Abstract:
This presentation discusses a case history where an innovate technology consisting of helical soil nails with high tensile wire mesh facing was used. Starting in 2018, construction began on a training room expansion and remodel at the Denver Broncos practice facility in Englewood, Colorado. Within the existing facilities, the expansion and remodel required the construction of a new basement which created the need for temporary shoring on four faces, totaling approximately 100 linear feet, to support vertical excavations of up to 10.5 feet. With limited access due to tight horizontal and vertical clearances, a helical pile soil nail wall with a high-tensile steel wire mesh facing and two rows of nails was designed and installed for temporary shoring along with helical pile underpinning of existing columns. The helical soil nails were 10-foot long, 1.5-inch square bar shaft with one 8-inch helix and three 10-inch helices. The 5-foot-long lead section contained two helices, and a 5-foot extension contained the remaining two helices. During installation, with roughly 1 foot of pile shaft extending beyond the face of the excavation, end caps were bolted onto the soil nails. The end caps mated up to the installation drive tool, and were driven into the soil. A thread bar was then installed into the cap, filter fabric and steel wire mesh facing were installed over the soil face, and the soil nails were fastened to the steel wire mesh with a plate and nut. This process was repeated for each cut of soil. Soil nails were successfully installed allowing the project to stay on schedule and on budget.