Environmental and climatic risk of degradation of network structures

该研究计划的总体目标是评估一组结构在不同气候条件下对公路网的环境影响。环境影响考虑退化、维护和恢复活动对气候变化、生态系统质量、人类健康和自然资源的影响。在土木工程结构中观察到的退化特别受加拿大领土上的气象和化学条件的影响。拟议的研究包括三个主要的科学阶段。第1阶段在国家、省和大城市级别建立三个典型网络。数据可以从气象站、加拿大不同地区路面上积极的药剂使用政策调查和交通流量中收集。可以在特定地点部署MeXStUL移动气象站。结构的暴露可以在地方一级对每个元素进行量化。第二阶段包括开发非线性模型，以评估结构因腐蚀而退化的情况，如TransChlor2DR。这个模型的优点是它考虑了第一阶段研究的结构元素的真实暴露。它计划在这个模型中加入其他病理因素。阶段3包括对在阶段1中选择的结构使用非线性模型。条件在两个水平上进行评估，即结构的安全性和适用性水平，以及在两个尺度上，即构件和整体结构。使用结果树的分析允许我们从每个元素获得结构的全局评级，考虑到整个结构中每个元素的脆弱性。阶段4包括考虑结构维护和更换的历史或情景，并以时间方式评估网络指数。该网络指数考虑了网络的脆弱性，例如某些结构的完全或部分关闭、绕行以及对用户的影响(拥塞、时间损失等)。这一指数与生命周期分析中确定的成本和环境因素相结合，如气候变化、生态系统质量、人类健康和自然资源。然后对这些数据进行优化分析。结构的可持续性是这些结构所有者的优先事项，网络保护活动的时间安排是基于当地标准和有限的预算。这个项目超越了业主通常的经济野心，因为它允许在几个规模、元素、结构和一个全新的网络上整合决策。此外，这项研究整合了可持续发展工具，因为除了经济部分外，还将整合环境部分，为决策者打开一个新的政治视角，这也将是这一决策的新概念的开始。

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.