Provo River Water Users Association – Siphon and Penstock Realignment
Mining operations created slope instability conditions as the headwall of a 300-foot slope continued to cut back towards the pipeline, posing a stability/rupture risk to this critical network. The project included relocating over 7,000 feet of 60- and 70-inch diameter welded steel pipe through steep terrain and abandoned tailings pond. Gerhart Cole provided geotechnical design services associated with relocating pipelines and stabilizing the hillside, including:
- Field Studies – 480 feet of Becker Hammer Drilling and penetration testing to characterize coarse-grained materials, mud rotary drilling, and fixed-piston sampling to characterize soft tailing deposits, and ODEX drilling/sampling.
- Laboratory Studies – consolidated drained triaxial testing to characterize drained friction angle and its degradation with increasing stress representative of hillside and stabilization berm.
- Seismic Hazard Assessments – given the project’s close proximity to several significant fault zones, both probabilistic and deterministic ground motions were evaluated to select design ground motions appropriate for a range of structural periods anticipated.
- Geotechnical Analysis/Design - design and construction of a 250-foot high stability berm to buttress the sloughing slope and stabilize the new pipe line alignments (static and seismic); stability evaluation for excavation cuts through tailings area.