Latest News

Masonry buildings perform extraordinarily well in earthquake

September 13, 2011
KEYWORDS earthquake / IMI / masonry / seismic
/ Print / Reprints /
ShareMore
/ Text Size+
ANNAPOLIS, MD -- The International Masonry Institute [IMI] in Annapolis, MD, recently released some information regarding the performance of reinforced masonry structures during the 5.8 earthquake that centered in Mineral, VA, on August 23, 2011.

"Reinforced masonry structures performed extraordinarily well in the recent earthquake, particularly when you consider that most of these buildings were not designed for a 5.8 earthquake," said David Sovinski, National Director of Technical Service for the IMI. "This real world experience supports recent testing done on the behavior of properly designed masonry buildings. When you apply research from the laboratory to proper training for craftworkers and contractors, you have an unbeatable combination; well designed buildings that are built according to that design. This improves our public safety and the value of our infrastructure."

The August 23 earthquake illustrates some common facts and fallacies about building design and construction. Structural engineers excel at designing structures to handle predictable forces on a building, those coming from the weight of the building itself, the loads from the occupants and environmental loads.

What is less simple are the occasional, harder to predict seismic loads from earthquakes. These operate primarily from side to side, with the force and energy coming in waves. As one wave moves the building to the side it will continue moving due to inertia briefly until it then begins to return to its original position. As the ground shifts, the building will continue to sway back and forth occasionally resulting in damage or failure.

A common solution for structural engineers is to stiffen or provide enough ductility for the building to resist anticipated drift back and forth from the seismic loads. A cost effective solution is reinforced masonry -- combining the strengths of masonry and steel to provide a building system that can withstand seismic and other building loads.

Q. Why don't we just use West Coast building codes on the East Coast?

A. This is a common fallacy. Actually national model codes use Seismic Design Categories (SDC) in determining requirements for buildings. The SDC takes into account several factors, including earthquake potential, soil types and the type of building -- for example, hospitals may have additional requirements than perhaps a corner carry-out.

 

Q. So all codes, East Coast and West Coast are essentially the same?

A. No, local jurisdictions do have the ability to modify the national or model code. So, for example, the California state building code has stricter seismic requirements for their structures than say Florida, where wind loads are a higher concern.

 

Q. So the building codes on the West Coast are identical to the East Coast?

A. The national model codes do not differentiate by coast, but states frequently modify the national model codes when adopting them in their jurisdictions, so the California state building code for example, does have what is considered stricter seismic requirements for their structures.

 

Q. In the U.S., are there areas other than the West Coast where the SDC is high?

A. Certainly the West Coast is almost all in the higher seismic design categories (SDC), but surprising to some, there are areas in the Mid-west and East Coast that have SDC ratings as high as those on the West Coast. The New Madrid fault (located along the boundaries of southern Illinois, western Kentucky, western Tennessee, eastern Missouri and eastern Arkansas) is one such location, as is the area around Charleston, SC.

 

Q. How do masonry structures perform in an earthquake?

A. Extremely well. Testing in a laboratory environment and experience in actual earthquakes show that reinforced masonry is an excellent solution for seismic design. Recent research, including testing of full-scale buildings, showed that masonry veneer when connected to the back-up system per current code requirements performs very well under even extreme seismic loading.

 

"Since the building stock on the East Coast was not necessarily built with earthquakes in mind, it is gratifying to see how well the masonry buildings performed," said Sovinski.  "The more massive buildings naturally perform better, and the newer, reinforced buildings withstood the earthquake as well. Combining good design with good craftsmanship is critical. At IMI we have a special program of Grout Certification for craftworkers, and a Structural Masonry Certificate Program for contractors, which enables members of the International Union of Bricklayers and Allied Craftworkers and their contractors to build to the highest standards of design.

Did you enjoy this article? Click here to subscribe to Stone World 

You must login or register in order to post a comment.

Multimedia

Videos

Image Galleries

November 2013 Stone Products Gallery

Take a look at some of the latest stone industry products.

THE MAGAZINE

Stone World Magazine

April 2014 stone world cover

2014 April

In this month's issue of Stone World, check out an extensive preview of Coverings 2014, which will be celebrating its 25th anniversary in April. Also learn more about various types of limestone that were used to build private residences.

Table Of Contents Subscribe

Contemporary Stone & Tile Design Magazine

CSTD_Spring2014_Cover.jpg

2014 Spring

This issue of Contemporary Stone & Tile Design includes our annual focus on Kitchen and Bath design

Table Of Contents Subscribe

Training Program

How formal is your training program for new employees?
View Results Poll Archive

The Stone World Store

How_To_Polish_&_Restore_Mar.gif
How to Polish & Restore Marble Flooring

This video will show you step-by-step how to resurface and polish marble flooring from grinding and removing lippage and scratches to achieving a highly reflective polish.

More Products

Italian Trade Commission Coverings exhibitor preview

Italian Trade Commission logo 2

The Italian Trade Commission is presenting a large group of the most innovative and internationally renowned Italian suppliers of dimensional natural stones. We hope your busy schedule will allow you to join us for a “genuine” espresso in booth N. 4045 and explore the exciting Italian natural stone resources offered by our exhibitors. Check out Italian stone producers exhibiting at Coverings 2014 here!

  

Stone Industry Education

stone industry educationStone Industry Education is sponsored by Stone World Magazine and Marble Institute of America. The SIE events will help you: strengthen your skills, build your business, and  increase profit in your shop.  Check out stoneindustryeducation.com to register for upcoming fabricator and installer seminars.

STAY CONNECTED

facebook logo Twitter  YouTube