Federal Reserve Bank of Atlanta- Birmingham Branch

The Federal Reserve Bank of Atlanta, Birmingham Branch is a 238,000 gross square foot bank operations Center located in Liberty Park just off Interstate I-459. The Birmingham branch is one of the most technologically advanced and security conscience buildings that has been designed within the last three years in the United States.

This major federal project incorporates state of the art structural, communications and security systems. The building was designed to be able to maintain operations throughout any natural or manmade diseaster. The facility is planned for maximum efficiency and future flexibility. The building is three stories with a basement and has a significant vault area. The column loads for this three-story building, due to the column spans, were relatively high and in the range of 1000 kips.

The Federal Reserve Bank had initially approached BHATE to assist in the site selection due to our extensive experience with subsurface conditions and underground mines in the US 280 corridor and the Liberty Park area. BHATE became involved with the project in January of 1996 after selection of the design team, to aid in the site selection process.

The presence of an abandoned underground coal mine was discovered by BHATE during a preliminary evaluation. The mine depth below the proposed structure was less than 100 feet and in some cases less than 75 feet deep. Coal mine maps indicated that the supports in the mine were removed as the mine was abandoned.

BHATE performed a routine geotechnical study, as well as a supplementary exploration program focusing on the mines. The mine exploration included eight air-rotary borings that were extended through the mine and into the strata underlying the mined coal seam. The air-tight rotary borings provided relatively fast and economical method of gaining information concerning underground mine conditions such as mine depth, the presence or absence of coal pillars, rubble and the extend of roof collapse or flooded conditions.

The exploration also included a borehole video camera survey of the strata and conditions at each of the accessible boring locations. The borehole camera provided a method of visually evaluating specific conditions within and above the mine. What was determined during this process was that coal had been extracted from beneath the future structrue, and the mine roof was partially collapsed beneath most of the building footprint resulting in small voids and fractures in the shale overburden. Also, some water had accumulated on the mine floor, however, a majority of the mine was not flooded.

The Birmingham Branch of the Federal Reserve Bank of Atlanta is an excellent example of creative engineering using innovated solutions that allow the owner to locate the building on the site of their choice. The building is also an example of teamwork between BHATE and the design team to solve a difficult problem.