An experimental study of expansion deformation characteristics of weak expansive soil under multi-stage load
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摘要: 为研究压实弱膨胀土的膨胀变形特性，对取自高淳某边坡的弱膨胀土进行固结及浸水膨胀变形试验，研究了在300，200，150，100，75，50，25和12.5 kPa共8种上覆压力下不同初始干密度及初始含水率土体的固结及膨胀变形特征。试验结果表明：初始含水率及初始干密度对弱膨胀土的膨胀变形特性均存在一定的影响，在其余条件相同的情况下，膨胀土的膨胀变形量随着初始干密度的增大而增大，随着初始含水率的增大而减小。分析了膨胀土固结及膨胀变形过程的典型曲线特点，研究了不同初始干密度及初始含水率下土体固结与膨胀曲线膨胀区与压缩区分界点特征，得出在初始含水率相同时，分界点的上覆压力与分界点孔隙比及土体的初始干密度均呈正比关系。通过对土体试验数据的分析拟合，结合土体变形过程中的孔隙比与初始状态关系的推导，提出了弱膨胀土的膨胀变形量计算方法，结合工程包边法路堤填筑的荷载分布，采用分层总和法推导了工程包边法膨胀土路堤填筑的膨胀变形量计算方法，并用于路堤膨胀量的预估中。Abstract: In order to study the expansion deformation characteristics of compaction weak expansive soil, the tests of consolidation and expansive deformation characteristics of the weak expansive soil from a slope in Gaochun were conducted. The consolidation and expansive deformation characteristics under pressures of 300, 200, 150, 100, 75, 50, 25 and 12.5 kPa in different water content and different initial water content were analyzed. The test results show that the initial dry density and water content have certain influence on the weak soil's expansive deformation, under the same other conditions, expansion deformation increases with the increasing initial dry density, and decreases with the increasing initial water content. The typical curve characteristics of the process of consolidation and deformation of the expansive soil were also analyzed. The characteristics of the boundary point on the curve of the soil consolidation and expansive between expansive area and compression area under different initial dry density and water content are summarized, and the results are given that the overlying press of a boundary point has the linear relationship between the boundary point void ratio and the initial dry density under the two initial water content. Through the analysis and fitting of the soil tests data and combined with the derivation of the relationship between the void ratio and the initial state in the process of soil deformation, the calculation methods of the expansion deformation amount of the weak expansion soil is proposed. Combined with the load distribution in the engineer wrapper methods of embankment, the layered summation method is used to deduce the calculation methods of the expansive deformation amount in the embankment, to propose the prediction calculation methods in the expansive deformation value of embankment.
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[1] 黄斌,何晓民,谭凡. K0应力状态膨胀土膨胀模型试验研究[J].岩土力学,2011, 33(增刊1):442-447.[HUANG B, HE X M, TAN F. Experimental study on expansion model of expansive soil in state of K0 stress[J].Rock and Soil Mechanics, 2011,33(Sup 1):442-447.(in Chinese)]
[2] 李振, 邢义川. 侧限条件下膨胀土增湿变形计算模式研究[J]. 西北农林科技大学学报(自然科学版), 2011, 39(5):215-222.[LI Z, XING Y C. Study on the calculation methods of the moistening deformation for the expansive soil under lateral restraint condition[J]. Journal of Northwest A & F University(Natural Science Edition), 2011, 39(5):215-222.(in Chinese)]
[3] 郑健龙, 张锐. 公路膨胀土路基变形预测与控制方法[J]. 中国公路学报, 2015, 28(3):1-10.[ZHENG J L, ZHANG R. Prediction and control method for deformation of highway expansive soil subgrade[J]. China Journal of Highway and Transport, 2015, 28(3):1-10.(in Chinese)]
[4] 刘清秉, 吴云刚, 项伟, 等. K0及三轴应力状态下压实膨胀土膨胀模型研究[J]. 岩土力学, 2016, 37(10):2795-2802.[LIU Q B, WU Y G, XIANG W, et al. Swelling model study of expansive soil at K0 and triaxial stress state[J]. Rock and Soil Mechanics, 2016, 37(10):2795-2802.(in Chinese)]
[5] 王年香, 章为民. 膨胀土地基膨胀变形计算方法研究[J]. 工业建筑, 2008, 38(6):58-61.[WANG N X, ZHANG W M. Calculation method for swelling deformation of expansive soil foundation[J]. Industrial Construction, 2008, 38(6):58-61.(in Chinese)]
[6] 姚海林, 程平, 吴万平. 基于固结试验的膨胀土地基变形预测方法[J]. 岩石力学与工程学报, 2005, 24(21):3911-3915.[YAO H L, CHENG P, WU W P. Prediction of ground heaves in expansive soils based on consolidation tests[J]. Chinese Journal of Rock Mechanics and Engineering, 2005, 24(21):3911-3915.(in Chinese)]
[7] NELSON J, REICHLER D K, CUMBERS J. Parameters for heave prediction by oedometer tests[C]//Fourth International Conference on Unsaturated Soils, April 2-6, 2006, Carefree, Arizona, USA. Reston, VA, USA:American Society of Civil Engineers, 2006.
