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城市垃圾填埋场有机物降解沉降模型的研究 总被引：15，自引：4，他引：11
研究城市垃圾填埋场的有机物降解沉降是非常重要的,有机物的降解沉降是填埋场的主要沉降,并且降解沉降将持续很长一段时间,较大的沉降能够导致防渗系统的渗漏并损坏覆盖系统。由于垃圾的非均匀性,其土工特性随地域及时间而改变,所以,计算垃圾填埋场的降解沉降是比较困难的。在试验及理论推导的基础上,提出了一种有机物的降解沉降模型,该模型参数较少,利用该模型预测了天子岭垃圾填埋场的库容及有机物的降解沉降。 相似文献
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Prediction of long‐term settlement and control of gas pollution to the environment are two principle concerns during the management of municipal solid waste (MSW) landfills. The behavior of settlement and gas flow in MSW landfills is complicated due to the combined effect of mechanical deformation of the solid skeleton and continuous biodegradation of the waste. A one‐dimensional settlement and gas flow model is presented in this paper, which is capable of predicting time evolution of settlement as well as temporal and spatial distribution of gas pressure within multi‐layered landfills under a variety of operating scenarios. The analytical solution to the novel model is evaluated with numerical simulation and field measurements. The resulting efficiency and accuracy highlight the capability of the proposed model to reproduce the settlement behavior and gas flow in MSW landfills. The influences of operating conditions and waste properties on settlement and gas pressure are examined for typical MSW landfills. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
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Behavior of a municipal landfill from field measurement data during a waste-disposal period 总被引：2，自引：0，他引：2
The behavior of a municipal waste landfill on marine clay was analyzed from field measurement data. Instruments, e.g., a groundwater level sensor, piezometer, earth pressure gauge, settlement plates, inclinometer, etc., were installed and operated during the disposal period from October 1992 to November 2000. A database system was developed to manage the data from this landfill using Access (Microsoft) with Delphi programs. From the analyses, it was determined that the settlement of the landfill during the initial period of waste disposal was small because of the high leachate level in the landfill. As the level of waste became higher than the leachate level, the settlement of the landfill increased significantly due to the increasing effective pressure within the landfill. From a stability point of view, the critical time for the landfill in this study was the initial period of landfill disposal, which was caused by either the impact load of waste disposal or the time schedule of waste disposal, which was faster than the consolidation of foundation clay caused by the waste load. 相似文献
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M. Keramati N. Shariatmadari M. Sabbaghi M. Sadegh Abedin 《International Journal of Environmental Science and Technology》2018,15(6):1257-1264
In order to analyze the stability of a landfill site, it should analyze some properties of waste introducing the main structural elements. Up to now, it has not been done much research on the properties of municipal solid waste. In addition, due to the differences in waste properties from one country to another and even from one to another landfill site, it is impossible to generalize the results. These conditions caused local research on the evaluation of static and dynamic parameters of municipal solid waste to be done. Because Iran is a seismic country, the short-term behavior of waste controls landfill sites stability during seismic loads; so it is necessary to know the dynamic behavior of these materials. In this paper, about 18 cyclic tests were performed, and in addition to determining the dynamic parameters of municipal solid waste of Tehran Kahrizak Disposal Site using cyclic triaxial test, the effect of confining stress and loading frequency on dynamic properties of these materials was evaluated. The results have shown that with increasing the confining stress and loading frequency, shear modulus and damping ratio was increased and decreased, respectively, and it is related to the composition of the municipal solid waste materials. 相似文献
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Mohsen Asadi Nader Shariatmadari Mehran Karimpour-Fard Ali Noorzad 《Geotechnical and Geological Engineering》2017,35(5):2003-2015
The increasing demand of engineering landfills requires that designers propose a framework for landfill design, construction, repair and maintenance. As municipal solid waste (MSW) is a major part of a landfill, the analysis should consider MSW mechanical behavior using a constitutive model. To investigate this, 18 direct shear (DS) and triaxial (TX) tests were conducted on MSW samples with different fiber contents. Different shearing mechanisms lead to understand effects of fibers on stress–strain response. Based on obtained results the hyperbolic model Duncan and Chang (J Soil Mech Found Div 96(5):1629–1653, 1970) has been employed to simulate the TX results indicating the ability of the model to predict stress–strain behavior of MSW. This model could also be employed to the DS test results with some assumptions. The model can capture DS stress–strain response well whereas for TX tests the predictions were just enough. The experimental results and two sets of proposed MSW parameters of hyperbolic model have been compared and discussed. 相似文献
