Owner: Ridgecrest Client: Ridgecrest Scope: 40 Helical Piles, Ranging from 20-28 ft in Depth Location: Frederick, MD Capacity: 50 Kips
Background: The north side of this metal sided-open span building was built on non-structural fill in order to obtain the footprint required as it encroached on a hillside leading to the project settlement pond. Over the three years or so since the building was constructed, the column footings had settled, moving the interior slab with it. This movement initiated cracking in the slab and interior partition walls. The slab supports a full size roller hockey rink just inside the row of columns in question. CCGI was brought in to evaluate the issue and produce a plan to solve the problem.
The Problem: Stop the settlement of the exterior column footings without access to the inside of the structure, which had to be kept in service. This coupled with only five feet of access on the exterior of the building next to a slope dropping some 20 to 30 feet created unique access challenges.
Solution: In order to determine the most cost effective solution, CCGI started by initiating a complete geotechnical exploration and slope stability analysis in order to pin point the cause of the settlement. The study determined that settlement of poorly place fill and not slope failure was the cause for movement. We then turned our attention to physical solutions to the ongoing problem. This solution had to overcome the considerable access issues while delivering a permanent solution to the geotechnical problem. Our cost versus capacity analysis determined that Helical Piles would be the best option.
The System: After evaluating several systems from minipiles to ground modification CCGI determined that Helical Steel Piles would be the most efficient system to solve the problem. First, the Helical system provided more than the required 50 kip ultimate vertical component required to relieve the load from the fill and deliver the load to the residual weathered strata just above the parent bedrock. In addition the limited size of the equipment required for installation solved the considerable access problem. Another benefit of the system is the ability for the Helical pile components to be hand carried into the work area. The bracket for the Helical Pile System is the ideal connection detail for this type of foundation retrofit.
Owner: Ridgecrest
The Problem: Stop the settlement of the exterior column footings without access to the inside of the structure, which had to be kept in service. This coupled with only five feet of access on the exterior of the building next to a slope dropping some 20 to 30 feet created unique access challenges.