[8] NELSON J D, CHAO K C, OVERTON D D. Design of pier foundations on expansive soils[C]//Proceedings of 3rd Asian Conference on Unsaturated Soils. Nanjing, China:Science Press, 2007.
[9] RAO R R, RAHARDJO H, FREDLUND D G. Closed-form heave solutions for expansive soils[J]. Journal of Geotechnical Engineering, 1988, 114(5):573-588.
[10] 韦秉旭, 黄震, 高兵. 压实膨胀土表面裂隙发育规律及与强度关系研究[J]. 水文地质工程地质, 2015, 42(1):100-105.[WEI B X, HUANG Z, GAO B. Research on the relationship between fracture development rules and strength of the compacted expansive soil[J]. Hydrogeology & Engineering Geology, 2015, 42(1):100-105.(in Chinese)]
[11] 侯超群, 席瑶, 孙志彬, 等. 基于IPP图像处理的膨胀土微观结构定量研究[J]. 水文地质工程地质, 2019, 46(2):156-161.[HOU C Q, XI Y, SUN Z B, et al. A quantitative study of microstructure of expansive soil based on IPP image processing[J]. Hydrogeology & Engineering Geology, 2019, 46(2):156-161.(in Chinese)]
[12] 公路土工试验规程:JTG E40-2007[S].北京:人民交通出版社,2007.[Test Methods of soil for Highway Engineering:JTG E40-2007[S].Beijing:China Communication Press,2007.(in Chinese)]
[13] 郑健龙,杨和平.公路膨胀土工程[M].北京:人民交通出版社,2009.[ZHENG J L, YANG H P. Highway expansive soil engineering[J]. Beijing:People's Communications Press, 2009.(in Chinese)]
[14] 中华人民共和国行业标准.公路路基设计规范:JTG030-2015[S].北京:人民交通出版社,2015.[Specification for Design of Highway Subgrades:JTG030-2015[S]. Beijing:China Communications Press,2015.(in Chinese)]
[15] 余飞, 陈善雄, 许锡昌, 等. 合肥地区膨胀土路基处置深度问题探讨[J]. 岩土力学, 2006, 27(11):1963-1966.[YU F, CHEN S X, XU X C, et al. Study on determination of treatment depth for expansive soil subgrade in Hefei[J]. Rock and Soil Mechanics, 2006, 27(11):1963-1966.(in Chinese)]
[16] 杨和平, 章高峰. 包盖法填筑膨胀土路堤的合适包边宽度[J]. 公路交通科技, 2008, 25(7):37-42.[YANG H P, ZHANG G F. Appropriate wrapping width of expansive soil embankment built by enveloping method[J]. Journal of Highway and Transportation Research and Development, 2008, 25(7):37-42.(in Chinese)]
[17] 膨胀土地区建筑技术规范:GB J50112-2013[S].北京:中国建筑工业出版社,2013.[Technical code for buildings in expansive regions:GB J50112-2013[S]. Beijing:China Architecture and Building Press,2013.(in Chinese)]
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