城市生活垃圾填埋场沉降监测与分析

2006年9月起于上海老港填埋场开展了示范工程沉降监测项目。该生活垃圾填埋场占地面积约为200 m×125 m，共填埋了约15×104 t来自上海城区的生活垃圾，最大填埋厚度约为9 m。通过填埋期间埋设的水平沉降管，监测到该填埋场不同埋深处的沉降值。介绍了沉降监测系统的工作原理，分析了2006年底至2008年底为期两年的沉降数据。填埋场底部沉降管监测数据表明，场底地基沉降较小，两年的平均沉降为 ～ cm；中部沉降管监测数据表明，该沉降管下方生活垃圾在上方垃圾填埋后产生了较大的压缩，从上方垃圾开始填埋至填埋完毕3个月内的压缩应变约为0.197～0.242；顶部沉降管和中部沉降管监测数据表明，该填埋场垃圾主压缩完成时间约为3个月；由于填埋垃圾有机物含量较高，其修正次压缩指数较大，约为0.066～0.070。

Field monitoring and analysis of municipal solid waste landfill settlement

Settlement monitoring of a field-scale municipal solid waste landfill site in Shanghai Laogang Landfill was conducted since September 2006. The landfill site covered an area of 200 m×125 m and accepted about 150 000 tones of municipal solid waste from Shanghai. Maximum height of the wastes is about 9 m. Settlements at different depths of the landfill site during filling and after closure were monitored through horizontal inclinometers. The working principle of the horizontal inclinometer was introduced. Two years’ monitoring data showed that bottom horizontal inclinometers settled from -3.6 cm to -5.7 cm. Wastes under the middle horizontal inclinometers experienced large compression due to the deposition of overlying wastes. The compression strain from the beginning of the overlying wastes’ deposition to three months after the end of the deposition was about 0.197-0.242. Monitoring data from the top and middle horizontal inclinometers indicated that the time needed for the primary compression of wastes in the test site was about 3 months. Modified secondary compression index C’α was about 0.066-0.070, and was relatively large compared to published data which might due to the large amount of organic matter in the landfilled wastes.