粗颗粒含量对川西地区混合土压缩特性的影响
|
摘要
为解决川西地区混合土路基压缩变形问题,为该地区高速公路、铁路建设提供理论分析基础,针对该地区路基常用混合土,考虑粗颗粒含量影响,进行天然混合土大型压缩试验研究。选取川西地区3组典型天然混合土土样,对其分别采用筛分法剔除20,10,5 mm粒径颗粒,制备粗颗粒含量不同的天然混合土土样,进行粗粒土压缩试验研究。通过对比不同粗颗粒含量的土样在相同试验条件下的孔隙比及压缩模量的不同变化情况,分析川西地区混合土压缩特性受粗颗粒含量的影响规律及其影响机理,确定粗颗粒含量对川西地区混合土压缩特性的影响过渡区间。结果表明:大于5 mm粗颗粒含量对川西地区混合土压缩特性有显著影响,同种混合土中大于5 mm的粗颗粒含量越高,在相同竖向荷载下的单位沉降量越小,孔隙比变化越小,压缩模量越大;大于5 mm粗颗粒含量对川西地区混合土压缩特性的影响过渡区间为30%～45%,土体压缩时,混合土中大于5 mm粗颗粒含量小于30%时,细颗粒起主要承担作用,土体可压缩性高,此时粗颗粒含量的增加,对于混合土的压缩特性影响不大;当粗颗粒含量超过30%时,粗、细颗粒共同作用,粗颗粒骨架逐渐形成,粗颗粒对混合土压缩特性的影响开始逐渐起作用;当大于5 mm粗颗粒含量大于45%时,粗颗粒的骨架作用起主要作用,土体可压缩性显著降低;土体中的矿物成分对压缩特性也产生影响,高岭石含量高的土样,强度较高,但压缩性较低。
There is a need to solve the problem of the mixed soil subgrade compression and deformation and to provide a theoretical basis for the construction of the expressway and railway in the Western Sichuan area. Hence, large-scale compression tests were carried out on natural mixed soils considering the influence of the coarse particle content. Three groups of typical natural mixed soil samples were selected from Western Sichuan and processed using the sieve method to separate the 20 mm, 10 mm, and 5 mm particles each. These soil samples with different coarse particle contents were prepared for use in a large-scale compression test. The influence of coarse particle content on the compression characteristics of mixed soil, its influence mechanism, and its influence interval were analyzed by comparing the void ratio and compression modulus of the soil samples with different coarse particle content under the same test conditions. The results demonstrate that the content of coarse particles greater than 5 mm(>5 mm) had a significant influence on the compression characteristics of mixed soil. The compression modulus is greater when the content of coarse particles(>5 mm) is higher in the same mixed soil. The appropriate coarse particle content affecting the compression characteristic transition interval is observed to be 30%-45%. When the coarse particle content is less than 30%, the fine particles played a major role in the compression process, thus leading to high soil compressibility, whereas the increase in coarse particle content demonstrated little effect on the compression characteristics. When the coarse particle content is over 30%, a coarse particle skeleton is gradually formed, which played a gradual role on the compression characteristics of the mixed soil. When the coarse particles content is higher than 45%, the skeleton function of the coarse particles played a significant role in decreasing soil compressibility. The mineral composition in the soil also had an effect on the compression characteristics wherein soil samples with high kaolinite content demonstrated higher strength but lower compressibility.
