June 14, 2022

Case Study: SCC Beatrice Academic Excellence Center

Learn how Olsson utilized the entire RISA Suite (RISA-3D, RISAFloor, RISAFoundation and RISAConnection) to design the newest addition to the Southeast Community College campus located in Beatrice, NE.

To learn more visit the project case study page:

SCC Beatrice Academic Excellence Center

Tags: RISA, New, News, Case Study

August 30, 2019 | Slab, RISAFoundation, New, Reinforcement

Add Single Layer of Reinforcement anywhere in Slab

RISAFoundation has the ability to create a single layer of reinforcement anywhere in a slab. This improvement allows for a more straightforward design of thin, lightly loaded slab-on-grade where two layers of reinforcement (top/bottom) would be unnecessary. In order to add a single layer of reinforcement, users select Single Layer from the Rebar Options drop-down found in the Mat Slab tab of the Design Rules spreadsheet. When a user selects Single Layer, only the inputs for Top Bar size and the Max/Min Top Bar Spacing are used. Additionally, the value of Top Cover found in the General tab is used to define the depth of the bar in the slab. Note: When Mid-Depth Only is selected, the Bottom Bar size, the Max/Min Bot Bar Spacing and the Bot Cover are used. The design of the slab will differ based on whether the reinforcement is placed above or below the mid-depth of the slab. When the single layer is placed above mid-depth, the slab will be designed according to slab-on-grade requirements found in ACI 360-R and ACI 223. These provisions focus mainly on design in response to crack control. When the single layer is placed below mid-depth, the reinforcement is assumed…

June 16, 2020 | Loads, Load Combinations, New, Basic Load Case, Load Category

Understanding differences between Basic Load Cases, Load Categories…

One of the questions our support team receives often is the difference between Basic Load Cases (BLC), Load Categories and Load Combinations (LC). Understanding how these containers are used and how they work together when loading a structure is an essential part of creating an accurate model in RISA. Basic Load Cases (BLC) When loads are defined, they are assigned into Basic Load Cases (BLC's). BLCs are the basic container of the final load combinations applied to the structure. A BLC can consist of any type of load; such as nodal loads, distributed loads, member point loads, surface loads, etc. The Basic Load Cases (BLC) can be assigned to different Load Categories such as Dead Load (DL) and Live Load (LL). It is also possible to assign different BLCs to the same Load Category. The BLCs and Load Categories can be used together to define Load Combinations that will be used for the analysis. Load Categories Load Categories are predefined groups in the program such as Dead Load (DL), Live Load (LL) and Earthquake Load (EL) that cannot be modified or added to by users of the program. Many of these groups are associated with IBC and ASCE 7 provisions…

March 27, 2013 | RISA-3D, Loads, RISA-2D, Load Combinations, New

Nesting Load Combinations

The Load Combinations spreadsheet in RISA-3D is limited to ten columns of BLC and Factor combinations. However, there are times where you may need to include additional entries to your Load Combination. To do this, you can simply “nest” your load combinations. This means that if you need more than eight BLC entries in a single load combination, you can define the common BLCs (such as Self Weight, DL, and/or LL) in one load combination that you can then reference in the other load combinations. Entering “Lnn” in the BLC field will include all the BLCs (and their factors) from the load combination on line “nn” of the spreadsheet, thereby “nesting” the combination. This can also be used to simplify your input. For instance, you may have a model that needs to combine the effects of static loads and moving loads, or static loads and the Response Spectra results, but because of space limitations in the spreadsheet, it is impossible to fit them all into one row. Additionally, while investigating the performance of a structure, you may need to multiple entire load combinations by a "safety factor". In this example, the load combination (L22) is given additional factoring and has…