CAMP HUMPHREYS, South Korea—The U.S. Army Corps of Engineers, Far East District southern resident office, has been at the forefront of a PH-1 Defense Logistics Agency (DLA) warehouse construction project which began construction in Sept. of 2017.
This $54 million project is currently scheduled for an on time completion of Feb. 2021. Tony Hambrick, resident engineer, southern resident office, provided details on the warehouse.
“The project includes a 250,000 square foot (SF) general purpose warehouse and a stand-alone 20,000 SF hazardous material (HAZMAT) and Petroleum, Oil, and Lubricants (POL) storage facility isolated from the main warehouse,” said Hambrick. “The general purpose warehouse will be two-story reinforced concrete with EIFS finish for first floor level and 2nd floor construction and a PEB system for the 2nd floor level and roof construction.”
Hambrick went on to state that the warehouse will be climate controlled with floor to floor clearances up to 30 feet and floor load capacitates up to 500 pounds per square foot. The roofing system is stand seam metal roofing with insulation and vapor barrier on steel purlins.
The demolition of other structures within the area, along with site improvements, had to take place in order for the warehouse construction to be completed.
“The project included demolition of several existing buildings to include 300mm concrete pavement, concrete aprons, roadway pavement, fuel oil tanks, and various utility lines,” said Hambrick. “All demolition work is completed. New site improvements include a new concrete retaining wall due to limited site area, new paved access roads, perimeter security fencing, trucking yard, open storage yard, loading docks, parking areas, site electrical, various utilities and all features required for a fully functional warehouse. In addition, approximately 50,000 square feet of covered Pre-Engineered Building (PEB) swing spaces is required. The swing spaces were turned over to DLA in December 2018.”
The project is programmed to be LEED Silver Certifiable. LEED certification is an official recognition that a project complies with the requirements prescribed within the LEED rating systems as created and maintained by the U.S. Green Building Council. The LEED certification program is administered by Green Business Certification Inc.
As construction on the site has progressed, the FED SRO team had to overcome some trials to ensure the project stayed on track. According to Pak, Ki Hong, a southern resident office project engineer, there were two significant challenges associated with this project. However, the team was able to find solutions to aid in developing a quality warehouse.
“During test pile operation, the required design pile capacity was not obtained at the designed depth. It was revealed through a PDA test that the lack of pile capacity was the result from unpredictable high toe quake.” said Pak. Over 20 piles were broken or damaged during the test pile operation due to slippage occurring at the boundary of the overburden soil. Weathered rock and fatigue strength resulted from excessive pile driving over 300-400 blows.”
Pak stated that one of the solutions included conducting ten additional soil borings to better define the subsurface conditions. He went on to state that based on the soil boring data, the team tried to find the adequate pre-drilling depths to avoid pile damage and to meet pile design capacity.
Other solutions included, changing the pile installation method to pile socketing and to provide stable end bearing conditions at pile toe. Also test piles were performed under the conditions of deeper-predrilling and socketing, so finally no pile damages were observed and the required pile capacity was obtained.
“MND [Ministry of National Defense], CM [Construction Management], the contractor, and FED gave all efforts to reduce construction delay due to test pile installation,” said Pak. “FED came up with a technical solution, MND and CM gave all the administrative support on contract changes immediately, and the contractor immediately brought all equipment for additional testing so that we could minimize the loss of construction time and cost for this critical path activity. We didn't spend unnecessary time, and this quick decision would be impossible without the cooperation of the decision makers of each parties,” said Pak.
The second challenge was converting gravel pavement to AC pavement for the swing space areas.
“In the contractor design, swing space was supposed to have gravel roads, but the gravel road was deemed inappropriate for the operation of a forklift because forklift,” said Pak. “So, there was a concern from the user that the designed gravel roads may cause the load to fail or the forklift to overturn.”
The solutions included conducting onsite forklift operation testing right after the issue was raised. The contractor provided a temporary gravel road and the user brought in forklifts for operation testing.
According to Pak, the testing revealed that the gravel road failed to meet its required operation use. Through meetings and discussions between parties, it was decided to change from the gravel road to AC pavement, which was considered to be the most economical and easy to construct.
“This was also the critical path activity,” said Pak. “The DLA commander actively intervened in this case and decided to expedite this change. Also, MND and CM made an effort to expedite the contract change and tried not to spend time for unnecessary process,” said Pak.
Fabio Vallejo, a district quality assurance representative, highlighted two other challenges associated with this construction project.
Vallejo stated that coordination with the signal unit for higher access permissions to enable power outages at the start of the warehouse construction site was needed. Also, fire department coordination was needed due to the unknown ability of the adjacent hydrant water pressure capacity.
“To overcome these challenges, we needed the correct timing coordination with SATCOM to switch over to other systems so no interruption of services occured,” said Vallejo. “Water pressure testing and calculations for needed capacities for the warehouse and connecting office building was conducted.”
Vallejo highlighted a lesson he learned during the warehouse construction that he can take with him on future large structure projects.
“The method used to build the large structure allowed an efficient use of crews and time to move the project forward even when issues pop up,” said Vallejo. “The area was divided into four zones and four major crews followed each activity phase from one to the other non-stop.”
According to Vallejo, partnerships between the various agencies aided in the completion of this warehouse.
“Good coordination with the Garrison agencies (Fire department, DPW, Signal, DES, PMO) and DLA has been achieved throughout the project at every monthly meeting,” said Vallejo.
Lee, Hung Sub, a MND Defense Installation Agency project manager, stated that whenever there is an issue, the various agencies are able to resolve them during the monthly coordination meeting. He went on to mention that this coordination has aided in the overall success and on-time construction of this $54 million project.