... newdiscontinuitiesLess discontinuitiesinduced in good qualityrock mass4,1 4,2 4,34,44 ,5 4,6 5, 1 5, 2 5, 3 5, 4 5, 5 5, 66,1 6,2 6,3 6,4 6 ,5 6,6Larger caverns maybe created in betterquality rock massesFig. 13.2a ... therock mass is excavated4. Squeezing Minor squeezing(ua/a =1–2 .5% )Severe squeezing(ua/a =2 .5 5% )Very severe squeezing(ua/a =5 10%)Extreme squeezing(ua/a>10%)(Hoek, 2001)Rock mass ... cellsIn a particular section of a 3.0 m diameter tunnel at Yamuna Hydroelectric Project, inbrecciated, crushed and sheared shales supported by 150 ì 150 mm, H.H. Section R.S.joints spaced at 0 .5 m;...