Transportation
planning relies on traffic demand forecasting process. The conventional process
is impeded by extensive amount of socioeconomic data. One of the most
widely-used models which mitigate this problem is the TransCAD Model. This
model is rarely used in Gaza Strip for traffic demand forecasting, and most of
the practices depend mainly on a constant growth rate of traffic. Therefore,
the main objective of this research is to apply this model in Gaza City for
traffic estimation. This model estimates the origin-destination matrix based on
traffic count. The traffic count was carried out at 36 intersections
distributed around Gaza City. The results of traffic flow estimation obtained
from TransCAD are assigned to the Gaza maps using the GIS techniques for
spatial analysis. It is shown that the most congested area at present is the
middle of the city especially at Aljala-Omer Almokhtar intersection. Therefore,
improvement scenarios of this area should be carried out. The results of
calibration of traffic flow estimation show that the differences between the
estimated and the actual flows were less than 10%. In addition, network
evaluation results show that the network is expected to be more congested in
2015. This work can be used by transportation planners for testing any network
improvement scenarios and for studying their network performance.
Thursday, 2 July 2015
Seismic Response and Stability Analysis of Single Hinged Articulated Tower
Offshore
structures subjected to wave, earthquake or wind loads or a combination of
these loads show non-linear transient behaviour. As oceanic waves are better
modelled as stochastic process, there is a need to investigate the stochastic
stability of flexible offshore structures as well. Present study has been
carried out to determine seismic response of Single Hinged Articulated Tower
(SHAT) under different categories of wave loads and earthquake followed by its
dynamic stability analysis. Different phases of wave/earthquake loading on SHAT
have been explored to investigate dynamic instabilities existing during each
phase. Two dimensional phase plots have been used to identify phases of dynamic
instability existing within the responses of SHAT under various conditions of
loading.
Website: http://www.arjonline.org/engineering/american-research-journal-of-civil-and-structural-engineering/
Website: http://www.arjonline.org/engineering/american-research-journal-of-civil-and-structural-engineering/
Influence of the Elastic Modulus of the Soil and Concrete Foundation on the Displacements of a Mat Foundation
The
objective is to highlight the soil-structure interaction particularly the
influence of the rigidities of the soil and the concrete on the subgrade
reaction (k) and the displacements of the mat foundation subjected to vertical
loads. From plate theory and the soil-structure interaction, the general equation
is reached. This equation depends more on the subgrade properties than the
concrete foundation properties. Consequently, the behavior of the mat
foundation is more influenced by soil properties than the concrete.
Website: http://www.arjonline.org/engineering/american-research-journal-of-civil-and-structural-engineering/
Website: http://www.arjonline.org/engineering/american-research-journal-of-civil-and-structural-engineering/
Safety Assurance for Challenging Geotechnical Civil Engineering Constructions in Urban Areas
Safety
is the most important aspect during design, construction and service time of
any structure, especially for challenging projects like high-rise buildings and
tunnels in urban areas. A high level design considering the soil-structure-
interaction, based on a qualified soil investigation is required for a safe and
optimised design. Due to the complexity of geotechnical constructions the
safety assurance guaranteed by the 4-eye-principle is essential. The
4-eye-principle consists of an independent peer review by publicly certified
experts combined with the observational method. The paper presents the
fundamental aspects of safety assurance by the 4-eye-principle. The application
is explained on several examples, as deep excavations, complex foundation
systems for high-rise buildings and tunnel constructions in urban areas. The
experiences made in the planning, design and construction phases are explained
and for new inner urban projects recommendations are given.
Website: http://www.arjonline.org/engineering/american-research-journal-of-civil-and-structural-engineering/
Website: http://www.arjonline.org/engineering/american-research-journal-of-civil-and-structural-engineering/
Experimental Behavior of Partially Prestressed High Strength Concrete Beams
It currently becomes more desirable as it has
better mechanical properties and durability performance. Major defect of fully
prestressed concrete is its low ductility; it may produce less alarming signs
than ordinary reinforced concrete via smaller deflection and limited cracking.
Therefore, partially prestressing is considered an intermediate design between
the two extremes. So, combining high strength concrete with partial
prestressing will result in a considerable development in the use of
prestressed concrete structures regarding the economical and durability view
points. This study presents the results of seven partially prestressed high
strength concrete beams in flexure. The tested beams are used to investigate
the influence of concrete compressive strength, prestressing steel ratio and
flange width on the behavior of partially prestressed beams. The experimentally
observed behaviors of all beams were presented in terms of the cracking load,
ultimate load, deflection, cracking behavior and failure modes.
Website: http://www.arjonline.org/engineering/american-research-journal-of-civil-and-structural-engineering/
Website: http://www.arjonline.org/engineering/american-research-journal-of-civil-and-structural-engineering/
3-D Modelling of the Confederation Bridge Using Data of Full Scale Tests
Long-span
bridges are special structures that require advanced analysis techniques to
examine their performance. This paper presents a procedure developed to model
the Confederation Bridge using 3-D beam elements. The model was validated using
the data collected before the opening of the bridge to the public. The bridge
was instrumented to conduct fullscale static and dynamic tests. The static
tests were to measure the deflection of the bridge pier while the dynamic tests
to measure the free vibrations of the pier due to a sudden release of the
static load. Confederation Bridge is one of the longest reinforced concrete
bridges in the world. It connects the province of Prince Edward Island and the
province of New Brunswick in Canada. Due to its strategic location and vital
role as a transportation link between these two provinces, it was designed using
higher safety factors than those for typical highway bridges. After validating
the present numerical model, a procedure was developed to evaluate the
performance of similar bridges subjected to traffic and seismic loads. It is of
interest to note that the foundation stiffness and the modulus of elasticity of
the concrete have significant effects on the structural responses of the
Confederation Bridge.
Website: http://www.arjonline.org/engineering/american-research-journal-of-civil-and-structural-engineering/
Website: http://www.arjonline.org/engineering/american-research-journal-of-civil-and-structural-engineering/
Similarity Study on Snowdrift Wind Tunnel Test
The
model for snowdrift wind tunnel test needs to be similar with the prototype.
Based on detailed analysis in aspects of geometry, kinematics and dynamics, the
major similarity parameters that need to be satisfied are gained. The
contradiction between the Reynolds number and Froude number as well as the
problem of time scale is introduced, and the selections of the model parameters
are specified. Lastly, an example of snowdrift wind tunnel test by adoption of
quartz sand as the model of snow grains is presented. The flow field and the
snow distributions on a typical stepped roof were investigated. The results
show that the flow filed characters are in good agreement with the field
observations, and the stepped roof snow depth distributions are basically
consistent with the observation results.
Website: http://www.arjonline.org/engineering/american-research-journal-of-civil-and-structural-engineering/
Website: http://www.arjonline.org/engineering/american-research-journal-of-civil-and-structural-engineering/
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