A Chronology of Improvements in the Building Code for Seismic Design

Considering the several chapters in the latest ASCE 7 that are devoted exclusively to seismic provisions, along with the sheer breadth of the exam you're currently preparing for, it may surprise you to know that the first structural seismic provisions in the United States weren't published until 1959. Not only that, but after the so-called "Blue Book" was published in 1959, the guidance remained largely unchanged until after the 1971 San Fernando Earthquake. 

Since then, the Uniform Building Code (UBC) and, more recently, the International Building Code (IBC), have been repeatedly updated to reflect new research, typically spurred by common failure mechanisms observed after a major earthquake. 

Below we'll cover some of the major earthquakes, the damage observed, and the developments in the subsequent codes. I hope this serves to provide some context to the seismic code provisions and sheds some light on the importance of seismic engineering. 

The 1933 Long Beach Earthquake 

The 1933 Long Beach Earthquake exposed the vulnerability of unreinforced masonry (URM) structures. According to the Federal Emergency Management Agency (FEMA), 86% of the URM structures in the city of Long Beach suffered significant structural damage or collapse as a result of this earthquake. This observed damage spurred the adoption of the Field Act of 1933 which, among other things, specified specific design forces for important public structures such as schools. 

The "Blue Book" (1959) 

In 1959, the Structural Engineers Association of California (SEAOC) published the first edition of the Recommended Lateral Force Requirements and Commentary (also known as the "Blue Book"), to standardize and share the latest seismic design knowledge. These provisions were later adopted into the 1961 UBC. 

One development in seismic performance that was adopted during this period was proper out-of-plane anchorage at the connection of wood framed members and concrete foundation elements. 

The 1971 San Fernando Earthquake 

In 1971, the San Fernando Valley (near Los Angeles) experienced a 6.5 magnitude earthquake, which killed about 60 people. 

Common damage observed included the failure of roof-to-wall anchorage in concrete tilt-up structures, which relied on a bolted wood ledger acting in cross-grain bending. This connection type was found to be inadequate and an update was nearly immediately made to the 1973 UBC. 

As more research was done after the earthquake, other provisions were written and added to the 1976 UBC. These included the first provisions on ductile detailing for concrete structures, increased design forces for wall anchorage in concrete tilt-up structures, and a change in the calculation approach to determine the shear capacity of wood-framed shear walls. 

Continued Research through the 1980s 

While there were no notable earthquakes that spurred code upgrades in the early 1980s, the 1982 and 1988 UBC editions included major improvements in seismic provisions and lateral force resistance. These improvements included stricter building drift limits, increased provisions for wall anchorage, and increased detailing for ductility in concrete and masonry shear walls. 

The 1994 Northridge Earthquake 

In 1994, the northern region of Los Angeles experienced another major earthquake-this one with a magnitude of 6.7, killing 57 people. 

The most notable damage observed following the Northridge Earthquake was in the form of failure at beam-column connections in steel moment frames. It was determined that the welded connections were inadequate in a major seismic event. Several improvements were developed with regard to welding technologies including an increase in weld-metal toughness requirements, the removal of backing bars, and the regulation of the workmanship and welding quality. The building code also moved away from using a prescriptive detail and moved toward performance-based criteria. 

Present and Future Codes 

Research continued following the 1994 Northridge earthquake, and several more improvements were adopted in to the 1997 UBC. The 1997 UBC is generally considered the "benchmark" building code for several building types, indicating that the seismic provisions developed by the adoption of this building code were sufficient for the life safety limit state. 

The building code will continue to evolve, and will no doubt become even longer as it does. I hope this gave some context to some of the major upgrades over the last 100 years and will get you up to speed with some of the lessons learned. 

References:

https://www.fema.gov/media-library-data/20130726-1442-20490-5595/fema_313.pdf

https://en.wikipedia.org/wiki/1971_San_Fernando_earthquake

https://en.wikipedia.org/wiki/1994_Northridge_earthquake

https://global.ctbuh.org/resources/papers/download/1664-developments-in-us-building-codes-for-seismic-resistant-steel-buildings.pdf

About the Author: Erin E. Kelly

Ms. Kelly is an experienced structural engineer with a focus on seismic risk. She has extensive experience in structural failure investigations, seismic structural design, and seismic risk assessments. Through the School of P.E., she has taught a 32-hour course for the California Seismic P.E. Exam, authored several blog posts, and contributed to other review products. She has a Bachelor of Science in Civil Engineering from Johns Hopkins University and a Masters of Engineering in Structural Engineering from Lehigh University.

