冻融循环对非饱和粉质粘土渗透性影响的试验研究
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摘要
冻融作用下土体渗透性的变化不仅受冻融温度、冻融次数等因素影响,样本的密实度,饱和度等因素也会影响冻融效果。为探究冻融循环作用下土体渗透系数的演化规律,配制不同饱和度,不同密实度的试样在冻融循环作用后进行渗透试验。试验结果表明,土体在冻融作用后其孔隙率、渗透系数增大,且受饱和度的影响,饱和度越大,冻融之后土体的孔隙率、渗透系数的增量越大,冻融对土体结构的劣化作用越显著;密实度越大,土体渗透性受冻融作用的影响越小,达到稳定所需冻融次数越少。经分析认为,土体在反复的冻融过程中,水的相变引起土体结构和孔隙结构的改变,贯通了非连通孔隙,使得土体的渗透性增大,同时土体孔隙率的变化是渗透性改变的重要原因。
The change of soil permeability under freezing and thawing is affected not only by freezing thawing temperature,freezing thawing times,but also by sample density,saturation and other factors. In order to explore the evolution law of soil permeability coefficient under the action of freeze-thaw cycle,the samples with different saturation and different compactness were prepared and tested after freeze-thaw cycles. The test results show that the soil freezing and thawing in the porosity,permeability coefficient,and is affected by saturation,greater saturation of soil after freeze-thaw increment of porosity,permeability coefficient is bigger,freeze-thaw deterioration of soil structure is more obvious,the greater the degree of compaction,influence the permeability of soil freezing and thawing the role of the smaller,less required to achieve stable freezing and thawing cycles. According to the analysis,during the freezing thawing process of soil,the phase transformation of water causes the change of soil structure and pore structure,and through the non-connected pores,the permeability of soil is increased. At the same time,the change of soil porosity is an important reason for permeability change.
The change of soil permeability under freezing and thawing is affected not only by freezing thawing temperature,freezing thawing times,but also by sample density,saturation and other factors. In order to explore the evolution law of soil permeability coefficient under the action of freeze-thaw cycle,the samples with different saturation and different compactness were prepared and tested after freeze-thaw cycles. The test results show that the soil freezing and thawing in the porosity,permeability coefficient,and is affected by saturation,greater saturation of soil after freeze-thaw increment of porosity,permeability coefficient is bigger,freeze-thaw deterioration of soil structure is more obvious,the greater the degree of compaction,influence the permeability of soil freezing and thawing the role of the smaller,less required to achieve stable freezing and thawing cycles. According to the analysis,during the freezing thawing process of soil,the phase transformation of water causes the change of soil structure and pore structure,and through the non-connected pores,the permeability of soil is increased. At the same time,the change of soil porosity is an important reason for permeability change.
引文
[1]郑郧,马巍,邴慧.冻融循环对土结构性影响的试验研究及影响机制分析[J].岩土力学,2015(5):1282-1287,1294.
[2]常丹,刘建坤,李旭.冻融循环下粉砂土屈服及强度特性的试验研究[J].岩石力学与工程学报,2015(8):1721-1728.
[3]连江波,张爱军,郭敏霞,等.反复冻融循环对黄土孔隙比及渗透性的影响[J].人民长江,2010,41(12):55-58,62.
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[6]肖东辉,冯文杰,张泽,等.冻融循环作用下黄土渗透性与其结构特征关系研究[J].水文地质工程地质,2015,42(4):43-49.
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[8]董晓强,陈瑞锋.冻融循环作用下土体特性研究进展[J].太原理工大学学报,2017,48(3):275-287.
[9]许健,王掌权,任建威,等.冻融条件下重塑黄土渗透规律试验分析[J].西北农林科技大学学报(自然科学版),2017,45(7):134-142.
[10]安鹏,张爱军,刘宏泰,等.重塑饱和黄土长期渗流劣化机制及其渗透性分析[J].岩土力学,2013,34(7):1965-1971.
[11]肖东辉,冯文杰,张泽.冻融循环作用下黄土孔隙率变化规律[J].冰川冻土,2014(4):907-912.
[12]王铁行,杨涛,鲁洁.干密度及冻融循环对黄土渗透性的各向异性影响[J].岩土力学,2016,37(S1):72-78.
[13]王红雨,唐少容,邢毓航,等.冻融循环作用下宽级配砾质土的渗透特性[J].工程地质学报,2015,23(3):498-504.
[14]连江波.冻融循环作用下黄土物理性质变化规律[D].咸阳:西北农林科技大学,2010.
[2]常丹,刘建坤,李旭.冻融循环下粉砂土屈服及强度特性的试验研究[J].岩石力学与工程学报,2015(8):1721-1728.
[3]连江波,张爱军,郭敏霞,等.反复冻融循环对黄土孔隙比及渗透性的影响[J].人民长江,2010,41(12):55-58,62.
[4]王大雁,马巍,常小晓,等.冻融循环作用对青藏粘土物理力学性质的影响[J].岩石力学与工程学报,2005(23):4313-4319.
[5]肖东辉,冯文杰,张泽,等.冻融循环对兰州黄土渗透性变化的影响[J].冰川冻土,2014,36(5):1192-1198.
[6]肖东辉,冯文杰,张泽,等.冻融循环作用下黄土渗透性与其结构特征关系研究[J].水文地质工程地质,2015,42(4):43-49.
[7]倪万魁,师华强.冻融循环作用对黄土微结构和强度的影响[J].冰川冻土,2014(4):922-927.
[8]董晓强,陈瑞锋.冻融循环作用下土体特性研究进展[J].太原理工大学学报,2017,48(3):275-287.
[9]许健,王掌权,任建威,等.冻融条件下重塑黄土渗透规律试验分析[J].西北农林科技大学学报(自然科学版),2017,45(7):134-142.
[10]安鹏,张爱军,刘宏泰,等.重塑饱和黄土长期渗流劣化机制及其渗透性分析[J].岩土力学,2013,34(7):1965-1971.
[11]肖东辉,冯文杰,张泽.冻融循环作用下黄土孔隙率变化规律[J].冰川冻土,2014(4):907-912.
[12]王铁行,杨涛,鲁洁.干密度及冻融循环对黄土渗透性的各向异性影响[J].岩土力学,2016,37(S1):72-78.
[13]王红雨,唐少容,邢毓航,等.冻融循环作用下宽级配砾质土的渗透特性[J].工程地质学报,2015,23(3):498-504.
[14]连江波.冻融循环作用下黄土物理性质变化规律[D].咸阳:西北农林科技大学,2010.