粗粒含量对砂卵石土宏细观力学特性影响分析
|
摘要
砂卵石土粗粒含量对基坑及隧道围岩等稳定性影响较大,然而不同粗粒含量砂卵石土宏细观力学特性尚不明确。采用室内大型粗粒土三轴试验与数值三轴试验相结合的方法,对不同粗粒含量砂卵石土宏观及细观力学特性开展研究。研究结果表明:随着粗粒含量增加,砂卵石土的应力应变曲线表现为应变软化性;围压不变时,砂卵石土随着粗粒含量增加,应力峰值增大而达到峰值时的应变逐渐减小。建立了砂卵石土粗粒含量与内摩擦角和黏聚力等力学指标之间函数关系,随着粗粒含量的增加,砂卵石土的内摩擦角与黏聚力也以线性趋势增大;提出了不同粗粒含量砂卵石土的接触模量、颗粒刚度比、摩擦系数、接触粘结强度等颗粒离散元细观参数。研究成果为砂卵石地层工程精细化设计及施工提供理论支撑。
The coarse-grained content of sandy cobbled soil has a great influence on the stability of the foundation pit and tunnel surrounding rock,but the macroscopic and micromechanical properties of sand and gravel with different coarse contents are not clear. The macroscopic and meso-mechanical properties of different coarse-grained sand-pebbled soils were studied using a combination of a large-scale coarse-grained soil triaxial test and a numerical triaxial test. Research indicates that with the increase of coarse-grain content,the stress-strain curve of sand-pebble soil shows strain softening. When the confining pressure is constant,the sand pebble soil increases with the increase of coarse grain content,and the stress peak value increases,and the strain at the peak value gradually decreases. The functional relationship between the coarse-grained content and the internal friction angle and cohesion of sand-pebble soil was established. With the increase of coarse-grain content,the internal friction angle and cohesion of sand-pebble soil increased linearly; the parameters such as the contact modulus,friction coefficient,particle stiffness ratio,and contact bonding strength of different coarse-grained sand-pebble soils were proposed. The research results provide theoretical support for the refinement design and construction of sand and gravel strata.
The coarse-grained content of sandy cobbled soil has a great influence on the stability of the foundation pit and tunnel surrounding rock,but the macroscopic and micromechanical properties of sand and gravel with different coarse contents are not clear. The macroscopic and meso-mechanical properties of different coarse-grained sand-pebbled soils were studied using a combination of a large-scale coarse-grained soil triaxial test and a numerical triaxial test. Research indicates that with the increase of coarse-grain content,the stress-strain curve of sand-pebble soil shows strain softening. When the confining pressure is constant,the sand pebble soil increases with the increase of coarse grain content,and the stress peak value increases,and the strain at the peak value gradually decreases. The functional relationship between the coarse-grained content and the internal friction angle and cohesion of sand-pebble soil was established. With the increase of coarse-grain content,the internal friction angle and cohesion of sand-pebble soil increased linearly; the parameters such as the contact modulus,friction coefficient,particle stiffness ratio,and contact bonding strength of different coarse-grained sand-pebble soils were proposed. The research results provide theoretical support for the refinement design and construction of sand and gravel strata.
引文
1司洪洋.论无粘性砂卵石与堆石的力学性质[J].岩土工程学报,1990,12(6):32-41Si Hongyang.On the mechanical properties of cohesionless sand cobbles and rockill materials[J].Chinese Journal of Geotechnical Engineering,1990,12(6):32-41
2白永学.富水砂卵石地层盾构施工诱发地层塌陷机理及对策研究[D].成都:西南交通大学,2006Bai Yongxue.Mechanism of formation collapse induced by shield construction of water-rich sand and gravel stratum and its countermeasures[D].Chengdu:Southwest Jiaotong University,2006
3郭庆国.粗粒土的工程特性及应用[M].郑州:黄河水利出版社,1998Guo Qingguo.Engineering characteristics and application of coarse granular soil[M].Zhengzhou:The Yellow River Water Conservancy Press,1998
4魏厚振,汪稔,胡明鉴,等.蒋家沟砾石土不同粗粒含量直剪强度特征[J].岩土力学,2008,29(1):48-51Wei Houzhen,Wang Ren,Hu Mingjian,et al.Strength behaviour of gravelly soil with different coarse-grained contents in Jiangjiagou Ravine[J].Rock and Soil Mechanics,2008,29(1):48-51
5简鹏,路军富,钟英哲.基于不同密度与含水率下的砂卵石强度参数研究[J].科学技术与工程,2016,16(24):257-261Jian Peng,Lu Junfu,Zhong Yingzhe.Study on strength parameter of sandy pebble soil based on different density and moisture content[J].Science Technology and Engineering,2016,16(24):257-261
6贾革续.粗粒土工程特性的试验研究[D].大连:大连理工大学,2003Jia Gexu.Experimental study on engineering characteristics of coarse soil[D].Dalian:Dalian University of Technology,2003
7刘松玉,童立元,邱钰,等.煤矸石颗粒破碎及其对工程力学特性影响研究[J].岩土工程学报,2005,27(5):505-510Liu Songyu,Tong Liyuan,Qiu Yu,et al.Crushable effects on engineering mechanical properties of colliery wastes[J].Chinese Journal of Geotechnical Engineering,2005,27(5):505-510
8 Cundall P A,Strack O D L.A discrete numerical model for granular assemblies[J].Geotechnique,1979,29(1):47-65
9耿丽,黄志强,苗雨.粗粒土三轴试验的细观模拟[J].土木工程与管理学报,2011,28(4):24-29Geng Li,Huang Zhiqiang,Miao Yu.Meso-mechanics simulation triaxial test of coarse-grained soil[J].Journal of Civil Engineering and Management,2011,28(4):24-29
10徐肖峰,魏厚振,孟庆山,等.粗粒含量对砾类土直剪过程中强度与变形特性影响的离散元模拟研究[J].工程地质学报,2013,21(2):311-316Xu Xiaofeng,Wei Houzhen,Meng Qingshan,et al.Dem simulation on effect of coarse gravel content to direct shear strength and deformation characteristics of coarse-grained soil[J].Journal of Engineering Geology,2013,21(2):311-316
11齐阳,唐新军,李晓庆.粗粒土应力诱发各向异性真三轴试验颗粒流模拟研究[J].岩土工程学报,2015,37(12):2292-2300Qi Yang,Tang Xinjun,Li Xiaoqing.Stress-induced anisotropy of coarse-grained soil by true triaxial tests based on PFC[J].Chinese Journal of Geotechnical Engineering,2015,37(12):2292-2300
12张超,展旭财,杨春和.粗粒料强度及变形特性的细观模拟[J].岩土力学,2013,34(7):2077-2083Zhang Chao,Zhan Xucai,Yang Chunhe.Mesoscopic simulation of strength and deformation characteristics of coarse grained materials[J].Rock and Soil Mechanics,2013,34(7):2077-2083.
