Non Destructive Testing of Structures for Seismic Compliance 1

[abe]

I am looking into a device which is supposed to "measure" the ability of older structures to withstand earthquake forces. This is to be used on structures built abroad before the codes dealt with seismic design. Does such a device exist in the States?

 

[Qshake]

I've not heard of such a device and regularly perform seismic analysis, design and retrofit for structures.

I would hope that something of this nature would be documented through one of the many earthquake engineering databases. In that regard, I suggest you check

http://www.eeri.org

and look into the Earthquake Spectra. There is also a link on the EERI site to access another database. Check out the Quakeline database available at MCEER.

 

[Taro]

Seismic resistance is not a property that can be measured by a testing machine. Seismic resistance is a combination of strength and ductility that is designed into the structure by choosing material properties, member sizes, and proper detailing. There are many testing procedures you can use (magnetic, ultrasonic, etc.) that will give you information about the material properties and member sizes. However, that is just the beginning of the story. With that initial information, you must analyze the structure to determine if the capacity is adequate for the anticipated seismic demand.

You can make some preliminary judgments about seismic performance from the age of the building and structural system used. But to accurately predict seismic resistance you need an engineer experienced in seismic design, not a testing machine.

In the U.S., some good references to start with are distributed free of charge by the Federal Emergency Management Agency. FEMA 154, 178, 273, 306, 310, and 356 (and companion documents of supporting information) will get you started.

 

[Structuralist]

There are numerous ways to interpret the original message:
I have been involved with the retrofit of Unreinforced Masonry buildings in California for many years. There are test methods to determine the stength of the mortar (in-plain shear testing) where a brick is removed an a piston is placed in the cavity. The equiptment measures the first movment of the bed and head joints so that the strength of the wall can be evaluated. The UCBC Appendix Chapter 1 sets a minimum value for the strength of the wall in shear and this "push-test" is one of the evaluation tools.

From another side, the author of the original post may be talking about Risk Mangament - Probable Maximum Loss studies which are becomming much more popular as businesses and their insurance carriers are concerned with the risk and expected life of their investment.

There are many companies which specialize in Probable Maximum Loss reports and if this is what you are considering, then you might start by looking up companies that specialize in this area. In fact, there are some major players that subcontract to engineers around the country and train them to produce reports using their materials.

The California Department of Insurance has a webpage with CA Earthquake Liability Questionnaire Form and Instruction to perform a Maximum Loss Evaluation. This is located at their site at:

http://www.insurance.ca.gov/RRD/RSU/PML/PML2000.htm

I did a Google search on "Probable Maximum Loss" and found a great deal of information on this type of work.

Hope this helps. The Structuralist

http://www.structuralist.net

http://www.structuralist.net/cgi-local/yabb/YaBB.cgi

 

[ishvaaag]

What there is as well is a

Counterrotating eccentric weight vibration generator. You can see it in fig 3.3.1 in p. 81

Dynamics of Structures
Anil K. Chopra
Prentice Hall

from its use attached to one structure some experimental evaluation of some parameters relevant to seismic excitation can be gained. Since the excitation in any case quite different form an earthquake, and much limited in intensity by comparison, results are interesting but never give "the strength of the structure".