垃圾土蠕变-降解沉降特性试验研究

为了研究垃圾土蠕变降解沉降特性，选取重庆市某垃圾场典型试样，基于室内蠕变观测试验得到蠕变降解沉降过程曲线（0~330 d），建立了符合其沉降变形特性的PTH计算模型，验证了该模型合理性，同时对沉降影响因素进行了详细分析。结果表明，因外部应力和内部蠕变降解引起的沉降总量可达试样高度的33.2%，渗滤液在前期的溢出量受外部荷载和有机物含量的控制；垃圾土中有机物的降解规律可用Richards 模型来表示，累计沉降量和累计渗滤液产量之间符合指数函数关系；有利于初期压缩变形和后期降解沉降的最优有机物含量区间为29.1%～36.47%；内部温度监测结果显示，20～41 ℃是一个可加快内部有机物降解速率的温度区间，且在41 ℃时作用最大。

Experimental Analysis on the Decomposition-Creep Settlement Properties of Municipal Solid Waste

In order to study the creep-degradation settlement properties of municipal solid waste, the change of static-creep-settlement for fresh municipal solid wastes which collected from the Chongqing landfill was observed elaborately during the 330 days Laboratory test, and the PTH Model which would fit the settlement properties better was funded. By analyzing leachate-degradation-strain-time relational curves, the number of total creep settlement caused by external load and inner degradation in the waste can reach 33.2% of the sample height. The leachate production can be controlled by the external load and organic content. The tests results indicate that the degradation rule of MSW can be expressed as the Richards model,and the relation of cumulative sellenment with cumulative leachate fit the Exponential function model. The corresponding section for organic content that suit for the initial compression deformation and the creep-degradation settlement could be ranged from 29.1% to 36.47%. During the monitoring for settlement and internal temperature field in the anaerobic reaction stage, an optimum temperature zones that varied from 20℃ to 41℃ are found, which could accelerate degradation speed of organic matters in the waste. Moreover, degradation speed of organic matters becomes maximum when the temperature reaches 41℃.