Abstract
In conditions as fault zone, soft mudstone, etc., the ground around an opening made in it generates the plastic flow and it results in load on the supports. In such good conditions as granite, sandstone, etc., the ground around an opening relaxes due to ex-plosion, weathering, etc., and the supports bear the load due to relaxations.
This paper deals experimentally, in conformity to results of investigations in tunnels conducted by the author, with the rock pressure generated by the relaxation due to explosion, weathering, etc., and with the supports suitable to the openings in good ground.
