U. S. Highway 90 Bridge
Burns Cooley Dennis, Inc. (BCD) was a subconsultant to HNTB providing geotechnical engineering and construction materials testing services for the Design/Build team. BCD's responsibilities included field and laboratory investigations, approach embankment analysis and dynamic pile testing. The field investigation consisted of 24 borings which included six embankment borings on land, 12 borings made within St. Louis Bay from a barge, two seawall borings and four retaining wall borings. The laboratory investigation included routine index tests, triaxial compression tests on clays and sands and consolidation tests. Settlement and slope stability analyses were performed for the embankments. Wick drains and a surcharge load were required to accelerate settlement of the east approach embankment. Geosynthetic reinforcement was required to improve the stability of the embankment. PDA testing (initial drive and multiple restrikes) was performed on 22 out-of-position indicator piles. BCD also provided construction materials monitoring and testing services that included concrete placement, embankment construction and asphalt roadway placement for the construction of the replacement bridge and roadway. The BCD/HNTB team won the 2009 Grand Conceptor Award for the project from the American Council of Engineering Companies-Mississippi (ACEC-MS) and also an ACEC National Honor Award as one of the Top 25 engineering projects by American engineering companies worldwide.