There is a need to solve the problem of the mixed soil subgrade compression and deformation and to provide a theoretical basis for the construction of the expressway and railway in the Western Sichuan area. Hence, large-scale compression tests were carried out on natural mixed soils considering the influence of the coarse particle content. Three groups of typical natural mixed soil samples were selected from Western Sichuan and processed using the sieve method to separate the 20 mm, 10 mm, and 5 mm particles each. These soil samples with different coarse particle contents were prepared for use in a large-scale compression test. The influence of coarse particle content on the compression characteristics of mixed soil, its influence mechanism, and its influence interval were analyzed by comparing the void ratio and compression modulus of the soil samples with different coarse particle content under the same test conditions. The results demonstrate that the content of coarse particles greater than 5 mm(>5 mm) had a significant influence on the compression characteristics of mixed soil. The compression modulus is greater when the content of coarse particles(>5 mm) is higher in the same mixed soil. The appropriate coarse particle content affecting the compression characteristic transition interval is observed to be 30%-45%. When the coarse particle content is less than 30%, the fine particles played a major role in the compression process, thus leading to high soil compressibility, whereas the increase in coarse particle content demonstrated little effect on the compression characteristics. When the coarse particle content is over 30%, a coarse particle skeleton is gradually formed, which played a gradual role on the compression characteristics of the mixed soil. When the coarse particles content is higher than 45%, the skeleton function of the coarse particles played a significant role in decreasing soil compressibility. The mineral composition in the soil also had an effect on the compression characteristics wherein soil samples with high kaolinite content demonstrated higher strength but lower compressibility.
引文
[1] 吴丽君.高速铁路非饱和土固结压缩特性及地基加固技术研究[D].成都:西南交通大学,2011. WU Li-jun. Study on Compressibility and Consolidation of Unsaturated Soil and Reinforced Technique on High-speed Railway [D]. Chengdu: Southwest Jiaotong University, 2011.
[2] 刘恩龙,宋长航,罗开泰,等.粗-细粒混合土动力特性探讨[J].世界地震工程,2010,26(增1):28-31. LIU En-long, SONG Chang-hang, LUO Kai-tai, et al. Investigation on Dynamic Mechanical Properties of Mixed Soils Composed of Fine-coarse Particles [J]. World Earthquake Engineering, 2010, 26 (S1): 28-31.
[3] 刘松玉,邱钰,童立元,等.煤矸石的强度特征试验研究[J].岩石力学与工程学报,2006,25(1):199-205. LIU Song-yu, QIU Yu, TONG Li-yuan, et al. Experimental Study on Strength Properties of Coal Wastes [J]. Chinese Journal of Rock Mechanics and Engineering, 2006, 25 (1): 199-205.
[4] 崔凯,林维康.非饱和混合土动剪切模量与阻尼比试验研究[J].西南交通大学学报,2016,51(5):1033-1040. CUI Kai, LIN Wei-kang. Experimental Study on Dynamic Shear Modulus and Damping Ratio for Unsaturated Mixed Soil [J]. Journal of Southwest Jiaotong University, 2016, 51 (5): 1033-1040.
[5] JIANG X, CUI P, GE Y. Effects of Fines on the Strength Characteristics of Mixtures [J]. Engineering Geology, 2015, 198: 78-86.
[6] LI Y L, HUANG R, CHAN L S, et al. Effects of Particle Shape on Shear Strength of Clay-gravel Mixture [J]. KSCE Journal of Civil Engineering, 2013, 17 (4): 712-717.
[7] 姜景山,程展林,左永振,等.材料状态对粗粒料力学特性影响的试验研究[J].岩土力学,2017,38(增2):131-137. JIANG Jing-shan, CHENG Zhan-lin, ZUO Yong-zhen, et al. Experimental Study of Influence of Material State on Mechanical Properties of Coarse-grained Materials [J]. Rock and Soil Mechanics, 2017, 38 (S2): 131-137.
[8] 冯春,李志刚,李世海.脆性土石混合体单轴压缩特性的影响因素研究[J].计算力学学报,2018,35(3):356-363. FENG Chun, LI Zhi-gang, LI Shi-hai. Study on Uniaxial Compression Characteristics of Brittle Rock and Soil Aggregate [J]. Chinese Journal of Computational Mechanics, 2018, 35 (3): 356-363.
[9] 姜景山,程展林,左永振,等.干密度对粗粒料力学特性的影响[J].岩土力学,2018,39(2):507-514. JIANG Jing-shan, CHENG Zhan-lin, ZUO Yong-zhen, et al. Effect of Dry Density on Mechanical Properties of Rockfill Materials [J]. Rock and Soil Mechanics, 2018, 39 (2): 507-514.
