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

土工膜本质上是一大片塑料，可为城市固体废物填埋场、危险废物填埋场和流体石油/矿物开采设施中包含的各种污染物提供卓越的环境保护，包括碳氢化合物、重金属和氰化物污染的水域、高酸性水域、水力压裂液等。目前的安装指南侧重于确保安装时的焊缝完整性。然而，焊接过程也会影响与焊缝相邻的土工膜(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定应力的影响。即使是在250米x 110米的相对较小的设施中，热影响区的长度也超过4000米。在安装后几周至几个月内，在靠近焊缝的这一区域观察到故障；特别是当安装在加拿大冬季常见的非常寒冷的环境条件下进行时。该项目旨在了解焊接时寒冷的环境条件和不同的焊接参数如何相互作用来影响土工膜的性能及其对过早损坏的敏感性。皇后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了一个框架，从而提供更有效和可靠的地下水和地表水保护。与领先的加拿大土工膜安装公司的合作将确保实验条件反映常见的现场条件，并确保研究成果应用于行业应用。这项研究将涉及两名HQP的培训。

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.