Engineering Rock Mechanics

Additional points 309

2

and from these we find that

• vertical stress


• ‘\

and

1

a, = 4 x [ 2n P x 0.855 = 1.632 MPa.

17.3 Additional points

An International Workshop on Rock Foundations was held in association
with the ISRM 8th Congress in Tokyo in 1995, and the 70 papers
are published in Yoshinaka and Kikuchi (1995)4. In their preface, the
editors note that Terzaghi’s theory for the bearing capacity of soil was
systemized in the early 1940s, but related work on rock foundations
did not develop then because rock was assumed to be a sound material
compared to soil. However, the Malpasset Dam failure in 1959, which
was caused by the failure of foundation rock, stimulated the necessary
work.
Yoshinaka and Kikuchi also note that our modern infrastructure in-
cludes “high dams constructed on complex formations, highway bridges
built on slopes consisting of weathered and/or fissured rocks, high-rise
pylons for electric transmission lines, strait crossing long-span bridges,
and nuclear power stations” and all of these could be subjected to earth-
quake or other types of loading. Moreover, the processes of foundation

Yoshinaka R. and Kikuchi K. (eds) (1995) Rock Foundafimt. Proceedings of the Intema-
tional Workshop on Rock Foundation, Tokyo, Balkema, Rotterdam, 457pp.