Reducing the Risks of Nonstructural Earthquake Damage

摘要

For commercial construction such as office buildings, hotels, and hospitals, the nonstructural components and contents typically represent 80-90% of the capital investment at risk during an earthquake. Not surprisingly, post-earthquake reconnaissance following recent earthquakes in the U.S. shows that the majority of losses are the result of damage to nonstructural components and contents. Many nonstructural components also represent a life safety risk to building occupants. Recent studies by EERI and FEMA have found that, with some notable exceptions, there is still relatively poor compliance with code provisions that address nonstructural components and most contents are not covered by code provisions; thus, most nonstructural components and contents remain vulnerable to earthquake damage. In order to improve compliance, these studies recommend better education regarding nonstructural hazards and effective design solutions, more detailed design aids to assist those responsible for designing nonstructural restraints, and clarification of the parties responsible for the design and construction of nonstructural seismic restraints. FEMA E-74, Reducing the Risks of Nonstructural Earthquake Damage -A Practical Guide, has been recently revised and published as an electronic document and is intended to help improve compliance with nonstructural restraint requirements. FEMA E-74 explains the sources of nonstructural damage and provides practical methods for reducing the potential risks by providing extensive visual information in the form of photographs of earthquake damage to nonstructural components and contents, photos of properly installed nonstructural restraints, and drawings and details of appropriate nonstructural restraints. The updated edition includes illustrated mitigation examples for 50 nonstructural items as well as an example seismic code block now in use in some jurisdictions to define design responsibility for nonstructural restraints.