January 1, 2021

Quickly Evaluate Graphical One-Way Shear Results in ADAPT-Builder

The ability to quickly evaluate results and make data-based design decisions is a key aspect of user-focused structural software. One-way shear is a critical in the design of RC and PT beams and in particular, sizing of beams and associated economy of a design. ADAPT-Builder 2020 delivers new and improved graphical analysis and design tools for one-way shear meant for quick delivery of results.

For reinforced concrete and post-tensioned models including beams and one-way slabs requiring one-way shear reinforcement, new graphical options have been added to Result Display Settings. These graphical results include Shear Stress Check, Concrete Shear Strength (Vc), Vu/Vc ratio, Asv (required shear reinforcement), Asv (provided shear reinforcement), and shear stirrup reinforcement.

Shear Stress Check

This option shows a graphical code check for each design section along a beam or one-way slab design strip for the selected strength load combination or strength envelope. The available code check status indicators of NA, OK, REINFORCE, and EXCEED CODE are reported.

Concrete Shear Strength

Reports the concrete shear capacity, øVc (or equivalent for other non-ACI design codes) of each design section. The calculated concrete shear capacity is calculated per code requirements for reinforced concrete or post-tensioned sections.

Demand vs Capacity Ratio

Reports the demand/capacity ratio (Vu/øVc) for the selected strength load combination or envelope.

Area of Shear Reinforcement Required

Reports the required area of reinforcement (Asv) per ft (US units) or per meter (SI units) based on calculation.

Area of Shear Reinforcement Provided

Reports the provided area of reinforcement (Asv) per ft (US units) or per meter (SI units) based on input of number of legs and stirrup size selected for the design.

Shear Stirrups

Reports the number of stirrups and associated spacing in each reinforcement zone along the beam or one-way slab. The total length is given for each reinforced zone.

To learn more about the graphical reporting of one-way shear results, view the video below:

Tags: ADAPT-Builder, ADAPT, Slab, New

November 16, 2018 | New, RISAConnection, Welds

Using & Disabling the Base Material Proration Factor

The base material at the location of a weld may have less strength than the weld itself. In this case it will control the overall strength of the welded connection. In order to account for this, RISAConnection uses a weld strength reduction factor (α) which we call the Base Material Proration Factor. This factor is a re-arrangement of AISC Steel Design Manual equation (9-2) which is presented as a thickness limitation. In order to include this limitation in the capacity calculation, this equation is rewritten as a factor which is then applied to the weld strength calculation. Per page 9-5 of the Steel Design Manual, this factor shall apply whenever the “available strength of the connecting element is not directly calculable”. This is a subjective statement and we as engineers have done our best to include this factor wherever we thought necessary, such as a weld connected to the wall of an HSS column, or the web of a supporting column. If you prefer not to include this factor, you can easily turn it off by unselecting the “Check Weld Base Mat. Thick” checkbox from the Solution tab of (Global) Model Settings…

November 16, 2018 | New, RISAConnection, Transfer Forces

Include Transfer Forces in Vertical Brace Connections

RISAConnection assumes by default that your vertical brace connection is a one-sided connection without any outside influence or load transfer from other connected elements. Using this assumption, the design shear and axial force at the beam to column sub-connection is determined using simple statics per the Uniform Force Method in the AISC Steel Design Manual. However, it is very possible that this connection is also seeing forces from other connected elements, such as out of plane horizontal braces. You may now take these into account by entering them as the new Transfer Forces input. These inputs will be included in the final calculation of the axial and shear design forces at the beam to column sub-connection. The equations shown below are based on statics as well and combine all components of the loads at the beam to column intersection. The final load calculations are shown in detail in the Required Load Calculation report on the Beam/Column results report tab…

November 8, 2018 | RISAFoundation, New, Safety Factors, Overturning, Sliding

Mat Slab Overturning and Sliding Safety Factors

RISAFoundation v11.0 includes two new tabs in the Safety Factors results spreadsheet that breakdown the slab’s stabilizing and destabilizing forces for each category. The new Overturn/Resist by Category and Sliding/Resist by Category tabs make it easy to understand how the program calculates the safety factor results for a mat slab demand and resisting forces for both overturning and sliding. RISAFoundation calculates the safety factors using the True Safety Factor Method, which involves looking at each category within a load combination and deciding whether it has a stabilizing to de-stabilizing effect. This means that each category will act as either a demand or resisting force, depending on the net sliding or overturning result for each local x and z direction. This is why it is important to assign your load categories appropriately to get a better sense of the true tendency of the structure to overturn. In this example, the foundation support for a four leg tower has two load combinations applied for (DL + WLX) and (DL + WLZ). The breakdown in the Overturn/Resist by Category and Sliding/Resist by Category tabs show DL acts as a stabilizing force for both overturning and sliding while the wind loads in the X…