Week 3: Rock Mechanics

In true sense, it was a ROCKing weak. Prof Barbera started with brilliant comprehensive lectures on the basics of rock mechanics covering the geotechnical models, discontinuities, mechanical characterization of intact rock and rock mass and classification. She further took us to the Politecnico di Torino Geotechnics and Rock Mechanics laboratory DIPLAB (DIsaster Planing LABoratory) where we saw an army of triaxial apparatus for different requirements of tests apart from other soil and rock testing equipment. What intrigued us was the direct shear test machine for snow which was developed in PoliTo. We were also trained in DIPS software in the LAIB practising on a real time data provided by Prof Barbara. Prof Migliazza focussed on moderately fractured and jointed rocks in her lecture on unstable block analysis. She covered discontinuity surveys by classical methods and most advanced methods like Digital Surface Modelling by photogrammetry, laser scanner etc., by showing us results from actual projects comparing both systems and procedural approach of advanced methods.

Further Dr Russo introduced us various Geomechanical classifications studies on rock mass and their application in prediction of excavation behaviour and design choices and calculations. His lecture was beautifully structured into step-by-step methods of classifications by different authors from Terzaghi (1946) to Palmstrom (1995)’ He also explained us the most inclusive and widely used method in Geodata for Simplified approach for a preliminary setting of excavation behaviour formulated by him, GD Classification Rosso 2007 by involving us in classroom exercise. His lecture also presented a cross-checking of the reliability of the multiple graphs by documented Case-Histories. He shared with us alarming videos showing different types of rockbursts from various tunnelling sites around the world.

This week though being intensive and exhaustive ended with another brilliant lecture from where he introduced us different types of supports for conventional tunnels laying a great foundation for the lectures to follow. Prof peila discussed different types of rock bolts and shotcrete and the necessary aspects to take care while designing these support systems.