Abstract

Four series of centrifuge tests were performed using a model rock made from a mixture of sand, bentonite, cement, and water. Tests were conducted to determine the effect of horizontal and vertical discontinuities in the bedrock on the load settlement response of a rigid, shallow footing. A prototype footing, measuring 1 m × 1 m, was simulated in the study. Horizontal and vertical joints, in-filled with compressible material, were simulated by incorporating thin seams of styrofoam. Results from this study are compared to the commonly used methods used to predict the ultimate bearing capacity of footings on jointed rock mass. It is concluded that the existing methods to predict the bearing capacity are conservative for the range of design parameters studied in this research.

References

1.
Canadian Geotechnical Society
,
1992
,
Canadian Foundation Engineering Manual
, 3rd ed.,
Bi-Tech Publishers
,
Vancouver, Canada
.
2.
Coates
,
D. F.
,
1967
, “
Rock Mechanics Principles
,”
Department of Energy, Mines and Resources
,
Ottawa, Canada
.
3.
Dykeman
,
P.
and
Valsangkar
,
A. J.
,
1996
, “
Model Studies of Socketed Caissons in Soft Rock
,”
Canadian Geotechnical Journal
 0008-3674, Vol.
33
, No.
5
, pp.
747
-
759
.
4.
Indraratna
,
B.
,
1990
, “
Development and Applications of a Synthetic Material to Simulate Soft Sedimentary Rock
,”
Geotechnique
 0016-8505, Vol.
40
, No.
2
, pp.
189
-
200
.
5.
Kosar
,
K.
,
Phillips
,
R.
,
Becker
,
D. E.
, and
Turnham
,
J.
,
1997
, “
Physical Modelling of Foundations for the Northumberland Strait Crossing
,”
Transportation Research Record
, No. 1582,
National Academy Press
, pp.
8
-
12
.
6.
Kusakabe
,
O.
,
1996
, “
Foundations
,”
Geotechnical Centrifuge Technology
,
Taylor
R. N.
, Ed.,
Chapman and Hall
,
London
.
7.
Leung
,
C. F.
,
Khan
,
A.
, and
Ko
,
H.-Y.
,
1991
, “
Capacity of Drilled Piers
,”
Proceedings, Centrifuge '91 Conference
,
Ko
H.-Y.
, Ed.,
Balkema
,
Rotterdam
, pp.
269
-
276
.
8.
Leung
,
C. F.
and
Ko
,
H.-Y.
,
1993
, “
Centrifuge Model Study of Piles Socketed in Soft Rock
,”
Soils and Foundations
, Vol.
33
, No.
3
, pp.
80
-
91
.
9.
Pells
,
P. J. N.
and
Turner
,
R. M.
,
1980
, “
End-Bearing on Rock with Particular Reference to Sandstone
,”
Proceedings, International Conference on Structural Foundations on Rock
,
Sydney, Australia
, Vol.
1
, pp.
181
-
190
.
10.
Rosenbland
,
L. J.
,
1968
, “
Development of a Rock like Material
,”
Proceedings, 10th Symposium on Rock Mechanics
,
Austin, TX
, pp.
331
-
361
.
11.
Rowe
,
R. K.
and
Armitage
,
H. H.
,
1987
, “
Theoretical Solutions for Axial Deformation of Drilled Shafts in Rock
,”
Canadian Geotechnical Journal
 0008-3674, Vol.
24
, No.
1
, pp.
114
-
125
.
12.
Schofield
,
A. N.
,
1980
, “
Cambridge Geotechnical Centrifuge Operations
,”
Geotechnique
 0016-8505, Vol.
30
, No.
3
, pp.
227
-
268
.
13.
Stimpson
,
B.
,
1970
, “
Modelling Materials for Engineering Rock Mechanics
,”
International Journal of Rock Mechanics and Mineral Science
, Vol.
7
, pp.
77
-
121
.
14.
Teng
,
W. C.
,
1962
, “
Foundation Design
,”
Prentice-Hall
,
Englewood Cliffs, NJ
.
15.
U.S. Army Corps of Engineers
,
1996
, “
Rock Foundations
,”
ASCE Engineering and Design Guides
,
ASCE Press
,
New York
.
16.
Zhang
,
L.
and
Einstein
,
H. H.
,
1998
, “
End Bearing Capacity of Drilled Shafts in Rock
,”
Journal of Geotechnical and Geoenvironmental Engineering
 1090-0241 https://doi.org/10.1061/(ASCE)1090-0241(1998)124:7(574), Vol.
124
, No.
7
, pp.
574
-
584
.
This content is only available via PDF.
You do not currently have access to this content.