ASCE Example - CAESAR II - Help

CAESAR II Users Guide

Language
English
Product
CAESAR II
Search by Category
Help
CAESAR II Version
13

For further information on the Seismic Wizard see the example below and ASCE 7 Wind and Seismic Load Combinations.

Importance Factor IP = 1

Component Response Modification Factor RP = 3.5, from Table 13.6-1, "Piping in accordance with ASME B31,"

Mapped MCE Spectral Response Acceleration Ss = 1.552, Mapped MCE Spectral Response Acceleration at short periods according to Section 11.4.1.

Site Coefficient (Fa) = 1.0 for Site Class D, according to Table 11.4-1.

Maximum Considered Earthquake MCE SMS - The MCE is adjusted for site class effects as defined in Section 11.4.3,

SMS = Fa SS = 1.552

SDS - Design elastic response acceleration at short period (0.2 sec), from Section 11.4.4.

SDS= 2/3 SMS = 2/3 * 1.552 = 1.0347

The appropriate seismic acceleration is aH

= [ (0.4aPSDS) / ( RP / IP )] ( 1 + 2z/h)

= [(0.4 x 2.5 x 1.0347)/(3.5/1.0)](1 + 2 * 0.5)

= 0.59126

Check limits on aH:

aH <= 1.6 * SDS* IP = 1.6 * 1.0347 * 1.0 = 1.65552

aH >= 0.3 * SDS * IP = 0.3 * 1.0347 * 1.0 = 0.31041

aH = 0.59126

av = 0.2 SDS= 0.2 * 1.0347 = 0.20694

The software does not include the 0.7 multiplier in the seismic wizard calculations. Apply the multiplier in the load case definitions.

CAESAR II displays the calculated gravity factor on the Uniform Loads tab.