John W. Andrew, P.E.

Course Outline

This course highlights the earthquake regulations of ASCE 7-05, Minimum Design Loads for Buildings and Other Structures, Chapters 11-13 and 15-23.  The course is designed to help architects and structural engineers get familiar with the latest requirements for determining the seismic response coefficient (Cs) and the seismic design category (SDC) for typical low rise buildings.  A copy of ASCE 7-05 is required for this course.  A downloadable Excel© spreadsheet is provided to assist with the calculations.

This course includes a multiple-choice quiz at the end, which is designed to enhance the understanding of the course materials.

Learning Objective

At the conclusion of this course, the student will be able to:

• Determine the occupancy category and seismic importance factor;
• Determine the response modification factor;
• Determine the spectral response accelerations;
• Determine the fundamental period of the building;
• Determine the seismic response coefficient; and
• Determine the seismic design category.

Intended Audience

Structural Engineers and Architects.

Benefits to Attendee

The determination of the seismic response coefficient and the seismic design category are required for the design of buildings subject to earthquake ground motions.  The seismic response coefficient is used to determine the magnitude of the seismic horizontal forces to which the building will be subjected.  The seismic design category determines permissible structural systems, height limits, permissible analysis procedures, detailing requirements and requirements for nonstructural components.

Course Introduction

The seismic response coefficient, Cs, is used to determine the design seismic base shear using the equivalent lateral force procedure in accordance with the provisions of Section 12.8.  The design base shear is the product of the seismic design coefficient, Cs, and the effective seismic weight of the structure, W.

The SDC classification is important in the seismic design of a building.  If a building is classified as category A, then the building may be designed in accordance with Section 11.7 only.  Each subsequent letter classification (B through F) results in an increase in seismic design requirements.  This includes permissible structural systems, height limits, permissible analysis procedures, detailing requirements and requirements for nonstructural components.

The earthquake provisions of ASCE 7-05 chapters 11-13 and 15-23 are based on the 2003 NEHRP Provisions.  Calculation of the seismic design coefficient, CS, is based on the spectral response accelerations, seismic importance factor, fundamental period of the building, long-period transition period and response modification factor.  These factors are determined using the occupancy category, site class and building period coefficients.

Course Content

The course content is in the following PDF file:

You are also requested to study the Spreadsheet in Excel:

CE_Seismic.xls

Please click on the above underlined hypertexts to view, download or print the document for your study. Because of the large file size, we recommend that you first save the file to your computer by right clicking the mouse and choosing "Save Target As ...", and then open the file in Adobe Acrobat Reader.

Course Summary

This course covered the latest requirements for determining the seismic response coefficient (Cs) and the seismic design category (SDC) for typical low rise buildings in accordance with ASCE 7-05.  A downloadable Excel© spreadsheet was provided to assist with the calculations.