填埋场渗漏条件下的漏洞电阻特征与影响因素

Characteristics and Influencing Factors of Leak Resistance under Leakage Conditions in Landfill Sites

复杂填埋环境下,HDPE膜(高密度聚乙烯膜)漏洞处电阻率特征及其影响因素、影响机制不明,制约了电法精准量化渗漏量在填埋领域的应用.基于防渗层渗漏电法检测原理,采用模拟渗漏装置和填埋场等效电路模型探析激励电压(20~200 V)、漏洞半径(1.0~12.5 mm)和渗滤液电阻率(0.68~2.60Ω·m)等关键因素对测量总电阻和漏洞电阻的影响规律和机制.结果表明:漏洞半径对于测量总电阻的影响呈幂函数趋势,在漏洞半径小于4 mm、激励电压在20~40 V区间时,测量总电阻稳定性较差,而漏洞半径大于4 mm、激励电压大于40 V时,测量总电阻稳定性较好;漏洞电阻随渗滤液电阻率变化明显且与渗滤液电阻率呈线性关系,表明渗滤液电阻率是影响漏洞电阻的主要因素之一.研究显示,测量总电阻、渗滤液电阻率与漏洞半径之间存在显著相关关系,受实际场地条件差异的影响,不同填埋场地关系模型存在差异,可通过现场试验构建以测量总电阻和渗滤液电阻率为变量的漏洞半径表征关系模型,扩大基于电法的渗漏量化精准评估方法的适用范围.

The resistivity characteristics of HDPE membrane vulnerabilities and its influencing factors and mechanisms are unknown in complex landfill environments,which restricts the application of electrical methods to accurately quantify leakage in landfills.Based on the principle of electrical leakage detection of impermeable layers,the key factors such as excitation voltage(20-200 V),leak radius(1.0-12.5 mm)and leachate resistivity(0.68-2.60Ω·m)were used to investigate the influence of the simulated leakage device and landfill equivalent circuit model on the measurement of total resistance and leak resistance and the mechanism.The results showed that the influence of the leak radius on the measured total resistance was a power function,and the stability of the measured total resistance was poor when the leak radius was less than 4 mm and the excitation voltage was in the range of 20-40 V.The stability of the measured total resistance was better when the leak radius was greater than 4 mm and the excitation voltage was greater than 40 V.The leak resistance varied significantly with the leachate resistivity and showed a linear relationship with the leachate resistivity,indicating that the leachate resistivity was the main influence on the leak resistance.This indicates that the leachate resistivity is one of the main factors affecting the leak resistance.The study shows that there is a significant correlation between the measured total resistance,leachate resistivity and leak radius,and the relationship model differs between different landfill sites due to the difference in actual site conditions.