Probabilistic assessment of the vulnerability of buildings in seismic regions

风险评估和减轻潜在的自然灾害是大多数加拿大城市面临的关键问题。这些任务需要准确预测危险和仔细评估建筑物的脆弱性，尽管存在不确定性。从技术上讲，灾害可以定量地描述为“特定地区发生特定强度事件的可能频率”，而脆弱性可以定义为“增加社区对灾害影响的敏感性的物理、社会、经济和环境因素或过程所决定的条件。“在自然灾害中，地震是加拿大某些地区特别重要的灾害。地震风险管理需要能够量化地震负面影响的风险分析。理想的情况是，这种分析应包括一个对影响进行概率量化的过程。为了更好地评估这些风险，本项目旨在开发一个损害模拟器，将评估地震危险区内发现的建筑物的脆弱性。该模拟器的开发需要一个相当精确的三维地质模型，适当的地震小区划的领土，现有的基础设施和建筑物的适当的脆弱性评估。 该研究项目的第一步是开发该领土的三维地质模型，为确定区域地震危险提供基础。该模型应包括多个变量，包括表层存款层的厚度和类型，基岩的深度和类型，以及地下水位。以魁北克的Charlevoix-Haute-Escherte-Nord地区为例，将建立一个表层沉积物的三维模型，通过该模型，我们将能够确定与根据该地区密度不同的现有数据估计表层沉积物厚度相关的不确定性的影响。第二个步骤是根据Charlevoix-Haute-Escherte-Nord地区的现有数据和作为该项目一部分进行的一些新的实地测量，对区域地震危险进行小区划。已经提出了多种方法来确定土壤剪切波速度，所有这些方法都受到不确定性的影响。项目的这一部分将侧重于确定土壤类别和地震风险小区带时地震剪切波速度（Vs）的不确定性的影响。第三步将根据建筑物易损性函数及其区域建筑物类型的不确定性，开发一个损害模拟器，其中包括评估灾害和易损性的应用方法。概率方法可以解释与地震相关的可变破坏水平和每种地震情景发生的概率。这种损害模拟器将成为参与管理地震风险的不同行为者的决策支持工具。

Risk assessment and mitigation of potential natural hazards are critical issues facing most Canadian cities. These tasks require both an accurate prediction of the hazard and a careful evaluation of the vulnerability of buildings despite existing uncertainties. In technical terms, a hazard can be described quantitatively as "the likely frequency of occurrence of an event of a specific intensity in a given area," whereas vulnerability can be defined as "the conditions determined by physical, social, economic, and environmental factors or processes that increase the susceptibility of a community to the impact of hazards." Among natural disasters, earthquakes represent a particularly important hazard in certain regions of Canada. Seismic risk management requires a risk analysis that can quantify the negative impacts of an earthquake. Ideally, this analysis should include a process for the probabilistic quantification of impacts. To better assess these risks, this project aims to develop a damage simulator that will assess the vulnerability of buildings found within seismic hazard area. The development of this simulator requires a fairly exact 3-D geological model, an adequate seismic microzonation of the territory, and an appropriate vulnerability assessment of existing infrastructure and buildings. The first step of the research project involves developing a 3-D geological model of the territory that provides the basis for establishing regional seismic hazards. This model should include multiple variables including the thickness and the type of surficial deposit layers, the depth and type of bedrock, and groundwater levels. Using the Charlevoix-Haute-Côte-Nord region of Quebec as a case study, a 3-D model of surficial deposits will be produced from which we will be able to determine the effect of uncertainties associated with estimating the thickness of surficial deposits from available data that varies in density across the region. The second step is the microzonation of regional seismic hazards based on existing data for the Charlevoix-Haute-Côte-Nord region and some new field measurements carried out as part of this project. Multiple methods have been proposed for determining the soil shear wave velocity; all these methods are affected by uncertainties. This part of the project will focus on the effects of uncertainty vis-à-vis seismic shear wave velocity (Vs) in determining soil classes and seismic risk microzonations. Based on a building vulnerability function and its uncertainties for the regional building types, the third step will develop a damage simulator that incorporates the applied methodologies for assessing hazard and vulnerability. A probabilistic approach can account for both the variable levels of damage associated with earthquakes and the probability occurrence of each seismic scenario. This damage simulator will represent a decision-support tool for the different actors involved in managing seismic risks.