以湖北宜昌弱膨胀土为研究对象，通过掺砂改良后的室内回弹模量试验，研究了改良膨胀土的回弹模量与干湿循环次数、风化砂掺量之间的关系。结果表明①在相同的风化砂掺量下，改良膨胀土的回弹模量随着干湿循环次数的增加而逐渐降低，回弹模量的衰减幅度在第1次干湿循环时达到最大，之后逐渐减小，当干湿循环进行至4～5次时，回弹模量基本趋于稳定，回弹模量与干湿循环次数可以用指数函数关系进行拟合，且相关性较好；②在经历相同的干湿循环后，随着风化砂掺量的增加，回弹模量衰减幅度以及土体微裂缝的数量逐渐减小；③通过综合考虑干湿循环次数以及风化砂掺量的耦合影响，建立了干湿循环作用下掺砂改良膨胀土回弹模量的三维非线性预估模型，该预估模型参数较少，形式简单，准确性较高，具有一定的推广价值。
Abstract
The relationships between resilient modulus of improved expansive soil and wettingdrying cycle and dosage of weathered sand respectively were researched through testing the resilient modulus of expansive soil improved by weathered sand. The weak expansive soil in Yichang was taken as the research object. Results showed that 1) with the same dosage of weathered sand, the expansive soil’s resilient modulus gradually decreased with the increasing number of wettingdrying cycles. The decay rate reached maximum at the first wettingdrying cycle, and then gradually decreased. When the wettingdrying came to the fourth to fifth cycle, the resilient modulus is basically stable. Resilient modulus and wettingdrying cycle can be fitted with exponential function, and the correlation is quite well; 2) after the same wettingdrying cycles, the decay rate of resilient modulus and the amount of soil’s microcracks decreased with the increase of weathered sand dosage; 3) in consideration of the coupling effects of wettingdrying cycles and weathered sand dosage, the threedimensional nonlinear prediction model of weathered sand improved expansive soil’s resilient modulus under wettingdrying cycles was established. The prediction model is of simple form and high accuracy, hence it is worth promotion.
关键词
膨胀土 /
风化砂 /
干湿循环 /
回弹模量 /
预估模型
Key words
expansive soil /
weathered sand /
wettingdrying cycles /
resilient modulus /
prediction model
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参考文献
［1］慕现杰，张小平. 干湿循环条件下膨胀土力学性能试验研究[J]. 岩土力学，2008,28(增)：580-582. (MU Xianjie, ZHANG Xiaoping. Research on Mechanical Properties of Expansive Soil under Wettingdrying Cycle[J]. Rock and Soil Mechanics, 2008,28(Sup.): 580-582. (in Chinese))
[2] 郑健龙. 公路膨胀土工程[M]. 北京：人民交通出版社，2009：24-29.(ZHENG Jianlong. Highway Expansive Soil Engineering[M]. Beijing: China Communications Press, 2009：24-29.(in Chinese))
[3] 石 鸿，谷志文，王选仓. 公路路基回弹模量承载板试验方法研究[J]. 公路，2008,9(9)：118-122. (SHI Hong, GU Zhiwen, WANG Xuancang. Research on Resilient Modulus of Subgrade Bearing Plate Test Method[J]. Highway, 2008, 9(9): 118-122. (in Chinese))
[4] 陈开圣，沙爱民. 压实黄土回弹模量试验研究[J].岩土力学，2010，3(3)：748-753. (CHEN Kaisheng, SHA Aimin. Research on Resilient Modulus Test of Compacted Loess[J]. Rock and Soil Mechanics, 2010, 3(3): 748-753. (in Chinese))
