With the recent introduction of our new LSSR rafter hangers for 2x lumber, we thought we’d provide some background on how these new hangers were developed and why.
As one of the top 10 private homebuilders in the US (and one of the top 25 overall), Gehan Homes has explored its fair share of technologies promising efficiency and productivity gains. When it came to pulling home designs, plans, elevations, and options into full job start packets (JSPs), the Texas-based homebuilder managed to generate about 400 JSPs per year before the productivity cost of eight hours each began to limit growth.
Resiliency is a term which is becoming more commonplace within the field of structural engineering, not just in North America but worldwide. As part of a nation that prides itself on being progressive, engineers in seismic zones of Canada are already exploring innovative solutions that may help create economic structures with resiliency in mind. But what do we mean by resiliency?
In the fields of engineering and construction, resiliency is the ability of a structure to absorb or avoid damage without suffering complete failure. Structural resiliency is the ability of a building or structure to remain sufficiently sound and intact following a shock event as to allow rapid resumption of normal use.
Every year on October 17, we take a moment to reflect on the 1989 Loma Prieta earthquake. The 6.9-magnitude earthquake was one of the most powerful and costly quakes to shake the San Francisco Bay area since the 7.9-magnitude earthquake of 1906. The quake caused an estimated $6 billion in damage and, tragically, resulted in 63 deaths and 3,757 injuries.
Many of those casualties were due to failing infrastructure when sections of the Nimitz Freeway collapsed.
Simpson Strong-Tie was founded in Oakland, California — practically in the heart of the Bay Area. Earthquakes were never far from the minds of our founders. It’s why even before Loma Prieta our mission was to provide solutions that help people design and build safer, stronger structures. However, it’s safe to say the earthquake not only reinvigorated our mission but inspired countless structural engineers who would go on to define the next 30 years of Simpson Strong-Tie research and development into community resilience.
In the last few years, Simpson Strong-Tie has heard from a number of structural engineers expressing frustration with the lack of performance data for shallowly embedded, post-installed anchors (shallow anchors). Engineers of Record (EOR) have identified a common application for shallow anchors as those related to attachment of sill plates for structural and nonstructural wall-to-podium slab connections. One dilemma faced by the EORs originates in their desire to prevent damage to concrete podium slab reinforcement, especially where reinforcement is located close to the slab’s top surface to resist negative bending moments. EORs further indicate that shallow anchors are frequently needed for the following attachments: hanging MEP fixtures; attaching nonstructural components associated with tenant improvements; and anchoring light equipment.
Since the introduction of strength design for post-installed anchors in IBC 2000, determining the designed capacity of anchors has become increasingly complex. Dozens of variables, such as geometry, concrete conditions, and the specific properties of different anchor types, make a quick, straightforward comparison of design options almost impossible. Leaving behind printed tables and digital spreadsheets, many manufacturers now offer software to simplify anchor design and provide design feedback in real time. Simpson Strong-Tie offers Anchor Designer software to specifiers as a free, intuitive design tool that streamlines the anchor design process.
As I look back on the past year and a half and think about all the madness surrounding Covid-19, I can’t help but feel as if I’m emerging from some strange cosmic time warp. The time that has passed since the early days of the pandemic feels so slow in the moment, yet, when I think about all that has happened in my life during this period, the time has passed by surprisingly quickly. Continue Reading
Whether you’re designing and building a one- or two-story single-family residence, or doing the same for a multifamily, mid-rise wood-frame structure, fire and smoke protection features must be considered, and in most cases are required. When a fire starts, time is of the essence and the longer the flame and gases can be contained and the spread of the fire to adjacent spaces is kept in check, the greater the chance firefighters and first responders will have to defeat the blaze. Though many building jurisdictions have slightly different requirements and provisions, the three primary modes of fire rating that codes consider are an F-rating (flame), a T-rating (temperature rise), and an L-rating (air or gas leakage). The F and T ratings are gauged on a resistance per hour basis and the L rating is based on a rating of air leakage in cubic feet per minute per square foot of opening, or CFM/sq.ft. These ratings and provisions are in place to help safeguard against the spread of fire and smoke within the immediate structure as well as to contain the spread of fire to other structures.
In this post, we follow up on our July webinar, Innovations in Strength and Versatility: Overview of the Strong-Wall® High-Strength Wood Shearwall, by answering some of the interesting questions raised by attendees. Continue Reading
We’re excited to share another fiber-reinforced polymer (FRP) project that required both flexural and shear strengthening (photo below) of reinforced concrete joists to enable the slab floors to carry more live load. The structure is in Southern California, and appears to have been built in the 1950s or 1960s when pan joist construction was common. The EOR for this project, Structural Focus, is an experienced structural engineering firm known for seismic retrofit solutions. The FRP applicator was FD Thomas Structural Specialties, a contractor with decades of FRP installation experience.