Abstract

Road infrastructures and bridge networks are becoming increasingly complex systems due to the development of technology in transportation engineering and the continual growth of urban communities. Infrastructure disservice due to seismic events may lead to unacceptable discomfort for commuters. Moreover, network downtime results into economic losses for the affected community, to be quantified in monetary terms by user costs. Seismically vulnerable bridges are also affected by aging and deterioration processes that can reduce the bridge structural performance over time. This paper presents a comprehensive life-cycle cost-based probabilistic framework for seismic risk assessment of spatially distributed aging bridge networks. The seismic risk measure is formulated in terms of annual exceedance rate of a target threshold of user costs. The methodology is applied to a road system in Lombardy region, Italy, reproducing network connectivity and daily travel demands among four major cities and smaller neighbouring municipalities. Despite the area of interest is characterized by low seismicity, the results allow to quantify the impact of aging and deterioration in exacerbating the network seismic risk, highlighting the need for a life-cycle-informed approach to optimal management of infrastructure systems.

抽象的

由于交通运输工程技术的发展以及城市社区的不断发展，道路基础设施和桥梁网络正变得越来越复杂。由于地震而导致的基础设施失灵可能导致通勤者无法接受的不适。此外，网络停机会给受影响的社区带来经济损失，用用户成本来量化。易受地震影响的桥梁也会受到老化和劣化过程的影响，这些过程会随着时间的推移降低桥梁的结构性能。本文提出了一种基于生命周期成本的综合概率框架，用于空间分布老化桥梁网络的地震风险评估。地震风险度量是根据用户成本目标阈值的年度超出率制定的。该方法适用于意大利伦巴第地区的道路系统，可在四个主要城市和较小的邻近城市之间再现网络连接和日常出行需求。尽管感兴趣的区域具有较低的地震活动性，但结果仍可以量化老化和恶化对加剧网络地震风险的影响，从而突出显示了需要以生命周期为依据的方法来优化基础设施系统的管理。