13中华人民共和国水利部.土工试验规程:SL 237-1999[S].北京:中国计划出版社,1999Ministry of Water Resources of the PRC.Specification of soil test:SL237-1999[S].Beijing:China Planning Press,1999
2白永学.富水砂卵石地层盾构施工诱发地层塌陷机理及对策研究[D].成都:西南交通大学,2006Bai Yongxue.Mechanism of formation collapse induced by shield construction of water-rich sand and gravel stratum and its countermeasures[D].Chengdu:Southwest Jiaotong University,2006
3郭庆国.粗粒土的工程特性及应用[M].郑州:黄河水利出版社,1998Guo Qingguo.Engineering characteristics and application of coarse granular soil[M].Zhengzhou:The Yellow River Water Conservancy Press,1998
4魏厚振,汪稔,胡明鉴,等.蒋家沟砾石土不同粗粒含量直剪强度特征[J].岩土力学,2008,29(1):48-51Wei Houzhen,Wang Ren,Hu Mingjian,et al.Strength behaviour of gravelly soil with different coarse-grained contents in Jiangjiagou Ravine[J].Rock and Soil Mechanics,2008,29(1):48-51
5简鹏,路军富,钟英哲.基于不同密度与含水率下的砂卵石强度参数研究[J].科学技术与工程,2016,16(24):257-261Jian Peng,Lu Junfu,Zhong Yingzhe.Study on strength parameter of sandy pebble soil based on different density and moisture content[J].Science Technology and Engineering,2016,16(24):257-261
6贾革续.粗粒土工程特性的试验研究[D].大连:大连理工大学,2003Jia Gexu.Experimental study on engineering characteristics of coarse soil[D].Dalian:Dalian University of Technology,2003
7刘松玉,童立元,邱钰,等.煤矸石颗粒破碎及其对工程力学特性影响研究[J].岩土工程学报,2005,27(5):505-510Liu Songyu,Tong Liyuan,Qiu Yu,et al.Crushable effects on engineering mechanical properties of colliery wastes[J].Chinese Journal of Geotechnical Engineering,2005,27(5):505-510
8 Cundall P A,Strack O D L.A discrete numerical model for granular assemblies[J].Geotechnique,1979,29(1):47-65
9耿丽,黄志强,苗雨.粗粒土三轴试验的细观模拟[J].土木工程与管理学报,2011,28(4):24-29Geng Li,Huang Zhiqiang,Miao Yu.Meso-mechanics simulation triaxial test of coarse-grained soil[J].Journal of Civil Engineering and Management,2011,28(4):24-29
10徐肖峰,魏厚振,孟庆山,等.粗粒含量对砾类土直剪过程中强度与变形特性影响的离散元模拟研究[J].工程地质学报,2013,21(2):311-316Xu Xiaofeng,Wei Houzhen,Meng Qingshan,et al.Dem simulation on effect of coarse gravel content to direct shear strength and deformation characteristics of coarse-grained soil[J].Journal of Engineering Geology,2013,21(2):311-316
11齐阳,唐新军,李晓庆.粗粒土应力诱发各向异性真三轴试验颗粒流模拟研究[J].岩土工程学报,2015,37(12):2292-2300Qi Yang,Tang Xinjun,Li Xiaoqing.Stress-induced anisotropy of coarse-grained soil by true triaxial tests based on PFC[J].Chinese Journal of Geotechnical Engineering,2015,37(12):2292-2300
12张超,展旭财,杨春和.粗粒料强度及变形特性的细观模拟[J].岩土力学,2013,34(7):2077-2083Zhang Chao,Zhan Xucai,Yang Chunhe.Mesoscopic simulation of strength and deformation characteristics of coarse grained materials[J].Rock and Soil Mechanics,2013,34(7):2077-2083.
13中华人民共和国水利部.土工试验规程:SL 237-1999[S].北京:中国计划出版社,1999Ministry of Water Resources of the PRC.Specification of soil test:SL237-1999[S].Beijing:China Planning Press,1999