November 21, 2022

Model & Analyze Post-Tensioned Elements in Ramps

ADAPT-Builder provides the user with the ability to add post-tensioning to ramps modeled within the program. Users can add tendons in ramp slabs as well as add tendons in beams supporting the ramp. The tendons and effects of the tendons on the structure will be included in the analysis of the model. To learn more about this feature, watch the video below:

Additional information about the modeling and analysis of post-tensioned tendons in ramps can be found by reviewing the ADAPT-Builder Online Help file:

Tags: Tendons, ADAPT-Builder, ADAPT, New, Ramps, Popular

November 2, 2016 | Seismic, RISA-3D, New, Loading

Basic Code Terms for Seismic Behavior and Why We Use Them

Seismic Forces are generated automatically using seismic parameters R, SD1, and SDS in the Seismic Load Generator when using the Director to go from RISAFloor to RISA-3D or when inserting Seismic Loads on a rigid diaphragm in RISA-3D. Additionally, Seismic Load Combinations can be generated using the seismic parameters ρ, Ωo, and SDS and applied to the structure. These seismic parameters are used to approximate the inelastic response of the structure subjected to seismic design lateral forces. Figure 1 shows a simplified example of what some of the seismic parameters represent when looking at force versus drift for a lateral system. In RISA-3D, the seismic load generator is accessed by selecting the Advanced tab and then clicking on Seismic. When the load generator opens and the loads are calculated the dialogue looks like the image below. R is the Response Modification Factor as defined in Table 12.2-1 of ASCE 7-16. It provides a reduction for the design seismic force based on the ductility of the system. The program offers a single user-input R value in each Global direction. R is used in the calculation of the Seismic Response Coefficient, Cs, which determines the Seismic Base Shear, V, and these values…

February 25, 2025 | Featured, Structural Engineering

A Day in the Life of an Industrial Structural Engineer

If you've ever wondered what it’s like to be an industrial structural engineer, let me paint you a picture: Imagine juggling a dozen problems at once—steel frames, conveyor supports, pipe racks, tank foundations—all while trying to decipher a set of drawings that look like they were faxed from 1997. And, of course, every single solution is needed yesterday. But don’t worry! With the right tools (cough RISA and ADAPT cough), navigating this daily chaos becomes a lot more manageable. So, grab your coffee (black, obviously), and let’s walk through a typical day. 6:30 AM: Morning Coffee & Evaluating Additional Loads The first email of the day: “Can we add another 10,000 lbs of equipment to the mezzanine? What about seismic drift and vibration?” Instead of a lengthy hand calculation, you fire up RISAFloor and check gravity load distribution. Exporting to RISA-3D, you analyze modal frequencies and check if the additional weight will push the structure into an uncomfortable range for human occupancy. Seismic drift is next. A quick response spectrum analysis in RISA-3D confirms that the drift is still within acceptable limits. You send your report with confidence—no major framing changes required. 9:00 AM: Field Issue - Pipe Rack Base…

December 13, 2010 | RISA-3D, Plates, Loads, RISA-2D

Rebar Design using the Internal Force Summation Tool in RISA-3D

When you have a plate model for a slab or wall in RISA-3D, the Internal Force Summation Tool (IFST) is a very useful analysis tool to get exactly the forces that you want to design for. To use the tool, you must: Be looking at the model in a plan or elevation view (i.e. 2D View only). Have selected ONLY the portion of the model that you want to sum the forces for (all other elements are Un-selected). Let’s look at a slab example. Here we have an elevated slab that is supported on all edges, with a column that lands in the center of the slab. The slab is modeled with plate elements. After we solve the model for that load, we can view our plate contours and use the selection tools to select a representative strip. The representative strip would be a strip through our slab/wall that we want to get the forces for so we can then design reinforcement for this strip. To use the IFST, select the button on the left side of the screen. Clicking twice on our strip will create a plane that the program cuts through the model and will then display the…