As recently as 25 to 30 years ago, the steadily increasing availability of concrete with compressive strengths above 6,000 psi had the industry’s rapt attention. Back then, in many regions, strengths this high were considered revolutionary. Some people even questioned the need. …
It is estimated that the concrete repair industry in the United States generates between 18 and 25 billion dollars per year in construction spending. Unfortunately, repairs that do not perform as intended, either due to poor design or execution, require “repairs to the repairs”, which form a substantial component of the total figure. …
After overcoming the initial growing pains (insufficient experience, track record, and knowledge overshadowed by overzealous euphoria with “magic” material capabilities), externally-bonded fiber reinforced polymer (FRP) systems have become one of the preferred technologies for repair and strengthening of concrete and masonry structures in the United States. …
Steel plate shear wall (SPSW) technology is advancing, making more wide-spread implementation of seismic force resisting systems possible. These stiff and ductile systems have had years of research that has demonstrated their excellent seismic performance, explored various details and configurations, and resulted in the design provisions in ANSI/AISC 341-10, where they are denoted special plate shear walls. The key principal for design is that yielding is expected in the web plates, at the beams ends and at the column bases. …
A completed tilt-up structure relies upon connections to the roof and floor diaphragms to transfer lateral loads to a lateral force-resisting system, such as shear walls or bracing. During construction, however, temporary wall bracing is needed to resist lateral forces. The most significant lateral force that most panels will experience is wind loading. …
The title of this article may seem like a trivial question, but it deals with an issue that in large measure might be overlooked. At first glance, one might think, “Of course not; gravity columns are designed for gravity, so why would I need to address the seismic provisions in Chapter 21 of ACI 318-11?” The answer is a simple matter of deformation compatibility, which ASCE 7-10 addresses for Seismic Design Categories (SDC) D through F in Section 12.12.5. …
Between September 20th and October 2nd of 1841, an estimated eighty thousand people visited the Third Charitable Mechanic Association Exhibition held in Boston’s Faneuil Hall and Quincy Market. …
On the subject of deferred submittals, let us touch on an issue relating to when an engineered design (containing a deferred submittal) is considered final. Virtually every building department requires an engineered set of plans to be stamped by the EOR as a condition of granting a building permit. This is often before any deferred submittal documents have been finalized and reviewed by the EOR and submitted to the building official for approval. …
Part 1 of this series (STRUCTURE, June 2014) built the foundation for understanding structural engineering malpractice. We explained concepts like liability and claims, generally, and tort liability specifically. On top of that foundation, we erected the framework, examining the basic elements of structural engineering malpractice, starting with the concept of duty. …
What is the value of your idea? No, not what is the value of your ideas to people in society in terms of the benefits they enjoy by safely crossing the river, or riding out the storm protected in the building you designed, but what is the monetary value of your ideas to your client? Put another way, how much profit do you think should accrue to you and your firm as a result of your dedication, creativity and hard work from a business relationship with another party who will rightfully exploit your ideas to the fullest extent possible for their own benefit? …