Etude du comportement sismique de batiments industriels avec systemes de contreventement en acier de faible ductilite.

摘要

Steel framed industrial buildings generally have performed well in recent earthquakes. Most of the reported structural damage in these buildings has been limited to the failure of individual components such as bracing members or connections, not to structural collapse. Despite this overall satisfactory structural performance record, structural and non-structural damage in past seismic events has resulted in disruption of operations in several industrial plants. Industrial buildings can house a wide variety of manufacturing, assembly, refining mining or material handling processes, covering a broad range of products. They may also be used in critical facilities such as power plants and communication systems. Downtime periods may therefore have detrimental economical and social consequences, including unemployment and loss of revenues for the industry, or shortage of goods, electrical power and communications. Some buildings also serve for the production or storage of hazardous materials, which can pose a major risk in the case of leakage or of operational malfunction resulting from an unsatisfactory seismic structural response.;The objective of the research presented in this thesis is to verify if the current design code provisions ensure an adequate seismic performance of industrial buildings. This is an exploratory project aiming to improve the knowledge of the seismic problem in this type of structure and to identify issues to be investigated in further research. The results of this project should also be used to propose recommendations relative to the analysis and design of industrial buildings. This project includes analytical studies and experimental tests.;The analytical part of the research is conducted on two steel industrial buildings selected to represent a significant number of real structures which are designed according to common practices as conventional construction. The first building is a crane-supporting structure and the second one is a heavy industrial building housing a vertical mechanical process and characterized by structural irregularities of mass, geometry and torsional sensitivity. The seismic behaviour of the two selected buildings is determined using different methods. A comparison is made of the responses estimated by the equivalent static forces and response spectrum methods with those obtained by elastic time-history analyses. The results show that the methods recommended by the codes are generally conservative despite the dynamic characteristics of the buildings studied. On the crane-supporting structure, the seismic inelastic demand under earthquake loading is also determined. The analyses indicate that inelastic response in this type of building is likely to develop in the form of buckling of the lower column segment, a failure mode that exhibits limited ductility. Finally, the use of anchor rod yielding in order to reduce the seismic loads induced in crane-supporting structures is assessed. This study shows the effectiveness of that kind of system to protect the lower column members.;The experimental part of the project aims to obtain data on the cyclic inelastic behaviour of large bracing members such as those used in industrial buildings. The tested specimens are characterized by their walls not meeting the slenderness criteria of the Canadian steel code (CSA S 16-01) to be used in bracing systems other than conventional construction category. The tests are used to determine the inelastic deformation capacity of such members and to demonstrate the effect of the wall slenderness on their cyclical behaviour. The experimental tests carried out show that the tested bracing members satisfy the seismic deformation demand anticipated for conventional construction.;Appropriate seismic design provisions for industrial buildings are therefore needed to achieve adequate performance. Unfortunately, current code seismic design requirements have been developed for conventional offices or residential buildings with regular and well-defined lateral force resisting systems, which are not representative of industrial buildings that typically have complex and irregular geometries, uneven mass and/or stiffness distribution. Applying these current code provisions to industrial buildings also poses difficulties to practicing engineers and can even leads to inappropriate designs.