EVALUATING A ROAD CONSTRUCTION FAILURE, SEMESTER PROJECT FOR CAPSTONE COURSE IN APPLIED GEOLOGY

The capstone course for senior undergraduates in environmental and engineering geology at Purdue University focuses primarily on a major construction project involving applied geology aspects. This is patterned after the Senior Design course that Civil Engineers take as a final course of study. In Spring 2006 the semester project involved the expansion of an existing road over a bog containing thick deposits of peat and marl. It was located near the University so that field investigations were possible. An embankment was required to raise the elevation of the road and extend it from two lanes to four. The embankment failed, as a classic rotational slump during construction, and to stabilize it, concrete piles were placed through the soft soils into glacial till below. However, the subgrade mat below the pavement failed to transfer loads onto the piles and the road developed a roller coaster shape. Design and construction documents including the subsurface investigation were available for the project. The class was able to decipher these complications through a series of weekly problem sets and calculations.