共查询到18条相似文献，搜索用时 171 毫秒
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垃圾土一维压缩修正公式及有机物降解验证试验研究 总被引：2，自引：1，他引：1
针对垃圾填埋场沉降计算问题,考虑垃圾土中有机物降解及对降解过程中重度变化,在张振营压缩量计算方法的基础上推导了垃圾土一维压缩计算的修正公式;通过垃圾土有机物降解试验和计算分析,研究了有机物的降解规律;以相同配比的垃圾土进行了垃圾土柱的沉降和计算参数试验,对推导的垃圾土一维压缩计算修正公式进行了验证。研究表明,修正的计算公式能考虑更多的影响因素,有机物的降解规律可以用Richards生物生长规律来模拟,修正的计算公式能够合理地计算出垃圾土沉降的过程。 相似文献
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文章针对填埋场沉降计算问题,对垃圾压缩机理进行了研究,建立了常应力作用下的垃圾压缩模型。该模型将城市生活垃圾的压缩分为主压缩和降解压缩,其中,主压缩与压力有关,降解压缩与压力和降解条件有关。降解条件包括有机质含量和降解速率;结合对填埋场分级堆填过程的分析,建立了考虑降解和分级堆填影响的填埋场一维沉降计算方法,并对计算参数的取值方法进行了研究。 相似文献
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考虑填埋场沉降和生物降解作用下的孔隙度仿真预测研究 总被引：5，自引：0，他引：5
垃圾填埋场上覆层的压缩以及自身的降解作用使内部孔隙结构发生了改变。沉降和生物化学反应的双重作用改变了填埋场原有孔隙度分布。将垃圾压缩变形和微生物降解所引起的产气过程相结合,建立了描述填埋场孔隙度-位移-气体压力相互作用的耦合数学模型,并给出了耦合模型的数值格式。通过数值计算得到了垃圾填埋体的沉降应变、孔隙度、孔隙渗透及扩散特性的变化规律。计算结果表明,填埋场运营前10年垃圾降解对孔隙度作用较明显,孔隙度呈线性增大,随后增大幅度减缓,达到峰值后逐渐减小,减小过程主要受垃圾沉降作用影响;不同成分的有机质含量对孔隙度的影响也存在差异;受有机质降解作用的影响,填埋约为190个月时固有渗透率可达到1.4 10-12 m2,Dg/D0可达到0.178。因此,开展填埋场沉降和生物降解作用下孔隙度的预测研究,对于评价填埋气体的有效控制以及填埋场安全指标体系的完善都具有重要的现实意义。 相似文献
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城市生活垃圾填埋场沉降监测与分析 总被引：3，自引：0，他引：3
2006年9月起于上海老港填埋场开展了示范工程沉降监测项目。该生活垃圾填埋场占地面积约为200 m×125 m,共填埋了约15×104 t来自上海城区的生活垃圾,最大填埋厚度约为9 m。通过填埋期间埋设的水平沉降管,监测到该填埋场不同埋深处的沉降值。介绍了沉降监测系统的工作原理,分析了2006年底至2008年底为期两年的沉降数据。填埋场底部沉降管监测数据表明,场底地基沉降较小,两年的平均沉降为 ～ cm;中部沉降管监测数据表明,该沉降管下方生活垃圾在上方垃圾填埋后产生了较大的压缩,从上方垃圾开始填埋至填埋完毕3个月内的压缩应变约为0.197～0.242;顶部沉降管和中部沉降管监测数据表明,该填埋场垃圾主压缩完成时间约为3个月;由于填埋垃圾有机物含量较高,其修正次压缩指数较大,约为0.066～0.070。 相似文献
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考虑有机物降解的变形试验和计算方法研究 总被引：2，自引：1，他引：1
垃圾土变形中有机物降解是一个非常重要的因素,又是很复杂的过程。进行了温度与湿度小范围波动、无压力、持水率条件下有机物降解的质量跟踪试验和垃圾土柱沉降试验,且在质量跟踪试验中还进行了淋滤液产生量的同步测定,分析了有机物降解的质量变化、质量变化速率的规律,初步明确了有机物降解的规律性结论。在质量跟踪试验的基础上,初步提出了有机物降解随时间变化规律的数学表达和3个基本计算参数的确定方法,计算结果与试验结果比较接近。用质量跟踪试验的研究结果对垃圾土柱试验进行了计算模拟,分别计算和分析了次压缩和有机物降解沉降随时间变化的过程。计算结果表明,在总的长期沉降中有机物降解引起的沉降比次压缩影响要大,考虑有机物降解和次压缩的计算结果与试验结果吻合较好。 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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地表水入渗对垃圾填埋场水质水量影响的数值模拟分析 总被引：3，自引：0，他引：3
将填埋垃圾视作一种特殊土体,建立了综合描述垃圾填埋场内渗滤液水分的饱和-非饱和渗流、垃圾土体沉降变形、有机污染物的释放、迁移、转化,以及微生物的生长、衰减等物理化学过程的多场耦合仿真分析模型,将任意的Lagrangian- Eulerian（ALE）方法引入到模型求解中,基于自行开发的仿真分析程序,开展了地表水入渗对垃圾填埋场水质、水量影响的数值仿真分析研究。模拟结果表明：300 d的非饱和水分入渗及内源水产生可使填埋单元内渗滤液饱和液面最高达6 m;地表水入渗对水相可溶性可降解有机物浓度和厌氧微生物浓度具有显著的影响,并间接地影响固相可溶性可降解有机物和微生物的浓度分布。 相似文献
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城市垃圾填埋场的沉降问题一直是长期困扰从事垃圾填埋研究工作者的一个非常重大的问题，它的解决对于提高垃圾场的潜在处理能力、增加填埋场的有效存贮容量有着十分重大的意义。本文首先分析了垃圾场的沉降原理，并给出了计算方法；而后应用灰色系统理论，对沉降实际数据进行处理，建立灰色动态GM模型，作出对填埋过程中和封顶后的沉降预测，取得了较好的效果。 相似文献
