Civil Engineering

Permanent URI for this collectionhttps://etd.hu.edu.et/handle/123456789/675

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End date: 2019Has files: Yes

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    ASSESSMENT OF TRAFFIC CONGESTION AND ITS IMPACT OVER SELECTED ROAD CORRIDOR IN ADDIS ABABA CITY
    (Hawassa Inversity, 2019-10-19) DAWIT GETACHEW ERGA
    Traffic congestion problem is becoming a common problem in most developing countries of world. This study was conducted with an objective making assessment of traffic congestion and its impact over the selected road corridor in Addis Ababa City. Through reconnaissance survey the corridor from ‘Awutobis Tera’ Bus station to ‘Lamberet Menahereya’ in Addis Ababa city was identified and for analysis purpose the corridor was divided into three sections. The study was conducted starting from June up to October, 2019. Both quantitative and qualitative approach were used. 384 samples were used to conduct questionnaire survey for traffic congestion cause analysis. Out of this 32.5% of the required sample were drawn from section A, 27% from section B and the rest 40.5% was from section C. For making analysis on the performance level of road corridors and economic cost of traffic congestion, traffic volume, travel time delay, average travel speed and vehicle occupancy data were collected manually for a period of 12 hours a day at 15 minutes intervals on respective road corridors and for intersections the data were collected for two hours interval during rush periods. In addition to traffic condition data, the geometric data were also measured as part of the study. The analysis on causal factors for traffic congestion was conducted by SPSS software and analysis on level and economic cost of traffic congestion of the selected road corridor was conducted by utilizing both SIDRA and Microsoft excel. Based on the result of analysis multi variable linear regression model, the imbalance between vehicle volume and road capacity, number of pedestrians that cross and move along the side of the road, inflexible work schedule, inadequate mass transit service along the corridor and illegal on street vehicle parking were identified as the main causes of traffic congestion over the road corridor. As the result from SIDRA and Microsoft excel showed that the intersections along the corridor and the road corridor in section C were operating beyond the standard set by HCM 2010 which recommends LOS ‘C’ or ‘D’. As per the economic analysis result of the study showed about 2667.8 person-hours/year and ETB104048.75 /year per individual traveler are being wasted due to traffic congestion over the study road corridor. Building vehicle parking apartment, elevated pedestrian crossway and improving performance of intersections were some of the engineering measures recommended to overcome the traffic congestion problem of the corridor.
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    MODELING LEVEL CROSSINGS’ TRAVEL TIME AND DELAY CHARACTERISTICS OF ADDIS ABABA LIGHT RAIL TRANSIT (AA-LRT)
    (Hawassa University, 2019-04-17) DARIC TESFAYE
    Traffic modeling is simplified representation of a part of traffic reality that provides a better understanding and interpreting of the complex traffic interactions. The objectives of this study is modeling level crossings travel time and delay characteristics of Addis Ababa light rail transit (AA-LRT) using simulation and mathematical models and evaluate the operational characteristics of the level crossings. In the process of achieving the objectives, the study investigate about peak period vehicle volumes, compositions, routings, LRV arriving frequency ,speed and the delays experienced. To meet the objective of this research intersection geometry data from field and traffic flow data at selected intersections is done by video recording and manual counting. In addition travel time data using light rail transit and minibus taxi is collected by traveling using these modes to a statistical number of repetitions. Suitable data inputs in forms of traffic volume, vehicle composition, vehicle routing, speed, train headway, travel time and delay at different incidences including level crossings are prepared. These suitable data inputs are introduced into VISSIM and SPSS analysis soft wares. Finally, the results were interpreted and the key research findings were presented in two types; i.e. through VISSIM simulation and SPSS statistical models. At the CMC level crossing the baseline without LRT scenario the average delay of traffic is 134.62s/veh ,the actual scenario with 00:05:41 LRV headway the average delay of traffic is 135.2 s/veh the delay increased by 0.43% and twice arrival frequency scenario the delay is 136.22s/veh with an increase in delay of 0.76% from the actual conditions. At the Sebategna level crossing the baseline without LRT scenario the average delay of traffic is 22.31s/veh ,the actual scenario with 00:06:30 LRV headway the average delay of traffic is 23.53 s/veh the delay increased by 5.47% and twice arrival frequency scenario the delay is 33.11s/veh with an increase in delay of 40.7% from the actual conditions. Additionally as observed in the mathematical model equation, the train’s travel time is dependent on running time, delay at grade intersection, open door close door time, close door start movement time and stop open door time in descending order. It is concluded that the average additional delays at level crossings increase from the base scenario and with increasing light rail crossing frequencies. In addition, delay at the level crossing is the second important variable that contributes for the variability of train travel time at peak hours.
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    Assessment of causes of delay on selected asphalt road Projects in the Southern Region of Ethiopi
    (Hawassa University, 2017-10-18) Mengistu G/kirosGesesew
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    SKILLED LABOR PERFORMANCE ASSESSMENT ON SELECTED PUBLIC BUILDING CONSTRUCTION PROJECT OF SNNPRS
    (Hawassa University, 2019-10-13) BIZUNESH BEKELE
