青藏高原季冻区砂砾土冻胀特性试验
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摘要
为探索青藏高原季冻区砂砾土的冻胀特性,为机场工程防冻胀设计提供依据,首先进行颗粒分析实验、击实实验等砂砾土的基本特性实验,为冻胀率室内实验提供相应依据,然后在传统冻胀率室内实验装置的基础上针对砂砾土粒径大的特点进行改进,利用改进后装置进行一系列正交试验,研究含水率、含泥量、压实度、上覆荷载、补水对冻胀率的影响规律.试验结果表明:在封闭条件下,冻胀率随含水率的增大而线性增大;随含泥量的增大呈非线性关系递增;随压实度的增大呈先增大后减小的趋势,在压实度为95%的状态下达到最大值;随上覆荷载的增大呈线性关系平缓递减.在外界补水条件下,冻胀率增大3倍以上.经多元回归分析,得到了多因素综合影响下的回归预报公式.各个因素对冻胀率的影响从大到小依次为:补水,含水率,含泥量,压实度,上覆荷载.在工程实际中,控制补水、含水率、含泥量是防冻胀设计的关键.
In order to explore frost heaving properties of gravel soil containing mud in seasonal frozen region of Qinghai-Tibet Plateau,and provide the foundation for airport engineering anti-freezing expansion design,Particle analysis experiment and compaction experiment were conducted to provide the basis indoor frost heaving rate experiment. Then it improved for gravel soil particle size characteristics of large heaving rate based on traditional means of laboratory experiments,following the improved apparatus a series of sets of orthogonal frost heave indoor tests were conducted to study the influence of factors including degree of compaction,moisture content,silt content,overlying load,water replenishing on frost heaving ratio by the improved experiment device. The test results show that frost heaving ratio of gravel soil containing mud in seasonal frozen region of Qinghai-Tibet Plateau showed a trend of decrease after the first increase with the increase of degree of compaction in a sealed environment,and approaches its maximum at the compaction degree of 95%; increases linearly with the increase of moisture content,increases with the increase of silt content corresponding to a polynomial function; Gently decreases at an exponential functional with the increase of overlying load. Frost heaving ratio increases over three times under the condition of the water replenishing. Multi-factor regression forecast formula is obtained by the multiple regression analysis. The influence of various factors on frost heaving ratio decreasing order: water replenishing,moisture content,silt content,degree of compaction,overlying load. Consequently,it is the key of anti-freezing expansion design to control water replenishing,moisture content,silt content.
In order to explore frost heaving properties of gravel soil containing mud in seasonal frozen region of Qinghai-Tibet Plateau,and provide the foundation for airport engineering anti-freezing expansion design,Particle analysis experiment and compaction experiment were conducted to provide the basis indoor frost heaving rate experiment. Then it improved for gravel soil particle size characteristics of large heaving rate based on traditional means of laboratory experiments,following the improved apparatus a series of sets of orthogonal frost heave indoor tests were conducted to study the influence of factors including degree of compaction,moisture content,silt content,overlying load,water replenishing on frost heaving ratio by the improved experiment device. The test results show that frost heaving ratio of gravel soil containing mud in seasonal frozen region of Qinghai-Tibet Plateau showed a trend of decrease after the first increase with the increase of degree of compaction in a sealed environment,and approaches its maximum at the compaction degree of 95%; increases linearly with the increase of moisture content,increases with the increase of silt content corresponding to a polynomial function; Gently decreases at an exponential functional with the increase of overlying load. Frost heaving ratio increases over three times under the condition of the water replenishing. Multi-factor regression forecast formula is obtained by the multiple regression analysis. The influence of various factors on frost heaving ratio decreasing order: water replenishing,moisture content,silt content,degree of compaction,overlying load. Consequently,it is the key of anti-freezing expansion design to control water replenishing,moisture content,silt content.
引文
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[2]MILLER R D.Lens initiation in secondary frost heaving[R].Lulea,Sweden:Int Symp on Frost Action in Soils,1977.
