Concrete Pier Cap Code Check T [SIG]

General

Load Combination Table: The load combination table is used to map the analysis result cases and their corresponding factors to the template, along with the limit states. It serves as the basis for all finite element analysis results used in the code check equations.

Select State Provisions[FDOT/PENNDOT…]: The code check component uses AASHTO 9th Edition standards as the default to calculate DC ratios and determine whether equations have passed or failed. Choosing a state specification does not impact these AASHTO-based computations, but rather serves as an additional requirement in OpenBrIM. The pass/fail status according to AASHTO and DOT standards are displayed in two separate summary tables, which usually exhibit similar outcomes, with the DOT standards often being the more stringent. However, in some unique cases, a bridge component may fail AASHTO equations but pass due to overriding state specifications. Nonetheless, this is not a common scenario and DOT requirements are typically conservative.

PS Load Case: If the pier cap is stressed by tendons, a result extraction case that includes tendon forces should be selected here.

Design Parameters

Procedures for Shear Resistance Parameters β and θ [Simplified / Generalized(Eqn) / AppendixB5(Table)]: The simplified method follows the AASHTO 5.7.3.4.1 standard and uses fixed values of 2.0 for β and 45 degrees for θ. Large-scale experiments (Shioya et al., 1989) have shown that using fixed values of β and θ, such as 2 and 45 degrees, can be seriously unconservative for large members without transverse reinforcement. As a result, it is important for users to exercise caution when using the general procedure. The preferred method for computing β and θ may be determined either through the general procedure or through the provisions outlined in AASHTO Appendix B5. When the user selects the general procedure, the computation follows AASHTO 5.7.3.4.2 to calculate the values of β and θ. The method outlined in Appendix B5 utilizes tabulated values of β and θ instead of using equations 5.7.3.4.2-1, 5.7.3.4.2-2, and 5.7.3.4.2-3 to compute these values.

Include Axial Effects on Flexure and Shear Computation? [NO/YES] : There are situations where small tension or compression forces act on pier cap finite elements, which can impact computations such as flexure, rebar stress, and shear capacity. To exclude axial forces from these computations, users can select "No". However, if the pier cap has a tendon, this option should never be disabled.

Flexure Sign(Effective Shear Depth)[Use Critical Shear Concurrent Bending Moment/User Positive Flexure/Use Negative Flexure/Use Pos and Neg Flexure]:This option allows the user to choose which flexure type should be used to compute the effective shear depth, as the value may differ under positive or negative bending. By selecting "Use Critical Shear Concurrent Bending Moment", the library component finds the critical shear force from all limit states and checks its concurrent bending moment, using either positive or negative flexure according to its sign. Choosing "Positive Flexure" or "Negative Flexure" forces the library object to compute the effective shear depth without considering any analysis results for the flexure sign. Finally, selecting "Use Pos and Neg Flexure" computes the effective shear depth for both flexures, and the critical one is used.

Resistance Factor Tension Controlled Section: By default, 0.9 is used and can be changed according to user preferences. In the screenshot below, you can see the related section of AASHTO.

Open

Resistance Factor Compression Controlled Section: By default, 0.75 is used and can be changed according to user preferences. In the screenshot below, you can see the related section of AASHTO.

Open

Resistance Factor Shear and Torsion: By default, 0.9 is used and can be changed according to user preferences. In the screenshot below, you can see the related section of AASHTO.

Maximum Aggregate Size: The maximum aggregate size to be used in related checks can be specified with this parameter.

Section Analysis

Ignore Rebar Tendon in Section Property Calc [Yes/No]: Section property computations, such as inertia and section modulus, can either include or exclude rebars and tendons based on this flag parameter.

Section Analysis Refinement (Total Fiber Count): Strain compatibility-based section analysis(flexural capacity) divides the section into a selected number of fibers. Using a higher number increases the design time by 4-5 seconds per code check station.