Limiting local tensions in landfill geomembranes

加拿大每年产生约3000万吨固体废物(统计数据，2005年)。尽管减少、再利用和回收废物的努力取得了实实在在的成果，但在可预见的未来，加拿大人将继续需要垃圾填埋场来安全处置城市和工业固体废物。由覆盖在低渗透粘土上的土工膜(一层薄塑料板)组成的屏障系统被用来衬砌垃圾填埋场的底部。屏障系统的目的是通过最大限度地减少有毒化学物质(如重金属和碳氢化合物)逃逸到周围环境中来防止地下水污染。持久的土工膜是确保充分的长期环境保护的关键。土工膜在掩埋在大量废物下时的物理反应直接影响到它能持续多久，特别是覆盖在沙砾颗粒下的土工膜可能产生的局部张力。将设计和进行物理实验，并开发和应用数值分析来防止由于垃圾填埋场土工膜局部张力而导致的土工膜破裂。由于局部张力取决于塑料薄膜、周围土壤、废物量、温度和时间，拟议的研究结合了岩土工程、土工合成工程和工程力学的必要元素。这项研究建立在申请人在解决环境应用中使用的埋藏聚合物结构问题方面的良好记录基础上。四名博士生和五名硕士研究生将在五年内接受高级培训。由于垃圾填埋场屏障系统过早失效可能会因地下水污染而导致重大的长期社会、环境和可能的健康影响，拟议的研究将改善土工膜衬里的长期物理性能，并将使加拿大人受益于提供更大长期环境保护的垃圾填埋场。

Around 30 million tonnes of solid waste is generated each year in Canada (StatsCan 2005). Despite tangible results from efforts to reduce, reuse and recycle waste, Canadians will continue to require landfills for the safe disposal of municipal and industrial solid waste for the foreseeable future. Barrier systems comprised of a geomembrane (a thin plastic sheet) overlying low permeability clay are used to line the bottom of landfills. The purpose of the barrier system is to prevent groundwater contamination by minimizing the escape of toxic chemicals (like heavy metals and hydrocarbons) into the surrounding environment. A long-lasting geomembrane is key to ensuring adequate long-term environmental protection. The physical response of the geomembrane when buried beneath large amounts of waste directly impacts how long it will last, especially the local tensions that can develop in the geomembrane from overlying gravel particles. Physical experiments will be devised and conducted, and numerical analyses will be developed and applied to prevent geomembrane rupture from local tensions in landfill geomembranes. As local tensions depend on the plastic membrane, the surrounding soil, the amount of waste, temperature and time, the proposed studies combine necessary elements from geotechnical engineering, geosynthetics engineering and engineering mechanics. This research builds on the applicant's strong track record of solving problems involving buried polymer structures for use in environmental applications. Four Doctoral and five Masters students will receive advanced training over five years. As premature failure of landfill barrier systems may result in substantial long-term social, environmental and possible health impacts as a result of groundwater contamination, the proposed research will improve the long-term physical performance of geomembrane liners, and will benefit Canadians with landfills that provide greater long-term environmental protection.