EXAMINING ANISOTROPY OF SEDIMENTARY SOFT ROCK
关于沉积软岩固有各向异性特性的研究

The inherent anisotropy of stiffness and strength of about 2 million years old sedimentary soft mudstone was investigated using core samples obtained from 50 m deep testing tunnel. In the triaxial compression test, the elastic modulus and compressive strength of the samples with the axis being horizontal in-situ were slightly larger than those with the axis being vertical, but the difference is not larger than 30%. So, strong anisotropy of the stiffness and strength was not seen in the site. The inherent anisotropy would depend on at least the geological history, and original rock type and depositional environment should be considered.