The Art of Historic Preservation

Saturday, August 18, 2012

Seismic Retrofit of Carmel Mission

Chapel at San Carlos Borromeo' de Carmelo Mission
"Carmel Mission"

 Carmel Mission, Circa 1880
A recent blog post introduced the seismic retrofit project underway at the historic Carmel Mission in Monterey, CA.
Blach Construction, a Silicon Valley leader in construction technology, has been asked to assume the task of completing the retrofit of the historic Mission's attic and ceilings while minimizing the impact to the daily operations of the Mission. No easy task given the myriad functions of the Mission's campus/facilities. Founded in 1771, San Carlos Borromeo' de Carmel Mission stills holds regular mass and church services, is home to the Junipero Serra School, operates a museum and a retail store. As you can imagine, disruptions caused by construction could have major negative impacts on tourism, class schedules and services.

Carmel Mission, 1915
The retrofit of any historic building has its challenges. Buildings built by hand over 2 centuries ago are uniquely challenging. Traditional construct methods called for a large section of the roof to be removed for access to the attic. The next step would involved detailed measurements and documentation of the structure and the condition of the construction materials. This process could take several days, and require a number of workers to do the job. The roof would need to remain open for the duration of the project, covered by a tarp of some sort. An exposed roof and active construction area means safety concerns, noise issues, parking concerns and restricted traffic flow in areas affected by the project. Inevitably , there would be some negative impact to the daily operation of the Mission, the objective of contractors would be to minimize the impact as much as possible.

Collector- Carmel Mission Attic
Laser Scans Courtesy of Blach Construction
Blach Construction's approach to this project is to utilize technology that can help bridge the gaps between project requirements, customer service, safety and profitability. Working with FARO Laser Scanning equipment and Point Tools Software, the crew at Blach Construction were able to scan the attic of the Mission over the course of several days. The scanning process required no major construction work or demolition. The footprint of the project is greatly reduced, the disruptions such as noise are practically non-existent.There is no need for large work crews; the data is collected quickly and efficiently. This all translates into a more streamlined process. There is less labor involved. The data is collected quickly and precisely. There is no need to return to re-measure or confirm previous findings. The impact to business operations is minimal. Customer service is improved. The end result is the accurate collection of massive amounts of data for a fraction of the labor cost.
Collector- Carmel Mission Attic
Laser Scans Courtesy of Blach Construction

The data gathered from the laser scan has all the details and information necessary to analyze the condition of the materials, the ceiling joist, rafters and ties. The users can access the information to design the supporting structure for the seismic retrofit and/or plan future preservation projects.

Ceiling Truss- Carmel Mission Attic
Laser Scans Courtesy of Gino Cecchettto, Blach Construction

Gino Cecchetto, Manager of Blach Construction's BIM Programs, is heading up the seismic retrofit project at Carmel Mission. As previously mentioned, Gino is one of the most knowledgeable BIM professionals in the business and has been instrumental is establishing Evergreen Valley College's BIM/VDC programs. While the benefits of laser scanning has been well documented, this particular project has demonstrated the true value of the technology. The ability to seamlessly capture information with little or no impact on the surrounding environment is a key advantage to this technology.

Ceiling Truss- Carmel Mission
Laser Scan Courtesy of Gino Cecchetto, Blach Consturction

San Carlos Borromeo' de Carmelo Mission
Mission Carmel