城市固体废弃物残余变形特性试验研究

Experimental study on residual deformation behaviors of municipal solid waste

利用中型动三轴仪,对城市固体废弃物(MSW)进行了残余变形试验研究,采用改进的沈珠江模型对MSW的残余变形模型参数进行拟合,在此基础上,讨论了不同破坏标准下的应力水平对模型参数的影响,建议了适合MSW的残余变形模型应力水平指数。MSW属于应变硬化型材料,应力和应变曲线没有明显的峰值,不同破坏标准条件下,相同固结比的MSW具有不同的应力水平,因此建议用固结应力比来代替应力水平,提出了适用于MSW的残余变形修改模型,修改后的模型不必考虑破坏标准对残余变形参数的影响,应用更加方便。

Medium-scale dynamic triaxial tests are carried out to investigate the residual deformation behaviors of simulated municipal solid waste（MSW）.Based on revised Shen Zhu-jiang model,parameters for modeling residual deformation of MSW are derived.Given three typical failure criteria,the effect of stress levels on model parameters is studied,and a stress level index is fitted to model the residual deformation of MSW.As the MSW is a kind of strain-hardening material,no clear peak is shown on stress-strain curve.The MSW with the same consolidation ratio results in varied stress levels in the model if multiple failure criteria are considered.To eliminate the choice of failure criterion and make the model parameter derivation straightforward,the stress level is replaced by the consolidation stress ratio,which leads to a modified and simplified model to estimate residual deformation of MSW.The modified model is verified by using the test results and will be used conveniently regardless of different failure criteria.