Limiting local tensions in landfill geomembranes

加拿大每年产生大约3000万吨固体废物（StatsCan 2005）。尽管减少、再利用和再循环废物的努力取得了切实的成果，但在可预见的将来，加拿大人将继续要求在垃圾填埋场安全处置城市和工业固体废物。土工膜（薄薄的塑料片）覆盖在低渗透性粘土上，构成屏障系统，用于填埋填埋场的底部。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）向周围环境的逸出来防止地下水污染。长效土工膜是确保长期环境保护的关键。当土工膜被埋在大量废物下时，其物理反应直接影响到它的持续时间，特别是土工膜上覆盖的砾石颗粒可能产生的局部张力。将设计和进行物理实验，并将开发和应用数值分析来防止土工膜因填埋土工膜的局部张力而破裂。由于局部张力取决于塑料膜、周围土壤、废物量、温度和时间，因此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。该研究建立在申请人解决涉及环境应用中使用的埋藏聚合物结构问题的良好记录之上。4名博士生和5名硕士生将接受为期5年的高级培训。由于地下水污染，填埋场屏障系统过早失效可能对社会、环境和健康造成重大的长期影响，因此拟议的研究将改善土工膜衬垫的长期物理性能，并将使加拿大的垃圾填埋场受益，从而提供更大的长期环境保护。

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.