NEESR-CR: Seismic Response of Landfills: In-Situ Evaluation of Dynamic Properties of Municipal Solid Waste, Comparison to Laboratory Testing, and Impact on Numerical Analyses

该奖项是NSF 09-524项目征集的结果。小布朗地震工程模拟网络（NEES）研究（NEESR）”竞赛，包括密歇根大学（牵头机构）、洛杉矶的加州州立大学（副奖）和Geosyntec咨询公司（副奖）。该项目将利用德克萨斯大学奥斯汀分校的NEES设备场地。每年产生的越来越多的城市固体废物（MSW）大部分都被填埋。现代（自20世纪90年代以来）MSW垃圾填埋场是环境敏感的，复杂的设施，大小与大型水坝相似。最近的美国地震（如1994年北岭地震）突出了MSW填埋场的潜在地震脆弱性。摇晃时过度移动可能会损坏垃圾填埋场？的遏制或覆盖系统或导致稳定性故障。这种失败对环境的影响可能是毁灭性的。利用城市固体废物的准确和有代表性的动力特性是可靠的地震工程分析和设计的要求，但我们对城市固体废物的动力特性的理解是初步的和缺乏的。该项目的智力价值在于首次使用NEES@UT提供的T-Rex移动的振动筛评估MSW的原位非线性动态特性。移动的振动筛是一种安装在卡车上的高容量振动筛，可以在废料中产生显著的循环应变。加速度计用于记录振动筛附近深处的废物质量的加速度，并得出废物材料的动态特性。使用霸王龙的测试将在四个地点进行，在四个精心挑选的城市固体废物填埋场（一个在得克萨斯州，三个在加州的高地震活动地区），重点是记录城市固体废物的变化和捕获因素，如年龄，降解和水分含量的影响。随后，将挖掘测试坑，收集废料，并在密歇根大学的大型实验室测试设施和洛杉矶的加州州立大学的较小规模测试设施中进行测试。实验室测试将使调查人员能够研究影响废物动态特性的各种因素（例如围压、密度、成分），并将结果与实地测试进行比较。将进行数值分析，以评估垃圾填埋场的抗震性能，并提供建议，用于抗震设计。 这项调查有可能改变地震工程实践中的垃圾填埋场设计提供了一种新的方法，现场测试的固体废物，验证大规模的实验室测试的城市固体废物的适用性，产生急需的现场和实验室数据，并制定推荐的方法，城市固体废物填埋场的地震分析的性能。 该项目更广泛的影响是地震地区城市固体废物填埋场的设计更安全，更可靠。该项目还将通过积极让本科生和高中生参与研究和指导活动来整合研究和教育。计划在一个垃圾填埋场举行的示范和学习活动期间向更广泛的高中生和社区进行宣传。这项研究将为至少一个博士学位提供基础。论文（在密歇根大学），并将促进主要研究和主要教学机构之间的合作。 还概述了向技术界广泛传播数据和研究成果的综合计划。该项目的数据将通过NEES数据库存档并向公众提供。 该奖项是国家减少地震灾害计划（NEHRP）的一部分。

This award is an outcome of the NSF 09-524 program solicitation ''George E. Brown, Jr. Network for Earthquake Engineering Simulation (NEES) Research (NEESR)" competition and includes the University of Michigan (lead institution), California State University in Los Angeles (subaward) and Geosyntec Consultants (subaward). This project will utilize the NEES equipment site at the University of Texas at Austin.The increasing amounts of municipal solid waste (MSW) generated every year are, in their majority, landfilled. Modern (since the 1990s) MSW landfills are environmentally sensitive, sophisticated facilities and are similar in size to large dams. Recent U.S. earthquakes (e.g. 1994 Northridge Earthquake) highlighted the potential seismic vulnerability of MSW landfills. Excessive movement during shaking may damage the landfill?s containment or cover system or cause stability failures. The impact of such failures on the environment can be devastating. The use of accurate and representative dynamic properties of Municipal Solid Waste is a requirement to reliable seismic engineering analyses and design, but our understanding of the dynamic properties of MSW is rudimentary and lacking. The intellectual merit of this project is in evaluating, for the first time, the in-situ nonlinear dynamic properties of MSW using the T-Rex mobile shaker available at NEES@UT. The mobile shaker is a truck mounted, high capacity shaker that can induce significant cyclic strains in the waste material. Accelerometers are used to record the accelerations of the waste mass at depths in the vicinity of the shaker and derive the dynamic properties of the waste material. Testing using T-Rex will be performed at four locations, at four carefully selected MSW landfills (one in Texas and three in areas of high seismicity in California) with emphasis on documenting the variability of MSW and capture factors such as effect of age, degradation and moisture content. Subsequently, test pits will be excavated and waste material will be collected and tested in large-scale laboratory testing facilities at the University of Michigan and smaller scale testing facilities at California State University in Los Angeles. The laboratory tests will allow the investigators to study the various factors (e.g. confining stress, density, composition) that affect the dynamic properties of waste and compare the results with the field testing. Numerical analyses will be performed to evaluate the seismic behavior of landfills and provide recommendations for use in seismic design. This investigation has the potential to transform seismic engineering practice in landfill design by providing a new methodology for field testing of solid waste, validating the applicability of large-scale laboratory testing of MSW, generating much needed field and laboratory data, and developing recommended methodologies for the performance of seismic analyses of MSW landfills. The broader impact of this project is the safer, more reliable, designs of Municipal Solid Waste landfills in seismic regions. The project will also be integrating research and education by actively involving undergraduate and high school students in research and mentoring activities. Outreach to a broader population of high school students and the community is planned during a demonstration and learning event at a landfill site. The research proposed will provide the basis for at least one Ph.D. dissertation (at U-M) and will promote collaboration between primarily research and primarily teaching institutions. A comprehensive plan for broad data and research results dissemination to the technical community is also outlined. Data from this project will be archived and made available to the public through the NEES data repository. This award is part of the National Earthquake Hazards Reduction Program (NEHRP).