利用弯曲-伸展元开展干砂小应变剪切波试验和除气水压缩波试验,研究了三轴试样的不同约束边界对弯曲-伸展元量测剪切波速和压缩波速的影响,并对波速试验结果进行分析。研究结果表明:以干砂为试验对象的剪切波速试验结果介于砂土中剪切波速与边界材料的剪切波速之间,受到约束边界的材质、长度和壁厚的显著影响;而以除气水为试验对象的压缩波速试验结果受样品约束边界的影响较小。在不同约束材质下,剪切波在干砂中的传播速度与约束材料的刚度有关,材料的刚度越小对干砂剪切波速测试结果影响越小。弯曲-伸展元激发频率的相关性与边界约束无关,只与测试材料有关。研究成果有助于获取准确的弯曲-伸展元波速试验结果。
Abstract
Bender-extender element test is performed to measure shear wave velocity of dry sand and compression wave velocity of deaerated water. Effects of different boundary constraints on the measurement result of shear wave velocity and compression wave velocity by bender-extender element test are investigated, and the causes of the results are explained. Test results of shear wave velocity are between the shear wave velocity of dry sand and the shear wave velocity of material of boundary constraints. The results of shear wave velocity are indeed affected by the material of constraints, length of constraints and thickness of constraints; but the results of compression wave velocity are less affected by boundary constraints. In tests with different materials of constraints, the results of shear wave velocity are related to the stiffness of the material of constraints. The smaller stiffness of the material, the smaller impact on the test results of shear wave velocity. The correlation of excitation frequency is independent of the boundary constraints and is only relevant to the soil. This study is conducive to obtain accurate test results of bender-extender element.
关键词
干砂 /
弯曲-伸展元 /
边界约束 /
剪切波 /
压缩波
Key words
dry sand /
bender-extender element /
boundary constraint /
shear wave /
compression wave
{{custom_sec.title}}
{{custom_sec.title}}
{{custom_sec.content}}
参考文献
[1] RICHART F E, HALL J R, WOODS R D. Vibrations of Soils and Foundations[M]. Angleworm Cliffs, New Jersey: Prentice-Hall, 1970.
[2] 周燕国. 土结构性的剪切波速表征及对动力特性的影响[D]. 杭州: 浙江大学, 2007.
[3] YANG J,YAN X R.Site Response to Multi-directional Earthquake Loading:A Practical Procedure[J].Soil Dynamics and Earthquake Engineering,2009,29(4):710-721.
[4] 陈云敏, 周燕国, 黄 博. 利用弯曲元测试砂土剪切模量的国际平行试验[J]. 岩土工程学报, 2006, 28(7): 874-880.
[5] LINGS M L, GREENING P D. A Novel Bender/Extender Element for Soil Testing[J]. Géotechnique, 2001, 51(8): 713-717.
[6] MONCASTER A M. The Shear Modulus of Sand at Very Small Strains[D]. Bristol: Department of Civil Engineering, University of Bristol, UK, 1997.
[7] ARULNATHAN R, BOULANGER R W, RIEMER M F. Analysis of Bender Element Tests[J]. Geotechnical Testing Journal, 1998, 21(2): 120-131.
[8] SANCHEZ-SALINERO I, ROESSET J M, STOKOE K H. Analytical Studies of Body Wave Propagation and Attenuation[M]. Austin: Civil Engineering Department, University of Texas of Austin, 1986.
[9] ARULNATHAN R, BOULANGER R W, RIEMER M F. Analysis of Bender Element Test[J]. Geotechnical Testing Journal, 1998, 21(2): 120-131.
[10]PENNINGTON D S, NASH D F T, LINGS M L. Horizontally Mounted Bender Elements for Measuring Anisotropic Shear Moduli in Triaxial Clay Specimens[J]. Geotechnical Testing Journal, 2001, 24(2): 133-144.
[11]ARROYO M, MUIR W D, GREENING P D. Source Near-field Effects and Pulse Tests in Soil Sample[J]. Géotechnique, 2003, 53(3): 337-345.
[12]LEONG E C, CAHYADI J, RAHARDJO H. Measuring Shear and Compression Wave Velocities of Soil Using Bender-extender Elements[J]. Canadian Geotechnical Journal, 2009, 46(7): 792-812.
[13]VIGGIANI G,ATKINSON J H. Interpretation of Bender Element Tests[J].Géotechnique,1995,45(1):149-154.
[14]LEE J S, SANTAMARINA J C. Bender Elements: Performance and Signal Interpretation[J]. Journal of Geotechnical and Geoenvironmental Engineering, 2005, 131(9): 1063-1070.
[15]柏立懂, 项 伟, SAVIDIS A S, 等. 干砂最大剪切模量的共振柱与弯曲元试验[J]. 岩土工程学报, 2012, 34(1): 184-188.
[16]顾晓强, 杨 峻, 黄茂松, 等. 砂土剪切模量测定的弯曲元、共振柱和循环扭剪试验[J]. 岩土工程学报, 2016, 38(4): 740-746.
[17]DYVIK R, MADSHUS C. Lab Measurements of Gmax Using Bender Element[C]//American Society of Civil Engineers. Advances in the Art of Testing Soils under Cyclic Conditions, Detroit, Michigan, United States, October 24, 1985. New York: ASCE, 1985: 186-196.
[18]SOUTO A, HARTIKAINEN J, OZUDOGRU K. Measurement of Dynamic Properties of Road Pavement Materials by the Bender Element and Resonant Column Tests[J]. Géotechnique, 1994, 44(3): 41-49.
[19]YOUN J U,CHOO Y W, KIM D S.Measurement of Small-strain Shear Modulus Gmax of Dry and Saturated Sands by Bender Element,Resonant Column,and Torsional Shear Tests[J].Canadian Geotechnical Journal,2008, 45(10): 1426-1438.
[20]YANG J, GU X Q. Shear Stiffness of Granular Material at Small Strain: Does It Depend on Grain Size?[J]. Géotechnique, 2013,63(2): 165-179.
[21]World Book Inc. The World Book Encyclopedia[M]. Chicago: World Book Inc., 1999.
[22]CAMACHO T J. Evaluation of the Small-strain Stiffness of Soil by Non-conventional Dynamic Testing Methods[D]. Lisbon: Technical University of Lisbon, 2011.
[23]JOVII V, COOP M R, SIMI M. Objective Criteria for Determining Gmax from Bender Element Tests[J]. Géotechnique, 1996, 46(2): 357-362.
[24]BLEWETT J, BLEWETT I J, WOODWARD P K. Phase and Amplitude Responses Associated with the Measurements of Shear Wave Velocity in Sand by Bender Elements[J]. Canadian Geotechnical Journal, 2000, 37(6): 1348-1357.
[25]LEONG E C, YEO S H, RAHARDJO H. Measuring Shear Wave Velocity Using Bender Elements[J]. Geotechnical Testing Journal, 2005, 28(5): 488-498.
[26]程 朋,王 勇,李雄威, 等. 砂雨法制备三轴砂样的影响因素及均匀性研究[J]. 长江科学院院报, 2016, 33(10): 79-83.
[27]吴家龙. 弹性力学[M]. 3版. 北京: 高等教育出版社, 2016: 295-299.
基金
国家自然科学基金项目(51579237,51779017)
PDF(2171 KB)
