Evaluation of geotechnical properties of fused quartz for transparent material

Transparent soil surrogates permit nonintrusive three-dimensional deformational measurements in geotechnical model tests. Fused quartz saturated with a matched refractive index oil blend is an appropriate surrogate for natural sands. This paper carried out oedometer tests, consolidated drained (CD) triaxial tests and permeability tests on loose and dense oil-blend-saturated fused quartz. The geotechnical properties of compressibility, strength and permeability of the fused quartz were investigated experimentally and compared to those of natural sands and other transparent soil materials. An optimum transparency was obtained with a volume ratio of #15 white mineral oil and n-dodecane of 10:7.5 at room temperature. The dense fused quartz was less compressible with the coefficient of compressibility ( α 1-2 ) being 0.192 MPa -1 . The intrinsic permeability ranged from 18.7 to 31.5 darcys and the differences from the natural sands were ignorable. The peak friction angle ranged between 40.9 and 47.3°, which was within the typical range of sands. The test results show that fused quartz serves as an applicable surrogate in scaled model tests such as tunnel face stability experiments.