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The primary objective of bioreactor landfill is to achieve adequate and rapid distribution of moisture in landfilled municipal solid waste (MSW) to accelerate the anaerobic biodegradation of the organic fraction within MSW. A horizontal trench system (HT) is commonly adopted for leachate distribution in MSW under pressurized conditions. However, this approach should be implemented carefully due to the potential instability of landfill slopes that comes from the generation and distribution of excessive pore fluid pressures. In this study, HT design charts are presented that determine the optimal location of horizontal trench systems from the side slope (i.e., minimum lateral setback distance) under continuous leachate addition with maximum applied injection pressures, for which the landfill slopes remain stable [factor of safety (FOS) where FOS ≥ 1.5]. Use of any higher injection pressure and/or shorter lateral setback distance of HT than the one presented in the design charts would result in an unacceptable design of the bioreactor side slope (FOS < 1.5). The design chart was developed based on a parametric study that used a numerical two-phase flow model that involved different slope configurations and landfill waste depths. MSW heterogeneity and anisotropy, as well as unsaturated hydraulic properties, were taken into consideration in these simulations. Transient changes in pore water and gas pressures due to leachate recirculation were accounted for dually in the slope stability computations. The importance of these design charts is illustrated using a practical example. Site-specific conditions and the expertise and prior experience of a designer or operator must also be adequately considered and utilized with the design charts presented here for the safe design of a horizontal trench system in a bioreactor landfill. 相似文献
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考虑生物降解的填埋场长期沉降研究 总被引：1，自引：0，他引：1
填埋场沉降是环境岩土工程主要研究课题,填埋场沉降主要由堆载瞬时沉降、与时间有关的填埋体骨架蠕变和有机物生物降解引起的沉降等3部分组成。迄今为止,国内外学者建立了许多估算填埋体沉降的数学模型。根据总结归纳的典型填埋体沉降计算模型,结合某填埋场沉降实测资料,探讨了计算模型的适用性。 相似文献
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正确分析评价垃圾填埋场的地质特征和防渗方案,对垃圾填埋场的选址、设计以及施工运营极为重要。从自然环境、地层结构及岩性特征等方面阐述了淮安市某垃圾填埋场的地质特征,分析了填埋区含水层分布、厚度、赋水性等水文地质条件;结合室内试验和野外试验,综合确定了填埋区岩土层渗透系数大于1×10^-7cm／s,表明填埋区不具备天然防渗的条件,需采用人工防渗系统才能有效的阻滞垃圾渗滤液对周边环境的影响。 相似文献
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填埋场扩建是增大库容的重要手段,而其引起的沉降变形对填埋场及内部构筑物的稳定性有重大影响。针对扩建填埋场自重应力作用下的沉降变形问题,采用能够模拟我国固废工程特性的人工固废开展了平原型填埋场竖向扩建的离心模型试验。结果表明,堆体自重应力沉降随固废龄期增大而减小,最大沉降可达到堆体初始高度的20%。新老堆体界面不均匀沉降随老堆体龄期增大而减小,界面水平位移最大值出现在新堆体坡肩附近,且随坡比增加和龄期减小而增大。坡比越小,龄期和垃圾坝的作用越明显。垃圾坝对填埋堆体变形的影响随其相对高度减小而减弱。试验结果略大于常用的填埋场一维沉降计算结果,为填埋场增容及中间衬垫设计和稳定评估等提供了参考。 相似文献
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During leachate recirculation, a bioreactor landfill will experience more rapid and complete settlement, which is mainly attributed to the weight of municipal solid waste (MSW) and its biodegradation. The settlement of MSW may cause the decrease of void ratio of MSW, which will influence the permeability of MSW and the leachate quantity that can be held in bioreactor landfills. In this study, a new one-dimensional model of leachate recirculation using infiltration pond is developed. The new method is not only capable of describing leachate flow considering the effect of MSW settlement, but also accounting separately leachate flow in saturated and unsaturated zones. Moreover, the effects of operating parameters are evaluated with a parametric study. The analyzing results show that the influence depth of leachate recirculation considering the effect of MSW settlement is smaller than the value without considering the effect. The influence depth and leachate recirculation volume increase with the increase of infiltration pond pressure head and MSW void ratio. This indicates that the field compaction of MSW has a great influence on the leachate recirculation. 相似文献
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A bioreactor landfill is operated to enhance refuse decomposition, gas production, and waste stabilization. Some of the potential
advantages of bioreactor include rapid stabilization of waste, increased landfill gas generation, gain in landfill space,
enhanced leachate treatment, and reduced post closure maintenance period. Due to the accelerated decomposition and settlement
of solid waste, bioreactor landfills are gaining popularity as an alternative to the conventional Subtitle D landfills. However,
the addition of leachate to accelerate the decomposition changes the physical and engineering characteristic of waste and
therefore affects the geotechnical characteristics of waste mass. The changes in the physical and mechanical characteristics
of solid waste with time and decomposition are expected to affect the shear strength of waste mass. The objective of this
paper is to analyze the stability of solid waste slopes within the bioreactor landfills, as a function of time and decomposition.
