Structure

Structure

Top Things to Know about HSS Connections – Brad Fletcher

Connections are often the most overlooked part of structural design. We as structural engineers are educated at school in the many ways to analyze structural systems and design beams and columns. But for many reasons, little time is spent on actual connection design. Perhaps in graduate school, we have the chance to take an advanced course on connection design, but often we are not truly exposed to the subtleties and complexities of steel connections until we are on the job, where, too often, we learn the biases and bad habits of our mentors.
In addition, most engineers in the US and Canada delegate the responsibility of connection design to the project’s fabricator. While this can be a good way to get cost-effective connections, the Engineer of Record (EOR) often provides member designs that make it challenging for the fabricator’s engineer to get the connections to work for the loads given without reinforcing the members or choosing a costly connection type. This is especially true for connections that involve Hollow Structural Sections (HSS).
HSS connections have often been a source of additional mystery for even the most experienced engineers. For many years, there were not many resources here in the US that we as engineers could turn to for guidance on HSS connections. In the mid to late 1990s, this started to change and over the past 20 years, many excellent resources have evolved, especially with the inclusion of Chapter K in AISC 360.
This 1-hour presentation attempts to de-mystify HSS connections. While this is not a “how-to” guide, the presentation will highlight areas of HSS connection design that are often overlooked or misunderstood. Connection types that are addressed include tension, bracing, shear, moment, and truss connections. Attendees will gain an appreciation of the similarities and subtle differences between HSS connections and other types of connections. Also addressed will be the effect certain design decisions have on fabrication and the cost of connections. Register Here.

LES Member price: $25
Non-member price: $35

 

Innovative Repair of Failed MSE Walls Using Geosynthetic Materials In Conjunction with Strength Elements – Will Brantley, PE

Mechanically Stabilized Earth (MSE) and steel pile walls are commonly used throughout the United States to repair landslides and create favorable site and road prism geometries. However, when improperly designed, these structures have an associated failure rate of 5%. Post-failure reconstruction and remediation often present challenges beyond those encountered during original construction, including difficult site access and critical infrastructure maintenance, and roadway traffic. Using case studies from five recent design/build MSE and pile wall repair projects in the Eastern United States, this presentation outlines some of the new and innovative methods available to designers. These methods are robust enough for structural repair and specific enough to prevent unnecessary impact to roadway users and critical infrastructure disruption. Relevant technologies include traditional soil nailing, reinforced architecturally sculpted shotcrete, reticulated micropile arrays, and Geosynthetically Confined Soil (GCS®) walls constructed with lightweight recycled aggregate. Register here

LES Member price: $25
Non-member price: $35