My Personal Experience in Preparing for the CA Seismic Exam

My personal experience in preparing for the CA Seismic exam was a really rocky road. I hope that by sharing some of the lessons I learned along the way, you'll have an easier time than I did. 

I started this journey to licensure by taking (and luckily passing) the national P.E. exam in New York state. At the time, I wasn't sure if I'd be moving to California, so I decided to take the exam in New York, where I was living at the time. After moving to California, I had to reapply and take the state-specific exams in order to be fully licensed there. 

Lesson #1: The California state-specific exams are offered on a rolling basis and you MUST take the test in the quarter after you are accepted to do so. 

I had been working in California for nearly a year when I decided it was time to apply for the state-specific exams. It was April, so I figured I would have until late October to take the test, based on the schedule I was used to for the national exam. However, when my application was accepted in June, I found out that I would have to take both the Seismic and Surveying exams between July 1 and September 30. 

I was not prepared for this change in schedule. I had just started a new job, my boyfriend had just broken his leg, we had summer travel plans, and I had just committed to presenting at a conference in Europe for work in mid-September. There was NO WAY I was going to be able to study for and pass these tests. 

I applied to defer to the following quarter, and the board said no. So, in the end of July I accepted that I would try to study and pass these exams. 

Lesson #2: Studying for the Seismic P.E. exam requires a different type of studying than that of the national P.E. exam. 

The national exam varies from this one in that it is both very broad and very long. For me, 40 problems in four hours meant that I had ample time to look things up during the exam. I also found, particularly for the morning section of the national exam, that a lot of the questions are definition based. 

The seismic exam is very different-it's fast paced and most of the questions are calculation based. You really need to both understand the material thoroughly and be prepared with tabs and tables, etc..., in your reference materials. 

Unfortunately, I didn't know that at the time, so I modeled my studying around what I had done for the national exam, as that had given me a passing result before. I obtained a copy of The Seismic Design Review Handbook by Hiner (which I highly recommend) and skimmed it, cover to cover. I completed all the multiple-choice questions and felt pretty confident. When it came to the more calculation-based problems, though, I felt pretty uncomfortable. But, based on the national test, I figured that was probably an OK way to feel. I sat for the test and, as you may have predicted, the preparation I had done was not enough.

Lesson #3: Studying and learning can be so rewarding-for the test and beyond. 

My second time through I was not messing around. I paid for a course from School of P.E., I studied the review book much more intensely than I did the first time. I also borrowed a copy of the SEAOC Seismic Design Manual Volume 1 from my work and completed every problem in that book, too. Surprisingly, I started to enjoy the studying and learning process! Sure, studying on nights and weekends was hard but I was truly learning the materials, and it was having the adding benefit of making me better at my job. It seemed to me that it was truly a good thing for me to have failed and been given the opportunity to try harder the second time. 

Lesson #4: Results are released (typically) on the 10th of the month after you take the test. 

The last error I made (although this was is ultimately minor and had no lasting effect) was taking the test at the start of a month. I took the seismic exam on June 6 and didn't find out until July 10 that I had passed. That felt like an eternity. So, my final piece of advice to you is to take the exam at the end of the month so you can dramatically reduce the waiting period.

Best of luck! I hope you can learn from my experiences and maybe even enjoy the journey 

About the Author: Erin E. Kelly

Ms. Kelly is an experienced structural engineer with a focus on seismic risk. She has extensive experience in structural failure investigations, seismic structural design, and seismic risk assessments. Through the School of P.E., she has taught a 32-hour course for the California Seismic P.E. Exam, authored several blog posts, and contributed to other review products. She has a Bachelor of Science in Civil Engineering from Johns Hopkins University and a Masters of Engineering in Structural Engineering from Lehigh University.

Why It's So Important to Take the FE Exam in Undergrad

The Fundamentals of Engineering (FE) exam is a comprehensive test of the knowledge and experience that is obtained in undergraduate education. The FE is the first step to becoming a professionally licensed engineer. This exam is administered by the National Council of Examiners for Engineering and Surveying (NCEES), a non-profit organization dedicated to advancing the field of engineering through professional licensure for engineering and surveyors. 

According to the NCEES, there are seven disciplines offered for the FE. Currently, the FE is a 6-hour, computer-based exam with 110 questions. Candidates interested in taking the FE should register through the NCEES website. Applicants should check with their state licensing boards to fulfill any additional requirements. Each state has their own fee structure, education requirements, and other licensing guidelines. Typically, most boards require candidates to be attending or have graduated from an ABET engineering program. 

