Long-term performance of geosynthetic barrier systems for groundwater protection

土工合成屏障系统用于大多数垃圾填埋场（占加拿大固体废物的68%），受污染的液体泻湖和许多采矿应用（例如，堆浸垫、尾矿储存设施;使用280，000，000平方米/年的土工膜），其中必须尽量减少污染流体向地表水或地下水的流失。历史上，该系统通常涉及单个复合衬垫，其具有在1 cm厚的土工合成粘土衬垫上的1.5 mm厚（塑料）土工膜衬垫的焊接面板（以减少通过土工膜中的孔的泄漏），并且过去的研究集中在这种情况下。 目前已知，单衬层仅适用于低风险项目，在两个复合衬层之间具有土工复合排水管的双系统通常用于大型垃圾填埋场或其他高风险应用。这些系统通常被期望限制污染物逸出（即，使用寿命在某些资源回收应用中为数十年，在大型垃圾填埋场中为数百年，在某些矿山废物中为数千年。目前，实际上还不知道化学相互作用或施加的载荷对复合材料衬里泄漏或双复合材料衬里系统的使用寿命的影响。这项研究代表了一个全新的调查领域，将是第一次研究这些问题。该研究利用了最近的研究突破，并采用了一种新的研究策略，考虑了双复合衬垫屏障系统的所有组件之间的相互作用，包括老化对二次排水层（土工复合排水）中流量的影响。它是独特的，新颖的和创新的新技术和设备正在开发，以检查这些关键系统的性能随时间的变化，不能修复或更换，如果他们失败。这项工作预计将导致关键底部衬垫的设计和施工的范式转变，这可能会导致通常使用的土工膜和排水层的完全改变。 它将对人类健康和环境产生深远的影响，因为它提供了：（一）对控制单、双复合衬里系统长期性能的过程的新的基本科学见解;（二）对使用寿命的科学估计;（三）垃圾填埋场和采矿应用屏障系统设计的新准则，及（iv）为21世纪世纪提供环境保护的法规提供科学依据。 这项研究将使加拿大设计顾问、监管机构、制造商、土工合成材料安装商、设施所有者/运营商、原住民和公众受益，他们都将能够更多地依赖这些屏障系统，并提高加拿大在环境可持续发展方面的国际竞争力和声誉。该研究将教育8名博士，2名硕士和5名本科生。

Geosynthetic barrier systems are used in most landfills (taking 68% of Canadian solid waste), contaminated fluid lagoons, and many mining applications (eg. heap leach pads, tailings storage facilities; using 280,000,000 m2/yr of geomembrane) where loss of contaminated fluid to surface or ground water must be minimized. Historically, this system has often involved a single composite liner with welded panels of a 1.5mm thick (plastic) geomembrane liner over a 1 cm thick geosynthetic clay liner (to reduce leakage through holes in the geomembrane) and past research has focused on this case. It is now known that a single liner is only suitable for low risk projects and a double system with a geocomposite drain between two composite liners is routinely being used for large landfills or other higher risk applications. These systems are typically expected to limit contaminant escape (ie. have a service-life of) from many decades in some resource recovery applications, to centuries for large landfills, to millennia for some mine waste. At present, virtually nothing is known about the effect of chemical interaction or applied loads on leakage through composite liners or the service-life of double composite liner systems. This research represents a completely new area of investigation and will be the first to ever examine these issues. The research capitalizes on recent research breakthroughs and adopts a new research strategy for considering the interactions between all components of a double composite liner barrier system including the effects of aging on flow in a secondary drainage layer (geocomposite drain). It is unique, novel & innovative in terms of the new techniques & equipment being developed to examine the time-dependent change in the performance of these critical systems which cannot be repaired or replaced if they fail. This work is expected to result in a paradigm shift in the design and construction of critical bottom liners that will likely result in complete change in the geomembranes and drainage layers typically used. It will have a profound impact on human health and the environment by providing: (i) new fundamental scientific insights into the processes controlling long-term performance of single and double composite liner systems; (ii) science-based estimates of service-life; (iii) new guidelines for the design of barrier systems for landfills and mining applications, & (iv) a scientific basis for 21st Century regulations to provide environmental protection. The research will benefit Canadian design consultants, regulators, manufacturers, geosynthetics installers, facility owners/operators, First Nations, and the general public who will all be able to place greater reliance on these barrier systems and enhance Canada's international competitiveness and reputation for environmentally sustainable development. The research will educate 8 PhD, 2 MASc & 5 undergraduate students.**