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城市生活垃圾填埋场地基沉降和垃圾堆体沉降受到的影响因素多,现行规范的计算方法直接采用与实际相差较大,为减少不均匀沉降对垃圾防渗层的影响、准确确定垃圾储量和保证垃圾堆体的稳定,开展垃圾填埋场沉降研究具有重要意义。垃圾填埋场沉降变形包括地基沉降和垃圾堆体沉降,垃圾堆体沉降又分为主沉降和次沉降,主沉降完成时间短于次沉降。通过对陕西省宝鸡市垃圾填埋场地基土进行沉降计算,最大沉降差超过100 mm,对垃圾防渗层不利影响较大;而对垃圾堆体沉降计算,修正后的计算值与沉降观测值非常接近。考虑不同地区地层差异和垃圾成分差异,积累沉降观测资料具有重要意义。 相似文献
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Bioreactor landfills are operated for rapid stabilization of waste, increased landfill gas generation for cost-effective energy
recovery, gain in landfill space, enhanced leachate treatment, and reduced post closure maintenance period. The fundamental
process of waste stabilization in bioreactor landfill is recirculation of generated leachate back into the landfills. This
creates a favorable environment for rapid microbial decomposition of the biodegradable solid waste. In order to better estimate
the generated leachate and design of leachate recirculation system, clear understanding of the permeability of the Municipal
Solid Waste (MSW) with degradation and the factors influencing the permeability is necessary. The objective of the paper is
to determine the changes in hydraulic properties of MSW in bioreactor landfill with time and decomposition. Four small-scale
bioreactor landfills were built in laboratory and samples were prepared to represent each phase of decomposition. Then, the
changes in hydraulic properties of MSW in bioreactor landfill with time and decomposition were determined. A series of constant
head permeability tests were performed on the samples generated in laboratory scale bioreactor landfills to determine variation
of permeability of MSW with degradation. The test results indicated that the permeability of MSW in bioreactor landfills decreases
with decomposition. Based on the test results, the permeability of MSW at the first phase of degradation was estimated as
0.0088 cm/s at density 700 kg/m3. However, with degradation, permeability decreased to 0.0013 cm/s at the same density, for MSW at Phase IV. 相似文献
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采用有代表性配比的人工配料垃圾土试样对瞬时模量变化规律进行了试验研究,结果表明：垃圾土有机质含量、初始含水率、初始孔隙比及降解程度的变化对瞬时模量都有影响,并得到了各影响因素下的变化规律。结合垃圾土自身特性对各因素影响机制及结果进行了分析,这些结论对未来的填埋场变形研究及工程设计是非常有意义的。 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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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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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