ABET stands for the Accreditation Board for Engineering and Technology. ABET is another non-profit, non-governmental organization that accredits post-secondary education programs in applied and natural science, computing, engineering, and engineering technology. According to the ABET website, accreditation is voluntary and provides assurance that a college or university program meets the quality standards of the profession for which that program prepares graduates. 

Since this exam is specifically designed to test knowledge and experience gained during undergrad at an ABET accredited institution, students are encouraged to take the exam during their college career. In some instances, this is not feasible. If the exam is not taken during undergrad, it is recommended that students take the FE immediately after graduating. The biggest reason that candidates take the exam during this time is because the material is still relatively fresh in their minds. Candidates are more familiar with the various concepts of the math, science, and engineering courses that are required within the specific engineering discipline. 

Other advantages of taking the FE during college are the on-campus resources available to students. Students can utilize libraries and other designated spaces to prepare for the exam with minimal distractions. Students also have a plethora of resources such as instructors, other students, and most importantly professors! The on-campus aspect also gives candidates the option for individualized tutoring sessions that are more difficult to source post undergrad. 

Students can also take advantage of group study sessions with other exam candidates. Additionally, preparing for the FE is easier during undergrad because the students are mentally more focused on institutional learning rather than other responsibilities such as having a full-time job. Full-time engineering jobs can be extremely time consuming and diminish the student's ability to focus and properly prepare for the exam. In some cases, ABET accredited institutions make it mandatory that students take and/or pass the exam. This can be a great motivational tool, but it can also be very overwhelming to students who still have their collegiate obligations. This can undoubtedly lead to extreme pressure causing severe test anxiety. However, the advantages of taking the exam far outweigh the disadvantages. 

If you are interested in taking the FE exam, School of PE can help you prepare for and pass your exam. Our FE exam prep courses include comprehensive lectures, practice problem and solution sheets, access to our FE exam Question Bank, and more! Click here for more information.

The Truth About Sustainability

Sustainability is a current theme among all engineering projects in today's world. This poses a challenge to engineers to design projects that encompass varying degrees of sustainability. 

According to the Environmental Protection Agency (EPA), sustainability is a simple principal premised on the balance between humans and nature. The overarching goal is for both to thrive harmoniously together in the present and future. 

There are many different definitions given to sustainability, and this adjective is dependent on factors including organization goals and stakeholder interest and input. 

According to youmatter.world, sustainability can be defined as the processes and actions through which mankind avoids the depletion of natural resources to keep an ecological balance so that our quality of life is not jeopardized. Youmatter goes on to explain that sustainability embodies three core pillars: economy, society, and the environment. These pillars are more informally seen as profit, people, and the planet. 

Historically, the National Environmental Policy Act (NEPA) of 1969 committed to sustainability by declaring it a national policy to create and maintain balance and fulfill the social, economic, and other requirements of the present and future, according to the EPA. Currently this topic has broadened, leaving way for varying influences and drivers. 

Sustainability encourages businesses to frame long-term decisions based on the three core pillars. This is opposed to the short-term goals of most businesses: profitability. According to Investopedia.com, a company's sustainability goal can be a commitment to zero-idling in company vehicles to reduce emissions by a certain percentage or ensuring that physical waste is disposed of properly to minimize the carbon footprint. In actuality, sustainability within companies began as an ethical response to public perception over "the long-term damage caused by a focus on short-term profits," Investopedia explains. 

Sustainability is a complex process. It can certainly involve higher upfront cost to implement efficiency and renewable sources, but this is more beneficial in the long run. Sustainability is most evident in energy generation. Electrical companies are moving toward sustainable sources such as wind, hydropower, and solar. Water infrastructure companies are focused improving water quality and exploring techniques for treatment that are environmentally friendly. 

Even though the framework of sustainability is positive, some experts argue that it is counterproductive and that there are little to no benefits for the environment. This is due to the green movement which promotes sustainable development. To be sustainable is to preserve and protect; to develop is to build or grow. The two words "sustainable development" together are misleading and represent two opposite ends of the spectrum. How can one grow and sustain? 

It is said that sustainable development excuses corporations, governments, and societies at large and it is truly enabling the destruction of the Earth. How can renewables save the Earth from future annihilation anyway? There is still the ever-present concern that habitats, the ecosystem, and the environment are all compromised with land development. So, instead of campaigning for sustainable developments, we should be advocating for sustainable nature that protects wild spaces, the entire ecosystem, and the species within these areas. This is when true sustainability happens.

