Environmental and climatic risk of degradation of network structures

点击翻译按钮获取中文摘要

The overall objective of the research program is to evaluate the environmental impact of a group of structures on a road network under different climatic conditions. The environmental impact considers the influence of degradation, maintenance, and rehabilitation activities on climate change, ecosystem quality, human health, and natural resources. The degradations observed in civil engineering structures are especially influenced by meteorological and chemical conditions in the Canadian territory. The proposed research consists of three major scientific phases. Phase 1 establishes three typical networks at the national, provincial, and large city levels. Data can be collected from weather stations, surveys of aggressive agent application policies on the pavement in various regions of Canada, and the amount of traffic. A MeXStUL mobile weather station can be deployed at specific sites. The exposure of structures can be quantified at the local level for each element. Phase 2 consists of pursuing the development of nonlinear models to evaluate the degradation of structures by corrosion, such as TransChlor2Dr. The strength of this model is that it considers the real exposure of a structural element studied in phase 1. It is planned to insert other pathologies in this model. Phase 3 consists of using a nonlinear model on the structures selected in phase 1. The condition is evaluated at two levels, namely, the structural safety and serviceability levels, and at two scales, the element and the overall structure. An analysis using consequence trees allows us to obtain a global rating of the structure from each element, considering the vulnerability of each element in the entire structure. Phase 4 consists of considering the history or scenarios of maintenance and replacement of the structure and to evaluate a network index in a temporal manner. This network index considers the vulnerability of the network, such as the complete or partial closure of certain structures, detours, and the impact on users (congestion, lost time, etc.). This index is combined with the costs incurred and environmental factors, as established in the life cycle analyses, such as climate change, ecosystem quality, human health, and natural resources. Optimization analyses will then be performed on these data. The sustainability of the structures is a priority for the owners of these structures, and the timing of the network preservation activities is based on local criteria and a limited budget. This project goes beyond the usual economic ambitions of the owners because it allows the integration of a decision on several scales, elements, structures, and a completely new network. Moreover, this research integrates sustainable development tools because in addition to the economic part, the environmental part will be integrated, allowing the opening of a new political perspective for the decision makers, which will also be the beginning of a new conception of this decision-making.