由管涌等水土内部侵蚀作用产生的贯通侵蚀孔道是土体结构破坏以及边坡、水坝、堤防等失稳的重要原因之一。利用溶解土样中预制水溶性化学添加物的方法在三轴试样中还原内部侵蚀效果,结合弯曲元测试系统,探讨初始密实度、围压对侵蚀后土体力学参数的影响。研究结果表明:随着侵蚀过程的加剧,砂土的剪切波速逐渐降低,且降低幅度随围压和密实度的增大而增加;相较于纯砂试样,侵蚀试样的峰值强度出现一定降低,但两者残余强度差别较小。土体的内部侵蚀发展过程较为复杂,利用葡萄糖粉末的溶解过程模拟细颗粒在渗流作用下被带出的管涌侵蚀作用,可以精确控制侵蚀产生和发展过程中孔隙通路的形成过程,为研究侵蚀后土体力学性质提供了新思路。
Abstract
Internal erosion of soil resulted from piping, seepage or overtopping is found to be responsible for a large number of hydraulic structure failures. In this research, a method of preparing samples subjected to piping effect is achieved by dissolving water soluble material (glucose) in sandy soil. Qualitative impacts of initial density and confining pressure on the mechanical properties of the disturbed soil were investigated through triaxial compression tests and bender element tests under different initial densities and confining pressures. According to the test results, obvious reduction in shear wave velocity as well as peak shear strength was observed in the eroded specimen, and such reduction intensified along with the increasing of confining pressure and density, while residual strength appeared to be less affected.
关键词
砂土 /
内部侵蚀 /
弯曲元 /
剪切波速 /
抗剪强度 /
三轴试验
Key words
sandy soil /
internal erosion /
bender element /
shear wave velocity /
shear strength /
triaxial test
{{custom_sec.title}}
{{custom_sec.title}}
{{custom_sec.content}}
参考文献
[1] 罗玉龙, 速宝玉, 盛金昌, 等. 对管涌机理的新认识[J]. 岩土工程学报, 2011, 33(12):1895-1902.
[2] 毛昶熙,段祥宝,蔡金傍,等.悬挂式防渗墙控制管涌发展的试验研究[J].水利学报,2005,36(1):42-50.
[3] 丁留谦,姚秋玲,孙东亚,等. 三层堤基管涌砂槽模型试验研究[J]. 水利水电技术, 2007, 38(2): l9-22.
[4] WAN C F, FELL R. Laboratory Tests on the Rate of Piping Erosion of Soils in Embankment Dams[J]. Geotechnical Testing Journal, 2004, 27(3): 295-303.
[5] BENAHMED N, BONELLI S. Investigating Concentrated Leak Erosion Behaviour of Cohesive Soils by Performing Hole Erosion Test[J]. European Journal of Environmental and Civil Engineering, 2012, 16(1): 43-58.
[6] 罗玉龙, 吴 强, 詹美礼, 等. 渗流-侵蚀-应力耦合管涌试验装置的研制及初步应用[J]. 岩石力学与工程学报, 2013,32(10):2108-2114.
[7] SATO M, KUWANO R. Laboratory Testing for Evaluation of the Influence of a Small Degree of Internal Erosion on Deformation and Stiffness [J]. Soils and Foundations, 2018, 58(3):547-562.
[8] FAM M A, CASCANTE G, DUSSEAULT M B. Large and Small Strain Properties of Sands Subjected to Local Void Increase [J]. Journal of Geotechnical and Geoenvironmental Engineering, 2002, 128(12):1018-1025.
[9] TRUONG Q H, EOM Y H, LEE J S. Stiffness Characteristics of Soluble Mixtures[J]. Geotechnique, 2010, 60(4): 293-297.
[10]CHEN C, ZHANG L M, CHANG D S. Stress-strain Behavior of Granular Soils Subjected to Internal Erosion[J]. Journal of Geotechnical and Geoenvironmental Engineering, 2016, 142(12): 1-6.
[11]INDIKETIYA S, PIRATHEEPAN J, PATHMANATHAN R. Evaluation of Defective Sewer Pipe-Induced Internal Erosion and Associated Ground Deformation Using Laboratory Model Test[J]. Canadian Geotechnical Journal, 2017, 54: 1184-1195.
[12]DE ALBA P.Elastic-wave Velocities and Liquefaction Potential[J].Geotechnical Testing Journal,1984,7(2):12.
[13]CLAYTON C R I, THERON M, BEST A I. The Measurement of Vertical Shear-Wave Velocity Using Side-Mounted Bender Elements in the Triaxial Apparatus[J]. Geotechnique, 2004, 54(7): 495-498.
[14]VIGGIANI G, ATKINSON J H. Interpretation of Bender Element Tests[J]. Geotechnique, 1997, 45(8): 373A.
[15]KELLY D, MCDOUGALL J, BARRETO D. Effect of Particle Loss on Soil Behavior[C]//Proceedings of 6th International Conference on Scour and Erosion. Paris, France. August 27-31, 2012: 639-646.
[16]林亚洲,王秋良,李井冈,等. 武汉后湖地区土层剪切波速与深度的关系[J]. raybet体育在线
院报, 2016, 33(4):91-94.
[17]HARDIN B O, RICHART JR F E. Elastic Wave Velocities in Granular Soils[J]. Journal of Soil Mechanics and Foundation Division, 1963, 89(1): 33-65.
[18]SANTAMARINA J C,KLEIN K A,FAM M A. Soils and Waves-Particulate Materials Behavior, Characterization and Process Monitoring [M].New York: John Wiley & Sons,2001.
基金
国家自然科学基金项目(51609171);中央高校基本科研业务费专项资金项目(22120180625);水文水资源与水利工程科学国家重点实验室“一带一路”水与可持续发展科技基金项目(2019492311)
PDF(2649 KB)
