A BIG thank you to Kirk Ellison, Andrew Yeskoo and Adrian Crowther of ARUP for the excellent field tour on Friday January 31st. We visited the deep excavation of Salesforce Tower where we heard about the project from both ARUP and the contractor, Clark Construction. We discussed, in depth, the innovative barrette foundation elements being used to support the building core. Next, we visited the Park Tower site in the early phases of pile installation. Fresh samples of Franciscan Bedrock were passed around as we discussed the challenges it posed for design. Finally, the we were treated to a lesson in seismic structural design when we toured the under construction, 181 Fremont Tower. We witnessed the mega-column support system in the building’s lobby before going to the 10th floor for a discussion on the structural damping system and some excellent views of the under construction Transbay Transit Center. Here are few photos highlighting the tour.
Altamont landfill is nestled in the rolling hills of Livermore, CA and has been around since the 1980s. As all active landfills do, its been steadily growing to accommodate our daily wastes. Expansion of the Altamont landfill has converted a nearby rolling hills site (visited by GGSS in 2012) into a big excavation that we were able to visit. Thanks to Geosyntec, we got to have a close look at how the site is engineered to prevent watertable contamination while maintaining slope-stability. Special thanks go to Chris Hunt for providing the tour and the schematics seen below.
You can’t miss the entrance.
The meeting room had a to-scale version of the engineered foundation of the landfill showing the different layers.
Pumps used to extract leachate from the bottom-most permeable (gravel) layer of the liner.
Near the pumps was this minimap showing the layout of the tubes.
Overview of the construction-site
Geotextiles are sewn together by some pretty rugged grandmas.
Detail of the geotextile used to make an impervious barrier that keeps leachate out of the ground-water system.
Local fauna (cat).
We could see the bottom drain being built and shaped precisely* according to the engineered solution (*close enough).
On October 28th. we had a field trip, thanks to DrillTech and especially Mike, to Folsom Dam construction site. The main concrete wall of the dam was finished with most of the infrastructure in place. Geotechnically, the trip was interesting because of the curtain wall grouting was taking place. We got to see the grouting process and talk with the experts about how its done and how they make sure the job is done right.
Additionally, we saw huge volumes of land movement and could talk to a geologist about the local geology and what they had found out by building the dam.
On January 25th, 2013 GGSS members toured the Transbay Transit Center Project in San Francisco, California. The trip was made possible by Stephen McLandrich and Michael Gardener of the ARUP San Francisco office and included both a presentation about the project and a full site visit. The project which is taking place near the corner of First and Mission Streets in downtown San Francisco involves replacing an old existing terminal with a new larger transit center. The Transbay Transit Center will serve as a regional hub and connect 11 different transit systems including the future California High Speed Rail.
GGSS members had the pleasure of touring the project excavation while accompanied by Stephen and Michael who explained the interesting geotechnical aspects of the project. All of GGSS would like to thank both Stephen McLandrich and Michael Gardener of ARUP for taking the time to be with us and providing a wonderful and exciting day!