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E. Cording Mughieda, Omer Sulieman 2015-09-25T21:04:57Z 2015-09-25T21:04:57Z 10000-01-01 1997 1997 Jennings method which assumes full shear strength along joint and rock bridge is a useful reference condition. The Bridge Mobilized Strength Ratio, BMSR, provides a means of assessing how much of the reference strength along the bridge is mobilized. The MBSR is the ratio of (mobilized shear strength minus shear strength of joint) to (Jennings shear strength minus shear strength of joint), for the average normalized stress at failure. Conditions causing BMSR to be different from the reference value include: (a) for mode 1, shear failure in the plane of the joints through bridge and non-persistent joints, BMSR decreases, as the ratio of normal stress, $\sigma\sb{\rm n}$, to compressive strength, $\sigma\sb{\rm n}$/$\sigma\sb{\rm c}$, decreases below 0.2. (b) for mass stiffness $<$ bridge stiffness, and as number of bridges increases, progressive failure can develop reducing BMSR. (c) for the case of $\phi\sb{\rm j} \ll \phi\sb{\rm i}$, it was observed for single joints that the BMSR was above one. It is concluded that the higher value was due to concentration of the normal stress on the stiffer bridge, thus giving a higher shear strength than computed by Jennings method, which assumes a uniform normal stress distribution. (d) offset of joints reduces confinement and increases tensile stress conditions between joint segments causing a reduction of strength. Made available in DSpace on 2015-09-25T21:04:57Z (GMT). No. of bitstreams: 2 license.txt: 4848 bytes, checksum: 96035ab3f5e1c23cc7138a224ce498bd (MD5) 9812716.pdf: 7861640 bytes, checksum: fe598c56d500d4fcc133f176306807e0 (MD5) Previous issue date: 1997 Embargo set by: Seth Robbins for item 84726 Lift date: Forever Reason: Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs U of I Only 256 p. Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1997. http://hdl.handle.net/2142/83445 (MiAaPQ)AAI9812716 eng Engineering, Civil Failure Mechanisms and Strength of Non-Persistent Rock Joints text Civil Engineering Civil Engineering University of Illinois at Urbana-Champaign Dissertation Ph.D.