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填埋后的城市固废因降解产生固相质量损失,从而造成在外力作用下的固结是一个相当复杂的过程。为研究饱和城市固废的降解固结特性,建立了一维降解固结普遍模型;基于已有城市固废降解、压缩和渗透特性研究,获得了考虑可降解固相水解、胞内水释放为孔隙水及降解导致压缩性衰变的一维降解固结简化模型;基于简化模型,针对饱和城市固废填埋层底部淤堵不透水和顶部自由排水工况,获得了一维降解固结解析解。针对国内填埋场新鲜城市固废的计算结果表明:在瞬时常荷载作用下,固结初期,填埋层底部的超静孔压值会超过初始值,这主要是因为降解引起固相质量损失导致骨架疏松、压缩性增大;固结后期,整个填埋层出现负的超静孔压,这是因为后期填埋层孔隙比因固相质量损失而增大,而压缩性衰变相对较小。参数敏感性分析表明:降解引起的次压缩速率越大,固结初期超静孔压越大;增加填埋层的先期固结压力会延缓超静孔压的消散。
Landfill after solid waste due to degradation of solid-phase mass loss, resulting in consolidation under the action of external force is a very complicated process. In order to study the degradation and consolidation characteristics of saturated solid waste in urban areas, a one-dimensional universal model for degradation and consolidation was established. Based on the studies on the degradation, compression and infiltration characteristics of urban solid waste, the biodegradable solid- Pore water and the one-dimensional degradation and consolidation model that leads to compressive decay. Based on the simplified model, a one-dimensional analytical solution of degradation and consolidation . The calculation results of solid waste in fresh municipal solid waste in landfill show that under the instantaneous normal load, the excess pore pressure at the bottom of the buried layer will exceed the initial value during the initial consolidation, mainly due to the loss of solid mass caused by degradation Resulting in a loose framework and increased compressibility. In the late consolidation period, the negative excess pore pressure appears in the entire landfill because the porosity of the later landfill layer increases due to the mass loss of the solid phase and the compressive decay is relatively small . Parameter sensitivity analysis shows that the larger the sub-compression rate caused by degradation is, the larger the excess pore pressure will be at the initial consolidation stage. Increasing the pre-consolidation pressure of the buried layer will delay the dissipation of the excess pore pressure.