Award Date


Degree Type


Degree Name

Master of Engineering (ME)


Civil and Environmental Engineering

First Committee Member

Moses Karakouzian

Number of Pages



The high-level nuclear waste repository at Yucca Mountain includes tuff containing lithophysae or natural voids. This study investigated the effect of voids (porosity, distribution, shape and size) on the mechanical properties of cubes of analog lithophysal tuff (HydroStoneTB). A systematic study was made using three different randomly generated patterns of voids varying in shape, size, and geometrical distribution over a void porosity range of 0 to 30%. Each specified void pattern was cast into 6 in. length cubes, in triplicate, and was tested under uniaxial compression to find uniaxial compressive strength (UCS) and Young's Modulus (E); The results indicate that the UCS and E values decrease with increasing specimen void porosity. From solid specimens there is roughly an 80 percent drop in UCS and a 45 percent drop in E at about 20 percent void porosity. Shape and size of void has significant effect on UCS values, but not on E values. Comparing the three different geometrical patterns, no significant differences in properties resulted.


Compression; Geometry; Influence; Like; Lithophysal; Rock; Tuff; Uniaxial

Controlled Subject

Civil engineering

File Format


File Size

3328 KB

Degree Grantor

University of Nevada, Las Vegas




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