The American Society for Testing and Materials (ASTM) is an independent organization devoted to the development of standards.

American Society for Testing and Materials

「脆弱性(Vulnerability)」とは何か

Social Vulnerability to Environmental Hazards

Minimum Design Loads for Buildings and Other Structures provides requirements for general structural design and includes means for determining dead, live, soil, flood, wind, snow, rain, atmospheric ice, and earthquake loads, as well as their combinations, which are suitable for inclusion in building codes and other documents. This Standard, a revision of ASCE/SEI 7-05, offers a complete update and reorganization of the wind load provisions, expanding them from one chapter into six. The Standard contains new ultimate event wind maps with corresponding reductions in load factors, so that the loads are not affected, and updates the seismic loads with new risk-targeted seismic maps. The snow, live, and atmospheric icing provisions are updated as well. In addition, the Standard includes a detailed Commentary with explanatory and supplementary information designed to assist building code committees and regulatory authorities. Standard ASCE/SEI 7 is an integral part of building codes in the United States. Many of the load provisions are substantially adopted by reference in the International Building Code and the NFPA 5000 Building Construction and Safety Code. Structural engineers, architects, and those engaged in preparing and administering local building codes will find this Standard an essential reference in their practice. Note: New orders are fulfilled from the second printing, which incorporates the errata to the first printing.

Minimum Design Loads for Buildings and Other Structures

Trees, and their derivative products, have been used by societies around the world for thousands of years. Contemporary construction of tall buildings from timber, in whole or in part, suggests a growing interest in the potential for building with wood at a scale not previously attainable. As wood is the only significant building material that is grown, we have a natural inclination that building in wood is good for the environment. But under what conditions is this really the case? The environmental benefits of using timber are not straightforward; although it is a natural product, a large amount of energy is used to dry and process it. Much of this can come from the biomass of the tree itself, but that requires investment in plant, which is not always possible in an industry that is widely distributed among many small producers. And what should we build with wood? Are skyscrapers in timber a good use of this natural resource, or are there other aspects of civil and structural engineering, or large-scale infrastructure, that would be a better use of wood? Here, we consider a holistic picture ranging in scale from the science of the cell wall to the engineering and global policies that could maximise forestry and timber construction as a boon to both people and the planet.

The wood from the trees: The use of timber in construction

Woodframe buildings have historically performed well during earthquakes primarily because of their high strength/stiffness to weight ratio. Even still, these structures possess the potential for significant damage and even collapse when exposed to very large earthquakes. New design techniques and advanced technologies can provide an alternative for improved building performance. The use of dampers and other seismic response modification devices is one such method being explored in earthquake engineering. In this paper, shape memory alloy (SMA) devices are investigated for the response modification of light-frame wood buildings during strong earthquakes. A numerical model for a suite of SMA wood shearwalls is developed based on existing data. The numerical models of the shearwalls are examined using incremental dynamic analysis at the single wall level. Design charts are developed for the shearwall models for a range of seismic weights and targeted performance levels. The wall database is then used...

Numerical Retrofit Study of Light-Frame Wood Buildings Using Shape Memory Alloy Devices as Seismic Response Modification Devices

Comparative Residential Property Loss Estimation for the April 25–28, 2011, Tornado Outbreak

Ground-truth measurements of damage caused by natural disasters are routinely used to determine which factors of the natural, built, and social environment contribute to losses from these e...

Discrete-Outcome Analysis of Tornado Damage Following the 2011 Tuscaloosa, Alabama, Tornado

Overhead sign support structures number in the tens of thousands throughout the trunk-line roadways in the United States. A recent two-phase study sponsored by the National Cooperative Highway Research Program resulted in the most significant changes to the AASHTO design specifications for sign support structures to date. The driving factor for these substantial changes was fatigue related cracks and some recent failures. This paper presents the method and results of a subsequent study sponsored by the Michigan Department of Transportation (MDOT) to develop a relative performance-based procedure to rank overhead sign support structures around the United States based on a linear combination of their expected fatigue life and an approximate measure of cost. This was accomplished by coupling a random vibrations approach with six degree-of-freedom linear dynamic models for fatigue life estimation. Approximate cost was modeled as the product of the steel weight and a constructability factor. An objective function was developed and used to rank selected steel sign support structures from around the country with the goal of maximizing the objective function. Although a purely relative approach, the ranking procedure was found to be efficient and provided the decision support necessary to MDOT.

Practical fatigue/cost assessment of steel overhead sign support structures subjected to wind load

This paper investigates collapse probability of steel buildings from mainshockaftershock sequences, as part of the ongoing research to develop a framework to integrate aftershock hazard into Performance-Based Engineering (PBE). During earthquake events, aftershocks can be observed following the mainshock. Aftershocks have the potential to cause severe damage to buildings and threaten life safety, even only minor damage is present from a mainshock. To date, the description of seismic hazard in PBE has not included the probability of aftershocks. Three approaches to generate collapse fragility for steel buildings that sustain certain level of damage from a mainshock are used to investigate the effects of mainshock-aftershock sequences. It is found that structural collapse capacity may reduce significantly when the building is subjected to a high intensity mainshock. As a result, the structure is likely to collapse even if only a small aftershock follows the mainshock.

John W. van de Lindt

Papers

Numerical Retrofit Study of Light-Frame Wood Buildings Using Shape Memory Alloy Devices as Seismic Response Modification Devices

Comparative Residential Property Loss Estimation for the April 25–28, 2011, Tornado Outbreak

Discrete-Outcome Analysis of Tornado Damage Following the 2011 Tuscaloosa, Alabama, Tornado

Practical fatigue/cost assessment of steel overhead sign support structures subjected to wind load

Consideration of Mainshock-Aftershock Sequences into Performance-Based Seismic Engineering