采用分层总和法,不考虑固体垃圾有机物降解的影响,提出了城市固体垃圾的一维应力压缩计算方法.该方法仅考虑材料的竖向压缩,而不考虑侧向挤出所引起的压缩,该方法既简单又实用.研究表明,初始孔隙比对城市固体垃圾的应力压缩起着重要的影响,而初始天然重度影响不大.然后考虑垃圾侧向挤出等因素,建立了城市固体垃圾的二维应力压缩计算方法.该方法采用Duncan-Chang模型编制二维应力压缩有限元计算程序,模拟了垃圾填筑的实际操作过程,该方法的计算结果比较接近工程实际情况.研究表明,固体垃圾边坡坡脚处的水平位移及竖向位移最大;实际填筑厚度与理论填筑厚度的关系可用直线表示,直线斜率为0.486.最后对一维与二维计算方法的结果进行比较,二维应力压缩计算结果为一维应力压缩计算结果的1.15~1.25倍.
Applying the layerwise summation method, a calculation method of one-dimensional stress compression was put forward without regarding for the organic degradation of municipal solid waste. This method takes the vertical compression into account and leaves out the compression caused by the lateral extrusion, which makes the method simple and practical. The calculation shows that the initial void ratio is a key factor for the stress compression of municipal solid waste, but the natural density has little impact. Then, considering the compression caused by the lateral extrusion, a calculation method of two-dimensional stress compression of municipal solid waste was also put forward. A two-dimensional finite element program using Duncan-Chang model was developed to simulate the process of municipal solid waste landfill. The simulation shows that the method is in accordance with the practical landfill procedure. The calculation shows that the maximum horizontal displacement and the maximum vertical displacement are located at the toe of waste slope, and that the relationship between the real and theoretical landfill thickness is linear with a slope of 0. 486. Finally, the comparison shows that the vertical displacement of the twodimensional method is about 1.15--1.25 times that of the one-dimensional method.