电法填埋场渗漏检测供电电极接地电阻研究

采用电法进行垃圾填埋场渗漏检测时，供电电极的接地电阻对回路电流起决定性作用.分别推导了半球状供电电极和圆柱状供电电极的接地电阻表达式，并对影响接地电阻大小的主要因素进行了分析和试验验证.结果表明:①电极的接地电阻主要由电极附近的土壤电阻决定；②随着电极埋深的增加，电极的接地电阻减少，但当埋深超过40 cm时，随着电极埋深的增加，电极接地电阻的减小趋势变缓；③随着电极直径的增加，电极的接地电阻减少.实际应用中，电极的埋深和直径应尽可能大一些，但电极直径较大时，电极质量也会显著增加，给操作带来不便.因此，可将电极直径定为10～15 cm.此外，由于土壤一般为颗粒状，这使得土壤和电极不能完全接触，为降低接地电阻，可对电极附近的土壤进行浇水. 

Grounding Resistance of Electrode in Landfill Leakage Detection Using Electrical Method

The ground resistance of the electrode plays a decisive role in the loop currents when detecting landfills by the electrical method. In this paper, ground resistance expressions for hemisphere electrodes and cylinder electrodes were derived. The main effect factors were also analyzed and verified by experiments. The results showed that the ground resistance of the electrode was mainly determined by the soil resistance around the electrode. With the increase of the depth and the diameter of the electrode, the ground resistance was reduced accordingly. Therefore, the depth and the diameter should be sufficiently large in practical applications. However, a bigger diameter means more weight, so the reasonable diameter be 10-15 cm for the covenience of operation. In addition, the soil isgenerally granular so that the electrode cannot make close contact with the soil; proper watering is effective to reduce the ground resistance.