Pipestem Dam Slide Remediation-PPT Presentation

PPT Presentation

Pdf Summary

Pipestem Dam, near Jamestown, North Dakota, was built in the early 1970s for flood control, wildlife enhancement, and recreation. In April 2024, a landslide occurred during excavation for a spillway modification project, affecting approximately 40% of the planned roller-compacted-concrete terminal structure.<br /><br />To remove unstable material before winter, the owner, general contractor, Keller, and Braun Intertec developed an accelerated remediation plan. Design and work-platform approvals were completed between May and early July. The platform used benches, drainage measures, and cement-treated material to support drilling equipment and stabilize the active slide area.<br /><br />The earth retention system consisted of 85 rock-socketed, 30-inch-diameter drilled soldier piles with double-channel beams, lagging, and two rows of temporary tieback anchors bonded in shale. Construction proceeded from August through October. Crews encountered boulders, cobbles, and wet sand, and excavation stopped short of the full planned depth after subsurface conditions differed from expectations. The wall was backfilled, anchors detensioned, and lagging removed before the winter shutdown.<br /><br />Key lessons included incorporating adequate structural reserve, clarifying the owner’s design objectives and evaluation requirements early, dedicating staff to coordination and communication, and drawing on the complementary expertise of the design team, contractor, and owner.

Keywords

Pipestem Dam

North Dakota

landslide remediation

spillway modification

flood control

roller-compacted concrete

soldier piles

temporary tieback anchors

construction coordination

shale excavation