The 2022 year for ASCE7 can now be selected in the Design Codes > Action codes setting, in both Global and Model settings, as shown in the picture below. This applies to both new and existing models. As usual, all previous year versions of the code are retained should their use be required.

When the ASCE7-22 code is selected, there is a new main Wizard option to “Consider Tornado Loads''. When this is enabled further settings and options applicable to this are activated in the subsequent pages.

Building Geometry Page - the following new Tornado Loads settings are added:

• Risk Category (RC) - a warning status + tooltip advises that Tornado loading is only applicable to category III and IV when lower categories are set.

• Effective plan area - a value is displayed which is automatically calculated from the Overall building dimensions and which can be overridden with a directly entered user-defined value if required.

Wind Data Page - a new group of Tornado related data is added when tornado loads are enabled and applicable. Note the convenient new link to the online Geodatabase ASCE Hazard Tool now also included on this page (this is also included when tornado loads are not enabled/ applicable) - when online click this to access the site in your default browser.

The Tornado speed V_T can be entered directly if you have the value, as can the value of Basic wind speed V taken from the Hazard Tool.

Example output from the ASCE Hazard Tool for Tornado loading is shown below. The Tornado speed values of the MRI = 1,700 yrs column correspond to those of the maps of Fig’s 32.5 1A through 32.5 2H in Chapter 32 of the ASCE7-22 code.

Alternatively you can use the “Calculate” option to determine V_T - this opens a secondary dialog as shown in the picture below. The smaller and larger Map effective plan areas are automatically set to those from the Map increments between which the model’s calculated/ entered plan area lies. Drop Lists for each area list the other Map increments above/ below the smaller and larger areas respectively, should you wish to change either of these.

When you manually enter the Tornado speeds from the Hazard Tool data corresponding to the smaller and larger areas, the value of V_T is automatically interpolated from these in the manner stipulated by the code/ Hazard tool. OK the dialog to populate this value to the main Wind Wizard dialog and continue.

Results Page - The final page of the Wizard lists the calculated Tornado velocity pressure q_Tmax and the detailed results accessed via the [Details…] button include a new Tornado Velocity Pressures section.

Wind Loadcases - When Tornado loading is active and applicable, the Wind Loadcases dialog now includes the option to create specific Tornado loadcases using the calculated velocity pressure q_Tmax. There is a new column headed “Wind/Tornado '' which lists the type of case - either ‘regular’ Wind or Tornado - and a new “Add Tornado” button to add a row for this specific type. The Auto Generate Wind Loadcases wizard also includes a new “Tornado” column of checkboxes to include this type for selected directions.

Further operation of Wind loading for Tornado loadcases is essentially the same as for ‘regular’ Wind cases in all previous releases:

• Load Combinations - the Load Combination Generator will automatically create additional Tornado wind combinations - denoted by “W_T” in the combination title - which include the Tornado type wind load cases in the same manner.

• Wind View - Net Pressures and Applied load etc can be viewed in the Wind View in the same manner.

For the ASCE7-22 code, the spectral response acceleration parameters now come from the Geodatabase ASCE 7 Hazard Tool. There are now two forms of code-specific Design Response Spectra; Multi-period Design Response Spectra or Two-period Design Response Spectra (as per ASCE 7-16 with some minor differences). The Seismic Wizard is updated to reflect this and now includes new radio buttons for these options, as well as a new link to the online Geodatabase ASCE 7 Hazard Tool as shown in the picture below. The Multi-Period option is enabled by default as the preferred option. For full details of the changes for ASCE7-22 see the Help Topic ASCE 7-22 updates. Below we detail some notable changes and additions to input and options.

As illustrated in the picture below, you can obtain all the required seismic loading data for any location from the Hazard Tool. Click “Details” then the “CSV” button to download the spectra graph data in the form of a comma separated variable (*.csv) file.

To input the spectra graph into Tekla Structural designer, simply; open the *csv file in a spreadsheet application - such as Microsoft Excel - select and copy the entire period and acceleration data then in the Seismic Wizard select the “Paste Data” button - the graph is then automatically generated and displayed adjacent to the pasted graph data, as shown in the picture below. Note the necessity to select the appropriate Shear wave velocity V_s on the page from the drop list below the graph data.

