1. State Key Lab for Geomechanics and Deep Underground Engineering, China University of Mining and Technology, Xuzhou 221008, China; 2. School of Mechanics and Civil Engineering, China University of Mining and Technology, Xuzhou 221008, China
Abstract：In order to make an investigation into the possible difference in coefficient B of saturated clay under high and normal pressures and the relevant contributory factors, isotropic consolidation tests on saturated clay under pressures of 2 MPa are conducted by GDS triaxial apparatus, and a novel test procedure is designed to check coefficient B before and after consolidation. The test results indicate that the reason for unusually small coefficient B of “saturated” clay after high-pressure consolidation is that the soil sample cannot reach 100% ideal saturation, rather than, as reported previously, the majority of the pore water in high pressure consolidation sample being bound water whose physical characteristics obviously differ from those of bulk water. In addition, the complete dissipation of the pore water pressure significantly lags behind the end of the primary consolidation in volume-logarithmic time curve during high pressure consolidation tests on saturated clay, and the process of coefficient B of consolidated clay under high pressure getting to be stable takes much longer time than that under normal pressure.
商翔宇, 郑秀忠, 周国庆. 高压下饱和黏土B系数研究[J]. 岩土工程学报, 2015, 37(3): 532-536.
SHANG Xiang-yu, ZHENG Xiu-zhong, ZHOU Guo-qing. Coefficient B of saturated clay under high pressure. Chinese J. Geot. Eng., 2015, 37(3): 532-536.
[1] 张永双, 曲永新. 鲁西南地区上第三系硬黏土的工程特性及工程环境效应研究[J]. 岩土工程学报, 2000, 22(4): 446-449. (ZHANG Yong-shuang, QU Yong-xin. Study on the engineering properties and engineering-environmental effects of neogene hard clays in south-west of Shandong province[J]. Chinese Journal of Geotechnical Engineering, 2000, 22(4): 446-449. (in Chinese)) [2] 许延春. 深部饱和黏土的力学性质特征[J]. 煤炭学报, 2004, 29(1): 26-30. (XU Yan-chun. Mechanics characteristics of deep saturated clay[J]. Journal of China Coal Society, 2004, 29(01): 26-30. (in Chinese)) [3] 马金荣, 秦 勇, 周国庆. 黏土的高压三轴剪切特性研究[J]. 中国矿业大学学报, 2008, 37(2): 176-179. (MA Jin-rong, QIN Yong, ZHOU Guo-qing. Research on tri-axial shear properties of clay under high pressures[J]. Journal of China University of Mining & Technology, 2008, 37(2): 176-179. (in Chinese)) [4] 商翔宇, 余海岁, 周国庆, 等. 高应力水平下深部黏土力学特性微观分析[J]. 岩土工程学报, 2012, 34(2): 363-368. (SHANG Xiang-yu, YU Hai-sui, ZHOU Guo-qing, et al. Micro analysis of mechanical characteristics of deep clay under high stress level[J]. Chinese Journal of Geotechnical Engineering, 2012, 34(2): 363-368. (in Chinese)) [5] 李文平. 饱水黏性土高压密实过程中孔压及体应变变化试验研究[J]. 岩土工程学报, 1999, 21(6): 666-669. (LI Wen-ping. Variation of pore water pressure and volume strain of saturated clayey soil during high pressure compression test[J]. Chinese Journal of Geotechnical Engineering, 1999, 21(6): 666-669. (in Chinese)) [6] 殷家瑜, 赖安宁, 姜 朴. 高应力下尾矿砂的强度与变形特性[J]. 岩土工程学报, 1980, 2(2): 1-10. (YIN Jia-yu, LAI An-ning, JIANG Pu. Strength and deformation characteristics of tailing under high pressure[J]. Chinese Journal of Geotechnical Engineering, 1980, 2(2): 1-10. (in Chinese)) [7] 三浦哲彦, 山本哲郎. 