电势分布对软土电渗排水效果的模型试验研究
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摘要
通过有限元软件得到不同阴阳极面积比情况下土体的电势分布情况,根据分析的结果设计模型试验,研究电势分布不同对软土电渗排水的影响。试验中记录电流、有效电势、排水速率、排水量,分析得到以下结论,保持阳极面积不变,扩大阴极面积,电渗排水效果提高不大;保持阴极面积不变,扩大阳极面积,排水效果提高明显。电极布置形式改变阴阳极界面电阻占比,是土体平均有效电势差产生变化的重要原因之一,阴极面积变化对平均有效电势差影响相对不大,阳极面积增大提高明显。电极布置形式改变对电渗运移量影响不大;电渗排水速率和平均有效电势差在电渗主要阶段基本呈线性关系。实际工程中应更重视阳极的布置形式。
Through the finite element software, the potential distribution of the soil under different area ratios of cathode and anode was obtained. Based on the results of the analysis, a model test was designed to study the effect of different potential distribution on the electroosmosis drainage of soft soil.Drainage, electric potential and current were measured during the electro-osmotic treatment. Further, the effect of different electric potential distribution on electro-osmosis for soft soil is analyzed. The experimental results show that enlarging the cathode area has little effect on electro-osmotic drainage and its rate when anode area remains unchanged. Meanwhile, enlarging the anode area can increase the electroosmotic drainage its rate significantly. For the test conditions, the analysis of average effective potential difference is conducted involving the interface electric resistance of anode and cathode. The analysis shows that the interface electric resistance ratio changing with the different layout types of electrodes,which is one of the important causes for changing of average effective potential difference. Variation of cathode area has little effect on the average effective potential difference. Layout types of electrodes and voltage has little effect on the water transported per unit charge. The variation tendency of drainage rate is similar to average effective potential. The relationship between them is basically linear in the main stage.More attention should be paid to the layout types of anodes in practical engineering.
Through the finite element software, the potential distribution of the soil under different area ratios of cathode and anode was obtained. Based on the results of the analysis, a model test was designed to study the effect of different potential distribution on the electroosmosis drainage of soft soil.Drainage, electric potential and current were measured during the electro-osmotic treatment. Further, the effect of different electric potential distribution on electro-osmosis for soft soil is analyzed. The experimental results show that enlarging the cathode area has little effect on electro-osmotic drainage and its rate when anode area remains unchanged. Meanwhile, enlarging the anode area can increase the electroosmotic drainage its rate significantly. For the test conditions, the analysis of average effective potential difference is conducted involving the interface electric resistance of anode and cathode. The analysis shows that the interface electric resistance ratio changing with the different layout types of electrodes,which is one of the important causes for changing of average effective potential difference. Variation of cathode area has little effect on the average effective potential difference. Layout types of electrodes and voltage has little effect on the water transported per unit charge. The variation tendency of drainage rate is similar to average effective potential. The relationship between them is basically linear in the main stage.More attention should be paid to the layout types of anodes in practical engineering.
引文
[1]Casagrande L.Electroosmosis in soils[J].Geotechnique,1949,1(3):159-177.
[2]王柳江,刘斯宏,朱豪,等.电极布置形式对电渗加固软土效果的影响试验[J].河海大学学报:自然科学版,2013,41(1):64-69.
[3]Alshawabkeh A N,Gale R J,Ozsu-Acar E,et al.Optimization of2-D Electrode Configuration for Electro-kinetic Remediation[J].Journal of Soil Contamination,1999,8(6):617-635.
[4]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.
[5]温晓贵,胡平川,周建,等.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.
[6]龚明星,王档良,詹贵贵.考虑有效电势变化的软土一维电渗固结理论[J].水文地质工程地质,2015,42(4):61-66.
[7]Gray D H,Mitchell J K.Fundamental Aspects of Electro-Osmosis in Soils[J].Journal of the Soil Mechanics and foundations Division,1967,93(6):209.
[2]王柳江,刘斯宏,朱豪,等.电极布置形式对电渗加固软土效果的影响试验[J].河海大学学报:自然科学版,2013,41(1):64-69.
[3]Alshawabkeh A N,Gale R J,Ozsu-Acar E,et al.Optimization of2-D Electrode Configuration for Electro-kinetic Remediation[J].Journal of Soil Contamination,1999,8(6):617-635.
[4]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.
[5]温晓贵,胡平川,周建,等.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.
[6]龚明星,王档良,詹贵贵.考虑有效电势变化的软土一维电渗固结理论[J].水文地质工程地质,2015,42(4):61-66.
[7]Gray D H,Mitchell J K.Fundamental Aspects of Electro-Osmosis in Soils[J].Journal of the Soil Mechanics and foundations Division,1967,93(6):209.