The surface element technique: A new stress analysis method for excavation and tunnelling problems

Numerical modeling of rock stresses within a basaltic nuclear waste repository. Final report

“…The material properties of the basalt were assumed to be Shear Modulus G = 1.714 x 10^ MPa, Bulk Modulus K = 2.667 x 10^ MPa, and 3 a density of 2900 kg/m . The input motion was a vertical P wave applied at the base, that is the row of nodes where J = 1 in Figure VIII Figures VIII-6, VIII-7, VIII-8, VIII-9, VIII-10 and VIII-11 for zone centers (1,4). (2,4), (3,6), (3,7), (1,9) and (2,9), respectively.…”

“…The input motion was a vertical P wave applied at the base, that is the row of nodes where J = 1 in Figure VIII Figures VIII-6, VIII-7, VIII-8, VIII-9, VIII-10 and VIII-11 for zone centers (1,4). (2,4), (3,6), (3,7), (1,9) and (2,9), respectively. All stresses quoted in these figures are in Pascals (IPa = IN/m ) with a sign convention of tensile stresses positive.…”

“…Images are produced from the best available original document. II-l FIGURE II-2 FIGURE II-3 FIGURE II-4 FIGURE II-5 FIGURE III-l FIGURE III-2 FIGURE III-3 FIGURE III-4 FIGURE III-5 FIGURE III-6 FIGURE III-7 MESH PLOT OF FINITE DIFFERENCE GRID OF UNDER-GROUND ROOM HORIZONTAL (XX) AND VERTICAL (YY) STRESSES FOR CENTERS OF ZONE (1,4) Tables (continued) RHO-BWI-C-32 Page TABLE V-1 TABLE V-2 TABLE V-3 TABLE V-4 TABLE V-5 TABLE V-6 TABLE V-7 TABLE V-8 TABLE V-9 TABLE V-10 TABLE VII-1 TABLE VII-2 TABLE VII-3 TABLE VIII-1 TABLE VIII-2 In addition, the time frame over which the performance of the repository must be guaranteed is extremely long so that a full-scale demonstration over the life of a repository is impossible.…”

“…The input motion was a complete sine wave with maximum amplitude of 1 g acceleration with a period of 0.01 second. The horizontal and vertical stress histories at the center of zone (1,4) are illustrated in RHO-BWI-C-32…”

“…The porosity of the Intact basalt varies significantly depending upon the location within the flow. For flow tops, the porosity can be higher than 25% (Table II- 4); whereas the dense basalts are often lower than 1% (Agapito, et al"-J). From a hydrologic sense, the apparent or interconnected porosity is Important and because of the vesicular nature of the basalt pore spaces the apparent porosity can be significantly less than the true porosity.…”