In 1999, the City of Meridian, along with its contractors, made history by installing the largest pipe ever seen in the State of Mississippi. This massive Horizontal Ellipse pipe, measuring 28 feet across at its widest and 17 feet high at its tallest, was placed in a drainage easement on the property of Bill Ethridge Lincoln Mercury on the North Frontage Road on I-20 / I-59 in Meridian. Spanning approximately 400 feet, the pipe began at a concrete box culvert and terminated at an outfall to the Sowashee Creek.
Constructed on-site with plates fabricated by Contech, the pipe served its purpose for several years, with the surface above it used as a parking lot until 2015. However, on November 7th of that year, the pipe collapsed.
Design Engineering Inc (DEI) was retained to evaluate the conflicting expert reports and identify the most likely cause of the structure’s failure, as well as assist in the assignment of fault. DEI’s team performed an extensive review of multiple model results, construction reports from 1999, and evaluations of the engineering performed during the initial design, and the subsequent work that was completed immediately prior to the collapse. They were also provided with various video angles of the property before, during, and after the collapse.
DEI conducted site visits across the large basin to identify signs of increased erosion that would add to the sediment load of the drainage flow, and performed structural analysis to determine the likely loading required to cause a collapse in such a pipe when new, and after 20 years of normal wear and tear.
Our findings revealed that the initial design (20 years prior) did not account for an increased sediment load and the corrosive condition of the surrounding soils, leading to corrosion of the pipe making failure inevitable.