Traditional timber roof structures: Seismic vulnerability assessment and preservation

The assessment of the seismic vulnerability of structures is the first step in the decision process toward conservative strengthening interventions.Amethodology for assessing the seismic vulnerability of timber roof structures is proposed here. Among the elements considered in the process are the conceptual design of the structure, the type and state of the timber-to-wall connection, the type and quality of timber carpentry joints, and the general state of conservation. A series of dynamic and spectral analyses performed for different structural typologies, with geometrical data collected from real cases, constitute the basis for evaluating the effect of conceptual design on vulnerability. The vulnerability of carpentry joints is evaluated from their ability to maintain connection during alternate excitation and from their expected post elastic behavior. The paper presents a general outline of the method and analyzes in detail some of the evaluation elements.