Seismic Load Generation page

Used to input seismic load data—either directly or by parameters which the program will then use to calculate code-specified seismic loads. The following codes are supported:

ASCE 7-2005 (US)
IS-1893 Part 1 (Indian)

Seismic Load Generation calculation

Directly Input Seismic Loads - specify values for shear force and moment
Mass Table C.G. - (US code only) If mass data has been entered in the Time Period page for the calculation of the vessel's fundamental period, that data can also be used by the program to determine the center of gravity.
User Defined C.G. - Specify the center of gravity of the vertical vessel.

Setting	Description
< Previous	Steps the Wizard to the previous step.
Next >	Proceeds the Wizard to the next step.
Cancel	Exits the Wizard without creating a new Vertical Vessel Footing job.

Directly Input Seismic Loads

Depending on the load combination, operating seismic or empty seismic will be taken into consideration.

Setting	Description
Operating Seismic Load	seismic load subjected at top of pedestal for operating conditions.
Empty Seismic Load	seismic load subjected at top of pedestal for empty conditions.

Mass Table C.G. - US Code

The program will calculate seismic loads per ASCE 7-2005 for you. You have the option to use database mapped acceleration values based on Zip code or to specify values directly.

Select using Zip Code- Populates the Select Zip combo box with all U.S. zip codes. Choosing any one of them will (or simply type in the value to select faster) will selected mapped acceleration values for that geographic location.
Enter Value Manually- Specify values for S1 and Ss in the respective fields.

Setting	Description
City / Latitude / Longitude	(non editable) Displayed for the specified zip code to verify location.
S1 / Ss	The 1-second and short period acceleration values from ASCE 7 maps.
Site Class	Value of Fa and Fv, which are functions of Site Class and mapped acceleration values. Note: If Site Class is selected as F, Fa and Fv may be entered manually.
Response Modification Factor (R)	Select the response modification factor (either 2 or 3).
Occupancy Importance Factor (I)	Select the importance factor for the structure (1.00, 1.25, or 1.50)

User Defined C.G. - Indian Code

The program will calculate the seismic loads per IS-1893 Part 1 for you. You have the option to select a mapped acceleration value based on a Indian city or to specify values directly.

Setting	Description
Seismic Zone Selection	Set the option to either Select City from a list of Indian cities or Enter Value Manually to select the Zone (Z) from a list.
Average Response Acceleration Coefficient	Set the option to either Select Soil Type from a list of soil descriptions or Enter Value Manually to type the Sa/g value directly.
Response Reduction Factor (R)	Select the reduction factor from the list as defined in Table 7 of IS 1893 Part 1.
Importance Factor (I)	Select the importance factor from the list as defined in Table 6 of IS 1893 Part 1.

User Defined C.G.

Setting	Description
C.G. of Vessel	Specify the center of gravity of the vertical vessel above the finished surface, in the selected units.