砂の高压三轴压缩试验の结果に及ぼす2、3の要因にっぃて[M]// 日本土质工学会论文报告集, 1976, 16(3): 123-128. (MIURA Norihiko, YAMAMOTO Tetsuro. Some factors affecting the results of high pressure triaxial test on sands[M]// Mechanics and Foundation Engineering, 1976, 16(3): 123-128. (in Japanses)) [8] SKEMPTON A W. The pore-pressure coefficients A and B [J]. Géotechnique, 1954, 4(4): 143-147. [9] GRAHAM J. The effective stress concept in saturated sand clay buffer[J]. Canadian Geotechnical Journal, 1992, 29: 1033-1043. [10] JIANG Ming-Jing. Pre-failure behavior of deep Situated Osaka clays[J]. China Ocean Engineering, 1998, 12(4): 453-565. [11] SKEMPTON A W. Effective stress in soils, concrete and rocks[C]// Proceedings of the Conference on Pore Pressure and Suction in Soils. London, 1960: 4-16. [12] BISHOP A W. The influence of an undrained change in stress on the pore pressure in porous media of low compressibility[J]. Géotechnique, 1973, 23(3): 435-442. [13] LADE P V, DE BOER R. The concept of effective stress for soil, concrete and rock[J]. Géotechnique, 1997, 47(1): 61-78. [14] 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. (CHEN Jing-jing, LEI Guo-hui. Effective stress and pore pressure coefficient controlling the deformation of saturated geomaterials[J]. Rock and Soil Mechanics, 2012, 33(12): 3696-3703. (in Chinese)) [15] OKA F. Validity and limits of the effective stress concept in geomechanics[J]. Mechanics of Cohesive-Frictional Materials, 1996, 1: 219-234. [16] AKAI K, ADACHI T, NISHI K. Mechanical properties of soft rocks[C]// Proc 9th ICSMFE. Yokyo, JSSMFE, 1977: 7-10. [17] BISHOP A W. The measurement of soil properties in the triaxial test[M]. London: Edward Arnold Publishers LTD, 1957: 131-136. [18] BLACK D K, LEE K L. Saturating laboratory sample by back pressure[J]. Journal of Soil Mechanics and Foundations Division, 1973, 99: 75-93. [19] 娄 炎. 孔隙水压力系数与饱和度的关系[J]. 岩土工程学报, 1985, 7(3): 62-67. (LOU Yan. The relationship of pore water coefficient and saturability[J]. Chinese Journal of Geotechnical Engineering, 1985, 7(3): 62-67. (in Chinese)) [20] 王志玲, 方涤华, 吕洪予. 击实黏土固结前后孔隙水压力系数的变化及对强度特性的影响[J]. 岩土工程学报, 1996, 18(2): 47-54. (WANG Zhi-ling, FANG Di-hua, LÜ Hong-yu. Pore pressure parameter of compacted clay consolidation and its effect on strength properties[J]. Chinese Journal of Geotechnical Engineering, 1996, 18(2): 47-54. (in Chinese)) [21] SHANG Xiang-yu, ZHOU Guo-qing, KUANG Lian-fei, et al. Compressibility of deep clay in East China subjected to a wide range of consolidation stresses[J]. Canadian Geotechnical Journal, 2014, 52(10): 1139. [22] 李文平, 于双忠, 王柏荣, 等. 煤矿区深部黏性土吸附结合水含量测定及其意义[J]. 水文地质工程地质, 1995, 22(3): 31-34. (LI Weng-ping, YU Shuang-zhong, WANG Bai-rong, et al. The measurement and significance on adsorbed bound water of deep cohesive clay in diggings[J]. Hydrogeology & Engineering Geology, 1995, 22(3): 31-34. (in Chinese)) [23] 钱家欢, 殷宗泽. 土工原理与计算[M]. 北京: 中国水利水电出版社, 2007. (QIAN Jia-huan, YIN Zong-ze. Theory and numerical calculation of soil engineering[M]. Beijing: China Water Power Press, 2007. (in Chinese))
