的增大而减小，且最优含水率以后变化较为明显；由于原状Q3黄土各向异性，竖向原状试样渗气系数始终大于同一埋深横向试样的渗气系数；相同干密度条件下，含水率对重塑黄土渗气系数的影响要比原状黄土大。根据试验结果提出考虑干密度、充气孔隙度(饱和度)和各向异性等因素影响的原状黄土渗气系数计算公式，其计算结果与试验结果吻合较好。

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关键词 ：土力学, 非饱和Q3黄土, 渗气系数, 干密度, 含水率, 各向异性

Abstract：A series of tests considering influences of soil water content，dry density，and anisotropic property，were carried out to research the gas permeability coefficient of unsaturated undisturbed and remoulded Q3 loess，by using a modified triaxial gas permeable apparatus. The results show that，in a lower pressure condition，the results of gas permeability coefficient calculated by Darcy law and Fick law get close to each other；and in a higher pressure condition，the method obtained from Darcy law has an advantage over that got by Fick law. Gas flow of unsaturated undisturbed loess can be expressed by Darcy law. Gas permeability coefficient of unsaturated undisturbed loess decreases with the increase of water content and dry density；and this variation is more obvious in excess of optimum water content. Gas permeability coefficient of vertical undisturbed loess samples is greater than that of horizontal samples in the same buried depth because of anisotropic property. Comparing with gas permeability coefficient of undisturbed loess samples in case of same dry density，the influence of water content on that of remoulded loess is more significant. According to test data，formulas are proposed to compute gas permeability coefficient considering the influence of dry density，gas-filled porosity(saturation ratio) and anisotropic property. The computed results are in accordance with test data.

Key words： soil mechanics;unsaturated Q3 loess;gas permeability coefficient;dry density;water content anisotropic property

收稿日期: 2012-02-05

引用本文:

姚志华1，2，陈正汉1，2，黄雪峰1，2，覃小华1，2，章峻豪1，2. 非饱和Q3黄土渗气特性试验研究[J]. 岩石力学与工程学报, 2012, 31(6): 1264-1273.
YAO Zhihua1，2，CHEN Zhenghan1，2，HUANG Xuefeng1，2，QIN Xiaohua1，2，ZHANG Junhao1，2. EXPERIMENTAL RESEARCH ON GAS PERMEABILITY OF UNSATURATED Q3 LOESS. , 2012, 31(6): 1264-1273.

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http://www.rockmech.org/CN/Y2012/V31/I6/1264