[10] 李鹏.川西山区崩坡积混合土非饱和压缩特性及其影响因素试验研究[D].成都:西南交通大学,2010. LI Peng. Experimental Study of Unsaturated Consolidation Characteristics and Its Influencing Factors for Chuanxi Talus Mixed Soil [D]. Chengdu: Southwest Jiaotong University, 2010.
[11] WANG G X, KUWANO J. Modeling of Strain Dependency of Shear Modulus and Damping of Clayey Sand [J]. Soil Dynamics and Earthquake Engineering, 1999, 18 (6): 463-471.
[12] 付红梅.西北地区混合土的固结试验研究[J].甘肃科学学报,2015,27(6):86-90. FU Hong-mei. Experimental Research on the Consolidation of Composite Soil in North-western Area [J]. Journal of Gansu Sciences, 2015, 27 (6): 86-90.
[13] 王丽艳,高鹏,陈国兴,等.掺合钢渣的新型混合土工填料压缩变形与强度特性研究[J].岩土工程学报,2013,35(增2):126-132. WANG Li-yan, GAO Peng, CHEN Guo-xing, et al. Experimental Study on Deformation Behavior and Shear Strength of Mixed Soil Blended with Steel Slag [J]. Chinese Journal of Geotechnical Engineering, 2013, 35 (S2): 126-132.
[14] 张福海,陈庆,张晓阳,等.海砂-海泥混合料作为海堤填料的可行性试验研究[J].岩土工程学报,2017,39(增1):182-186. ZHANG Fu-hai, CHEN Qing, ZHANG Xiao-yang, et al. Experimental Study on Feasibility of Sea Sand-mud Mixture Used as Seawall Filler [J]. Chinese Journal of Geotechnical Engineering, 2017, 39 (S1): 182-186.
[15] 李广信.论土骨架与渗透力[J].岩土工程学报,2016,38(8):1522-1528. LI Guang-xin. On Soil Skeleton and Seepage Force [J]. Chinese Journal of Geotechnical Engineering, 2016, 38 (8): 1522-1528.
[16] 张进发.土石混合非均质填料的压实特性与质量控制[J].公路,2005(10):164-166. ZHANG Jin-fa. Compaction Characteristics and Quality Control of the Heterogeneous Filling of Rock and Soil Aggregate [J]. Highway, 2005 (10): 164-166.
[17] 张宇辉,张献民,程国勇.土石混合介质中石料间隙土压实度剪切波速评价研究[J].岩土工程学报,2011,33(6):909-915. ZHANG Yu-hui, ZHANG Xian-min, CHENG Guo-yong. Evaluation of Compactness Degree of Interval Soil in Soil-stone Mixtures by Use of Shear-wave Velocity [J]. Chinese Journal of Geotechnical Engineering, 2011, 33 (6): 909-915.
[18] MENG Q X, WANG H L, XU W Y, et al. A Numerical Homogenization Study of the Elastic Property of a Soil-rock Mixture Using Random Mesostructure Generation [J]. Computers and Geotechnics, 2018, 98 (6): 48-57.
[19] WANG Y, LI C H, HU Y Z. Use of X-ray Computed Tomography to Investigate the Effect of Rock Blocks on Meso-structural Changes in Soil-rock Mixture Under Triaxial Deformation [J]. Construction and Building Materials, 2018, 164: 386-399.
[20] 杨冰,杨军,常在,等.土石混合体压缩性的三维颗粒力学研究[J].岩土力学,2010,31(5):1645-1650. YANG Bing, YANG Jun, CHANG Zai, et al. 3-D Granular Simulation for Compressibility of Soil-aggregate Mixture [J]. Rock and Soil Mechanics, 2010, 31 (5): 1645-1650.