What is the difference between the PE Civil Breadth and the PE Civil Depth Exam?

Are you thinking about taking the PE Civil exam? If so, you may be wondering what the difference is between the breadth section of the exam and the depth section. We've broken down the differences below:

Table of Contents

1. About the PE Civil Breadth Exam

2. About the PE Civil Depth Exam

3. How to Prepare for Both Sections of the PE Civil Exam

 

About the PE Civil Breadth Exam

What is the PE Civil breadth exam?
The breadth section of the PE Civil exam is a section that all examinees must take. It's often thought of as the "general" portion. The purpose of the breadth section is to test one's knowledge without going in depth into segmented specialties.

How many questions are on the PE Civil breadth exam?
The exam consists of 40 multiple choice questions.

What is the time limit for the PE Civil breadth exam?
The time limit is 4 hours.

Below are the topics that are found on the PE Civil breadth exam:

1. Project Planning
2. Means and Methods
3. Soil Mechanics
4. Structural Mechanics
5. Hydraulics and Hydrology
6. Geometrics
7. Materials
8. Site Development

From there, examinees then must take their chosen depth exam. 

About the PE Civil Depth Exam

What is the PE Civil depth Exam?
The depth portion of the PE Civil exam is considered the "specialty" portion of the exam. When registering for the exam, examinees must choose one depth to be tested on. The depth exam portion is given after the breadth portion.

How many questions are on the PE Civil depth exam?
The exam consists of 40 multiple choice questions.

What is the time limit for the PE Civil depth exam?
The time limit is 4 hours.

What are the different depths to choose from for the PE Civil exam?
There are 5 different depths one can choose from when registering for the exam: Construction, Geotechnical, Structural, Transportation, & Water Resources and Environmental.

Which depth to register for
It is recommended that examinees register for a depth exam that correlates with their career goals. For example, if one wants to focus on environmental civil engineering, they should register for the Water Resources and Environmental depth.

How to Prepare for Both Sections of the PE Civil Exam

We get that preparing for two different sections of an exam can be overwhelming, and we're here to help! If you're looking for a comprehensive review course that covers both the breadth and depth section of your choice, check out our PE Civil exam review course. This 84-hour review course is split into 2 sections. 56 hours of review is dedicated to the breadth exam and 28 hours are dedicated to the depth section of your choice.

What are PDH Engineering Credits?

If you're familiar with the engineering world or industry, you've probably heard the term "PDH." This three-letter acronym plays a big part in engineering license renewal. If you're wondering what it really means, and how it impacts the engineering community, learn more below: 

Table of Contents

1. What is a PDH?

2. What Engineers Need to Obtain PDH Credits?

3. How do Engineers Obtain PDH credits?

4. Do State Boards Differ in Their Continuing Education Requirements?

5. Why Do Professional Engineers Need PDH Credits to Maintain Their License?

What is a PDH?

PDH stands for "Professional Development Hour." In the engineering industry, those who are professionally licensed as an engineer in most states need to earn PDHs to maintain an active license. 

What Engineers Need to Obtain PDH Credits?

Currently, 42 out of the 50 state boards require some sort of continuing education and PDH for engineers. Engineers in those states who have taken and passed the Principles and Practice of Engineering Examination must participate in some sort of continuing education activity depending on their state board's requirements. 

How do Engineers Obtain PDH credits?

In most states, Professional Engineers obtain PDH Engineering credits by participating in continuing education activities. These activities can include attending webinars, going to an engineering conference, or taking a self-study online engineering continuing education course. 

Do State Boards Differ in Their Continuing Education Requirements?

Yes. Out of the 42 states that require some sort of continuing education, engineering state boards can greatly differ in their PDH requirements. For example, Texas has an annual renewal period while Kansas has a biennial renewal period. States requirements can also differ in the amount of PDHs an engineer has to obtain in their renewal period. Mississippi, for instance, requires an engineer to obtain 15 PDH credits for license renewal while Nevada requires 30 PDH credits. If you're a Professional Engineer, it's always a good idea to check with your state board to determine your PDH requirements for license renewal. 

Why Do Professional Engineers Need PDH Credits to Maintain Their License?

Engineers have a big responsibility in keeping the general public safe. Think about it- engineers design bridge structures, buildings, roadways, etc. By requiring engineers to obtain Engineering PDH credits to maintain an active engineering license through continuing education, states are able to ensure that their licensed engineers are up-to-date with different practices and technology.