STRENGTH ESTIMATION OF COLUMNAR JOINTED BASALTIC MASS BASED ON GEOLOGICAL STRENGTH INDEX

The strength parameters of jointed rock mass are important to rock engineering design.The columnar jointed basaltic mass is special with columnar mosaic structure and the similar engineering case lacks.The strength of columnar jointed basaltic mass currently becomes an advanced research hotspot in hydropower project.This paper reviews domestic and international researches on strength of columnar jointed basaltic mass.Taking the columnar jointed basaltic at Baihetan Hydropower Station as an example,the GSI and Hoek-Brown Criterion are applied to estimate strength parameters of columnar mosaic blocky and cataclastic basaltic masses under different blasting damages.The result is proved by in situ tests at Baihetan Hydropower Station.It is concluded that the GSI-based Hoek-Brown Criterion can better reflect real strength parameters of columnar jointed basaltic masses.