[21] 徐文杰,胡瑞林,岳中琦,等.基于数字图像分析及大型直剪试验的土石混合体块石含量与抗剪强度关系研究[J].岩石力学与工程学报,2008,27(5):996-1007. XU Wen-jie, HU Rui-lin, YUE Zhong-qi, et al. Research on Relationship Between Rock Block Proportion and Shear Strength of Soil-rock Mixtures Based on Digital Image Analysis and Large Direct Shear Test [J]. Chinese Journal of Rock Mechanics and Engineering, 2008, 27 (5): 996-1007.
[22] 徐文杰,胡瑞林.土石混合体概念、分类及意义[J].水文地质工程地质,2009(4):50-56. XU Wen-jie, HU Rui-lin. Conception, Classification and Significations of Soil-rock Mixture [J]. Hydrogeological Engineering Geology, 2009 (4): 50-56.
[2] 刘恩龙,宋长航,罗开泰,等.粗-细粒混合土动力特性探讨[J].世界地震工程,2010,26(增1):28-31. LIU En-long, SONG Chang-hang, LUO Kai-tai, et al. Investigation on Dynamic Mechanical Properties of Mixed Soils Composed of Fine-coarse Particles [J]. World Earthquake Engineering, 2010, 26 (S1): 28-31.
[3] 刘松玉,邱钰,童立元,等.煤矸石的强度特征试验研究[J].岩石力学与工程学报,2006,25(1):199-205. LIU Song-yu, QIU Yu, TONG Li-yuan, et al. Experimental Study on Strength Properties of Coal Wastes [J]. Chinese Journal of Rock Mechanics and Engineering, 2006, 25 (1): 199-205.
[4] 崔凯,林维康.非饱和混合土动剪切模量与阻尼比试验研究[J].西南交通大学学报,2016,51(5):1033-1040. CUI Kai, LIN Wei-kang. Experimental Study on Dynamic Shear Modulus and Damping Ratio for Unsaturated Mixed Soil [J]. Journal of Southwest Jiaotong University, 2016, 51 (5): 1033-1040.
[5] JIANG X, CUI P, GE Y. Effects of Fines on the Strength Characteristics of Mixtures [J]. Engineering Geology, 2015, 198: 78-86.
[6] LI Y L, HUANG R, CHAN L S, et al. Effects of Particle Shape on Shear Strength of Clay-gravel Mixture [J]. KSCE Journal of Civil Engineering, 2013, 17 (4): 712-717.
[7] 姜景山,程展林,左永振,等.材料状态对粗粒料力学特性影响的试验研究[J].岩土力学,2017,38(增2):131-137. JIANG Jing-shan, CHENG Zhan-lin, ZUO Yong-zhen, et al. Experimental Study of Influence of Material State on Mechanical Properties of Coarse-grained Materials [J]. Rock and Soil Mechanics, 2017, 38 (S2): 131-137.
[8] 冯春,李志刚,李世海.脆性土石混合体单轴压缩特性的影响因素研究[J].计算力学学报,2018,35(3):356-363. FENG Chun, LI Zhi-gang, LI Shi-hai. Study on Uniaxial Compression Characteristics of Brittle Rock and Soil Aggregate [J]. Chinese Journal of Computational Mechanics, 2018, 35 (3): 356-363.
[9] 姜景山,程展林,左永振,等.干密度对粗粒料力学特性的影响[J].岩土力学,2018,39(2):507-514. JIANG Jing-shan, CHENG Zhan-lin, ZUO Yong-zhen, et al. Effect of Dry Density on Mechanical Properties of Rockfill Materials [J]. Rock and Soil Mechanics, 2018, 39 (2): 507-514.
[10] 李鹏.川西山区崩坡积混合土非饱和压缩特性及其影响因素试验研究[D].成都:西南交通大学,2010. LI Peng. Experimental Study of Unsaturated Consolidation Characteristics and Its Influencing Factors for Chuanxi Talus Mixed Soil [D]. Chengdu: Southwest Jiaotong University, 2010.
[11] WANG G X, KUWANO J. Modeling of Strain Dependency of Shear Modulus and Damping of Clayey Sand [J]. Soil Dynamics and Earthquake Engineering, 1999, 18 (6): 463-471.
