Materiały konferencyjne SEP 2018

XXVII SCHOOL OF UNDERGROUNDMINING 2018 , Cracow, Poland PRINCIPLES FOR TESTING OF APPLIED BOLTS Convergence measurement:  Extensometers have to be placed every 25 m (geomechanical station)  Roof displacement have to be observed minimally 2.5m to the depth (5 m every 50 m)  Check of extensometers have to carry out every shift  Critical value of displacement is 2% of length used extensometr  Convergence measurement have to carry out in geomechanical stations  Critical value for convergence is 10% of size of roadway