Additional Eccentricity and Building Importance Coefficient in Existing Buildings

According to Earthquake Code Section 7, Article 7.4.8, additional eccentricity should not be applied in existing building assessment and strengthening projects. When the "This project is an existing building assessment and/or strengthening project" option is checked on the Project General Settings/Performance page, the program automatically disables the 5% additional eccentricity option.

According to Earthquake Code Section 7, Article 7.4.2: "In the definition of earthquake effect, the elastic (unreduced) acceleration spectrum given in 2.4 shall be used, but the building importance coefficient shall be taken as I = 1.0 regardless of the building's usage class." Therefore, the building importance coefficient is automatically set to 1.0 for existing building assessments.