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U.S. Department of Energy
Office of Scientific and Technical Information

Test plan: Heated axisymmetric pillar

Technical Report ·
OSTI ID:10155836

The Heated Axisymmetric Pillar in situ test in room H is an intermediate step in validating numerical techniques for design and performance calculations for radioactive-waste repositories. Because the completely isolated cylindrically shaped pillar is centrally located in an annular drift and is two-dimensional or axisymmetric, numerical calculations to predict the pillar response can nearly duplicate the configuration. The axisymmetric approximation applies to both structural and thermal fields. Consequently, to a first approximation the adequacy of the constitutive model at elevated temperature for a large 10,180-ft {sup 3} (950-m{sup 3}) in situ rock mass is being primarily explored in the test. Satisfactory agreement between measured and predicted response will aid in the confirmation that laboratory-generated constitutive parameters and models can be applied to large rock masses. The macrostratigraphy of clay seams, disseminated clay, anhydrite layers, and polyhalite contents, if any, will be well known because the entire pillar surface is exposed before the test. The surface of the pillar will be heated by an insulated blanket heater so as to increase its mean temperature by about 40{degrees}C in 3 years. Instruments will be installed to measure vertical and horizontal drift closures, deformations of the salt within the pillar and around the drift up to a distance of 50 ft (15.240 m) into the salt, and stresses (pressures) in the salt in the pillar and around the drift up to 50 ft (15.240 m) into the salt. Thermocouples will be installed to measure temperatures of the salt around the drift and pillar. Deformation and fracture of the pillar will be monitored by acoustic-emission triangulation. Also, fracture will be monitored by visual observations of the pillar surface at designated locations. Measurements will continue for at least 3 years.

Research Organization:
Sandia National Labs., Albuquerque, NM (United States)
Sponsoring Organization:
USDOE, Washington, DC (United States)
DOE Contract Number:
AC04-76DP00789
OSTI ID:
10155836
Report Number(s):
DOE/DP/00789--T272; ON: DE93012203
Country of Publication:
United States
Language:
English