The Anatomy of A Challenging Construction Project, Extension of the Roadway Across a Celery Bog, West Lafayette, Indiana

摘要

Rapid population growth of West Lafayette, IN, adjacent to Purdue University, required the city to widen the road across the Celery Bog from two lanes to four. Celery Bog is a marsh containing thick deposits of peat and marl that fill a large kettle lake of Wisconsin age. Distance across the bog was about 800 feet. An embankment was required to raise the elevation of the road and to extend it from two lanes to four. The embankment portion across the bog failed as a classic rotational slump during construction. Some concerns have arisen in retrospect regarding the thoroughness of the exploration program, laboratory testing prior to construction, earthwork placement, and construction supervision. Next, to stabilize the bog crossing, grout columns were placed through the soft soils into the glacial till below. However, the subgrade mat below the pavement failed to transfer loads onto the piles, placed at six-foot centers, causing the road to develop a washboard effect. In an attempt to add stiffness to the subgrade the city repaved the road with an asphalt overlay but the washboard effect returned. As a last resort a bridge was constructed over the bog, which nearly doubled the cost of the road-widening project. Steel H-piles approximately 100 feet in length, were driven into the glacial till and gravel layer to support the bridge. The original cost of about S3 million was increased to about $ 12 million for the total road project extending about 6350 feet in length. Litigation between the contractor and the state highway department was conducted in an attempt to determine the cause of failures and the level of responsibility.