Basic Information page - this is updated with the new expanded ASCE7-22 Site class options. The page also includes a link to the Hazard Tool from which you can obtain the S_s and S₁ acceleration values required to be input for either the Multi-Period or Two Period options.

Structure Irregularities & Analysis Procedure page - the structure irregularities have been updated reflecting the new concept of Torsional Irregularity Ratio* (TIR) introduced by ASCE7-22 – so there is now only one plan irregularity for torsion.

• *The calculated TIR value is reported in the Seismic Design Report in the section titled “Structure Plan Irregularities - User Defined”

There is also an additional new option “Amplify accidental torsion moment” as shown in the picture below. This is automatically enabled and fixed when the irregularity settings made require it. It can also optionally be enabled at your discretion when not required by the irregularity settings. By doing this you can ensure that torsional irregularity is always checked - amplification factors will only actually be applied if required. For more about the process of torsional irregularity check and amplification see the “Torsion” section of the Help Topic Introduction to seismic analysis and design.

Note that this process of checking torsional irregularity and amplification requires the use of the Modal Response Spectrum Analysis (RSA) procedure, hence selection of this is forced when this option is enabled. Tables with details of the seismic+torsion displacements assessed and amplification factor A_x determined and applied can be viewed in the “Seismic Design” report after completing the Seismic RSA analysis.

This setting is also replicated in the Seismic Wizard for the previous year versions of ASCE7.

In the 2024 Service Pack 2 release a new option has been added to this page as shown in the picture below. This enables the engineer to directly control the inclusion of the Seismic Accidental Torsion load case in seismic combinations produced by the combination generator.

The new option is active and can be set enabled/ disabled as required by the user for the 2016 and 2022 year options of ASCE7, since the code for these years details specific circumstances in which accidental seismic torsion need not be applied. This is provided Plan irregularity type 1 is not specified - when it is the new setting is automatically enabled and cannot be changed, enforcing the inclusion of accidental seismic torsion. For the 2005 and 2010 year options of ASCE7 the setting is still displayed, however it is automatically enabled and cannot be changed, replicating the previous release behavior for these code years. Note the following:

• For the ASCE 7-2022 year option, the Torsional Irregularity Ratio (TIR) is only calculated when this new option is enabled and accidental torsion is included in seismic combinations. If this is not the case, then "TIR not calculated - accidental torsion not applied" is stated in the Seismic Design Report.

• For existing models created in versions prior to the 2024 Service Pack 2 release - if Accidental Seismic Torsion load cases exist in the model, then the new setting will be automatically enabled and Accidental Seismic Torsion load cases will remain in all combinations containing them. Subject to the code year set and provided Plan irregularity type 1 is not specified - as detailed above - the user can then optionally re-run the Seismic Wizard and disable the new setting if they wish to re-generate seismic combinations without accidental seismic torsion.

• This new option must be enabled in order to enable the “Amplify accidental torsional moment” setting. Both settings are automatically enabled and fixed when the irregularity settings made require this.

Seismic Drift Check - the final page of the Seismic Wizard now includes a new option (for all years of ASCE7) headed “Calculate Seismic Story Drift at” to specify how the check is performed, shown highlighted in the picture below.

The options are:

• Automatic - Center of Mass/ Edge of Structure - the drift check is carried out at a single location in each level which is automatically set as either the center of mass (CoM) or at the edge of the structure, as required by the code and the settings made on the Structure Irregularities page. As in all previous releases, the CoM is automatically determined for all load combinations and can be viewed in any model view by enabling the Scene Content “Center of Mass” option as described in this article What are the Center of Mass and Center of Rigidity?

• Every Column / Wall Stack - how the check was performed in all previous releases.

The Seismic Drift report table is updated for the new option when enabled, as shown in the picture below.

Seismic Drift in the Review View - in the 2024 Service Pack 2 release the Review View > Seismic Drift view has been enhanced with COM/Edge results as shown in the picture below. The yellow highlighted operation step description now gives the check location of either (Edge) or (CoM). For the Edge location check, the columns/ walls at the governing edge are color coded with the check status while for the CoM the level diaphragms are. In both cases the cursor tooltip includes details of the drift check for a selected column/ wall/ diaphragm.