【作者】 吴忠良；

【导师】 涂帆；

【作者基本信息】 华侨大学 ， 结构工程， 2008， 硕士

【摘要】 通过对填埋场垃圾土的成份分析,选择有代表性的垃圾组成配置试样,进行室内试验,研究垃圾组成、击实功、含水量和上覆压力对垃圾密度和干密度的影响。试验结果表明:对垃圾进行击实可以有效提高垃圾密度,垃圾的干密度与击实能的关系可以用对数函数表达,垃圾组成对对数函数表达式的影响主要体现在函数式的截距项上;垃圾土的最大干密度和最优含水量随击实能的变化规律与一般土相同;垃圾土的密度有随上覆压力增大的趋势,但上覆压力达到一定界限,密度的增长趋势明显减缓,该界限值与垃圾土的击实能有关;对于同一组成的垃圾土,干密度的初始值因压实能和含水量而异,且随上覆压力的增大而增大并趋于定值。填埋场边坡衬垫系统和最终覆盖系统的稳定性计算,目前有好几种方法,其中采用最多的是极限平衡分析法,包括双楔体法、无限边坡法和全平衡法等。通过对这几种方法的分析,寻找比较适合实际情况的计算方法。计算结果表明,无限边坡法的安全系数最小,因为它既没有考虑坡脚抗力,也没有考虑填埋场边坡土工防渗膜拉力对稳定性的影响;全平衡法的安全系数最大,因为该法考虑了坡脚抗力和边坡土工防渗膜的拉力对稳定性的影响;双楔体法的安全系数介于这两种方法之间,因为它只考虑坡脚的抗力,没有考虑土工防渗膜的拉力。本文着重研究填埋场的平移滑动破坏问题。在建立考虑垃圾坝与被动楔体间作用力方向的三角形垃圾坝的三楔体模型后,又建立了梯形垃圾坝的三楔体模型,此模型可以考虑垃圾坝与被动楔体之间摩擦角的作用,而且垃圾坝的断面为可以变化的梯形,根据该模型,求解填埋场沿衬垫和垃圾坝底部滑动的安全系数,并分析有关参数对稳定性的影响。分析结果表明,垃圾坝与被动楔体之间的摩擦角对填埋场的整体稳定性影响不大;填埋场安全系数随填埋场前坡倾角α和后坡倾角β的增大而减小,随主动楔体和被动楔体下复合衬垫各接触面中最小摩擦角的增大而增大,随垃圾土内摩擦角的增大而增大,随垃圾坝高度和垃圾坝底部与地基之间摩擦角δD的增大而明显增大;垃圾坝后背坡角对填埋场整体稳定性影响较大,后背坡角越小,安全系数越大;修筑垃圾坝能有效提高填埋场的稳定性;对于设有垃圾坝的填埋场,如果不考虑垃圾坝的作用,计算结果偏于保守。填埋场在运营过程中,因为填埋场的库容大,使用时间长,需要进行科学有效的管理和有步骤的垃圾分区填埋。分区填埋的单元稳定性是分区填埋设计的重要内容,填埋场在分区填埋时,只要每一分区的顶宽和高度的比值B/H在一定的数值范围内,便能保证分区填埋的安全稳定。更多还原

【Abstract】 According to the analyzing the composition of refuse in landfills, the composition of refuse sample is determined and the experiments are carried out in lab to investigate the influence of composition, compaction effort, water content and pressure to density and dry density of refuse. The results show that the density and dry density are increasing with the increase of compaction effort. And the relationship between dry density and compaction effort can be expressed by a log function in which the interception indicates the influence of composition of refuse. The rule of the compaction curve of refuse is consistent with the general soil. The density is increasing with the increase of pressure, but the rate of increase slows down significantly after pressure reaches a certain value which is relevant with the initial density and compaction effort. Initial dry densities in a same composition are different with the compaction efforts and water contents, but the values tend to same with the increasing pressure.The stability on active wedge and final cover of landfill is impotent in construction of landfill. There are many methods for studying stability. The most used method is limit equilibrium analysis including two wedges analysis, infinite slope, full equilibrium methods and etc. The methods are compared to find the differences. The results show that the safety factor calculated by infinite slope is smallest because the resistance on slope feet is ignored due to the assumption of infinite slope and the geo-membranes tensile of slope isn’t considered. The safety factor calculated by full equilibrium method is a biggest one because the geo-membranes tensile on slope and the resistance of slope feet are both considered. The safety factor calculated by the method of two wedges is between the others because the geo-membranes tensile of slope is not considered while the resistance of slope feet is considered in the method.The translation failure is studied in this paper. A limit equilibrium analysis is used to calculate the factor of safety for landfill translation failure along the underlying liner system. The landfill is divided into three parts: an active wedge lying on the back slope that tended to cause failure, a passive wedge and waste dam resting on the foundation or liner system that helped to resist movement. In addition, we set a mode of three parts wedge of trapezia, the friction between passive and waste dam can be considered in this mode, and the shape of waste dam is able to change, solution the factor of safety, the influence on stability is studied in this mode. With the increasing of the back slope angle of waste dam, the factor of safety FS was decreased; There is a little variety on the factor of safety FS with the change of friction angle between waste dam and passive wedge; The factor of safety FS was increased with the increasing of height of waste dam; It was found that the retaining wall significantly affected the stability of landfill,the calculate result were be conservative if the effect of waste dam weren’t considered.Because of landfill is always big and used in a long time, so landfill needs to be filled in sequence and needs to be manage effectively. It is important to assure the stability of cell. When cell of landfill is designed, every cell will be save if make sure the value about B/H in a acceptable range, and some parameter likeα,β,γSW,θ,δis no change.更多还原