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Comparison of Various Bracing System for Self-Supporting Steel Lattice Structure Towers
Abdulaqder M. Tah,
Kamiran M. Alsilevanai,
Mustafa Özakça
Issue:
Volume 5, Issue 2, March 2017
Pages:
60-68
Received:
27 December 2016
Accepted:
7 January 2017
Published:
4 February 2017
Abstract: This paper deals with the effectiveness of various bracing systems used in lattice towers. Seven types of bracings used in 4-legged square based self-supporting power transmission and telecommunication towers and four types of bracings used in 3-leg triangular based self-supporting telecommunication towers are analyzed. The investigated bracing systems are K, KD, Y, YD, D, XB and X. This study has focused on identifying the economical bracing system for a given range of tower heights. Towers of height 40 to 60 m for telecommunication and 35 m for transmission towers have been analyzed under critical loads such as wind and earthquake loads. The load cases include diagonal wind has been found to be most critical cases for towers. The performance of various bracing system has been identified and reported.
Abstract: This paper deals with the effectiveness of various bracing systems used in lattice towers. Seven types of bracings used in 4-legged square based self-supporting power transmission and telecommunication towers and four types of bracings used in 3-leg triangular based self-supporting telecommunication towers are analyzed. The investigated bracing sys...
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Problem Solving and Counter Measures for Road Accident Prone Environments
Geena Kuruvilla,
Jawahar Saud
Issue:
Volume 5, Issue 2, March 2017
Pages:
69-74
Received:
12 January 2017
Accepted:
20 January 2017
Published:
24 February 2017
Abstract: Safe roads are the foundation for the traffic safety. An accident is an unintentional injury, incidental and unplanned event that are caused by the transfer of energy between the human body and the environment. It involves a minimum of one road vehicle during which at least a minimum of one person is dislocated or killed. They impose a huge socio-economic cost in terms of untimely deaths, injuries, and loss of potential income and hence road safety has become an issue of national concern. Two main factors responsible for road accidents are heavy traffic on roads and rash driving. Reducing exposure to risk through transport and land use policies is the main factor behind the crashes. Shaping the road network for road injury prevention is one of the main step to be adopted. The main objective of this study is to describe the basic principles of road traffic injury control that differentiate the current situation of traffic accidents, and define the specific interventions that can be implemented in different settings to prevent the road traffic injuries and reduces the number of blackspots and to suggest various measures to strengthen the disaster risk governance to manage the risk of the disaster so that new efforts can be implemented to correlate the traffic accidents.
Abstract: Safe roads are the foundation for the traffic safety. An accident is an unintentional injury, incidental and unplanned event that are caused by the transfer of energy between the human body and the environment. It involves a minimum of one road vehicle during which at least a minimum of one person is dislocated or killed. They impose a huge socio-e...
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Modelling and Simulation of Water Absorption from Locally Occurring 3/8 Gravel at Different Water Cement Ratio and Curing Age Applying Deterministic Modelling Approach
Issue:
Volume 5, Issue 2, March 2017
Pages:
90-103
Received:
23 August 2016
Accepted:
31 October 2016
Published:
4 March 2017
Abstract: Water absorption in all in one aggregate concrete formation was monitored applying deterministic modeling approach. Several experts in the field has been applying empirical method through calibrating of experimental values, these has been developing water absorption parameters in various mix proportions to monitor strength development of concrete. But the application of deterministic concept has not been applied to monitor water absorption thus all in one aggregate concrete, the study applying these concept monitored water absorption at every twenty four hours and the conventional method of seven days interval, predictive values express the increase and decline rate of water absorption at various water cement ratios and curing age, these concept predicted different method expressing best fits of both concepts, the vacillation found in the study at different water cement ratios were base on the variations of mix proportions thus compaction level that determine the rate of concrete porosity in all in one aggregate concrete. The study is imperative because the application of these concept has been developed thus it can generate water absorption in hours and interval of days.
Abstract: Water absorption in all in one aggregate concrete formation was monitored applying deterministic modeling approach. Several experts in the field has been applying empirical method through calibrating of experimental values, these has been developing water absorption parameters in various mix proportions to monitor strength development of concrete. ...
