Abstract:In order to study the size effect, a model experiment on the electro-osmosis combined with loading is designed and conducted. Through the comparison among model experiment on electro-osmosis combined with loading, model experiment on simple electro-osmosis and in-situ experiment on electro-osmosis, it is demonstrated that the large difference of cracks is the main reason why the model experiment on simple electro-osmosis draws an opposite conclusion with the in-situ experiment. The size effect caused by geometric boundary can be eliminated by reasonable loading, which makes the cracks similar to those in the in-situ experiment, so the model experiment on electro-osmosis combined with loading can better simulate the in-situ experiment. As the size effect is eliminated, the main factor influencing the electro-osmosis dewatering is the effective electric field rather than the current density. Among hexagonal, rectangular, and parallel and transposition configurations, the hexagonal configuration which has the maximum area of effective electric field is the most effective and economical, so it is recommended to be employed for electro-osmotic treatment.
温晓贵,胡平川,周建,李一雯,陶燕丽. 裂缝对电渗模型尺寸效应影响的试验研究[J]. 岩土工程学报, 2014, 36(11): 2054-2060.
WEN Xiao-gui, HU Ping-chuan, ZHOU Jian, LI Yi-wen, TAO Yan-li. Experimental research on influence of cracks on size effect of electro-osmosis model. Chinese J. Geot. Eng., 2014, 36(11): 2054-2060.
[1] GLENDINNING S, LAMONT-BLACK J, JONES C J F P. Treatment of sewage sludge using electrokinetic geosynthetics[J]. Journal of Hazardous Materials, 2007, A139: 491-499. [2] 李一雯, 周 建, 龚晓南, 等. 电极布置形式对电渗效果影响的试验研究[J]. 岩土力学, 2013, 34(7): 1972-1978. (LI Yi-wen, ZHOU Jian, GONG Xiao-nan, et al. Experimental research on the effect of electrodes array to electro-osmotic dewatering[J]. Rock and Soil Mechanics, 2013, 34(7): 1972-1978. (in Chinese)) [3] 王学滨, 刘 杰, 王 雷, 等. 基于梯度塑性本构理论的岩样侧向变形分析(II):尺寸效应及弹性回跳[J]. 岩土力学. 2004, 25(7): 1127-1130. (WANG Xue-bin, LIU Jie, WANG Lei, et al. Analysis of lateral deformation of rock specimen based on gradient-dependent plasticity(II): size effect and snap-back[J]. Rock and Soil Mechanics, 2004, 25(7): 1127-1130. (in Chinese)) [4] ODA M A. Method for evaluating the representive elementary volume based on joint survey of rock mass[J]. Canadian Geotechnical Journal, 1998, 25(3): 281-287. [5] BAZANT Z P, DESMORAT R. Size effect in fiber or bar pullout with interface softening slip[J]. Journal of Engineering Mechanics, 1994, 120(9): 1945-1962. [6] WITTLE J Ke, ZANKO L M, FALK D, et al. Enhanced stabilization of dikes and levees using direct current technology[C]// Geocongress 2008: Geosustainability and Geohazard Mitigation. ASCE, 2008: 686-693. [7] FOURIE A B, JONES C J F P. Improved estimates of power consumption during dewatering of mine tailings using electrokinetic geosynthetics (EKGs)[J]. Geotextiles and Geomembrances, 2010, 28(2): 181-190. [8] ALSHAWABKEH A N, GALE R J, OZSU-ACAR E, et al. Optimization of 2-D electrode configuration for electrokinetic remediation[J]. Journal of Soil Contamination, 1999, 8(6): 617-635. [9] BAZANT Z P, XIANG Y Y. Size effect in compression fracture: splitting crack band propagation[J]. Journal of Engineering Mechanics, 1997, 123(2): 162-171. [10] CARPINTERI A, CHIAIA B. Multifractal scaling laws in the breaking behaviors of disordered materials[J]. Chaos, Solitons & Fractals, 1997, 8(2): 135-150.