Bridges are among the oldest structures used by mankind. From meeting purely utilitarian necessities, bridges have evolved with time to become symbols of human progress, of cities and entire countries. Among the thousands of bridges around us are the bridges that we all admire, the bridges that are the symbols of the eternal human aspiration for building longer and taller, stronger and faster. …
The intent of this 3-part series is to expand the engineer’s understanding of the realities and opportunities in fatigue and fracture design. After reading this segment, the reader may have more questions than answers. This is not because the reader will not learn anything, but because they will better know the questions they should be asking. …
This article discusses Federal Laws, Executive Orders, Building Codes and Standards that apply to the seismic design of nonstructural building components. It highlights various aspects of the seismic design requirements. The discussion is not all-inclusive; however, it does include requirements that are either new or commonly overlooked. References to specific nonstructural building components and seismic sway brace components are provided as examples. …
Increased availability of cross-laminated timber (CLT) in North America, combined with successful use in projects worldwide, has generated interest in its properties and performance within the U.S. design community. With the inclusion of CLT in the 2015 International Building Code (IBC) and 2015 National Design Specification® (NDS®) for Wood Construction, curiosity is evolving, with some developers, architects and structural engineers using CLT in projects. …
Recent fatalities associated with failed structural building elements have generated discussion about actual causation and whether building code changes are required. These failures have also increased the demand for architectural and structural inspections on similar existing elements.
The authors are consultants who frequently forensically diagnose alleged construction defect claims. Clients are typically developers, designers, contractors, insurance agencies, attorneys, manufacturers or building owners. This background provides a unique perspective on the relative risk to the structural engineer. …
Historically, reinforced concrete has been thought of as very forgiving when it comes to the amount of time the material performs in service. Although there is a lot of truth to this, the environment inevitably can shorten reinforced concrete’s life expectancy, resulting in costly repairs and disruption to everyday life. …
The perimeter of parking garages, and the edges of split ramps in the interior of parking garages, are required to have barriers, restraints or guardrails to stop the vehicles inside the structure from plunging down. The design and detailing of the perimeter walls has been a concern to public safety. The author has published three articles in STRUCTURE magazine on the subject calling for a rational design method for vehicular barrier systems. …
You may remember the days when Quality Assurance meant a simple review by the Engineer-of-Record immediately before sealing the drawings. That seal alone was the documented evidence of quality. Clients hired engineers for their expertise and expected them to get it right the first time. It was up to the engineers to develop habits (often unwritten) to ensure the quality of their work. …
Structural engineers have a peculiar vocabulary, when you think about it. What we call “stress” is not much like what psychologists call “stress”. What we call “strain” is not what the spectators think about when watching a weight lifting match. And when we ask what the moment is, a confused general public thinks that in our own strange way we are asking what time it is. …
A new method has been developed for measuring the force of ground shaking during earthquakes at particular locations. The proposed Earthquake Shaking Force (EqSF) rating is based on the maximum vector sum of the recorded ground accelerations in the three main directions scaled with the strong ground motion duration. …