利用带弯曲元波速测试的三轴仪对不同密实度下饱和丰浦砂进行了侧向静止土压力系数K0固结试验,旨在得出丰浦砂在不同密实度下K0值,并通过弯曲元波速测试计算K0固结条件下饱和砂的小应变剪切模量。研究表明:随着砂土密实度的增加,K0变小。同时,确定了K0固结下砂土的小应变剪切模量G0随有效围压和密实度的变化,并确定了G0预测公式中的参数A和n的值。基于试验成果,进一步尝试建立了丰浦砂K0系数和其小应变剪切模量G0的关系。
Abstract
One-dimensional consolidation tests were carried out in a stress path triaxial to investigate the coefficient of lateral earth pressure K0 of saturated Toyoura sand with different densities. Bender elements for shear wave measurement were installed in the triaxial device. The shear wave velocity of sand specimens can be measured under the K0 stress state and then the small strain shear stiffness G0 of Toyoura sand can be calculated. Results demonstrated that the value of K0 decreases as the density of sand increases. Furthermore, the effects of effective mean confining pressure and density on shear modulus G0 at small strain were also investigated. Parameters A and n in the empirical equation for predicting the G0 of sand sample during the K0 stress rate were determined. Moreover, the relationship between K0 and G0 was analyzed and it was found that K0 decreases almost linearly as G0 increases.
关键词
砂土 /
三轴试验 /
密实度 /
侧向静止土压力系数K0 /
弯曲元 /
小应变剪切模量
Key words
sand /
triaxial test /
density /
lateral static earth pressure K0 /
bender element /
shear modulus at small strain
{{custom_sec.title}}
{{custom_sec.title}}
{{custom_sec.content}}
参考文献
[1] ATKINSON J H.Experimental Determination of Stress-strain-time Characteristics in Laboratory and in situ Tests[C]∥Proceedings of the 10th European Conference on Soil Mechanics and Foundation Engineering. Florence, Italy, May 26-30, 1991: 915-956.
[2] BURLAND J B.Small is Beautiful—The Stiffness of Soils at Small Strain[J].Canadian Geotechnical Journal,1989,26(4):499-516.
[3] 陈超斌, 武朝军,叶冠林,等.小应变三轴试验方法及其在上海软土的初步应用[J].岩土工程学报,2015,37(增2): 37-40.
[4] 柏立懂, 项伟, STAVROS S A,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.
[5] TAMURA S, TOKIMATSU K, ABE A, et al. Effects of Air Bubbles on B-value and P-wave Velocity of a Partly Saturated Sand[J]. Japanese Geotechnical Society, 2002, 42(1): 121-129.
[6] GU X, YANG J, HUANG M.Laboratory Measurements of Small Strain Properties of Dry Sands by Bender Element[J]. Soil and Foundations, 2013, 53(5): 735-745.
[7] 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.
[8] 刘麟, 顾晓强, 黄茂松. 利用带弯曲元应力路径三轴仪量测静止土压力系数研究[J]. 岩土工程学报, 2017, 39(增2):212-215.
[9] 梁发云, 贾亚杰, 丁钰津,等. 上海地区软土HSS模型参数的试验研究[J]. 岩土工程学报, 2017, 39(2):269-278.
[10] 姬美秀, 陈云敏, 黄博. 弯曲元试验高精度测试土样剪切波速方法[J]. 岩土工程学报, 2003, 25(6): 732-736.
[11] RASHIDIAN M, ISHIHARA K, KOKUSHO T, et al. Effect of Sample Preparation Methods on Shear Wave Velocity[C]∥Proceedings of the Second International Conference on Seismology and Earthquake Engineering, Teheran, Iran, 1995: 1501-1508.
[12] ALBA P, BALDWIN K, JANOO V, et al. Elastic-Wave Velocities and Liquefaction Potential[J]. Geotechnical Testing Journal, 1984, 7(2):12.
[13] GU X Q, YANG J, HUANG M S, et al. Bender Element Tests in Dry and Saturated Sand: Signal Interpretation and Result Comparison[J]. Soils & Foundations, 2015, 55(5): 951-962.
[14] MUTPHY W I.Effects of Microstructure and Pore Fluids on the Acoustic Properties of Granular Sedimentary Materials[D]. Stanford: Stanford University, 1982.
[15] 刘瑜, 夏唐代. 砂土颗粒粗糙度对剪切波速影响的试验研究[J]. 岩土工程学报, 2011, 33(2):285-290.
[16] 李博, 余闯, 曾向武. K0条件下砂土原生各向异性的动剪切模量试验研究[J]. 岩石力学与工程学报, 2013,(增2):4048-4055.
[17] BIOT M A.Theory of Propagation of Elastic Waves in a Fluid-Saturated Porous Solid. I. Low-Frequency Range[J]. Journal of the Acoustical Society of America, 2005, 28(2):179-191.
[18] 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.
基金
国家重点研发计划项目(2016YFC0800200); 中国矿业大学深部岩土力学与地下工程国家重点实验室开放基金项目(SKLGDUEK1712)
PDF(4647 KB)