[5] 陈声凯，凌建明，罗志刚. 路基土回弹模量应力依赖性分析及预估模型[J]. 土木工程学报，2007,40(6)：95-99. (CHEN Shengkai, LING Jianming, LUO Zhigang. Stressdependent Characteristics and Prediction Model of the Resilient Modulus of Subgrade Soils[J]. China Civil Engineering Journal, 2007, 40(6): 95-99.(in Chinese))
[6] 戈晓明，李术才，王松根，等. 非饱和粉土回弹模量的应力依赖性与水敏感性耦合分析[J]. 山东大学学报（工学版），2013,43（2）：84-88. (YI Xiaoming, LI Shucai, WANG Songgen, et al. Coupling Analysis of Stress Dependence and Water Sensitivity for the Resilient Modulus of Unsaturated Silt Soil[J]. Journal of Shangdong University (Engineering Science), 2013, 43(2): 84-88. (in Chinese))
[7] 凌建明，苏华才，谢华昌，等. 路基土动态回弹模量的试验研究[J]. 地下空间与工程学报，2010，6（5）：919-925. (LING Jianming, SU Huacai, XIE Huachang, et al. Laboratory Research on Dynamic Resilient Modulus of Subgrade Soil[J]. Chinese Journal of Underground Space and Engineering, 2010, 6(5): 919-925.(in Chinese))
[8] 李 聪，邓卫东，崔相奎. 干湿循环条件下完全扰动黄土路基回弹模量分析[J]. 交通科学与工程，2009，25（2）：8-12. (LI Cong, DENG Weidong, CUI Xiangkui. Study on Resilient Modulus of Remolded Loess in Wettingdrying Cycle Process[J]. Journal of Transport Science and Engineering, 2009, 25(2): 8-12. (in Chinese))
[9] 陈开圣，胡 鑫. 高液限红黏土回弹模量试验[J]. 公路，2010，(4):143-147. (CHEN Kaisheng, HU Xin. Resilient Modulus Test of High Liquid Red Clay[J]. Highway, 2010, (4): 143-147.(in Chinese))
[10]凌建明，陈声凯，曹长伟. 路基土回弹模量影响因素分析[J].〗建筑材料学报，2007，10（4）:446-451. (LING Jianming,CHEN Shengkai,CAO Changwei.Analysis of Influence Factors on Resilient Modulus of Subgrade Soils[J]. Journal of Building Materials, 2007, 10(4): 446-451. (in Chinese))
[11]杨 俊，黎新春，张国栋，等.风化砂不同掺入率对膨胀土特性影响的研究[J]. 工业建筑，2012,43(1)：55-60. (YANG Jun, LI Xinchun, ZHANG Guodong, et al. Research on the Influence on Expansive Soil Characteristics by Different Mixing Rates of Weathered Sand[J]. Industrial Construction, 2012, 43(1): 55-60.(in Chinese))
[12]李 聪，邓卫东，张 盛. 考虑非饱和土基质吸力影响的路基回弹模量研究[J]. 公路交通技术，2008，(4):5-7. (LI Cong, DENG Weidong, ZHANG Sheng. Research on Subgrade Rebounding Modulus Allowing for Influence of Unsaturated Soil Matric Suction[J]. Technology of Highway and Transport, 2008, (4): 5-7. (in Chinese))
[13]吕海波，曾召田，赵艳林，等. 膨胀土强度干湿循环试验研究[J]. 岩土力学，2009,30（12）：3797-3802. (LV Haibo, ZENG Zhaotian, ZHAO Yanlin, et al. Experimental Studies in Strength if Expansive Soil in Drying and Wetting Cycle[J]. Rock and Soil Mechanics, 2009, 30(12): 3797-3802. (in Chinese))
[14]黄 斌，何晓明，谭 凡. K0应力状态膨胀土膨胀模型试验研究[J]. 岩土工程学报，2011,33（增1）:442-447. (HUANG Bin, HE Xiaomin, TAN Fan. Experimental Study on Expansion Model of Expansive Soil in State of K0 Stress[J]. Chinese Journal of Geotechnical Engineering, 2011, 33(Sup.1): 442447. (in Chinese))
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