为模拟实际工程中土体经常受到的固结和剪切同时作用(即部分排水剪切条件),基于三轴压缩试验方法,采用不同的轴向应变速率加载,并在剪切过程中始终打开排水阀的方式,开展了重塑饱和高岭土试样的部分排水剪切试验,分析了其在体变和孔压共同作用下的应力-应变特性。试验结果表明:部分排水剪切条件下所引起的孔压随着轴向应变位移加载速率的增加而增加,而抗剪强度却随着轴向应变位移加载速率的增加而减小,临界状态线并不依赖于剪切过程中的加载速率和排水条件。研究成果可为考虑部分排水剪切条件下地基稳定性分析方法的构建提供依据。
Abstract
In practical situations, soils are frequently subjected to the simultaneous action of consolidation and shearing, namely, sheared under partially drained condition. To simulate this action, the triaxial compression testing method is adopted while keeping the water outlet valve open during shearing at different axial-strain rates. Partially drained shearing tests are carried out on remolded saturated kaolin specimens. The stress-strain behavior under the interactions of volumetric strain and pore-water pressure is analyzed. The test results show that under partially drained condition, the induced pore-water pressure increases and the shear strength decreases with the increase in the rate of axial strain. The critical-state line is, however, independent of the axial strain rate and the drainage condition.
关键词
饱和高岭土 /
部分排水剪切 /
应变速率 /
孔压 /
体变 /
抗剪强度
Key words
saturated Kaolin /
partially drained shearing /
strain rate /
pore pressure /
volumetric strain /
shear strength
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参考文献
[1] ROWE R K, LI A L.Reinforced Embankments over Soft Foundations under Undrained and Partially Drained Conditions[J]. Geotextiles and Geomembranes, 1999, 17(3): 129-146.
[2] 汪益敏, 徐超. 软土地基土工合成材料加筋堤的理论研究与设计方法[J]. raybet体育在线
院报, 2014, 31(3): 48-57.
[3] VAID Y P, ELIADORANI A.Undrained and Drained Stress-strain Response[J]. Canadian Geotechnical Journal, 2000, 37(5): 1126-1130.
[4] SIVATHAYALAN S, LOGESWARAN P.Behaviour of Sands under Generalized Drainage Boundary Conditions[J]. Canadian Geotechnical Journal, 2007, 44(2): 138-150.
[5] SIVATHAYALAN S, LOGESWARAN P.Experimental Assessment of the Response of Sands under Shear-volume Coupled Deformation[J]. Canadian Geotechnical Journal, 2008, 45(9): 1310-1323.
[6] YAMAMOTO Y, HYODO M, ORENSE R P.Liquefaction Resistance of Sandy Soils under Partially Drained Condition[J]. Journal of Geotechnical and Geoenvironmental Engineering, 2009, 135(8): 1032-1043.
[7] 路德春, 程星磊, 杜修力. 部分排水条件下饱和砂土的力学特性研究[J]. 岩土工程学报, 2012, 34(12): 2263-2269.
[8] GIBSON R E, HENKEL D J.Influence of Duration of Tests at Constant Rate of Strain on Measured “Drained” Strength[J]. Géotechnique, 1954, 4(1): 6-15.
[9] SEKIGUCHI H, NISHIDA Y, KANAI F.Analysis of Partially-drained Triaxial Testing of Clay[J]. Soils and Foundations, 1981, 21(3): 53-66.
[10] CARTER J P.Predictions of the Non-homogeneous Behaviour of Clay in the Triaxial Test[J]. Géotechnique, 1982, 32(1): 55-58.
[11] GB/T 50123—1999,土工试验方法标准[S]B/T 50123—1999,土工试验方法标准[S]. 北京: 中国计划出版社, 1999.
[12] SHEAHAN T C, LADD C C, GERMAINE J T.Rate Dependent Undrained Shear Behavior of Saturated Clay[J]. Journal of Geotechnical and Geoenvironmental Engineering, 1996, 122(2): 99-108.
[13] 朱启银, 尹振宇, 朱俊高, 等. 软黏土加载速率效应特性试验研究: 进展与趋势[J]. 岩土力学, 2014, 35(1): 7-24.
[14] SKEMPTON A W.The Pore Pressure Coefficients A and B[J]. Géotechnique, 1954, 4(4): 143-147.
[15] BISHOP A W.The Use of Pore Pressure Coefficients in Practice[J]. Géotechnique, 1954, 4(4): 148-152.
[16] MAYNE P W, STEWART H E.Pore Pressure Behavior of K0-consolidated Clays[J]. Journal of Geotechnical Engineering, 1988, 114(11): 1340-1346.
[17] FEDERICO A.Alternative Determination of Plastic Volumetric Strain Ratio[J]. Géotechnique, 1989, 39(4): 711-714.
[18] 王建国, 濮家骝, 李广信. 不同本构模型预测饱和土孔压生成的研究[J]. 岩土工程学报, 1989, 11(5): 51-63.
[19] PANDE G N, PIETRUSZCZAK S.A Rational Interpretation of Pore Pressure Parameters[J]. Géotechnique, 1990, 40(2): 275-279.
[20] 陈晶晶, 雷国辉. 决定饱和岩土材料变形的有效应力及孔压系数[J]. 岩土力学, 2012, 33(12): 3696-3703.
基金
国家自然科学基金项目(51578213,51778211); 中央高校基本科研业务费专项(2017B20614)
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