Tez ve Araştırma Arşivi
Sitemizde Dönem Dönem Hazırlanmış Tez ve Araştırmaların özetlerini bulabilirsiniz
Konu içerikleri ilgili sorunları adminlerimize bildiriniz.
By admin
This thesis analyzed the new parameter “hydrodynamic demand” repre-
senting the damage of tsunami waves on structures and coastlines,
maximum positive amplitudes and current velocities occurred during
tsunami inundation by using the numerical model TUNAMI-N2. Regular
shaped basins were used with two different bottom slopes in analyses in
order to understand the behaviour of tsunami wave and investigate the
change of important tsunami parameters along different slopes during
tsunami inundation. In application, different initial conditions were used for
wave profiles such as solitary wave, leading elevation single sinusoidal
wave and leading depression sinusoidal wave. Three different initial wave
amplitudes were used in order to test the change of distribution of the
hydrodynamic demand. The numerical results were compared and
discussed with each other and with the results of existing analytical and
experimental studies.
Read more »
By admin
In the scope of the study, prismatic roughness elements with different longitudinal
spacing and arrangements have been tested in a rectangular flume in order to reveal
their effects on fundamental characteristics of a hydraulic jump. Two basic
roughness types with altering arrangements have been tested. Roughness elements of
the first type extends through the channel width against the flow with varying length
and pitch ratios for different arrangements. The second type is of staggered essence
and produced by piecing the roughness elements defined in the initial type into three
parts which are equal in length. The doublet formed from the pieces on the sides is
shifted to the consequent row to make two successive roughness rows encapsulate
the channel span completely. Staggered roughness type is formed with the repetition
of this arrangement along the flume. Independent of their type and arrangement, the
entirety of roughness elements are embedded in the channel bed in order to avoid
their protuberance into the flow, based on the presumption that the crests of the
roughness elements levelled with the channel inlet would be less exposed to caving
effects of flow than the protruding elements. Read more »
By admin
Lateral load carrying capacities of reinforced concrete structures which are designed
by considering only gravity loads or according to outdated earthquake codes can be
insufficient. The most important problem for these buildings is the limited ductility
of the frame elements. How to evaluate the performance of an existing structure and
to what level to strengthen it had been major concerns for structural engineers.
Read more »
By admin
Dynamic behaviour of gravity and cantilever retaining walls is investigated by
finite element method, incorporating the nonlinear elasto-plastic material
properties of soil and seperation of the wall and backfill. Two dimensional finite
element models are developed employing the finite element software ANSYS. The
wall is modelled to rest on a soil layer allowing translational and rotational
movements of the wall. Soil-wall systems are subjected to harmonic and real
earthquake motions with different magnitude and frequency characteristics at the
base. The maximum lateral force and its application point during dynamic loading
are determined for each case. It is observed that the frequency content of the base
motion has a significant influence on the dynamic lateral soil pressures and the Read more »
By admin
This thesis offers a comprehensive risk assessment methodology that provides a decision
support tool, directed for Turkish construction organizations, which can be utilized
through the bidding decisions for international construction projects. Within this context
the analytic network process technique is implemented to develop a risk assessment
model, which is used to derive the relative priorities of the risk factors associated with
international construction projects. The findings of the risk assessment model have
demonstrated that the most significant sources of risk are vagueness of contract
conditions about risk allocation, client, and immaturity of legal system in the host
country. Factors such as low % of advance payment, geographical distance, and bribery
were found to be relatively insignificant. An international construction project risk rating
software application is then developed. The application incorporates the derived
priorities from the risk assessment model to calculate a risk rating for a given
international construction project.
To increase the credibility of the results a risk rating adjustment methodology was
integrated into the application. Its purpose is to count for the potential influencing
factors that may increase the risk level of a given project. The influencing factors which
were considered are the company’s experience, contract type, level of the available
project data from the outset, and project delivery system.
Read more »
By admin
After the 1999 Kocaeli Earthquake, the use of chemically bonded post-installed
anchors has seen a great growth for retrofits in Turkey. Currently, chemically bonded
post-installed anchors are designed from related tables provided by adhesive
manufacturers and a set of equations based on laboratory pullout tests on normal or
high strength concretes. Unfortunately, concrete compressive strengths of existing
buildings, which need retrofit for earthquake resistance, ranges within 5 to 16 MPa.
The determination of tensile strength of chemically bonded anchors in low-strength
concretes is an obvious prerequisite for the design and reliability of retrofit projects.
Read more »
By admin
Minimum requirements for lap splices in reinforced concrete members, stated in
building codes of TS-500 and ACI-318, have a certain factor of safety. These
standards have been prepared according to research results conducted previously and
they are being updated according to results of recent studies. However the reliability
of lap splices for minimum requirements needs to be investigated. For this purpose, 6
beam specimens were prepared according to minimum provisions of these standards.
The test results were investigated by analytical procedures and also a parametric
study was done to compare two standards. For smaller diameter bars both standards
give safe results. Results showed that the minimum clear cover given in TS500 is
insufficient for lap spliced bars greater than or equal to 26 mm diameter.
Read more »
By admin
Elastic layers bonded to reinforcing sheets are widely used in many
engineering applications, e.g., as elastic foundations to machinery, as seismic
isolators to structures, etc. Because of its practical importance, the behavior of
bonded elastic layers under some basic deformation modes (e.g., compression,
bending and shear modes) has attracted the attention of many researchers. However,
the analytical works available in literature involve, with the object of obtaining
design formulas, many simplifying assumptions. In this dissertation, a new Read more »
By admin
In this study, the seismic fragility assessment of low-rise and mid-rise reinforced
concrete frame buildings which constitute approximately 75 % of the total building
stock in Turkey is investigated to quantify the earthquake risk. The inventory used
in this study is selected from Düzce damage database which was compiled after
the devastating 1999 earthquakes in the Marmara region. These buildings are not
designed according to the current code regulations and the supervision in the
construction phase is not adequate.
Read more »
By admin
Efficient water resources planning and management must take into account multiple users,
criteria, and objectives. Due to this complexity of recent water management problems and
solutions, better analytical tools and methodologies are required. Accomplishment of this
requirement depends essentially on information gathered on natural and environmental
processes so the success of sustainable water resources management depends on
monitoring activities.
Many countries have developed extensive streamflow gauging networks. Such a
development has led to accumulation of significant amounts of data to eventually raise
questions whether they produce expected information, and whether monitoring should be
continued. These questions have led monitoring agencies to assess their current networks
for efficiency and cost-effectiveness. Read more »
