Use of Instrumented Grouting Packer on Us Army Corps of Engineers Projects-PPT Presentation

PPT Presentation

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The report describes the development and use of instrumented packers for dam grouting. Rather than estimating downhole pressure from surface gauges and calculated line losses, an instrumented packer measures pressure directly at the injection point. This provides more reliable control of effective grouting pressure, reduces uncertainty, and can improve safety and treatment effectiveness.<br /><br />The US Army Corps of Engineers first used the technology at Wolf Creek Dam during 2011–2012 grouting. The site had a history of extensive remedial grouting and suspected hydraulic connectivity, making accurate pressure measurement especially important. Early packer designs encountered operational problems, including sticking, difficult servicing, clogged components, and time-consuming calibration. Later generations improved reliability and production, with one project completing hundreds of water-pressure tests and grout measurements.<br /><br />Further designs were used at East Branch and Rough River dams. Properly calibrated instrumented packers performed reliably despite varying line lengths, turbulent flow, and thicker grout mixes. They also helped identify poor seals, grout bypass, drill-fluid connections, and possible “false refusal” in real time. Direct measurements sometimes showed actual pressures were lower than calculated values, allowing more effective grouting per stage.<br /><br />The technology can also apply gravity-pressure injections through the packer without filling the entire borehole with grout, reducing washing, redrilling, time, and cost. Project results indicate that instrumented packers can be used without reducing production rates while improving pressure control and reducing risks to dam foundations and embankments. The report concludes that measuring actual pressure provides better data and greater certainty than relying on estimates.

Keywords

instrumented packer

dam grouting

downhole pressure

effective grouting pressure

US Army Corps of Engineers

Wolf Creek Dam

pressure calibration

grout injection

hydraulic connectivity

grouting safety