Warming and its effects on foundations for northern infrastructure

加拿大北方的土木工程基础设施建设通常会移除植被，影响积雪，增加传热，改变排水模式，因此有助于永久冻土的融化。气候变暖也有助于永久冻土的融化。由于气候变暖或建筑活动导致的解冻可能会对建筑物、机场跑道、铁路路基、高速公路路基、河流交叉口和水电设施产生大的沉降和适用性问题。融化永久冻土和扩大基础设施系统需要改进设计、施工和维护。了解变暖土壤的应力-应变特性对于预测地基的性能以及随后减轻北方基础设施的地基破坏至关重要。 本研究将使用实验室测试方法来研究温度对土壤的机械、热和流动特性的影响。特别强调的是经常在加拿大北方发现的高塑性粘土和泥炭。科学家开发的气候变暖预测工具将用于预测地面温度及其对土壤特性和地基性能的影响。该研究将开发概念性数值模型，以模拟变暖对土壤性质的影响。实验室测试和数值模拟技术将被用作解释监测到的现场行为的手段。两个可用的仪器测试站点提供了一个现场性能数据库，并允许验证新开发的数值模型。 该研究将使用经过验证和微调的数值模型预测和减轻北方基础设施的过度变形和不稳定性。它将制定缓解措施，供今后的设计准则考虑，其中将包括受气候变化影响的基础设施的适应战略。这项研究对于气候变化对北方基础设施的“影响和适应战略”以及从北方向南方市场提供“清洁”能源具有重要意义和相关性。

Construction of civil engineering infrastructure in northern Canada usually removes vegetation cover, affects snow cover, increases heat transfer, changes drainage pattern, and therefore contributes to thawing of permafrost. Climate warming also contributes to thawing of permafrost. Thawing, either as a result of climate warming or construction activities, can produce large settlements and serviceability issues for buildings, airport runways, railway beds, highway embankments, river crossings, and hydroelectric facilities. Thawing permafrost and expanding infrastructure systems require improved designs, construction, and maintenance. Understanding the stress-strain characteristics of warming soils is essential in predicting the performance of foundations, and subsequently in mitigating failing foundations for northern infrastructure. This research will use laboratory testing methods to investigate the effects of temperature on mechanical, thermal, and flow properties of soils. Particular emphasis is placed on highly plastic clays and peats found frequently in northern Canada. Predictive tools in climate warming developed by scientists will be used in predicting ground temperatures and their effects on soil properties and foundation performance. The research will develop conceptual numerical models to simulate the warming effects on soil properties. Laboratory testing and numerical modeling techniques will be used as a means of explaining monitored field behaviour. Two available instrumented test sites provide a database of field performance and allow validation of the newly developed numerical model. The research will predict and mitigate excessive deformations and instabilities of northern infrastructure using validated and fine-tuned numerical models. It will develop mitigation measures for consideration in future design guidelines, which will include adaptation strategies for infrastructure impacted by climate change. This research is important and relevant for climate change 'impacts and adaptation strategies' for northern infrastructure and the delivery of 'clean' energy from northern to southern markets.