STAAD.Pro Help

Add New Seismic Definitions dialog

Used to define the parameters for performing a dynamic analysis using the static equivalent approach as outlined in the various seismic codes supported by STAAD.Pro.

Opens when the Seismic > <code name> tool is selected in the Define Load Systems group on the Loading ribbon tab.

Weights are added to a seismic definition through the other tabs of the Add New: Seismic Definition dialog. Seismic load items using this definition are applied using the Add New : Load Items dialog.

Seismic Parameters tab

SettingDescription
Type

Select the code you wish to use for defining seismic parameters.

Include Accidental Load

Select this option to calculate the accidental torsion component described in the appropriate code.

Include IS 1893 Part 4

(IS 1893 - 2002/2005 only) Set this option to specify loads per IS 1893 (Part 4) 2005 for industrial or stack-like structures. When set, the a value for ST is required (1 or 5). When set and ST of 5 is used, CV and DV are also required.

If this check box is clear, then IS 1893 (Part 1) 2002 is used.

Notes: To use IS 1893 (Part 4) 2015, select that code separately.

Generate (IS 1893 - 2002/2005 only) Opens the IS:1893 Seismic Parameters dialog box, which is used to populate the parameter fields with appropriate values for the IS 1893 - 2002 code.
Parameters table

A table of the code-relevant seismic parameters is listed.

Refer to TR.31.2 Definitions for Static Force Procedures for Seismic Analysis for technical details on each code parameter.

Note: Required parameters are marked with an "*".

Wall Area tab

Used to add shear wall areas for the first story above ground necessary to compute static seismic loads for IS1893 2016 only. Specify seismic resisting walls for each global direction (X and Z) only. The width is the thickness of the wall and length is the length along the global direction (i.e., plan dimensions of the walls).

Note: Specifying wall data for any seismic code other than IS1893 2016 has no effect.

Refer to Wall Area Definitions for details.

Self Weight tab

Used to add the selfweight of the structure.

SettingDescription
SelfWeight Factor The factor to be used to multiply the selfweight.

Joint Weights tab

Used to add the concentrated weights acting at one or more joints.

SettingDescription
Joint Weight

Specify the magnitude of the joint weight.

Member Weights tab

Used to add distributed and concentrated weights acting on member spans.

SettingDescription
Loading Type

Select either a Concentrated or Uniform load type.

Weight

Specify the intensity of the distributed weight or magnitude of the concentrated weight.

Starting / Ending Distance

Specify the location along the member where the weight is applied, in current units.

Element Weights tab

Used to add pressure loads on slabs if the structural model consists of plate elements representing entities like floor slabs.

SettingDescription
Pressure

Specify the magnitude of the uniform pressure, in the current units. Since it is a weight, it is a quantity without a sign.

Reference Load tab

Used to add reference loads to the seismic definition.

SettingDescription
Available Load Cases A list of all previously defined reference loads included in the STAAD.Pro input file. Reference loads are created using the Create Reference Load dialog.
Referenced Load

A list of included reference load cases for to be used in the seismic definition are included here. You may specify a different Factor value by which the reference load case is multiplied when used for the seismic load.

Along Select a global direction along which the reference load case acts as a weight.

Floor Weights tab

Used to add floor loads when no slab is present or defined in the structural model.

For additional information on the Floor Load command, refer to TR.32.4.3 Floor Load Specification . The parameters for Floor Weight are analogous to those for the Floor Load command.

Tip: If the floor has a shape consisting of a mixture of convex and concave edges, then break up the floor load command into several parts, each for a certain region of the floor. This will force the program to localize the search for panels and the solution will be better. See illustrative example at the end of this section
SettingDescription
Range Select this option to specify a Floor load or One-way load by specifying a range.
Group

Select this option to specify a Floor load or One-way load to act on a previously defined Floor group.

Groups are created using the Create Group dialog.

Pressure

Specify the magnitude of the uniform pressure, in the current units. The pressure value is provided as a quantity without sign because it is contributing to the overall weight - a numerically positive term.

Define Y/X/Z Range Specify Minimum and Maximum values to define a range in the global directions when the Range option is selected.
One Way Distribution Set this option to use a one-way load distribution. Refer to TR.32.4.2 One-way Load Specification for additional information on using a one-way load.
Towards (One-way Distribution only) Select an existing member onto which the loading is directed and defines the span direction for the one way loading. Otherwise, the load will be distributed to the longer member.
Member Group Select a previously defined floor group from the list.
Inclined (Group option only) This option is required to be set when a group of members that form a panel are inclined to the global XY, YZ, or ZX planes.