Starting the Wizard

To initiate the wizard:

Click Home > Model Settings > Design Codes
1. Set the Design Code for Seismic Loading to IS1893 (Part 1) and select the year required
2. Click OK
Click Load > Seismic Wizard...

The Seismic Wizard will start, and you can use its pages to define the necessary information. The first page displayed is Site Specific Spectra.

Site Specific Spectra page

You can choose the analysis procedure to be used, either:


Property	Description
Code Spectra	Choose this option to use the IS893 (Part 1) Horizontal Design Spectrum.
Site Specific Spectra	This option is appropriate for locations which use another country's loading and design codes where the code spectrum is not relevant. For this option you create a user defined spectrum by specifying the required curve parameters and slope options. See: Code spectra and site specific spectra.
Next	Clicking Next takes you to the Basic information page described below.

Note:

No vertical spectrum is considered in the current release.

Basic information page

The SZone Factor is determined on this page.


Property	Description
Structure details
Height to the highest level	This field defaults to the structure height (calculated from the base to the highest point on the structure).
Ignore seismic in floor (and below)	Only floors above this level are considered when the seismic weight combination is determined.
Number of storeys	This field defaults to the number of ticked floors in the Construction levels dialog less the ones ignored in field above.
Zone & Site
Seismic Zone	This field allows you to set the appropriate zone, II-V.
Site class	This field allows you to set the appropriate soil conditions, I-III.
Importance Factor, I	This is automatically derived from the occupancy class.
Next	Clicking Next takes you to the Structure Irregularities page described below.

Structure Irregularities page

This page is used to indicate any irregularities in plan or vertically.


Property	Description
Structure Plan Irregularities	Check the appropriate boxes to define any plan irregularities.
Structure Vertical Irregularities	Check the appropriate boxes to define any vertical irregularities.
Analysis procedure to be used	Having specified any irregularities, you then choose the analysis procedure. Use Equivalent Lateral Force Procedure Use Modal Response Spectrum Analysis Note: Based on the irregularities you have defined, one or both of the above methods may be unavailable. Any additional information, assumptions or warnings applicable to the selected a method are displayed for information.
Next	Clicking Next takes you to the Fundamental Period page described below.

Fundamental Period page

This page is used to determine the fundamental period, T_{Dir 1} and T_{Dir 2}.


Property	Description
Fundamental Period Definition
Use approx fundamental period T_a	This is automatically derived. If RSA was selected on the previous page this option is dimmed.
User defined fundamental period	If RSA was selected on the previous page this option is dimmed.
Use modal analysis	Modal analysis is run to determine fundamental periods of the structure in Dir1 and Dir2.
Fundamental Period Dir 1 and Dir 2
Structure Type	Select the structural type.
Approx fundamental period, T_a	This is automatically derived.
Fundamental period, T_{Dir 1}, T_{Dir 2}	Depending on your choice of definition this will either be taken as T_a, or it can be a user defined value, or it will be calculated from the modal analysis.
Next	Clicking Next takes you to the Seismic Force Resisting System page described below.

Seismic Force Resisting System page

This page is used to determine the response modification coefficient, R, and other factors in the directions 1 and 2.


Property	Description
Seismic force resisting system Dir 1 and Dir 2
Type	This field allows you to set the appropriate type.
System	This field allows you to set the appropriate system for the chosen type.
Coefficients & Factors Dir 1 and Dir 2
Response modification coefficient, R	This is automatically derived, but you are given the facility to edit the calculated value.
Next	Clicking Next takes you to the Effective Seismic Weight page described below.

Effective Seismic Weight page

This page is used to determine the Structure Seismic Dead Weight.

You should include those loadcases that you want to contribute to the Structure Seismic Dead Weight.

Note:

The effective seismic weight combination is used to develop the seismic design loading and is not used in any analysis of the structure.

Clicking Next takes you to the Localization page described below.

Localization page

On this page you can:

choose whether to perform seismic drift checks, and set the allowable story drift factor to be used
define appropriate localization parameters


Property	Description
Skip seismic drift checks - Check this box if you do not require seismic drift checks to be performed.
Allowable Story Drift Factor	The factor to be used when calculating the allowable story drift. Click 'override' if you want to enter your own value.
Include localization - Check this box in order to display the below 'ELF & RSA' and 'RSA only' localization settings.
ELF & RSA
Scale Factor between elastic and design spectra (Dir1 and Dir2)	This field allows you to override the code value for the scale factor.
User Defined Static Base Shear (Dir1 and Dir2)	This field allows you to override the code value for the static base shear.
% eccentricity for accidental torsion (Dir1 and Dir2)	This field allows you to override the code eccentricity for accidental torsion). Note: The same value is applied to all floors in the structure.
Vertical seismic load effect combination factor	This field allows you to override the combination factor for vertical seismic loading (usually a small additional factor for the dead loads in the combination).
RSA only	(only available if RSA has been selected)
% Mass participation for RSA	This field allows you to set your own required % mass participation. Note: This overrides the setting in Analysis Options/1st order seismic when running the Seismic Wizard. Note: It is not usually possible to achieve 100% mass participation in a modal analysis so max value is 99%. Note: This setting can benefit some users wanting nearer 100% to be conservative.
Scaling of forces (% of Base Shear) (Dir1 and Dir2)	This field allows you to set your required scaling factors
Scaling of Deflections for Drift Checks (% of Base Shear) (Dir1 and Dir2)	This field allows you to set your required scaling factors. Note: A zero factor means no scaling will be performed on deflections.
Finish	Click Finish to automatically generate the Seismic loadcases and open the Seismic Combination Generator described below.

Seismic Combination Generator

The Combination Generator sets up seismic combinations from the "core" combinations that include seismic loads.


Property	Description
Initial Parameters page
Delete / Replace combinations	Select whether to: Delete all previously generated combinations Replace only combinations generated by this run
Scenario	If you need to generate combinations for a range of different scenarios, ensure you type in (or choose from the droplist if appropriate) a scenario name. This scenario name is then added as a prefix to all the combinations generated in the this run of the generator. You can then rerun the generator to create additional scenarios.
	Clicking Next takes you to the Combinations page described below.
Combinations page
Generate	Select the seismic combinations to be generated with factors as specified.
Keep existing Seismic Combinations	If you want to retain previously set up Seismic Combinations you can select this checkbox to do so. Note: Warning - some factors may no longer be correct for these combinations after rerunning the Wizard.
Next	Click Next to specify the service factors.
Finish	Click Finish to generate the Seismic combinations.

Using the IS1893 seismic wizard