Alternative Title

Paper No. 7.11

Location

St. Louis, Missouri

Session Start Date

3-8-1998

Session End Date

3-15-1998

Abstract

The U.S. Army Corps of Engineers, Jacksonville District, recently completed a grouting program in Ponce, Puerto Rico, for the Portugués Dam. The program compared microfine cement to Portland cement and helped determine the most efficient and economical method to construct the grout curtain. The foundation rock consists of volcanic sediments. A diorite stock upstream of the site altered the volcanic sediments by low grade metamorphism to metasediments, cause numerous radiating dikes and shears and a highly fractured foundation. Most of the fractures are relatively tight or healed. A bore hole video camera recorded in-situ fracture frequency, orientation and aperture thickness before and after grouting. The camera logs revealed that 58% of all the fractures were less than 0.02 inches thickness, the groutable limit for Portland cement. ln addition to standard Corps of Engineer water pressure tests, Modified Lugeon Pressure tests were conducted in exploratory core holes drilled after grouting. All of the pressure test data was then reduced to determine the rock mass permeability and compared with corresponding grout data. Various mix designs and pressures using both Portland and three microfine cements were experimented with. The standard injection refusal criteria time was adjusted and a "Duration Grouting" procedure, has been developed for the Portugués Dam.

Department(s)

Civil, Architectural and Environmental Engineering

Appears In

International Conference on Case Histories in Geotechnical Engineering

Meeting Name

Fourth Conference

Publisher

University of Missouri--Rolla

Publication Date

3-8-1998

Document Version

Final Version

Rights

© 1998 University of Missouri--Rolla, All rights reserved.

Document Type

Article - Conference proceedings

File Type

text

Language

English

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Grouting Evaluation Program of the Best Methods for Use of Microfine and Portland Cements During Treatment of the Rock Foundation at the Portugues Dam

St. Louis, Missouri

The U.S. Army Corps of Engineers, Jacksonville District, recently completed a grouting program in Ponce, Puerto Rico, for the Portugués Dam. The program compared microfine cement to Portland cement and helped determine the most efficient and economical method to construct the grout curtain. The foundation rock consists of volcanic sediments. A diorite stock upstream of the site altered the volcanic sediments by low grade metamorphism to metasediments, cause numerous radiating dikes and shears and a highly fractured foundation. Most of the fractures are relatively tight or healed. A bore hole video camera recorded in-situ fracture frequency, orientation and aperture thickness before and after grouting. The camera logs revealed that 58% of all the fractures were less than 0.02 inches thickness, the groutable limit for Portland cement. ln addition to standard Corps of Engineer water pressure tests, Modified Lugeon Pressure tests were conducted in exploratory core holes drilled after grouting. All of the pressure test data was then reduced to determine the rock mass permeability and compared with corresponding grout data. Various mix designs and pressures using both Portland and three microfine cements were experimented with. The standard injection refusal criteria time was adjusted and a "Duration Grouting" procedure, has been developed for the Portugués Dam.