Location:
Salem Township, Auglaize County, Ohio

Owner:
Ohio Department of Transportation District 7

Project Completion Date:
2009

Project Description:
This is one of numerous task orders assigned to Barr & Prevost under a standing GES contract with ODOT District 7.  This project involved the replacement of a three-span continuous concrete slab supported on a pile foundation on S.R. 116 in Auglaize County.  The bridge spans an overflow channel of the St. Mary’s River. 

Barr & Prevost initially provided geotechnical drilling, testing and engineering to characterize subsurface conditions at the proposed bridge site and to provide foundation recommendations for the bridge replacement.  Two borings were drilled using a truck-mounted, Mobile B-61 rotary rig with 4.25-inch diameter, hollow stem augers.  Bedrock coring was accomplished by rotary drilling using an NQ size, diamond bit, conventional type, core barrel, with water as a circulating fluid.

Soil samples, rock core samples and field boring logs were recovered and tested in our AASHTO accredited testing lab.  All soil samples were tested to determine their in-place moisture content in accordance with AASHTO T-265.  Mechanical soil classification (Plastic Limit, Liquid Limit and gradation testing) was conducted on selected samples. Rock core samples were classified and evaluated to determine the RQD for each run. The final geotechnical engineering report included allowable stress analysis for foundations as well as analysis for foundation support of the continuous approach slab to alleviate future settlement and failure.

Based on the geotechnical findings, Barr & Prevost designed the replacement structure, a three-span concrete slab bridge made continuous with 25’ approach slabs.  The new bridge was designed using the Load Factor Design (LFD) method as set forth in the American Association of State Highway and Transportation Officials (AASHTO) Publication “LRFD Bridge Design Specifications 4th Edition”, and ODOT guidance.