What the human eye can’t see

In North America, a large portion of the buildings and infrastructure built last century are nearing the end of their design life. Nowadays, the most commonly used practice for investigating the health of these structures is through visual inspections. While these are able to detect deficiencies, there are times where more subtle issues, that are invisible to the human eye, are present. These issues can often lead to smaller structural problems becoming a costly repair and can leave the structure in a dangerous state.

In response, the practice of data-driven investigations is slowly becoming common practice in the world of structural engineering. Today, we see new structures being outfitted with different methods of structural health monitoring, namely sensors that collect a variety of information such as velocities, displacements or temperatures. While these can show trends in the long run, they say very little about the immediate state of the structure.

The solution? Using highly sensitive sensors, the inherent properties of a building can be extracted, and the proper structural performance can be determined. Recently, we have partnered with the Canadian firm Sensequake who has developed such a system. By using their extremely sensitive and wireless ambient vibration sensors, a rapid and non- intrusive test can be conducted on the structure at hand whether it be a residential structure, a building with a complex shape or a bridge. This simple test can then detect any small imperfection in the structure and can give insight to our structural team as to where the issue may be, leading to more in-depth investigations.

While this approach can be used as a means of finding any initial concerns in a structure, it works best when used in a periodic fashion every few years depending on the importance of the structure. After the initial test is conducted, a simplified version can be performed to easily detect any changes in the building’s inherent properties.

With Sensequake’s unique approach to structural investigations and our team’s engineering capabilities, Okamoto Structural Engineering can provide to our clients one of the most comprehensive structural investigation packages available today.

If you have any comments or questions please contact Deysi Menjivar at JMC² Civil + Structural Engineering at dmenjivar@jmc-2.com, (310) 241-6550 x221, www.jmc-2.com.