1. INTRODUCTION
Since the publication of Terzaghi’s theory on the ultimate
bearing capacity of shallow foundations in 1943, results of
numerous studies—both theoretical and experimental—by
various investigators have been published. Most of the stud-
ies relate to the case of a vertical load applied centrally to the
foundation. Meyerhof (1953) conducted several laboratory
model tests and provided empirical procedures for estimat-
ing the ultimate bearing capacity of foundations subjected
to eccentric and inclined loads. Based on the review of the
existing literature on the bearing capacity of shallow founda-
tions, it appears that very limited attention has been paid to
estimating the ultimate bearing capacity when the founda-
tion is subjected to an eccentrically inclined load, which is
the subject of this paper. A large number of laboratory model
test results for a strip foundation supported by dry sand are
presented. The test results have been used to develop a non-
dimensional reduction factor.
2. LITERATURE REVIEW
The ultimate bearing capacity of a strip foundation sup-
ported by granular soil and subjected to a vertical centric
load [Figure 1(a)] can be expressed as
q
u
= qN
q
d
q
+
1
2
γBN
γ
d
γ
(1)
where q
u
= ultimate bearing capacity; q = γD
f
; D
f
= depth of
foundation; γ = unit weight of soil; B = width of foundation;
N
q
, N
γ
= bearing capacity factors; d
q
, d
γ
= depth factors.
The bearing capacity factor N
q
used by most geotechnical
engineers is that given by Reissner (1924), or
N
q
= tan
2
45 +
ϕ
2
e
π tan ϕ
(2)
where ϕ = soil friction angle.
Similarly, the factors N
γ
used for estimating the ultimate
bearing capacity are those given by Meyerhof (1963) and
Vesic (1973), which can be expressed as follows:
Vesic (1973)
N
γ
= 2(N
q
+1) tan ϕ (3)
Meyerhof (1963)
N
γ
= (N
q
– 1) tan (1.4 ϕ) (4)
C. R. Patra,
1
R. N. Behara,
2
N. Sivakugan,
3
and B. M. Das
4
*
Ultimate bearing capacity of shallow strip
foundation under eccentrically inclined
load, Part I
ABSTRACT: Results of laboratory model tests to determine the ultimate bearing capacity of shallow strip foundation sup-
ported by sand and subjected to eccentrically inclined load are presented. The tests were conducted in dense and medium
dense sands. The embedment ratio (ratio of the depth of embedment D
f
to the width of the foundation B) was varied from
zero to one. The load eccentricity e was varied from zero to 0.15B as well as the load inclination from zero to 20 degrees. Based
on the results of the present study, an empirical nondimensional reduction factor has been developed. This reduction factor is
the ratio of the ultimate bearing capacity of the foundation subjected to an eccentrically inclined load to the ultimate bearing
capacity of the foundation subjected to a centric vertical load.
KEYWORDS: Load eccentricity, load inclination, sand, shallow foundation, reduction factor, ultimate bearing capacity
*Corresponding Author
1
National Institute of Technology, Rourkela, India, crpatra19@yahoo.co.in
2
National Institute of Technology, Rourkela, India, mbehara82@gmail.com
3
James Cook University, Townsville, Australia, siva.sivakugan@jcu.edu.au
4
California State University, Sacramento, USA, brajamdas@gmail.com
343
International Journal of Geotechnical Engineering (2012) 6: (343-352)
DOI 10.3328/IJGE.2012.06.03.343-352
J. Ross Publishing, Inc. © 2012