By: Lane Enterprises, Inc
The Pennsylvania DOT project provided for the slip line rehabilitation of an existing 156 inch diameter steel structural plate pipe culvert crossing of State Route 3023 at White Creek in Susquehanna County, PA, located in the upper northeast corner of the state. The slip line pipe used for the rehabilitation was a 135 foot long, 132 inch diameter steel structural plate pipe.
With over 20 feet of cover over the existing 156 inch diameter culvert, the owner decided that rehabilitation by slip line was the most cost effective option. To meet a 100 year service life requirement, the structural plate ring composing the 132 inch diameter pipe consisted of 1 gage bottom plates, 3 gage side plates, and 10 gage top plates.
PennDOT originally designed for a 144 inch diameter slip line pipe, but a slight bend approximately 25 feet into the structure from the inlet necessitated the 132 inch pipe finally used to effect the pipe rehabilitation.
The slip line was effected by a repeated process of assembling short segments, connecting them to the previously inserted segment, and then sliding the combined section into the host pipe until the entire length was reached. At over 426 pounds per foot, ultimately the slip line process had to move over 57,000 pounds of reline pipe on a rail system by pushing at one end while pulling on the other.