填埋场渗漏检测偶极子法的影响因素分析

Factors Affecting the Dipole Method for Landfill Leakage Detection

偶极子法属于高压直流电法的一种,具有操作简便、费用低廉,可操作性强,并能对防渗层进行百分之百的无损检测,已成为防渗层施工验收采用的主要方式.分析了影响偶极子法灵敏度的主要因素.在回路电压一定的情况下,膜上介质电阻率、膜上介质厚度、偶极子与HDPE膜的距离、偶极子间距等因素皆可对偶极子法的灵敏度产生影响.结果表明:①膜上介质电阻率越大,偶极子检测灵敏度越高.②膜上介质厚度越大,偶极子检测灵敏度越低.③偶极子与HDPE膜的距离越小,偶极子检测灵敏度越高.④偶极子间距越大,检测灵敏度越高.但偶极子间距过大,会有漏检情况发生.⑤对于多漏洞情况,当漏洞之间的距离大于偶极子的间距时,偶极子法可准确分辨出多个漏洞.

The dipole method, which utilizes high-voltage direct current, is a simple, low-cost, and highly workable method to fully detect the liner without destruction. The dipole method has become the primary method of inspection and acceptance of the liner. This article discusses the key factors impacting the dipole sensitivity. These factors include the resistivity and thickness of the medium above the liner, the distance between the dipole and the liner, the dipole spacing, and others. The results indicate that higher resistivity of the medium, thinner liner, shorter distance, and bigger dipole spacing all affect the sensitivity of the dipole method positively. However, the bigger dipole spacing often missed some leaks. Additionally, if the distance between two leaks is shorter than the dipole spacing, the dipole method can also detect multileaks.