Research on function model of lime-improved high liquid limit soil strength characteristics
-
摘要:
针对广西荔玉高速路基沿线产生的大量高液限土弃方问题,采用生石灰对高液限土进行改良处理。选取弃土场的高液限土,分别配制不同初始含水率、不同石灰掺量的试样进行侧限压缩试验和快剪试验,采用基本初等数学函数模型拟合不同饱和状态、不同初始含水率下石灰掺量对试件压缩特性和抗剪强度影响。结果表明:(1)高液限土的压缩系数随石灰掺量增加呈指数形式减小;(2)不同饱和状态试件的黏聚力和内摩擦角随石灰掺量增加呈二次函数形式变化;(3)高液限土具有水敏性,饱和素土试件最大抗剪强度对应的含水率较击实试验最大干密度对应的含水率高3%~6%;(4)当初始含水率不高于26.73%时,建议石灰掺量不低于6%,否则改良高液限土的石灰掺量不低于8%,可在满足经济性的前提下达到较好的改良效果。
Abstract:In view of the large number of high liquid limit soil abandonment problems along the roadbed of the Liyu Expressway in Guangxi, quick lime was used to improve the high-liquid limit soil. the high-liquid limit soil samples with different initial water content and different lime content from the spoil field were used to conduct lateral compression test and fast shear test, and the basic elementary mathematical function model was used to fit different saturation states and different initial water content. The effect of lower lime content on the compression characteristics and shear strength of the specimen is tested. The results show that: (1) The compression coefficient of high liquid limit soil decreases exponentially with the increase of lime content; (2) the cohesion and internal friction angle of the specimens in different saturated states change with the increase of lime content in the form of quadratic function; (3) High liquid limit soil has water sensitivity. The moisture content corresponding to the shear strength is 3%~6% higher than the moisture content corresponding to the maximum dry density of the compaction test; (4) When the initial moisture content is lower than 26.73%, it is recommended that the lime content is not less than 6%, otherwise the lime content of the modified high liquid limit soil is not less than 8%, which can be achieved under the premise of meeting economics and better improvement effect.
-
-
表 1 弃方段高液限土参数指标
Table 1. Parameters of high liquid limit soil of spoil
样品状态 取样深度/m 天然含水率/% 液限/% 塑限/% 土粒比重 原状土 2.1~2.3 31.30 53.30 28.50 2.76 原状土 6.5~6.7 36.30 52.10 33.70 2.74 扰动土 1.3~1.5 33.43 51.93 22.46 2.79 表 2 试件压缩系数与石灰掺量的指数模型拟合结果
Table 2. Fitting results of exponential model between compression coefficient and lime content
数学模型 初始含水率 20.84% 23.68% 26.73% 29.71% 33.75% 34.93% A 0.04±0.00 0.05±0.00 0.05±0.00 0.05±0.00 0.08±0.00 0.07±0.00 B 0.10±0.00 0.13±0.00 0.16±0.00 0.20±0.00 0.25±0.00 0.29±0.00 C 2.26±0.07 2.59±0.11 2.67±0.20 2.88±0.14 2.46±0.07 3.24±0.05 R2 0.9998 0.9996 0.9989 0.9996 0.9998 1.0000 Adj.R2 0.9996 0.9992 0.9977 0.9991 0.9997 0.9999 注:R2 为相关系数平方;Adj.R2为调整后相关系数平方。 表 3 不同状态试件黏聚力幂函数模型拟合结果
Table 3. Fitting results of power function model for cohesion of specimens in different states
