July 30, 2020

Introducing Integrated Design: Seamlessly Linking Architecture and…

Learn how Graphisoft and RISA are working together to leverage model information created by the architect to create a more seamless workflow, while minimizing the duplication that is typical of today's design process:

Feature	ADAPT-PT/RC	ADAPT-Builder
Preliminary Sizing	X	X

Tags: RISA, New, BIM, Archicad

October 29, 2020 | RISA-3D, RISAFloor, Concrete, RISAFoundation, New, v15, v19, v13

Interaction of Shear Forces Acting Along Orthogonal Axes in Concrete

Recent tests and analytical results for concrete columns have indicated that considering shear along each centroidal axis independently can be unconservative. Therefore RISA-3D v19, RISAFloor v15 and RISAFoundation v13 have included the consideration for the interaction of shear forces acting along orthogonal axes per ACI 318-19 equation 22.5.1.11. When Vu/ΦVn > 0.5 in both orthogonal directions, a new expandable section of the Detail Report will appear for the interaction equation. RISA-3D RISAFoundation…

April 7, 2020 | RISA-3D, Concrete, New, Shear Walls

Understanding Out-of-Plane Shear Capacity of Concrete Wall Panels

When designing concrete shear walls for lateral loading, RISA-3D includes design checks for both in-plane and out-of-plane shear. In the condition where a concrete wall is under both axial tension and out-of-plane shear, the out-of-plane shear limit state for a specific region within the concrete wall detailed report includes the details shown below: This limit state may cause users to ask the question: “why is the a phi*Vns term listed when no out-of-plane shear reinforcement is present?” The answer is that when calculating the out-of-plane shear capacity of the concrete wall, RISA-3D considers Shear Friction developed at the crack interface. ACI 318 code defines shear friction as the shear transfer across any given plane, such as an existing or potential crack, an interface between dissimilar materials, or an interface between two concretes cast at different times. In this case, the existing/potential cracks condition applies. When axial tension and out-of-plane shear are applied to the concrete wall, cracks will form across the wall thickness as explained by the simplified force diagram shown below: The shear sliding at the crack generates tensile forces Fs in rebar. In return, these tensile forces, Fs cause compression forces, Fc at the concrete crack interface. The…

January 20, 2016 | RISA-3D, RISAFloor ES, RISAFoundation, New

Why Did My Reinforcing Change in ACI 318-14?

The new ACI 318-14 code has been implemented into RISA-3D V14, RISAFloor V10, and RISAFoundation V8. One of the big changes between the ACI 318-11 and the ACI 318-14 was to minimum flexural reinforcement for one-way and two-way slabs, as well as foundation elements. In many cases this has the effect of increasing the required reinforcement in these elements. Here we will discuss why. ACI 318-11 In this code the flexural minimums are considered in Section 10.5. Sections 10.5.1 and 10.5.2 are where the minimum flexural reinforcement calculation is looked. For common values of reinforcement and concrete properties this would result in a rho = 0.0033. In Section 10.5.3 there is an additional provision that allows you to disregard 10.5.1 and 10.5.2 as long as the area of steel provided is at least 1/3 greater than required by analysis. There has always been a bit of gray area as to where this provision is applicable. In RISA this provision is applied to all beam and slab-type elements. ACI 318-14 This code re-arranged it’s sections to each element type and thus updated/clarified the language for each element. Section 7.6.1 & 8.6.1 Minimum flexural reinforcement in non-prestressed Slabs. For 60 ksi reinforcement…