排水竖井在垃圾填埋场滑移治理中的应用及效果分析

垃圾填埋场滑移会造成严重的人员财产损失和环境污染,填埋场稳定控制和滑移的治理方法较为缺乏。在国内某失稳填埋场开展竖井排水滑移治理试验,监测治理前后的表面位移、深层位移、渗滤液水位和渗滤液导排量,评估滑移治理效果。并进一步利用Geo-Studio软件评估排水竖井不同导排时间、导排流量及布置方式时的稳定控制效果。结果表明:排水竖井使用后,填埋场最大滑移面积从监测总面积的68%降为17%,深层平均滑移速率从2.43 mm/d降为0.95 mm/d;10口排水竖井的最大导排流量279 m~3/d,平均导排流量为164 m~3/d;模拟分析表明,排水竖井工作时间越长,导排流量越大,堆体越快趋于稳定;在相同导排总量的条件下,布置3排竖井滑移治理效果优于布置1排和2排的效果,当布置2排时,排间距为10 m的效果优于排间距为20 m的效果。排水竖井滑移治理和稳定控制应用效果较好,可为填埋场堆体稳定控制提供参考。

Application and analysis of drainage well in landfill slip control

Landfill slip will cause losses of lives and properties and serious environmental pollution. At present, the methods for stability of landfills are few. The drainage well to control the stability of the landfill at an instable landfill in China is investigated. The surface horizontal displacement, deep lateral displacement and leachate level are monitored to evaluate the method. The seepage and stability analysis software is used to analyze the effects of stability control of pumping time, pumping rate and arrangement. It is shown that after using this method the maximum slip area is reduced to 17% from the monitoring area of 68%, and the deep average slip rate is reduced to 0.95 mm/d from 2.43 mm/d. The maximum pumping rate of 10 drainage wells is 279 m³/d, and the average pumping rate is 164 m³/d. The simulation analysis shows that the longer the pumping time and the greater the pumping rate, the faster the landfill tends to be stable. Under the same flow rate, 3 rows are superior to the arrangements of 1 row and 2 rows in terms of slip control. Under the same row number of 2, the effectiveness of row spacing of 10 m is superior to that of 20 m. The proposed method has been proved to be successful in practice, and the application of drainage well may provide a successful example for control of the similar landfill slip.