CREWS GATHER UNDERWATER GEOTECHNICAL INFORMATION AT BOTH BRIDGE SITES
(July 2007) -- Engineers designing the new Downtown and East End Ohio River Bridges this month gathered information about the rock formations that will support the river piers for both bridges. Geotechnical explorations of the river bottom at the pier locations will provide information important to design of the river piers at both bridge locations.
The underwater surveys took place the weeks of June 18 and 25. A separate exploration will be executed for the shoreline piers, as well as the abutment on the Indiana side, at a later date.
“The drilling crew moved from near the Kentucky side to near the Indiana shore, following roughly the middle of the East End Bridge alignment, taking geotechnical samples at the river pier locations,” said Steve Slade, section design manager for the East End Bridge. “The tower piers, for instance, will rise approximately 100 feet above the water, so collecting accurate information about the bedrock in which they’ll be moored is vital.”
Special drilling equipment, mounted on a barge, was used to obtain soil samples every five feet from the bottom of the river to the top of the bedrock layer, a distance of about 40 feet, at each pier location. The drilling equipment then recovered continuous bedrock samples as deep as 50 feet into the bedrock strata.
Determining pier configurations is part of the preliminary design work now underway. During this stage of the bridge design process, bridge architects and engineers will incorporate public input in developing bridges that accent the two final bridge types selected last year. Stakeholder group meetings will be held to gather public feedback.
“We’re excited to be moving on to the detail work now that the bridge types have been selected,” said J.B. Williams, section design manager for the Downtown Bridge. “The public may forget that those ‘details’ include how the piers that support the bridge will be designed. Before we determine that, we have to collect as much information as we can about where those piers will be anchored.”
The results from the underwater survey will be reviewed in July and reported to the Bridges Project’s Bi-State Management Team. Pier design recommendations for both bridges will follow later this year.