试件状态 数学模型 初始含水率 20.84% 23.68% 26.73% 29.71% 33.75% 34.93% 未饱和 139.62±4.55 126.32±6.07 98.34±3.01 54.77±1.94 28.24±1.05 22.19±2.48 A 24.06±2.69 21.46±3.59 22.70±1.78 19.02±1.15 18.65±0.62 17.65±1.74 B −1.19±0.32 −0.92±0.43 −1.04±0.21 −0.89±0.14 −0.87±0.07 −0.76±0.18 R2 0.9947 0.9899 0.9976 0.9986 0.9996 0.9975 Adj.R2 0.9894 0.9798 0.9952 0.9971 0.9991 0.9949 饱和 12.89±2.05 22.30±2.76 15.94±1.47 10.58±1.32 4.14±1.17 3.08±0.71 A 11.56±1.21 15.26±1.63 13.36±0.87 8.20±0.78 5.57±0.69 4.57±0.42 B −0.62±0.15 −0.99±0.20 −0.77±0.10 −0.44±0.09 −0.29±0.08 −0.21±0.05 R2 0.9948 0.9929 0.9978 0.9958 0.9932 0.9968 Adj.R2 0.9896 0.9857 0.9956 0.9916 0.9863 0.9936 表 4 未经饱和试件内摩擦角的幂函数模型拟合结果
Table 4. Fitting results of power function model for internal friction angle of unsaturated specimen
函数模型 初始含水率 20.84% 23.68% 26.73% 29.71% 33.75% 34.93% 30.79±0.32 29.17±0.45 26.75±0.43 24.83±0.49 24.39±0.28 24.21±0.35 A 1.49±0.19 1.43±0.27 1.69±0.26 1.77±0.26 1.43±0.17 1.40±0.21 B −0.09±0.02 −0.06±0.03 −0.07±0.03 −0.07±0.03 −0.04±0.02 −0.04±0.02 R2 0.9913 0.9872 0.9915 0.9910 0.9966 0.9943 Adj.R2 0.9827 0.9745 0.9830 0.9821 0.9932 0.9887 表 5 试验设计方案
Table 5. Experimental design scheme
初始含水率/% 石灰掺量/% 黏聚力 内摩擦角 R Adj. R2 29.71 10 51.85 31.10 1.000 0.999 12 47.45 31.78 0.998 0.996 33.75 10 32.20 29.87 0.998 0.996 12 33.5 29.89 0.998 0.995 34.93 10 26.5 29.56 0.999 0.997 12 30.25 30.29 0.994 0.989 表 6 饱和试件内摩擦角拟合结果
Table 6. Fitting results of internal friction angle of saturated specimen
函数模型 方程 初始含水率 20.84% 23.68% 26.73% 29.71% 33.75% 34.93% 幂函数 23.14±0.14 24.12±0.72 24.36±0.95 23.92±0.76 23.79±0.23 23.58±0.12 A 2.00±0.08 2.51±0.43 2.74±0.56 2.53±0.45 1.98±0.14 1.97±0.07 B −0.15±0.01 −0.21±0.05 −0.23±0.07 −0.21±0.05 −0.16±0.02 −0.16±0.01 R2 0.9984 0.9702 0.9539 0.9672 0.9954 0.9988 Adj.R2 0.9968 0.9404 0.9078 0.9345 0.9908 0.9975 -
[1] 曾庆建, 刘宝臣, 张炳晖, 等. 红黏土崩解特性试验研究[J]. 水文地质工程地质,2018,45(3):93 − 97. [ZENG Qingjian, LIU Baochen, ZHANG Binghui, et al. An experimental study of the disintegration characteristics of red clay[J]. Hydrogeology & Engineering Geology,2018,45(3):93 − 97. (in Chinese with English abstract)
[2] 孙德安, 李培, 高游, 等. 红黏土浸水变形特性试验研究[J]. 水文地质工程地质,2015,42(5):74 − 78. [SUN Dean, LI Pei, GAO You, et al. An experimental study of deformation characteristics of lateritic clay due to wetting[J]. Hydrogeology & Engineering Geology,2015,42(5):74 − 78. (in Chinese with English abstract)
[3] 李健, 孙德安, 陈波, 等. 浙西饱和红黏土的物理力学特性试验研究[J]. 水文地质工程地质,2017,44(6):51 − 57. [LI Jian, SUN Dean, CHEN Bo, et al. An experimental study of the physical and mechanical behavior of the saturated lateritic clay in western Zhejiang[J]. Hydrogeology & Engineering Geology,2017,44(6):51 − 57. (in Chinese with English abstract)
