By Duane K. Miller

Many welds are evenly loaded: the applied loads are uniformly transferred through the throat and length of the welds. Such welds are easily designed and routinely perform as expected. Other welds, however, are unevenly loaded. One end of the length of the weld may be more severely loaded than the other, or the loading along the weld throat may be non-uniform. The design of these welded connections is more complicated.

By Kyle A. Karschner P.E., S.E., Jacob Sun, P.E., and Michael F. Hughes, P.E., S.E.

Building owners are turning to adaptive reuse of existing buildings to meet the market demand for alternative uses, such as life science, data, robotics, and other tech-related industries. These uses typically require upgrading the building’s mechanical, electrical, plumbing, and fire protection (MEP-FP) systems that use larger and heavier equipment than the building’s original structural design. As a result, this work can trigger costly structural upgrades for strength, serviceability, or both to comply with building code requirements.

By Timothy R. Donahue, P.E.

Generally speaking, for a given structure, the higher the seismic response factor (R) value is, the more ductile the structure is and the lower the total seismic load acting on the building. With this concept in mind, one might conclude that reducing the seismic load acting on a building by selecting a more ductile seismic force restraint system (SFRS) with a higher R value would ultimately lower the material cost; however, when evaluating the overall cost implications for what it takes to achieve the increased ductility, the cost savings may not always be realized. This is primarily due to the requirements of overstrength factors in the design and detailing of the straps and other protected components of the SFRS with an R greater than 3.