直剪剪切速率对粗粒土强度与变形特性的影响

徐肖峰; 魏厚振; 孟庆山; 韦昌富; 艾东海

直剪剪切速率对粗粒土强度与变形特性的影响 English Version

中国科学院武汉岩土力学研究所岩土力学与工程国家重点实验室，湖北武汉 430071

基金项目: 国家自然科学基金项目（11072255，41172283）；浙江省重大科技专项项目（2009C13010）

详细信息

作者简介:
徐肖峰(1988- )，男，浙江江山人，硕士研究生，主要从事粗粒土试验与离散元模拟研究。E-mail: xu_xiaofeng@live.cn。

中图分类号: TU411
计量
- 文章访问数: 0975
- HTML全文浏览量: 0
- PDF下载量: 0871
出版历程
- 收稿日期: 2012-04-25
- 发布日期: 2013-04-17

Effects of shear rate on shear strength and deformation characteristics of coarse-grained soils in large-scale direct shear tests

State Key Laboratory of Geomechanics and Geotechnical Engineering, Institute of Rock and Soil Mechanics, Chinese Academy of Sciences, Wuhan 430071, China

摘要

摘要: 土体的强度和变形对路基及边坡的稳定性具有控制作用，为分析剪切速率对粗粒土抗剪强度和变形特性的影响，基于THE-1000型室内大型直剪仪，对不同剪切速率下粗粒土的强度和变形特性进行试验研究。试验数据表明：不同剪切速率时的剪应力-剪切位移曲线均呈应变软化型；剪切速率为小于5 mm/min时，粗粒土强度理论公式拟合相关系数比较理想；随剪切速率的增加，内摩擦角有减小的趋势，约在27.8°～22.8°内变化，咬合力在90.3～112.2 kPa范围内振动变化；颗粒破碎率和最大垂直变形随着剪切速率减小或垂直压力增加而增大，即剪切速率越小越容易发生剪缩；剪切速率小而抗剪强度高的本质原因是：破碎后的细颗粒填充了由粗颗粒构成的土骨架孔隙，造成试样的密实度增加。
- 剪切速率 /
- 大型直剪 /
- 粗粒土 /
- 强度
Abstract: The strength and deformation of soils play an important role in the stability of slopes and subgrades. In order to analyze the influence of shear rate on shear strength and deformation characteristics of coarse-grained soils, the strength and deformation of coarse-grained soils under different shear rates are investigated by use of the THE-1000 lab large-scale direct shear apparatus. The experimental results indicate that the curves of shear stress versus shear displacement present themselves to be strain-softening ones under different shear rates. While the samples are sheared at the rate lower than 5 mm/min, the correlation coefficient is ideal. With the increase of the shear rate, the internal friction angle tends to decrease and ranges from 27.8° to 22.8°, and the interlocking force changes in the range between 90.30 to110.2 kPa. The breakage ratio and the maximum amount of shrinkage increase with the decrease of the shear rate or the increases of vertical stress. In other words, shrinkage occurs easily under a low shear rate. The essential reason why the shear strength shows a high value under a low shear rate is that the broken pieces of coarse particles fill the pores, which consist of the coarse particles, resulting in the increase of density of the soil samples.
- shearing rate /
- large-scale direct shear /
- coarse-grained soil /
- strength

HTML全文

参考文献(11)

[1]	刘斯宏,肖贡元,杨建州,等. 宜兴抽水蓄能电站上库堆石料的新型现场直剪试验[J]. 岩土工程学报, 2004,266:772-776. LIU Si-hong, XIAO Gong-yuan, YANG Jian-zhou, et al. New in-situ direct shear tests on rockfill materials at Yixing Pumped Storage Power Station Project[J]. Chinese Journal of Geotechnical Engineering, 2004, 266
[2]	董云,柴贺军. 土石混合料室内大型直剪试验的改进研究[J]. 岩土工程学报, 2005,2711:1329-1333. DONG Yun, CHAI He-jun. Improvement study of lab large-scale direct shear test of rock-soil aggregate mixture[J]. Chinese Journal of Geotechnical Engineering, 2005, 2711: 1329-1333. (in Chinese)
[3]	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, 2008,291:48-51. WEI Hou-zhen, WANG Ren, HU Ming-jian, et al. Strength behaviour of gravelly soil with different coarse-grained contents in Jiangjiagou Ravine[J]. Rock and Soil Mechanics, 2008, 291
[4]	冯俊德,李建国,汪稔,等. 云南某铁路冰碛土大型直剪强度特性试验研究[J]. 岩土力学, 2008,2912:3205-3210. FENG Jun-de, LI Jian-guo, WANG Ren, et al. Large scale direct shear test on strength behavior of railway moraine soils in Yunnan [J]. Rock and Soil Mechanics, 2008, 2912
[5]	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, 2005,275:505-510. LIU Song-yu, TONG Li-yuan, QIU Yu, et al. Crushable effects on engineering mechanical properties of colliery wastes[J]. Chinese Journal of Geotechnical Engineering, 2005, 275
[6]	张家铭,汪稔,张阳明,等. 土体颗粒破碎研究进展[J]. 岩土力学, 2003,24增刊:661-665. ZHANG Jia-ming, WANG Ren, ZHANG Yang-ming, et al. Advance in studies of soil grain crush[J]. Rock and Soil Mechanics, 2004, 24S0
[7]	周杰,周国庆,赵光思,等. 高应力下剪切速率对砂土抗剪强度影响研究[J]. 岩土力学, 2010,319:2805-2810. ZHOU Jie, ZHOU Guo-qing, ZHAO Guang-si, et al. Analysis of influence of shear rate on shear strength of sand under high stress[J]. Rock and Soil Mechanics, 2010, 319
[8]	张嘎,张建民. 粗颗粒土的应力应变特性及其数学描述研究[J]. 岩土力学, 2004,2510:1587-1591. ZHANG Ga, ZHANG Jian-min. Study on behavior of coarse grained soil and its modeling[J]. Rock and Soil Mechanics, 2004, 2510: 1587-1591. (in Chinese)
[9]	JTG E402007 公路土工试验规程[S]. 北京: 人民交通出版社, 2007. JTG E402007 Test methods of soils for highway engineering [S]. Beijing: China Communications Press, 2007.(in Chinese)
[10]	MARSAL R J. Large scale testing of rockfill materials[J]. Journal of Soils Mechanics and Foundation Engineering Division, ASCE,1967, 93SM2:27-43.
[11]	赵建军,王思敬,尚彦军,等. 香港全风化花岗岩饱和直剪试验中的剪胀问题[J]. 工程地质学报, 2005,131:44-48. ZHAO Jian-jun, WANG Si-jing, SHANG Yan-jun, et al. Dilatation in direct shear tests of Hong Kong completely decomposed granite CDG [J]. Journal of Engineering Geology, 2005, 131