Study on Feasibility of Columnar joint basalt as a high-arch dam foundation
Rock Engineering 2009 - Rock Engineering in Difficult Conditions
yun jie wei, lian jin Tao, lei fan, jian zhu,
Abstract: Columnar joint basalt is a poor integrity and fractured rock mass, exiting a lot of small spacing structural planes. Through a comprehensive study of the columnar shape of columnar joints, rugosity of the fracture surface and the chemical composition of basalt, the primary genetic mechanism for the columnar joints of Bai hetan dam area is the condensing shrinkage effect of magma. Columnar joint basalt alteration is mainly chloritization, kaolinization, epidotization, tremolitization and the content of columnar joints is mainly chlorite by thin section identification and chemical analysis. Columnar joint basalt showed high uniaxial tension test, low coefficient of friction and high cohesion by indoor physical and mechanical test. Columnar joints rock mass showed high strength and large deformation by in-situ shear test and deformation test. Columnar joints basalt can be used directly as a foundation of dam as long as we follow the rules and reduce disturbance strictly.
Key words: columnar jointed basalt, high-arch dam foundation, in-situ mechanics test, deformation test, compressive strength
columnar jointed basalt, in-situ mechanics test, deformation test, Compressive strength, high-arch dam foundation