CIVILTech ConfinaPro: Confined Masonry Design under NSR-10 Title D
ConfinaPro is DIADICA's calculation engine for confined masonry walls: P-M interaction diagrams from strain compatibility and a variable phi factor per NSR-10 Title D, aimed at the observations design reviewers raise most often.
Why reviewers flag masonry designs
It happens often: the engineer submits the structural design and, weeks later, receives an observation notice. The reviewer points out that the masonry wall P-M interaction diagram is too simplified, or that the variable phi reduction factor required by NSR-10 in section D.3.8.5 is not shown.
Each round of observations delays the project and costs both the designer and the client. We developed CIVILTech ConfinaPro to address that problem.
P-M diagram by section integration
Most spreadsheets compute only the pure compression, balanced, and pure tension points. Joined with straight lines, those three points form a triangle that does not represent the actual capacity of the wall.
ConfinaPro uses an iterative engine that sweeps the neutral axis (c) across the full section and computes strain compatibility in each reinforcing bar and in the masonry block. The result is a continuous P-M diagram, comparable to a fiber analysis in finite element software, obtained in seconds.
Automated code checks
The tool covers the points where reviewers most often find errors:
- Variable phi factor: instead of choosing between 0.70 and 0.90, the program interpolates the value linearly from the net tensile strain of the steel.
- Slenderness (Re): the maximum axial load reduction is computed from the clear height and effective thickness.
- Boundary detailing: along with the calculation, ConfinaPro checks graphically that the confinement length (lo) in tie columns is adequate.
ConfinaPro is available to other firms and is demonstrated at a meeting; DIADICA uses it on its own projects. To book a demonstration or send comments, write to oscar@diadicaing.com.
