Publications Details
Thermal expansion as a function of confining pressure for welded tuff from Yucca Mountain
Thermal expansion measurements were conducted as a function of confining pressure on welded specimens of Topopah Spring Member tuff recovered from borehole USW SD-12 at Yucca Mountain, NV, Each specimen was tested at confining pressures between 1 and 30 MPa over a nominal temperature range of 25 to 250 °C. On several specimens, the higher confining pressure thermal cycles were performed first to inhibit thermal effects, such as cracking, that occur at lower confining pressures in other rock types. The coefficient of thermal expansion for welded tuff increases with temperature. At temperatures below 100 °C the mean coefficient of thermal expansion range from 7.7 to 10.8 x 10-6 °C-1. As temperatures approach 250 °C, the thermal expansions increase markedly to values of 14.2 to 20.6 x 10-6 °C-1. The effect of confining pressure on thermal expansion for tuff is small.