DSpace Collection: Thesis - Structural Engineering
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SEISMIC ASSESMENT OF SIMPLY SUPPORTED Vs CONTINUOUS CONCRETE GIRDER BRIDGES
http://etd.aau.edu.et:80/dspace/handle/123456789/4936
Title: SEISMIC ASSESMENT OF SIMPLY SUPPORTED Vs CONTINUOUS CONCRETE GIRDER BRIDGES
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<br/>Authors: Yigrem, Zewdu
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<br/>Abstract: Seismic evaluations of typical concrete girder bridges are conducted for two existing
simply supported bridges, which are common to the Ethiopian highway construction, and
for their counterpart continuous girder bridges. These evaluations are performed for an
approximate hazard level of 0.1g ground acceleration by performing linear modal
response spectrum analyses on three-dimensional analytical models. The results show
responses in the deck girder, reinforced concrete columns and bearings at the supports of
the girders. In general, the longitudinal loading of the continuous bridges results in larger
demands than the transverse loading. Consequently, the continuous nature of the deck
tends to transfer seismic demand to different structural components. Therefore, the
demands of piers for continuous girder bridges become larger. The simply supported
bridges sustain bearing deformations in the transverse direction which are of the same
value as the longitudinal response. These results suggest that both longitudinal and
transverse loading are significant and should be considered when performing seismic
assessment of these bridges. And also the modal response spectrum analysis result shows
that the contribution of higher modes in seismic response of the continuous bridges is
insignificant. Whereas it is noted that, the contributing higher modes should be considered
to obtain the seismic responses of simply supported girder bridges.UNDERPASS PEDESTRIAN CROSSING CONNECTING THE TWO CAMPUSES OF ADDIS ABABA INSTITUTE OF TECHNOLOGY
http://etd.aau.edu.et:80/dspace/handle/123456789/4881
Title: UNDERPASS PEDESTRIAN CROSSING CONNECTING THE TWO CAMPUSES OF ADDIS ABABA INSTITUTE OF TECHNOLOGY
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<br/>Authors: Tiruye, Beshah
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<br/>Abstract: Road traffic accident is becoming the major problem globally. Our country is also facing the problem currently with increasing trend of the magnitude of the problem from time to time. Addis Ababa, the capital of the nation is the major area where traffic accident is occurring in the country.
One of the main reasons for road traffic accident is thought to be due to imbalance between the number of pedestrians, vehicle number and size of the road. These problems are also the main contributors for the road traffic accident in Addis Ababa.
To solve the above problems providing an appropriate path for pedestrians is vital. Constructing pedestrian underpass around Addis Ababa Institute of Technology is one solution for preventing the road traffic accident that happens in this area.
Civil Designer, AchiCAD, Excel and AutoCAD software were used for the design analysis of the pedestrian underpass.
The minimum loading requirements for determining loads and forces was taken from ERA’s Bridge Design Manual-2002 and AASHTO Geometric Design Manual 2001.
The final design of foundations was conducted based on the safe bearing capacity of the foundation computed from the geotechnical investigations.Investigation of Effective Length Method for Slender Reinforced Concrete Column Having Linearly Varying Cross-Section
http://etd.aau.edu.et:80/dspace/handle/123456789/4862
Title: Investigation of Effective Length Method for Slender Reinforced Concrete Column Having Linearly Varying Cross-Section
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<br/>Authors: Tinsae, Woldegebreal
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<br/>Abstract: Effective length is the length of the equivalent pin ended column, which has the same
elastic buckling load as the actual column. The effective length method has been used for
many decades as the basis for the design of columns made of reinforced concrete, structural
steel or steel-concrete components. The underlying assumption with this method is the
sweeping generalization that; because the actual column and the equivalent column have the
same elastic buckling load, they also posses the same design resistances in the ultimate limit
state. This assumption has been the subject of many investigations and it was found out that,
although the method gives reliable results that lie on the safe side in many cases, it could
sometimes lie on the unsafe side. The present investigation deals with slender reinforced
concrete columns with linearly varying cross-sections. The effective length method for such
columns poses an additional complication. That is; unlike prismatic columns, the choice of
cross-section for the equivalent column is not straight forward since the cross-section of
actual column is not constant. The results of the present investigation which is limited to pin
ended columns with equal and opposite end moments, have shown that the effective length
method gives reliable results if the cross-section of the equivalent column is chosen as per
certain rules and computations indicated in this document. Extensive tables are compiled for
the determination of equivalent section and effective length for any pin-ended tapered column
which has the same and opposite end moments. Computer programs, which are done using
FORTRAN (FTN95) programming language and MICROSOFT EXCEL spread sheets are
used as a supporting tools for analysis processes committed in this investigation. The result of
this research can be taken as an approach, which replaces the cumbersome and lengthy way of
traditional iterative analysis for tapered columns.DEVELOPMENT OF A COMPUTER PROGRAM FOR STRUCTURAL DESIGN OF CONCRETE SLAB CULVERT DECK
http://etd.aau.edu.et:80/dspace/handle/123456789/4813
Title: DEVELOPMENT OF A COMPUTER PROGRAM FOR STRUCTURAL DESIGN OF CONCRETE SLAB CULVERT DECK
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<br/>Authors: Andinet, Zeleke
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<br/>Abstract: Concrete slab culvert is an important structure used to convey trucks and pedestrian along a road corridor or in one of a range of other situations. This structure is highly constructed in highway road projects in Ethiopia. In this study, a FORTRAN program is developed for the structural design of reinforced concrete slab culvert deck according to the provisions given in AASHTO LRFD Bridge 2005 Edition. The developed program is expected to assist the structural designers and users to design the superstructure part of a reinforced concrete slab culvert deck efficiently with great accuracy. Both at grade and at fill slab deck thicknesses are computed according to the specification specified in AASHTO LRFD Bridge 2005 Edition. The reinforcement bars are also designed based on the requirements specified in the code. The program is developed in four steps. The first step is to define and analyze the problem; the second step is to develop an optimal solution and designing the program, the third step is coding the program and the final step is testing and documenting the program. FORTRAN 95 is a programming language used in the fields of scientific, numerical, and engineering fields. In this thesis, this language has been used to develop the program for the structural design of reinforced concrete slab culvert deck. The input data for at grade and at fill slab culverts are saved on a note pad in the external file folder which constitute the material properties, geometric features and proposed diameter of reinforcement bars of the slab culvert and its deck in the folder which contains FORTRAN 95 program. The output data is written on the note pad in the external folder based on the format assigned for each output in the folder which contains the design results of slab deck thickness and area, spacing and length of main, distribution and temperature reinforcement bars. Besides Edge beam design parallel to the traffic is executed and shown in the output result by the developed program.