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Title: Three dimensional modeling of the wedge pillar portion of the WIPP Geomechanical Evaluation (Room G) in situ experiment

Conference ·
OSTI ID:5882636

Pretest 3-D finite element creep calculations of the WIPP wedge pillar experiment have been performed. The calculation shows that the horizontal closure of the drifts on either side of the wedge pillar increase with distance from the tip of the wedge. Vertical closure is greatest at the tip of the wedge and smaller, though not significantly smaller, at the opposite end. The relative shift of the drift walls parallel to the drift axis is greatest at the wedge pillar tip and drops off rapidly with distance along the pillar. At distances of approximately one drift width the parallel shift is small enough that the configuration could be analyzed with a 2-D plane strain model. The results of 2-D plane strain calculations at one station of the 3-D model compare very well with 3-D results (deviations less than or equal to1%). Maximum horizontal closures along the wedge pillar are approximately twice those calculated from a 2-D plane strain single drift model of Morgan and Stone, 1985 that includes stratigraphy. Maximum vertical closures are approximately 1.5 times those obtained from the single drift model. Stresses calculated assuming instantaneous drift creation on both sides of the pillar indicate that wedge pillar failure can be expected at the wedge pillar tip. The distance the failure will propagate is difficult to quantify since the material models did not include a failure criterion. Also the stresses predicted are probably higher than what could be expected with a realistic simulation of the mining sequence.

Research Organization:
Sandia National Labs., Albuquerque, NM (USA)
DOE Contract Number:
AC04-76DP00789
OSTI ID:
5882636
Report Number(s):
SAND-86-0412C; CONF-860609-3; ON: DE86007394
Resource Relation:
Conference: 27. U.S. symposium on rock mechanics, Tuscaloosa, AL, USA, 23 Jun 1986; Other Information: Portions of this document are illegible in microfiche products
Country of Publication:
United States
Language:
English