Page 13 of 35 First Next Previous Last

Rock mechanics in the investigation and construction of Tumut 1 Underground Power Station, Snowy Mountains, Australia

In addition to these well-defined localized structures the rock mass is extensively jointed. The joint pattern is similar in both rock types, but the spacing of the joints is usually much closer in the gneiss than in the granite, and the character of the joint surfaces also differs. The joint pattern often is not easy to discern, but measurements show that most joints can be grouped into three principal sets (Fig. 4, a,b,c). There is a considerable range of strike and dip within each set:

Set a: Strike N. 40°–60° E, and dip 35° SE. These are parallel to fault A.

Set b: Strike N.30° E. and dip 65° W. to 80° E. Although grouped together there are probably two distinct sets, one dipping steeply west parallel to fault B, and the other dipping steeply east. The strike of these joints makes a small acute angle with the long walls of the machine hall.

Set c: Strike N. 130° E. and dip 8O° W, These joints are spaced 40–80 feet apart but are very persistent. A single joint may split into two or more closely spaced joints. The joint surfaces are rough and irregular, and many joints are gaping open to ¼ inch. The strike of these joints is nearly at right angles to the long walls of the machine hall.

Practically all the large ground-water inflows into the excavations occurred along the joints of set c, whereas sets a and b were practically dry.

In the gneiss the spacing of the joints of sets a and b is generally 6 inches to 2 feet with some areas of narrower and some of wider spacing. The joint surfaces are usually smooth and slickensided. They are dark green due to an almost continuous thin coating of chlorite.

Clay coatings are not common. Most joints are tightly closed.

In the granite the spacing of the joints of sets a and b is variable but generally in the range of 1 to 5 feet. The joints are sometimes curving, and many die out in short distances. Slickensided joints are much less common than in the gneiss, and most of them occur along the joints of set a and in set b parallel to fault B, Most of the joints are not coated.

Plate 2. –
    Machine Hall of T.1 Power Station, with Downstream Wall on Right. 
    Excavation Completed

Plate 2. – Machine Hall of T.1 Power Station, with Downstream Wall on Right. Excavation Completed

Details for this article:

Rock mechanics in the investigation and construction of Tumut 1 Underground Power Station, Snowy Mountains, Australia

X

Author: Moye, D.G. (1958)

Article Title: Rock mechanics in the investigation and construction of Tumut 1 Underground Power Station, Snowy Mountains, Australia

From: Engineering Geology Case Histories

Other Available Articles

Engineering geology for the Snowy Mountains Scheme

Moye, D.G. (1955)

Engineering geology for the Snowy Mountains Scheme.

J.I.E.Aust., Vol. 27 No.10 pp287–298

Rock Mechanics in the Investigation and Construction of T.1 Underground Power Station, Snowy Mountains, Australia

Moye, D.G. (1958)

Rock Mechanics in the Investigation and Construction of T.1 Underground Power Station, Snowy Mountains, Australia

In Engineering Geology Case Histories No.3 123–54 Geological Society of America 69 (12) p.1617

Existence of high horizontal rock stresses in rock masses.

Moye, D.G. (1962)

Existence of high horizontal rock stresses in rock masses.

Proc. Third Australia-New Zealand Conference on Soil Mechanics and Foundation Engineering. pp 19–22

Seismic Activity in the Snowy Mountains Region and its Relationship to Geological Structures

J. R. Cleary, H. A. Doyle, D. G. Moye (1964)

SEISMIC ACTIVITY IN THE SNOWY MOUNTAINS REGION AND ITS RELATIONSHIP TO GEOLOGICAL STRUCTURES

Journal of the Geological Society of Australia

Unstable rock and its treatment in the Snowy Mountains Scheme.

Moye, D.G. (1965)

Unstable rock and its treatment in the Snowy Mountains Scheme.

Proc. 8th Commonwealth Mining and Metallurgical Congress, Australia & New Zealand. Vol. 6, p. 423–441.

Diamond drilling for foundation exploration

Moye, D.G. (1967)

Diamond drilling for foundation exploration.

Paper 2150 presented at I.E.Aust. Site Investigation Symposium, September 1966. In Civil Engineering Transactions, with Discussion, April 1967.

Geology in Practice

Moye, D.G. (1970)

Geology in Practice. Presidential Address Section 3, Geology, ANZAAS Meeting.

Australian Journal of Science, 32 (12) June, p454–461.

* This paper was presented when Dan had been Director of Exploration of BHP for 3 years.

Field and Laboratory Tests in Rock Mechanics

Alexander, L. G (1960)

Field and Laboratory Tests in Rock Mechanics

Proceedings, 3rd Australian-New Zealand Conference on Soil Mechanics and Foundation Engineering, Sydney Australia, 1960, pp. 161–168.

Discussion at Technical Session No. 9—Rock Mechanics

Alexander, L. G. Moye, D. G. (1960)

Discussion at Technical Session No. 9—Rock Mechanics

Proceedings, 3rd Australian-New Zealand Conference on Soil Mechanics and Foundation Engineering, Sydney Australia, 1960, pp. 254–250