Soil-structure interaction and pre-failure deformation with reference to material degradation

在与基础设施相关的岩土工程中，土-结构相互作用问题是极其重要的，这些基础设施包括水坝、公路路面和市政设施，包括污水和供水管道。 虽然适当的设计可以将土壤强度不足导致的破坏风险降低到可接受的水平，但反复施加低于土壤强度的应力和/或环境变化引起的土壤退化可能会导致土壤累积变形，从而影响土壤上/土壤中建造的基础设施的功能。例如，由于反复的交通负荷和季节性环境变化（例如，湿度和温度）每年花费数百万美元来保持加拿大高速公路的良好状态。拟议的研究的主要目标是调查前失败的变形和退化的土壤受到（重复）的应力和环境变化，以及它们对功能的影响，建在土壤上的结构。这项研究包括土的特性和土-结构相互作用的试验研究和计算机模拟。将使用磁共振成像等图像技术测量和观察土壤性能的退化，同时将开发数字模型，模拟土壤退化引起的结构性能变化。所提出的研究是独特的，因为它占材料退化相关的循环荷载和环境变化时，分析土-结构相互作用。研究结果将为可靠和经济的结构设计以及受各种压力和环境条件影响的现有基础设施的修复提供有效的工具。这项工作将涉及研究生，他们将在课程结束时成为高素质的研究人员。

Soil-structure interaction problems in geotechnical engineering related to infrastructure, such as dams, highway pavements, and municipal utilities including sewage and water supply pipelines, are extremely important.  While appropriate designs reduce the risk of failure due to insufficient soil strength, to an acceptable level, a repetitive application of stresses lower than the soil strength and/or soil degradation induced by environmental change may induce accumulative deformation of the soil, and hence affect the function of infrastructure built on/in the soil. For example, degradation of granular base/subbase materials and subgrade soils owing to repetitive traffic loading and seasonal environmental change (e.g., moisture and temperature) costs millions of dollars every year to maintain Canadian highways in good condition. The main objectives of the proposed research are to investigate pre-failure deformation and degradation of soils subjected to (repetitive) stresses and environmental change, as well as their influence on the function of structures built on the soil. This research consists of both experimental study and computer modelling of soil behaviour and soil-structure interaction. Degradation of soil behaviour will be measured and visualized using image techniques such as Magnetic Resonance Imaging (MRI), while numerical models will be developed to simulate the variation of performance of structures induced by soil degradation. The proposed research is unique in that it accounts for material degradation related to both cyclic loading and environmental change when analyzing soil-structure interaction. The results will provide effective tools for reliable and economic design of structures as well as rehabilitation of existing infrastructure subjected to various stress and environmental conditions. The work will involve graduate students who will become highly qualified researchers at the end of the program.