Accession Number:

ADA261114

Title:

Snettisham Hydroelectric Project, Alaska Second Stage Development, Crater Lake. Final Foundation Report

Descriptive Note:

Final rept.

Corporate Author:

LACHEL AND ASSOCIATES INC GOLDEN CO

Personal Author(s):

Report Date:

1992-09-04

Pagination or Media Count:

284.0

Abstract:

The important geologic features and methods used to construct the Crater Lake stage of the Snettisham Hydroelectric project, built between 1985 and 1989, are discussed. The project added 31 megawatts of non-polluting, renewable electric power for Juneau, Alaska and the surrounding area. Features of the report include the power tunnel and access adits, penstock excavation, surge shaft, gate shaft and lake top. Construction aspects include the general geology, design features, construction methods, geologic conditions encountered, ground support requirements, grouting, instrumentation and tunnel filling. Foundation conditions for the Crater Lake status were excellent, permitting the power and penstock tunnel and shafts to be constructed essentially unlined. The basic rock type throughout the project is a high-quality, quartz diorite gneiss with randomly spaced, subparallel basalt dikes.... Unlined rock tunnels, Power tunnel, Penstocks, Lake tap, Surge shaft.

Subject Categories:

  • Geology, Geochemistry and Mineralogy
  • Soil Mechanics
  • Electric Power Production and Distribution
  • Civil Engineering
  • Construction Equipment, Materials and Supplies

Distribution Statement:

APPROVED FOR PUBLIC RELEASE