Did you know the conventional building codes profess a technique that gives highly uneconomical Seismic Retrofit solutions for buildings & bridges. This is because most engineers are taught analysis based on linear behavior of structures. It’s a well-known fact that structures don’t perform linearly. Therefore, much more advanced analysis software that captures “non-linear” behavior (or simply harnesses the hidden strength of the structure) has relatively recently been introduced in the market. These “non-linear” programs require a lot of as-built data of the existing building structure. On larger structures it’s almost commercially & practically impossible to implement. JMC² has partnered with Sensequake to implement a new technology that results in performing this advanced analysis without the need to perform the cumbersome task.

Team JMC² is excited to share their recent experience of implementing this art & science of Seismic Retrofitting that results potentially in reduced overall cost and putting money where it belongs. This is in collaboration with UC San Diego.

UC San Diego recently built a full scale 10 story wood frame building on their shake-table facility. This contraption can simulate the ground motion of an earthquake whose actual field data has been recorded or even those that have been artificially generated. So, this building will be subject to the most severe shaking of several large earthquakes before being tested to failure. The University was interested to see if the JMC²—Sensequake technology works.

The data collection for the non-linear program is done by placing sensors throughout the structure. The building information is collected as the sensors detect the building movement due to ambient vibration. Statistically this data is converted to the non-linear data already mentioned above, instead of manually inputting information into complicated non-linear software. When the data acquisition is complete our in-house model is subject to the same suite of earthquake records that UCSD researchers will subject their prototype structure and parallel non-linear program will be correlated with.

Our data collection & results have been completed and are ready to be compared with UCSD results to instill confidence in our customers and society in general. Please see the pictures showing how the building data was collected.

If you have any comments or questions please contact John M. Cruikshank, PE, President & CEO of JMC² Civil Engineering at jcruikshank@jmc-2.com, (310) 241-6550 x228, www.jmc-2.com.