الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
Although the bearing capacity term is well known among the geotechnical
engineers, when it comes to non-homogenous formation contains several
features like the jointed rock, this term becomes a little harder to adequately
estimated. The main feature highlighted in the jointed sedimentary rocks is how
it formed in nature and how this formation caused weak planes implanted inside
the rock mass. These weak planes are known as faults, beddings, and joints,
which are weak shearing zones subjected to loading.
The loading direction concerning the joint orientation (dip angles), had a
considerable effect on the bearing capacity of the whole mass, this effect can
accurately be represented only when the rock mass studied as discrete
formation, i.e., the intact rock and the joints separately simulated with their
individual parameters. Also, the spacing between these joint what makes the
rock behaves either as a sound rock when the spacing is widely spread within
the mass or behaves as fracture material when the spacing is closed then, more
joints exist under the footing.
To study the latter mentioned parameters, available results from the plate
load test performed in the Bakhtiary Dam in Iran were utilized to investigate
the Bearing Capacity of strip footings on a Limestone formation. A numerical
model was developed using the finite element method to simulate and validate
the Plate load test performed in the dam site. The numerical model was formed
as a discrete model.
The predicted ratio between the shear strength parameters (cohesion), the
modulus of elasticity of the intact rock, and the discontinuities gives a
reasonable agreement with the measured field settlements and the results from
ii
the numerical model. This result implemented in the parametric study along
with different ratios to compare it with an analytical BC. The analytical
approach’s parameters were based on empirical rating system (RMR) as it is a
simple system to use among engineers. Other approaches depended on the
unconfined compressive strength (qu), which is similar to the Mohr Columb
original solving method.
A further parametric study had been carried out with this different strength
and stiffness ratios, to show the effect of these ratios with presence of inclined
joints (30 and 45 degrees) on the allowable bearing capacity of the rock mass,
also studied the effect of (S/B) joint spacing with respect to the footing width
by changing the strip footing width. All the parameters stated above studied
with their effect on the allowable bearing capacity and represented on bearing
capacity – RMR curves mention the variant parameters.
Also, a study had carried out with constant famous number among engineers,
0.50 MPa (5.00 Kg/cm2) as allowable BC when shallow foundation lies on rock
mass, implementing the different stiffness and cohesion ratios between intact
blocks and joint, settlement – RMR curve was plotted.
Also, studying the differential settlement under the footings of one structure
located on different rock conditions had carried out in this study.
Keywords: Sedimentary Rocks; Jointed Rock; Bearing Capacity; Finite
Elements in rock mass; Mohr-Coulomb Criterion; Joint dip angles