Ultrafine Cement Tests and Drilling Warm Springs Dam

Clarke, William J.; Boyd, Millard D.; Helal, Maan; ,

Ultrafine Cement Tests and Drilling Warm Springs Dam

by William J. Clarke, Geochemical Corp, Ridgewood, United States,
Millard D. Boyd, Geochemical Corp, Ridgewood, United States,
Maan Helal, Geochemical Corp, Ridgewood, United States,

Document Type: Proceeding Paper

Part of: Geotechnical Practice in Dam Rehabilitation

Abstract:

Ultrafine cement was chosen by the Corps of Engineers for tertiary grouting the Warm Springs Dam because of its ultrafine particle size, low settlement, medium viscosity and longevity. The first half of the paper covers laboratory test results on M5 ultrafine cement obtained from Maan Helal's Doctoral Thesis on `Microstructure of Microfine Cement Grouted Sand and its Anisotropic Behavior', completed under the direction of Dr. Raymond Krizek at Northwestern University. In the second half of the paper, the Corps of Engineers report on precision drilling 300 feet deep holes close to a control shaft in the Warm Springs Dam. To accurately determine the position of the drill hole at any depth, subsurface surveying was necessary. Although the deviation from vertical exceeded 30 inches tolerance in some holes, it was not cost effective to hold strictly to these requirements provided the deflection was not towards the shaft. To drill long straight holes, it is recommended that thick walled drilling rods and/or large diameter rods be used in conjunction with percussion drilling. Portland Type II cement grout was used in primary and secondary holes which made up the outer ring of the test cell (Holes 1-15, Figure 8). Ultrafine cement was used in all interior holes. Water Cement ratio for ultrafine cement grout started at 3:1 mix and was decreased to 2:1 and 1:1 mix for hole 19. Laboratory tests results at these three water cement ratios, viscosity and strength behavior are discussed.

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