The finite element program PLAXIS is used for numerical modeling of bioreactor landfills. Stability analysis of bioreactor
landfills was also performed using limit equilibrium program STABL. Finally the results from finite element program PLAXIS
and limit equilibrium program STABL are compared. GSTABL predicted a factor of safety of more than 1 in all the cases analyzed,
whereas PLAXIS predicted a factor of safety of less than 1 at advanced stages for a slope of 2:1. However, the interface failures
between solid waste and landfill liners have not been considered in this paper. 相似文献
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The recovery and emission of landfill gas (LFG) is an important topic in landfill management. To produce an effective engineering design for an LFG collection system, designers must understand the migration of gas from the waste body to horizontal extraction wells. This paper develops a two-dimensional analytical solution to enable the study of the gas pressure distribution, well pressure and recovery efficiency in layered landfills with horizontal wells. A horizontal layered structure is used to accommodate the non-homogeneity of various municipal solid waste (MSW) aspects with respect to depth, including gas generation, permeability and temperature. The governing equations, subject to boundary and continuity conditions, are solved by using separation of variables and double finite integral transforms. The solution was verified against another analytical solution and a numerical simulation. Subsequently, a sensitivity analysis of single-well model parameters is performed to optimize a double-well system. The results show that a landfill with horizontal collection systems cannot be assumed to be one dimensional with increasing well spacing. Additionally, both the operational vacuum and maximum gas pressure can be reduced through the design of a double- or multiple-well system. Therefore, the proposed solution can be used for the verification of more complex models and the preliminary design of a horizontal well system. 相似文献
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Understanding the compression behavior of waste materials is important to the operation and rehabilitation of waste landfill
sites. Nevertheless, predicting this behavior is extremely difficult because waste materials are heterogeneous and highly
biodegradable. In terms of the mechanism, waste settlement comprises mechanical and biodegradation compressions. This research
performs a series of tests to study the mechanical compression behavior of waste materials by using a specifically designed
testing device. The device has the ability to keep the temperature low enough to impede the biodegradation of organics, thereby
allowing the mechanical compression behavior to be determined. In general, the observed mechanical compression indicates that
municipal solid waste (MSW) is very compressible. As the load increases, MSW becomes less compressible because the waste is
getting denser. MSW also has a very large creep compression rate, whereby the coefficient of compression of the primary phase
is only about 2–8 times that of the creep phase. The magnitude of loading and the elapsed time of loading affect the mechanical
compression behavior of MSW. The effects of some parameters on the mechanical behavior are studied herein. MSW with higher
dry density had a smaller compressibility. Higher water content also led to a higher compression rate in the primary and creep
phases. The waste containing more compressible constituents compressed to a larger extent but with an insignificant increase
in the compression rate. The biodegradation of organic constituents did not influence the mechanical compression behavior
significantly but increased the rate of creep compression notably. This research also developed a regression relationship
between the coefficient of volume compressibility and the dry density of the waste. The prediction of mechanical compression
in a field case validated the application of this regression relationship. 相似文献
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好氧降解作用对垃圾土沉降变形特性的定量评价是预测和评估好氧降解稳定化的重要基础。以武汉市典型生活垃圾组成配比人工制作的垃圾土为样本,开展了不同通风条件下垃圾土沉降特性试验,分析了好氧通风频率对沉降变形的影响。试验结果表明：厌氧条件沉降速率趋于稳定后,好氧通风可显著提高垃圾土的沉降速率;上、中、下3层垃圾在高通风频率下垃圾土沉降比低通风频率下沉降效率分别提高了145%、150%、100%;建立了厌氧-好氧联合型沉降模型,通过与试验监测得到的沉降值对比,初步验证了模型的可靠性。研究结果为好氧通风过程中垃圾土沉降稳定性评估提供了理论依据。 相似文献
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卫生填埋场动力分析和动力性状研究进展 总被引：1，自引：0，他引：1
城市固体垃圾卫生填埋场在动力荷载作用下反应分析是对卫生填埋场进行正确设计、施工和保证其正常运行的重要研究内容,本文评述了国内外城市因体垃圾卫生填埋场动力分析的最新进展情况,着重探讨了几种主要分析方法的长处和不足,以及影响卫生填埋场动力反应的主要因素和其在动力荷载作用下的动力性太,最后指出了今后卫生填场动力分析中急需改进的若干问题。 相似文献