Initial insights into the effect of geomembrane welding parameters on cold-climate welding

土工膜本质上是大片塑料，对城市固体废物填埋场、危险废物填埋场和流体石油/矿物提取设施（包括碳氢化合物、重金属和氰化物污染的水、高酸性水、水力压裂液等）中含有的各种污染物提供了优越的环境保护。土工膜通常通过将材料焊接在一起来安装。目前的安装指南主要是在安装时确保焊缝的完整性。然而，焊接过程也会影响焊缝附近的土工膜（称为热影响区或HAZ），该区域在焊接过程中会受到短期高温和一些应力的影响。即使是一个相对较小的250米× 110米的设施，热影响区的长度也超过4000米。在安装后几周到几个月，可以观察到焊缝附近区域的故障；特别是当安装在加拿大冬季非常寒冷的环境条件下进行时。该项目旨在了解焊接时的低温环境条件和不同的焊接参数如何相互作用，以影响土工膜的性能及其对过早失效的敏感性。女王大学拥有量化这些影响所需的独特专业知识和设备，并为改进安装实践提供框架，从而提供更有效和可靠的地下水和地表水保护。与加拿大领先的土工膜安装公司合作，将确保实验条件反映常见的现场条件，并将研究成果应用于工业应用。这项研究将包括培训两名HQP。

Geomembranes, which are essentially large sheets of plastic, offer superior environmental protection to various contaminants contained in municipal solid waste landfills, hazardous waste landfills, and fluids oil/mineral extraction facilities including hydrocarbon, heavy metals, and cyanide contaminated waters, highly acidic waters, fracking fluids, etc. Geomembranes are typically installed by welding sheets of material together. Current installation guidelines are focussed on ensuring weld integrity at the time of installation. However the process of performing the weld also affects the geomembrane adjacent to the weld (a region called the heat affected zone or HAZ) which is subjected to short term high temperature and some stress during welding. On even a relatively small facility of 250m x 110m, the length of heat affected zone exceeds 4000 m. Failures in this zone adjacent to the weld have been observed weeks to a few months after installation; especially when the installation was conducted in very cold ambient conditions common in the Canadian winter. This project seeks to understand how cold ambient conditions at the time of welding and different welding parameters interact to affect the performance of the geomembrane and its susceptibility to premature failure. Queen's University has the unique expertise and equipment necessary for quantifying these effects and provide a framework for improve installation practice and in so doing provide more effective and reliable groundwater and surface water protection. Collaboration with leading Canadian geomembrane installation company will ensure experimental conditions reflect common field conditions and that the research findings are applied to industry applications. The research will involve training of two HQP.