Uniform Building Code (1991 Edition)
This spectrum data can be accessed by selecting the file “UBC_1991.spe” available in the folder “Spectrum Library” through Layout window >Misc> Spectrums > File > Library. This library has predefined spectrums for three (3) types of soils as shown in the figure below (taken from Uniform Building Code 1991 Edition).
Rock and Stiff Soils (Soil Type 1) [Library Name in CAEPIPE: RASS (S1)]
Deep and Cohesionless or Stiff Clay Soils (Soil Type 2) [Library Name in CAEPIPE: DCSCS (S2)]
Soft to Medium Clays and Sands [Library Name in CAEPIPE: SMCS (S3)]
These spectrums must be scaled by the Zero Period Accelerations (ZPA), which is the product of Z and I, where Z is the seismic zone coefficient and I is the earthquake importance factor as given in UBC Tables 23-I and 23-L. They are reproduced from UBC code for easy reference. This product can be applied in CAEPIPE as a scale factor through Layout window > Loads > Spectrum > Factor (s).
