Ram Jack sponsored a large-scale shake table test at the University of California, San Diego to quantify the seismic response of helical piles in dry sands, the first of its kind. It was predicted that helical piles would perform well under seismic loads because their shaft is relatively slender compared to other foundation types. The slender aspect ratio of a helical pile helps dampen the destructive harmonics of an earthquake, which means that less of the shaking energy is transmitted to the supported structure. Seven earthquakes were tested, and nothing failed; the helical piles exceeded expectations for performance under seismic loading.
At the University of California, San Diego Ram Jack was apart of a groundbreaking test to show the perfomance of Helical Piles under an existing structure in seismic liquefaction zones. The test was funded by PEER (Pacific Earthquake Engineering Research Center) and was actually the first of its kind to be performed in the United States. The test was extremely successful in showing the performance of Ram Jack's Helical Piles in such conditions, a summary of the test is below.
During the first test there was no underpinning at all underneath the structure and it settled 11" when it went through the seismic event
During the second test there was 4 Ram Jack helical piles supporting the footing and with the same shake it only moved .5"
11" on a structure would likely cause it to collapse but .5" people would survive. Don't risk it, call Ram Jack West today!
Using Helical Piles for seismic upgrades allows us to mitigate a lot of the costs that is incurred by these seismic retrofits while having the least invasive solution.
Check out this case study below where Ram Jack designed and built customized micropile bracks for a seismic retrofit.