
December 16, 2015
Concrete Design per ACI 318-14 Concrete Code now Available
The new ACI 318-14 code has been implemented into RISA-3D v14, RISAFloor v10, and RISAFoundation v8.
With the adoption of ASCE 7-22, the concept of a multi-period response spectrum has been added to seismic design requirements. While this provides more accurate hazard representation, it also means engineers need to generate and input additional site-specific data. This quick workflow shows how to gather that data from the ASCE Hazard Tool and use it in RISA’s site parameters table for seismic load generation. Why This Matters for Engineers? Multi-period response spectra reflect more realistic ground motion characteristics and will increasingly be required as jurisdictions adopt ASCE 7-22. By pulling site-specific values directly from the ASCE Hazard Tool, engineers can ensure compliance and avoid unnecessary assumptions. The multi-period approach can result in higher or lower design forces depending on the building’s period and site class, but it always provides more accurate seismic representation than the traditional two-point method. Download the latest versions of RISA that supports ASCE 7-22 below. Step 1: Generate Multi-Period Spectrum Data Go to the ASCE Hazard Tool. Enter your project location (address, coordinates, or site description). Select ASCE 7-22 as the building code. Navigate to the seismic hazard results and download/export the Multi-Period Response Spectrum data. Step 2: Copy Data Points into RISA Open RISA…
Read More
The new ACI 318-14 code has been implemented into RISA-3D v14, RISAFloor v10, and RISAFoundation v8.
RISA-3D v14 introduced envelope detail reports for all material members. This means that you can see the enveloped solution (force diagrams and governing code check values) in the detail report for each member when you solve either an Envelope or Batch + Envelope solution type.
Time history analysis solves for normal analysis results (joint displacements, member forces, code checks, etc.) based on loading that varies with time. For some analyses it may be useful to view an animation of the deflected shape of the structure as a function of time. This blog topic serves as a...
You may notice discrepancies in the wood design values when comparing RISA with the NDS 2012 and older versions of the code. The American Wood Council updated the wood design values in the Addendum, which supersede the values used in the NDS 2012 and previous versions of the Design Values for Wood...
After solving a model, you will see in the Member Deflections spreadsheet the following deflection ratios:
The beams in a lateral force resisting system, such as a braced frame or moment frame, typically carry a significant axial force. In the example below (with no diaphragms) the beam (M4) carries a significant axial tension.
In the Seismic Loads dialog there is a checkbox for “Include structure weight in base shear”.
When running a Response Spectrum analysis for seismic design, the response for high frequency modes can be included without solving for their individual mode shapes. This is often done to save analysis time and memory. This topic discusses some of the technical background and gives references for...
RIAFloor designs the gravity system and then integrates with RISA-3D to design the lateral system. Only the lateral members are taken from RISAFloor over to RISA-3D. The loading is automated in this integration so one of the most common questions is: what loads are transferred when switching from...
Our monthly "Structural Moment" newsletter is the best way to keep up with RISA’s product updates, new releases, new features, training events, webinars and more...