DBA is pleased to be part of the Kiewit Massman Construction (KMC) design-build team delivering the first transportation design-build project in the State of Arkansas, 30 Crossing. The project will improve traffic patterns and capacity along a 3-mile urban corridor of Interstate 30 from the Interstate 630 interchange south of downtown Little Rock to the Interstate 40 interchange in North Little Rock. The project includes replacing the existing bridge over the Arkansas River with two bridges supporting 12 lanes of traffic. 30 Crossing is the capstone project of the Connecting Arkansas Program (CAP), one of the largest highway improvement programs ever undertaken by the Arkansas Department of Transportation (ArDOT).
Teamed with designers Burns & McDonnell and HDR, DBA is the lead geotechnical and foundation designer for the navigation unit and north approach unit of the new river bridges. The bridge foundations are 10-ft diameter drilled shafts socketed into shale bedrock. Due to the project’s proximity to the New Madrid Seismic zone, design of the bridges included seismic considerations for critical operational class structures. Geotechnical seismic analysis included liquefaction triggering and lateral spreading evaluation. DBA worked closely with the structural designers to consider kinematic loads induced by lateral spreading and the interaction of substructure and superstructure components during lateral spreading events. The north abutment includes a column supported MSE wall embankment (CSE). The CSE ground improvement is included to mitigate performance and stability issues associated with shallow, soft alluvial silts and liquefaction hazards associated with deeper, alluvial sands.
KMC is self-performing the drilled shaft construction and CSE installation. To date, all of the eastbound bridge drilled shafts have been installed in the river and for the north approach. The ground improvement elements as part of the CSE beneath the eastbound embankment has also been completed. Once the eastbound bridge is ready for traffic in 2022, both directions of Interstate 30 will be temporarily shifted to the eastbound bridge, and the existing bridge will be demolished to allow for construction of the westbound bridge in its place.
Senior Engineer, David Graham, P.E., is the geotechnical engineer of record and has been involved in all aspects of the project form pursuit phase to current construction activities with significant contribution and guidance of Senior Principal Engineer and COO, Paul Axtell, P.E., D.GE. Senior Engineer, Ben Turner, Ph.D., P.E., G.E., lead the geotechnical seismic design and analysis effort. Project Engineers, Dan Ding, Ph.D., P.E. and Nathan Glinski, P.E., continue to be heavily involved in construction support and observation.
Photos Credit: DBA