	Journal of Geotechnical Engineering，1993，15(3)：9-20.(in Chinese)) " target="_blank">
[1]	RATTAN L. Encyclopedia of soil science[M]. 2nd ed. Florida，USA：CRC Press，2005：60. " target="_blank">
[5]	SAMINGAN A S，LEONG E C，RAHARDJO H. A flexible wall permeameter for measurements of water and air coefficients of permeability of residual soils[J]. Canadian Geotechnical Journal，2003，40(3)：559-574. " target="_blank">
[6]	KAMIYA K，BAKRIE R，HONJO Y. A new method for the measurement of air permeability coefficient of unsaturated soil[J]. Geotechnical Special Publication，2006，147(2)：1 741-1 752. " target="_blank">
[8]	陈正汉，谢定义，王永胜. 非饱和土的水气运动规律及其工程性质研究[J]. 岩土工程学报，1993，15(3)：9-20.(CHEN Zhenghan，XIE Dingyi，WANG Yongsheng. Experimental studies of laws of fluid motion，suction and pore pressures in unsaturated soil[J]. Chinese
[9]	王永胜，谢定义，郭庆国. 非饱和土中气体的运动特性与渗气系数的测定[J]. 西北水电，1993，(1)：43-49.(WANG Yongsheng，XIE Dingyi，GUO Qingguo. Laws of gas motion in unsaturated soil and determination of air permeability[J]. Northwest Water Power，1993，(1)：43-49.(in Chinese))
[10]	刘奉银，张昭，周冬. 湿度和密度双变化条件下的非饱和黄土渗气渗水函数[J]. 岩石力学与工程学报，2010，29(9)：1 907-1 914. (LIU Fengyin，ZHANG Zhao，ZHOU Dong. Density-saturation- dependent air-water permeability function of unsaturated loess[J]. Chinese Journal of Rock Mechanics and Engineering，2010，29(9)：1 907-1 914.(in Chinese)) " target="_blank">
[12]	HAMAMOTO S，MOLDRUP P，KAWAMOTO K，et al. Effect of particle size and soil compaction on gas transport parameters invariably-saturated sandy soils[J]. Vadose Zone Journal，2009，(8)：986-995. " target="_blank">
[13]	TULI A，HOPMANS J W，ROLSTON D E，et al. Comparison of air and water permeability between disturbed and undisturbed soils[J]. Soil Science Society of America Journal，2005，69(5)：1 361-1 371. " target="_blank">
[16]	苗强强，陈正汉，张磊，等. 非饱和黏土质砂的渗气规律试验研究[J]. 岩土力学，2010，31(12)：3 746-3 750.(MIAO Qiangqiang，CHEN Zhenghan，ZHANG Lei，et al. Experimental study of gas permeability of unsaturated clayey sand[J]. Rock and Soil Mechanics，2010，31(12)：3 746-3 750.(in Chinese))
[11]	姚志华，黄雪峰，陈正汉等. 兰州地区大厚度自重湿陷性黄土场地浸水试验综合观测研究[J]. 岩土工程学报，2012，34(1)：65-74. (YAO Zhihua，HUANG Xuefeng，CHEN Zhenghan，et al. Comprehensive soaking test on self-weight collapse loess with heavy section in Lanzhou region[J]. Chinese Journal of Geotechnical Engineering，2012，34(1)：65-74.(in Chinese))
[15]	DELAGE P，CUI Y J，DE LAURE E. Air flow through an unsaturated compacted silt[C]// Proceedings of the 2nd International Conference on Unsaturated Soils. Beijing：[s.n.]，1998：563-568. " target="_blank">
[2]	JUCA J F T，Maciel F J. Gas permeability of a compacted soil used in a landfill cover layer[J]. Geotechnical Special Publication，2006，147(2)：1 535-1 546. " target="_blank">
[3]	SANCHEZ-GIRON V，ANDREU E，HERNANZ J L. Response of five types of soil to simulated compaction in the form of confined uniaxial compression tests[J]. Soil and Tillage Research，1998，48(1/2)：37-50. " target="_blank">
[7]	MOON S，NAM K，KIM J K，et al. Effectiveness of compacted soil liner as a gas barrier layer in the landfill final cover system[J]. Waste Management，2008，28(10)：1 909-1 914. " target="_blank">
[18]	DEXTER A R. Soil physical quality：part III：unsaturated hydraulic conductivity and general conclusions about S-theory[J]. Geoderma，2004，120(3/4)：227-239. " target="_blank">
[14]	王卫华，王全九，樊军. 原状土与扰动土导气率、导水率与含水率的关系[J]. 农业工程学报，2008，24(8)：25-29.(WANG Weihua，WANG Quanjiu，FAN Jun. Relationship between air permeability，water conductivity and water content for undisturbed and disturbed soils[J]. Transactions of the CSAE，2008，24(8)：25-29.(in Chinese))
[17]	THAVEESAK V，ABDELMALEK B. Gas permeability of partially hydrated geosynthetic clay liners[J]. Journal of Geotechnical and Geoenvironmental Engineering，2004，130(1)：93-103. " target="_blank">
[4]	MOLDRUP P，YOSHIKAWA S，OLESEN T，et al. Gas diffusivity in undisturbed volcanic ash soils：test of soil-water-characteristic based prediction models[J]. Soil Science Society of America Journal，2003，67(1)：41-51. " target="_blank">