Abstract
This article deals with some examples of geological investigation methods and matters to be considered with respect to geological f easibility in the reservoir which is to be founded on karstified or calcareous rocks. The illustrated reservoir to be planned by EGAT (Electricity Generating Authority of Thailand) is on the Quae Yai River in western Thailand. In connection with the technical co-operation extended to EGAT, EPDC has been carrying out the detail design of the dam (rockfill type; crest length 615m and maximum hight 140m) and geological investigation of the reservoir (surface area at NHWL, 404.65km2 and total strage capacity, 17, 200×106m3). The investigation methods of the reservoir site mainly consist of geological interpretation by air-photos, geological mapping, hydrogeological survey, some core borings and laboratory tests on the samples of rock, and water which were collected during the field survey.
Judging from the geiologic conditions revealed as a result of the recent investigations, EPDC has reached the conclusion that the fear of leakage which had been entertained is almost entirely eliminated.