[4] 徐奋强, 洪宝宁, 孟云梅. 高液限土路基掺沙改良路用特性试验[J]. 水利水电科技进展,2014(6):76 − 81. [XU Fenqiang, HONG Baoning, MENG Yunmei. Experimental study on road properties of high liquid limit soil improvement by mixing sand[J]. Advances in Science and Technology of Water Resources,2014(6):76 − 81. (in Chinese with English abstract) doi: 10.3880/j.issn.1006-7647.2014.06.016
[5] 吴帅峰, 蔡红, 魏迎奇, 等. 土石混合料剪切机理及抗剪强度分量特性研究[J]. 岩土工程学报,2019,41(z2):230 − 234. [WU Shuaifeng, CAI Hong, WEI Yingqi, et al. Shear mechanism and shear strength component characteristics of soil-stone mixtures[J]. Chinese Journal of Geotechnical Engineering,2019,41(z2):230 − 234. (in Chinese with English abstract)
[6] 阮波, 彭学先, 米娟娟, 等. 聚丙烯纤维加筋红黏土抗剪强度特性试验研究[J]. 铁道科学与工程学报,2017,14(4):705 − 710. [RUAN Bo, PENG Xuexian, MI Juanjuan, et al. Experimental study on shear strength of polypropylene fiber reinforced red clay[J]. Journal of Railway Science and Engineering,2017,14(4):705 − 710. (in Chinese with English abstract) doi: 10.3969/j.issn.1672-7029.2017.04.006
[7] El SHINAWI A. Instability improvement of the subgrade soils by lime addition at Borg El-Arab, Alexandria, Egypt[J]. Journal of African Earth Sciences,2017,130:195 − 201.
[8] AL-RAWAS A A, HAGO A W, AL-SARMI H. Effect of lime, cement and Sarooj (artificial pozzolan) on the swelling potential of an expansive soil from Oman[J]. Building & Environment,2005,40(5):681 − 687.
[9] 郭爱国, 孔令伟, 胡明鉴, 等. 石灰改性膨胀土施工最佳含水率确定方法探讨[J]. 岩土力学,2007,28(3):517 − 521. [GUO Aiguo, KONG Lingwei, HU Mingjian, et al. On determination of optimum water content of lime-treated expansive soil[J]. Rock and Soil Mechanics,2007,28(3):517 − 521. (in Chinese with English abstract) doi: 10.3969/j.issn.1000-7598.2007.03.016
[10] 刘顺青, 洪宝宁, 方庆军, 等. 高液限土和红黏土的水敏感性研究[J]. 深圳大学学报(理工版),2013,30(1):78 − 83. [LIU Shunqing, HONG Baoning, FANG Qingjun, et al. Study on the water sensitivity of high liquid limit soil and red clay[J]. Journal of Shenzhen University (Science & Engineering),2013,30(1):78 − 83. (in Chinese with English abstract)
[11] 梁伟, 欧孝夺. 南宁高液限土路基石灰改良试验研究[J]. 建筑科学,2008,24(7):57 − 60. [LIANG Wei, OU Xiaoduo. Experimental study on high liquid limit soil roadbed improved with lime in Nanning[J]. Building Science,2008,24(7):57 − 60. (in Chinese with English abstract) doi: 10.3969/j.issn.1002-8528.2008.07.014
[12] BELL F G. Lime stabilization of clay minerals and soils[J]. Engineering Geology,1996,42(4):223 − 237. doi: 10.1016/0013-7952(96)00028-2
[13] KHEMISSA M, MAHAMEDI A. Cement and lime mixture stabilization of an expansive overconsolidated clay[J]. Applied Clay Science,2014,95:104 − 110.
