Sector – Air Force Base, Government Facility, Office Building Upgrade
Location – Illinois
Application(s) – Hollow Bar Limited-Access Micropiles, Deep Foundations
The project consisted of upgrading the existing building at an Air Force Base. The upgraded building will be an advanced communication center that will include “black box” encrypted services and other “best of the best” communication technologies. The 1938 building had to be upgraded to newer, post 9-11, stringent building designs. Micropiles were chosen as the best solution to address new loading requirements and existing building construction challenges.
Requirements & Challenges
This work consisted of Micropiles being installed in a very limited access location, overhead clearance was approximately 9 feet.
Drilling spoils and drilling solutions would need to be brought out of the building for disposal.
This project was bid as a design build project. Loads were given per sheer wall, it was up to the micropile installer to come up with the number and depths of piles to meet the required compression, tension and lateral loads on each sheer wall.
The engineer of Record requested that the micropile installer design the pier caps along with the micropiles.
Helitech was selected as the micropile installer based on their expertise and experience in installing micropiles.
Helitech used their limited access rig to install approximately 20 foot of casing and ran hollow bar micropiles to depths up to 65 feet to achieve loads up to 252 kips in compression, 214 kips in tension, and 15 kips of shear.
Helitech designed and built the micropiles and pier caps for the various sheer walls. Helitech installed 232 total piles.
The micropile design was confirmed with the passing of three compression load tests. Installation of the micropiles were completed on time and on budget.
From the General Contractor
“The professionalism, timeliness, and quality of work that Helitech displayed throughout the project helped in its successful completion. Your work crews performed quickly and efficiently to get the job done in a safe manner. Your foreman did a great job working his crews in the existing building and we could count on receiving reliable work durations that helped us schedule other trades behind Helitech. We enjoyed working with your crews and the “team” attitude we received from you in the office, as well as Travis in the field, was much appreciated.”