[12] 付红梅.西北地区混合土的固结试验研究[J].甘肃科学学报,2015,27(6):86-90. FU Hong-mei. Experimental Research on the Consolidation of Composite Soil in North-western Area [J]. Journal of Gansu Sciences, 2015, 27 (6): 86-90.
[13] 王丽艳,高鹏,陈国兴,等.掺合钢渣的新型混合土工填料压缩变形与强度特性研究[J].岩土工程学报,2013,35(增2):126-132. WANG Li-yan, GAO Peng, CHEN Guo-xing, et al. Experimental Study on Deformation Behavior and Shear Strength of Mixed Soil Blended with Steel Slag [J]. Chinese Journal of Geotechnical Engineering, 2013, 35 (S2): 126-132.
[14] 张福海,陈庆,张晓阳,等.海砂-海泥混合料作为海堤填料的可行性试验研究[J].岩土工程学报,2017,39(增1):182-186. ZHANG Fu-hai, CHEN Qing, ZHANG Xiao-yang, et al. Experimental Study on Feasibility of Sea Sand-mud Mixture Used as Seawall Filler [J]. Chinese Journal of Geotechnical Engineering, 2017, 39 (S1): 182-186.
[15] 李广信.论土骨架与渗透力[J].岩土工程学报,2016,38(8):1522-1528. LI Guang-xin. On Soil Skeleton and Seepage Force [J]. Chinese Journal of Geotechnical Engineering, 2016, 38 (8): 1522-1528.
[16] 张进发.土石混合非均质填料的压实特性与质量控制[J].公路,2005(10):164-166. ZHANG Jin-fa. Compaction Characteristics and Quality Control of the Heterogeneous Filling of Rock and Soil Aggregate [J]. Highway, 2005 (10): 164-166.
[17] 张宇辉,张献民,程国勇.土石混合介质中石料间隙土压实度剪切波速评价研究[J].岩土工程学报,2011,33(6):909-915. ZHANG Yu-hui, ZHANG Xian-min, CHENG Guo-yong. Evaluation of Compactness Degree of Interval Soil in Soil-stone Mixtures by Use of Shear-wave Velocity [J]. Chinese Journal of Geotechnical Engineering, 2011, 33 (6): 909-915.
[18] MENG Q X, WANG H L, XU W Y, et al. A Numerical Homogenization Study of the Elastic Property of a Soil-rock Mixture Using Random Mesostructure Generation [J]. Computers and Geotechnics, 2018, 98 (6): 48-57.
[19] WANG Y, LI C H, HU Y Z. Use of X-ray Computed Tomography to Investigate the Effect of Rock Blocks on Meso-structural Changes in Soil-rock Mixture Under Triaxial Deformation [J]. Construction and Building Materials, 2018, 164: 386-399.
[20] 杨冰,杨军,常在,等.土石混合体压缩性的三维颗粒力学研究[J].岩土力学,2010,31(5):1645-1650. YANG Bing, YANG Jun, CHANG Zai, et al. 3-D Granular Simulation for Compressibility of Soil-aggregate Mixture [J]. Rock and Soil Mechanics, 2010, 31 (5): 1645-1650.
[21] 徐文杰,胡瑞林,岳中琦,等.基于数字图像分析及大型直剪试验的土石混合体块石含量与抗剪强度关系研究[J].岩石力学与工程学报,2008,27(5):996-1007. XU Wen-jie, HU Rui-lin, YUE Zhong-qi, et al. Research on Relationship Between Rock Block Proportion and Shear Strength of Soil-rock Mixtures Based on Digital Image Analysis and Large Direct Shear Test [J]. Chinese Journal of Rock Mechanics and Engineering, 2008, 27 (5): 996-1007.
[22] 徐文杰,胡瑞林.土石混合体概念、分类及意义[J].水文地质工程地质,2009(4):50-56. XU Wen-jie, HU Rui-lin. Conception, Classification and Significations of Soil-rock Mixture [J]. Hydrogeological Engineering Geology, 2009 (4): 50-56.