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[4]陈肖柏.砂砾料之冻胀敏感性[J].岩土工程学报,1988(3):23-29.
[5]王天亮,岳祖润.细粒含量对粗粒土冻胀特性影响的试验研究[J].岩土力学,2013,34(2):359-365,388.
[6]巨娟丽.白砂岩土的冻胀率试验研究[J].水利与建筑工程学报,2004,2(2):51-54.
[7]程佳,赵相卿,杨晓明.青藏铁路多年冻土区典型土样冻胀率特性研究[J].冰川冻土,2011,33(4):863-866.
[8]刘新华.季节冻土冻胀和融沉的影响因素研究[D].西安:长安大学,2007.
[9]高志华.青藏铁路路基冻胀变形特点研究[D].西安:长安大学,2010.
[10]张以晨,李欣,张喜发,等.季冻区公路路基粗粒土的冻胀敏感性及分类研究[J].岩土工程学报,2007,29(10):1522-1526.
[11]徐洪坤,杨祺,伍危.寒区机场道基冻胀预测模型[J].路基工程,2007(5):17-19.
[12]杨锐,王肖戎,许金余.高寒地区机场道面基层底面冻胀应力的计算[J].空军工程大学学报(自然科学版),2007,8(3):16-18.
[13]李博,蔡良才,张罗利.机场工程土基处理分析[J].四川建筑科学研究,2010,36(6):104-106.
[14]闫永刚,刘文录.西北戈壁滩机场水泥混凝土道面病害与对策研究[J].甘肃科技纵横,2010,39(3):151-154.
[15]沈哲,李永毅,李澎,等.高寒地区机场土基冻胀特性试验研究[J].施工技术,2010,39(增刊):8-11.
[16]交通部公路科学研究院.公路土工试验规程:JTG E40—2007[S].北京:人民交通出版社,2007:345-349.
[2]MILLER R D.Lens initiation in secondary frost heaving[R].Lulea,Sweden:Int Symp on Frost Action in Soils,1977.
[3]吴紫汪.土的冻胀性试验研究[M]//兰州冰川冻土所集刊第2号.北京:科学出版社,1981:82-96.
[4]陈肖柏.砂砾料之冻胀敏感性[J].岩土工程学报,1988(3):23-29.
[5]王天亮,岳祖润.细粒含量对粗粒土冻胀特性影响的试验研究[J].岩土力学,2013,34(2):359-365,388.
[6]巨娟丽.白砂岩土的冻胀率试验研究[J].水利与建筑工程学报,2004,2(2):51-54.
[7]程佳,赵相卿,杨晓明.青藏铁路多年冻土区典型土样冻胀率特性研究[J].冰川冻土,2011,33(4):863-866.
[8]刘新华.季节冻土冻胀和融沉的影响因素研究[D].西安:长安大学,2007.
[9]高志华.青藏铁路路基冻胀变形特点研究[D].西安:长安大学,2010.
[10]张以晨,李欣,张喜发,等.季冻区公路路基粗粒土的冻胀敏感性及分类研究[J].岩土工程学报,2007,29(10):1522-1526.
[11]徐洪坤,杨祺,伍危.寒区机场道基冻胀预测模型[J].路基工程,2007(5):17-19.
[12]杨锐,王肖戎,许金余.高寒地区机场道面基层底面冻胀应力的计算[J].空军工程大学学报(自然科学版),2007,8(3):16-18.
[13]李博,蔡良才,张罗利.机场工程土基处理分析[J].四川建筑科学研究,2010,36(6):104-106.
[14]闫永刚,刘文录.西北戈壁滩机场水泥混凝土道面病害与对策研究[J].甘肃科技纵横,2010,39(3):151-154.
[15]沈哲,李永毅,李澎,等.高寒地区机场土基冻胀特性试验研究[J].施工技术,2010,39(增刊):8-11.
[16]交通部公路科学研究院.公路土工试验规程:JTG E40—2007[S].北京:人民交通出版社,2007:345-349.