Owner: Veterans Administration Client: Proteus Scope: 173 Helical Piles, Ranging from 20-60 ft in Depth Location: Baltimore, MD Capacity: 80 Kips
Background: This project revolved around settlement of poorly placed fill between the buildings four stories of below grade construction and soldier pile and lagging wall installed to facilitate the basement construction. This settlement resulted in the disruption of utilities all around the building, considerable damage to all sidewalks and safety issues due to voids and tripping hazards.
The Problem: After years of patch work repairs, the Veterans Administration needed to facilitate the complete repair of all utilities and replace the sidewalks with a system that would not be affected by the up to 60 feet of bad fill between the construction retaining wall and the buildings below grade walls. This had to be accomplished while maintaining access to the building and pedestrian traffic on the sidewalks.
Solution: CCGI was contacted by the General Contractor to analyze foundations systems that could meet all of the constructability requirements, while delivering the required load transfer. After comparing the positive and negatives of several systems, such as Augered Cast in Place Piles and Mini Piles, CCGI determined Helical Piles would be the most cost effective solution.
The System: The Helical Pile produced several advantages over the other systems that were evaluated. The system does not require large cranes with swinging lead or crawler based mast rigs for installation. This size equipment would have proven impractical if not impossible to maneuver around the tight constraints of the site. The Helical System requires only a backhoe or mini excavator for installation. This also allowed for the continued use of the sidewalks without imposing safety hazards to pedestrians. By monitoring the torque during installation of the pile, a positive determination of every piles capacity could be made. This is known as positive capacity feedback and was crucial to the success of this project, as the quality and quantity of fill that had to be penetrated varied across the work site. Another benefit from this system is the lack of any spoil production, keeping the site clean and eliminating the costs associated with spoil cleanup and disposal.
Owner: Veterans Administration
The Problem: After years of patch work repairs, the Veterans Administration needed to facilitate the complete repair of all utilities and replace the sidewalks with a system that would not be affected by the up to 60 feet of bad fill between the construction retaining wall and the buildings below grade walls. This had to be accomplished while maintaining access to the building and pedestrian traffic on the sidewalks.