Evaluation of Lateral Earth Pressure Coefficients for Municipal Solid Waste

城市固体废物侧向土压力系数评估

• 批准号: 0556402
• 负责人: Edward Kavazanjian
• 金额: --
• 依托单位: Arizona State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-04-15 至 2008-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0556402&HistoricalAwards=false
• 关键词: Evaluation; Lateral; Earth; Pressure; Coefficients

ABSTRACTIn this project, laboratory testing will be conducted using unique large scale waste testing equipment to evaluate at rest, active, and passive lateral earth pressures in municipal solid waste (MSW). The magnitude of lateral earth pressures in municipal solid waste (MSW), including active, passive, and at-rest pressures, and the factors that influence these lateral pressures are largely unknown, despite their importance to a broad range of design problems. The lack of information on MSW lateral stresses affects not only design of landfill structures but also the evaluation of MSW shear strength, and hence landfill stability. To address this knowledge gap, at rest, active, and passive earth pressures will be measured on 0.75 m-long, 0.2 m-wide, 0.22 m-tall reconstituted specimens using a new lateral pressure measurement device. Lateral pressures will also be measured in simple shear tests on 0.45 m diameter specimens. The lateral pressure tests will provide lateral earth pressure coefficients for MSW as a function initial density, maximum particle size, and confining pressure. The testing program will also yield data on the development and evolution of normal stresses in simple shear testing. Interpretation of the data will provide insight as to how MSW shear strength and lateral stresses depend on stress state and compositional factors, including fibrous reinforcement and degradation of the MSW. Synergies between this testing program and previous testing programs will provide additional valuable fundamental information on the mechanical behavior of MSW, including important new insights on stress strain behavior, anisotropy, the influence of waste composition, and the influence of initial density.Broader impacts of the proposed test program include more economical and more protective landfill containment system design, an enhanced understanding of the potential impacts of waste pre-processing and waste degradation on shear strength and lateral earth pressures, more cost effective methods for increasing landfill capacity, improved landfill remediation strategies, and improved engineering methods for post-closure development on landfills using deep foundations. An enhanced understanding of waste shear strength will enable more accurate evaluation of landfill stability, providing for safer designs and possibly allowing for increased capacity at some sites, extending the life of facilities and thus minimizing the need for new sites. Enhanced understanding of the lateral stresses can also help identify conditions that impact liner integrity. The information developed in this research program will also help address the implications of the emerging technologies of bioreactors and waste pre-processing on the engineering behavior of the waste. The lateral pressure coefficients developed in this study will be invaluable in designing retaining wall system for vertical expansion of landfills, for landfill remediation, and for landfill closure design. This work will also facilitate post-closure landfill development for beneficial reuse of old landfills, as piles supporting buildings on top of closed landfills must carry the downdrag loads from the settling waste and lateral pressure coefficients as well as waste shear strength estimates are required to estimate downdrag.

摘要在这个项目中，实验室测试将进行使用独特的大型垃圾测试设备，以评估在休息，主动和被动的侧向土压力在城市固体废物（MSW）。 城市固体废物（MSW）的侧向土压力的大小，包括主动，被动和静止的压力，以及影响这些侧向压力的因素在很大程度上是未知的，尽管它们的重要性，广泛的设计问题。 缺乏关于垃圾侧向应力的信息不仅影响填埋场结构的设计，而且影响垃圾剪切强度的评估，从而影响填埋场的稳定性。 为了解决这一知识差距，在休息，主动和被动土压力将测量0.75米长，0.2米宽，0.22米高的重组标本使用一种新的侧压力测量设备。 还将在直径为0.45 m的试样上进行简单剪切试验，测量侧压力。 侧压力试验将提供MSW的侧土压力系数，作为初始密度、最大粒径和围压的函数。 测试程序还将产生简单剪切测试中正应力的发展和演变的数据。 数据的解释将提供洞察力如何城市固体废物剪切强度和横向应力取决于应力状态和成分因素，包括纤维增强和降解的城市固体废物。 本测试项目与以往测试项目的协同作用将为城市固体废物的力学行为提供更多有价值的基本信息，包括对应力应变行为、各向异性、废物成分的影响和初始密度的影响的重要新见解。拟议测试项目的更广泛影响包括更经济和更具保护性的填埋场控制系统设计，提高对废物预处理和废物降解对剪切强度和侧向土压力的潜在影响的认识，采用更具成本效益的方法增加填埋场容量，改进填埋场补救战略，改进填埋场关闭后利用深层地基进行开发的工程方法。 加强对废物剪切强度的了解将有助于更准确地评估填埋场的稳定性，提供更安全的设计，并可能增加某些场地的能力，延长设施的寿命，从而尽量减少对新场地的需求。 加强对横向应力的了解也有助于确定影响内衬完整性的条件。 在这项研究计划中开发的信息也将有助于解决生物反应器和废物预处理的新兴技术对废物工程行为的影响。在这项研究中开发的侧压力系数将是非常宝贵的设计挡土墙系统的垃圾填埋场的垂直扩展，垃圾填埋场修复，垃圾填埋场关闭设计。 这项工作也将促进关闭后的垃圾填埋场的发展，有益的旧垃圾填埋场的再利用，因为桩支撑建筑物的顶部关闭的垃圾填埋场必须进行下拉负荷从沉降废物和侧压力系数以及废物剪切强度估计需要估计下拉。