Luke Air Force Base Manhole Assessment And Lift Station Design
PRIME: EPS Group, Inc.
PROJECT OWNER: US Army Corps of Engineers
LOCATION: PHOENIX, AZ
BUDGET: $12 MILLION
COMPLETION: 2019
Evaluating existing structures can pose serious challenges due to often relying on incomplete or outdated information. Over 150 manholes needed to be evaluated, many of which were constructed out of brick and mortar around the 1950-60s. Many of the manholes to be inspected had both brick and precast concrete. The goal was to assess existing cracks, settlement, out of plane slipping, brick deterioration, mortar joint issues in brick manholes, and shear cracks and deterioration in the wall of the manholes through visual inspections. Organization of the assessment and standardization of the repairs would prove to be the greatest hurdle to overcome.
Prior to the assessment, Cornerstone determined that sorting the condition of the manholes into three categories would simplify the complexity of organizing the plethora of field data. These categories were deemed “Keep as is”, “Repairs needed”, and “Replace”. After performing the assessment and finding deterioration in the brick masonry manholes, Cornerstone determined that the sprayed-in-place liner procedure should be used. This repair method was chosen because it provides a long-term solution while also reducing the on-site construction time. In cases where repairing the damage exceeded the cost of replacing the manhole, a cast-in-place manhole was recommended to be used as a replacement.
Also, Cornerstone designed a lift station with a depth of 40 feet and a diameter of 11 feet at the base for the replacement sewer system. To ensure proper installation of this lift station, Cornerstone assisted the contractor by designing the shoring system.