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Deterministic Modelling Techniques on Strain Influenced by Compressive Strength from All in One Aggregate Concrete
Issue:
Volume 5, Issue 2, March 2017
Pages:
104-110
Received:
23 August 2016
Accepted:
31 October 2016
Published:
4 March 2017
Abstract: Experts has express strain from various materials on different type of aggregate grade, empirical and experimental analysis has been the concept of generating these parameters, empirical modeling are generated from experimental investigation, the study on these materials was to generate its rate of strength development from all – in- one grave aggregate. The developed strength are reflected on the strain, the values were generated from deterministic modeling techniques, the predictive values were subjected to comparisons using experimental values, both parameters express favorable fits validating the developed model predicting strain from all in one aggregate concrete. The study is imperative because experimental evaluation including empirical approach has been the only method of application or generation of strain thus stress-strain relationship, but deterministic techniques has been developed to predict the strain from all in one aggregate concrete, the strength development from these materials has also become another break through on concrete strength development.
Abstract: Experts has express strain from various materials on different type of aggregate grade, empirical and experimental analysis has been the concept of generating these parameters, empirical modeling are generated from experimental investigation, the study on these materials was to generate its rate of strength development from all – in- one grave aggr...
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Deterministic Model on Concrete Density from Local 3/8 Gravel Influenced by Variation of Water Cement Ratios and Curing Age
Issue:
Volume 5, Issue 2, March 2017
Pages:
111-118
Received:
23 August 2016
Accepted:
31 October 2016
Published:
4 March 2017
Abstract: Concrete densities varies base on some level of mix design, several experts has express the densities of concrete using various grades of coarse aggregate in there mix design, these study are to express the behaviour of locally occurring 3/8 gravel concrete also known as all in one aggregate 3/8 Aggregate gravel concrete. The development of concrete densities variation from experimental values compared with deterministic model simulation values were carried out in table and figures, from the graphical representation, fluctuation were observed in some values, while linear increase were express in some values, these fluctuation from the simulation values has also reflected the rate of concrete porosity varying at different water cement ratio and curing age, the heterogeneity of these densities from the predictive values are through variation from these porosity and mix proportions, water cement ratios variation were also observed to influenced the rate of concrete densities, the prediction of concrete densities at interval of seven day are the normal methods of monitoring concrete properties, but the developed model are predicting the increase of concrete densities at every twenty four hours, these method are new developed concept that can also be applied to predict other concrete parameters or properties.
Abstract: Concrete densities varies base on some level of mix design, several experts has express the densities of concrete using various grades of coarse aggregate in there mix design, these study are to express the behaviour of locally occurring 3/8 gravel concrete also known as all in one aggregate 3/8 Aggregate gravel concrete. The development of concret...
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Area-Type Adjustment Factors for Non-CBD Signalised Intersections
Abena Agyeiwaa Obiri-Yeboah,
Yaw Adubofour Tuffour,
Mohammed Salifu
Issue:
Volume 5, Issue 2, March 2017
Pages:
119-123
Received:
28 October 2016
Accepted:
4 January 2017
Published:
4 March 2017
Abstract: In the estimation of saturation flow at signalized intersections using the HCM model, the influence of area-type characteristics on flow is accounted for by the area-type adjustment factor (fa). The recommendation by the manual to use fa=0.9 for CBD-intersections and 1.0 for all others tacitly assumes that the nature of non-CBD areas does not influence flow. This may not hold for many developing country cities and metropolitan areas where the roadside environments associated with non-CBD intersections may be laden with a flurry of activities that impact traffic flow. For signalized intersections in such areas, the HCM-recommended area-type adjustment factor could lead to over-estimation of saturation flow rates if the activities create substantial roadside friction to flow. This study set out to develop area-type adjustment factors for non-CBD signalized intersections located within the Kumasi Metropolis in Ghana, to accurately reflect the impact of roadside character on saturation flow rates. Using field saturation flow data collected at selected signalized intersections in the metropolis, area-type adjustment factors were developed for three distinct roadside friction environments categorised in the study as low/none, medium, and high. Average fa values developed were 0.99 for low/none, 0.98 for medium, and 0.94 for high roadside friction environments. Also, a multiple linear regression model that attempts to relate fa to pedestrian traffic interfering with flow within the environment of the intersection was developed as an alternative procedure for determining site specific area-type adjustment factor. It is recommended to use the fa values developed in this study in the HCM saturation flow model in order to estimate more accurately the saturation flow rates at non-CBD signalized intersections within the Kumasi Metropolis.
Abstract: In the estimation of saturation flow at signalized intersections using the HCM model, the influence of area-type characteristics on flow is accounted for by the area-type adjustment factor (fa). The recommendation by the manual to use fa=0.9 for CBD-intersections and 1.0 for all others tacitly assumes that the nature of non-CBD areas does not influ...
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