Download Bearing Capacity Calculation Of Footings On Layered Soil Using

Bearing Capacity Calculation Of
Footings On Layered Soil Using
The Finite Element Method
A Thesis
Submitted To The College Of Engineering Of
The University Of Tikrit In Partial Fulfillment
Of The Requirements For The Degree Of
Master Of Science In Civil Engineering
BY
Wisam Thiab Khalaf Al-Juboory
(B.Sc. 2001)
1424 ‫ربيع الثاني‬
JULY 2004
Abstract
In this study the finite element method is utilized to
estimate the ultimate bearing capacity of layered soils under
strip and circular footings. Different values of the stratification
ratio are analyzed.
An elasto-plastic model is used to simulate the non-linear
behaviour of the soil. Von-Mises and Mohr-Coulomb yield
criteria are adopted to model the cohesive and cohesionless
soils, respectively.
The results of the study proved that the existence of a weak
layer near a footing resting on a shallow strong layer (exhibiting
general shear failure), reduces the bearing capacity, whereas the
presence of a strong layer near a footing resting on a weak one
does not improve the bearing capacity. Also, it can be realized
that the weighted average method suggested by Bowles (1982)
and by Vesic method (1975) over estimate the bearing capacity
for footings resting on weak layers compared to the finite
element method, so, they should be used cautiously.