In one of South Dakota’s most rugged regions, Iowa Trenchless delivered specialized trenchless installations for the South Dakota DOT’s multi-year reconstruction of Highway 385. Dense embankment rock fill, large boulders, and deep pipe runs made traditional jack-and-bore too risky, prompting Iowa Trenchless to propose a more reliable alternative: pneumatic pipe ramming.
Using TT Technologies pipe ramming equipment paired with the Casing Compass guidance system, the team installed multiple large-diameter steel casings—up to 54″—through difficult blasted rock embankments while maintaining precise line and grade for gravity-flow structures. Installations included:
- 176 feet of 54″ casing
- 214 feet of 54″ casing
- 134 feet of 42″ casing
- 146 feet of 42″ casing (final crossing anticipated Fall 2025)
The trenchless approach avoided deep open-cut excavations, preserved embankment integrity, and kept the massive roadway project on schedule. The result: safer roads above, and innovative engineering below.