[14] SHARMA L K, SIRDESAI N N, SHARMA K M, et al. Experimental study to examine the independent roles of lime and cement on the stabilization of a mountain soil: A comparative study[J]. Applied Clay Science,2018,152:183 − 195.
[15] PAULA F A, ANDRY R, HARIFIDY R, et al. Shear strength performance of marine sediments stabilized using cement, lime and fly ash[J]. Construction and Building Materials,2018,184:454 − 463. doi: 10.1016/j.conbuildmat.2018.06.231
[16] 刘鑫, 洪宝宁. 高液限土工程特性与路堤填筑方案[J]. 河海大学学报(自然科学版),2011,39(4):436 − 443. [LIU Xin, HONG Baoning. Engineering characteristics and construction schemes of high liquid limit soil in embankment filling[J]. Journal of Hohai University (Natural Sciences),2011,39(4):436 − 443. (in Chinese with English abstract)
[17] 何群, 冷伍明, 魏丽敏. 软土抗剪强度与固结度关系的试验研究[J]. 铁道科学与工程学报,2005,2(2):51 − 55. [HE Qun, LENG Wuming, WEI Limin. Experimental study on relationship between soft soil’s shear strength and degree of consolidation[J]. Journal of Railway Science and Engineering,2005,2(2):51 − 55. (in Chinese with English abstract)
[18] 闫小庆, 周翠英, 房营光, 等. 荷载作用下软土压缩模量与孔隙结构关系研究[J]. 中山大学学报(自然科学版),2018,57(5):57 − 63. [YAN Xiaoqing, ZHOU Cuiying, FANG Yingguang, et al. Research on relationship between compression modulus of soft soil under loading and its pore structure[J]. Acta Scientiarum Naturalium Universitatis Sunyatseni,2018,57(5):57 − 63. (in Chinese with English abstract)
[19] 谢里阳, 刘建中. 样本信息聚集原理与P-S-N曲线拟合方法[J]. 机械工程学报,2013,49(15):96 − 104. [XIE Liyang, LIU Jianzhong. Principle of sample polymerization and method of P-S-N curve fitting[J]. Journal of Mechanical Engineering,2013,49(15):96 − 104. (in Chinese with English abstract) doi: 10.3901/JME.2013.15.096
[20] 陈开圣. 干湿循环下红黏土裂隙演化规律及对抗剪强度影响[J]. 水文地质工程地质,2018,45(1):89 − 95. [CHEN Kaisheng. Fracture evolution and shear strength of red clay under dry wet cycles[J]. Hydrogeology & Engineering Geology,2018,45(1):89 − 95. (in Chinese with English abstract)
[21] 张祖莲, 梁谏杰, 黄英, 等. 干湿循环作用下红土抗剪强度与微结构关系研究[J]. 水文地质工程地质,2018,45(3):78 − 85. [ZHANG Zulian, LIANG Jianjie, HUANG Ying, et al. A study of the relationship between shear strength and microstructure of laterite under drying and wetting cycles[J]. Hydrogeology & Engineering Geology,2018,45(3):78 − 85. (in Chinese with English abstract)
[22] 王林峰, 田耘, 曾表, 等. 高液限红黏土的压实特性与路基填筑方案[J]. 材料导报,2019,33(10):1666 − 1670. [WANG Linfeng, TIAN Yun, ZENG Biao, et al. Compaction characteristics of high liquid limit red clay and subgrade filling scheme[J]. Materials Review,2019,33(10):1666 − 1670. (in Chinese with English abstract) doi: 10.11896/cldb.19020036
[23] 张燕清, 吴立坚, 宋常军. 高液限土的最大CBR强度与试验方法[J]. 公路交通科技,2016,33(10):53 − 59. [ZHANG Yanqing, WU Lijian, SONG Changjun. Maximum CBR strength of high liquid limit soil and test method[J]. Journal of Highway and Transportation Research and Development,2016,33(10):53 − 59. (in Chinese with English abstract) doi: 10.3969/j.issn.1002-0268.2016.10.009
-