Tasks Performed: Consultant responsible for providing an analysis of the geologic conditions for the development and installation of the rock mechanics instrumentation used to monitor the stability of the cavern and performance of the support system.
Duration: 1963-1967 (48 months)
Description: The Veytaux underground machine hall is a pumping and generating station, which is part of the Hongrin-Lehman Hydroelectric Development. The cavern is 135.5-meters-long, 30.5-meters-wide and 26.85-meters-high, and is located in marly limestone and limestone schist which is considerably fractured. The Veytaux cavern is the first large underground excavation which was constructed in accordance with the principles of the NATM by selecting pre-stressed rock anchors and pneumatically applied concrete as a support system. Tendons of 170 tons and 125 tons were used. The whole excavation, a total of 78,000-cubic meters, was completed in only 17 months.