Seismic Principles

Five Things You Should Know Before You Take the Test

The California Seismic Principles Exam is challenging and roughly half the people who take it each year do not pass. Keep the following five things in mind while you prepare.


1. You are going to have to work FAST. The exam has 55 questions to be completed in 2.5 hours, so you will have less than 3 minutes per questions on average. Increase your speed by:

  • working a timed practice exam (a free practice exam with solutions is provided on this site)
  • getting a reference book that has everything you need for each topic (explanations, formulas, tables, and examples) all on one page. The ultimate reference book is Seismic Principles.

2. You need to master the basics. There are handful of skills that are fundamental and required for a variety of problems. Fundamental skills include:

  • determining the Seismic Design Category (SDC) for a building
  • using the design base shear equations
  • finding a centroid (center of mass)
  • finding a center of rigidity

3. You need to learn how to analyze diaphragms. You may have learned about flexible diaphragms if you took a timber design class in school, but most people have never learned about rigid diaphragms. There is no description of flexible or rigid diaphragm analysis in ASCE 7 or the California Building Code so you will need an outside reference. The ultimate reference book is Seismic Principles, with two chapters and 47 fully-worked examples dealing with diaphragm analysis. The first few sections of Chapter 4 are available for free if you are ready to get started.

4. There are a few basic tables in ASCE 7 and the CBC that you should have tabbed and feel comfortable using. The most important tables are:

  • CBC Table 1604.5
  • CBC Tables 1613.3.3(1) and 1613.3.3(2)
  • CBC Tables 1613.3.5(1) and 1613.3.5(1)
  • ASCE 7-10 Table 20.3.1
  • ASCE 7-10 Table 12.2-1

5. It helps to be comfortable with basic structural engineering vocabulary and to know what stuff looks like. For example: diaphragms, collectors, chords, moment connections, continuity plates, backing bars, hoops, ties, purlins, reentrant corners, aspect ratios, sheathing, nonstructural components.

The book Seismic Principles has over 700 pictures and illustrations to help you see what everything is. Chapter 1 of Seismic Principles is available to everyone, and is a great place to get started.


Keep these five things in mind, and you are well on your way to pass. Good luck as you prepare for and take the exam.