    Skilled labor force is one of the vital elements for the continuity and successful implementation of construction. This study explored the current status of skilled labor performance in building project of SNNPRS. The main approaches used in collecting information for the study were through a questionnaire survey, case study, interview and personal observations of some major construction sites of SNNPRS. Methodological triangulation and member checking bolstered the trustworthiness of those interpretations. The questionnaire survey was distributed to 114 respondents and a total of 105 responses were received and case studies of seven projects of three trades for each which are concrete, masonry and bar bending was taken. For the analysis of the data, statistical analysis by using SPSS software and descriptive statistics were employed. The finding of the research indicated that most trade not fulfills individual level performance criteria. The crew level performance for most projects with productivity performance ability ratio (PAR) was greater than one indicating that the studied crews’ productivity performance was low. The main factor which affect performance of skilled labor in the order of their rank were lack of follow up the work progress, cash flow and financial difficulties, Lack of Training for workers, Inadequate briefing, too much work load and absence of clear uniform standard to accept work. Skilled labor capability impacts the project objectives which are safety, quality, cost and schedule. Thus the researcher recommends possible ways to manage or reduce such factors. Periodic training should prepare in advance in order to improve skill performance and Project managers shall introduce performance management system at individual and crew level so as to have reliable planning and controlling system to manage their work. This study will contribute contractors which undertake construction projects and about ways of improving their current status of skilled labor.
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    Effect of Cow Dung, Cement and Fiber on Earthen Brick
    (Hawassa University, 2018-10-13) Aster Memiru
    Now days demand for housing is increasing because of fast population growth. To fulfill this need it is better to search for alternative construction materials, which are economically affordable. Earth is one of the potential construction materials, which can fill this gap. Earth housing is the most common housing used around the world. In Ethiopia, the “cob” type of housing method is the most common one. This research focuses on Adobe blocks that constructed from earth material. The aim of this research is to study the effect of cement, fiber and cow dung on the property (compressive strength and water resistance) of adobe block. Types of stabilizer used are Enset fiber, cement and cow dung. The amount of stabilizer used for this study is 0.2, 0.4 and 0.6% for Enset fiber, 2, 4 and 6% for cement and 5, 10 and 15% for cow dung of the dry mass of the soil. The result of this research indicate that both type and amount of stabilizer (cement, fiber and Cow dung) used affect the property of Adobe block produced. Comparison between the effects of Enset fiber and chid fiber on compressive strength and water resistance of Adobe block is also studied and also their property at failure. The results indicate that blocks stabilized with Enset fiber performed well under compression load and water when soaked. The optimum amount of fiber for compressive strength and water resistance is also determined. The other important finding in this research is the positive effect of cow dung on Adobe block. Loss of material, water absorption and loss of strength after soaking of adobe block stabilized with Cow dung is very less than block stabilized with cement or fiber. Therefore, cow dung significantly improves durability of block. Generally, from this research it can be concluded that well stabilized Adobe block can serve as potential construction material
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    ASSESSMENT OF PROJECT PERFORMANCE: CASE OF 40/60 SAVING HOUSE DEVELOPMENT ENTERPRISE IN ADDIS ABABA BOLE AYAT LOT II
    (Hawassa University, 2018-10-22) ALIYA ABDOSH IBRAHIM
    Construction industry has complexity in its nature because it contains large number of parties as clients, contractors, consultants and other stakeholders. Construction projects suffer from many problems and complex issues in performance such as cost, time and quality. The aim of this thesis is to identify and evaluate the main factors affecting the performance of construction projects in the case of Bole Ayat 40/60 condominium. Literature reviews about performance were sited to identify the factors affecting the performance of construction projects. The methodology/research design followed was descriptive research. A questionnaire survey was conducted and 44 factors were identified, categorized, evaluated and ranked from small and micro enterprises, client, consultants and contractors perspectives. The results were analyzed and discussed to obtain the most performance indicators. The relative importance index (RII) method was used here to determine perceptions of the relative importance of the performance indicators in construction projects. The extremely significant factors affecting time performance were shortage of material, financial problem and poor communication and coordination with RII 0.75, 0.74 and 0.71 respectively. Whereas the factors affecting cost performance were fluctuation in the cost of material, lack of cost planning and design change with RII 0.77, 0.693 and 0.691 respectively and factors affecting quality performance were educated and experienced personnel, quality of materials and equipment used in the project with RII 0.81, 0.72 and 0.69 respectively. Recommendations were formulated to improve performance of construction projects. It was concluded that every party participating on the project should have good communication and coordination to avoid design discrepancies and disputes to improve performance; they should have to hire qualified personnel to overcome any technical and managerial problems
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    EVALUATION OF HORIZONTAL ALIGNMENT DESIGN CONSISTENCY FOR TWO – LANE RURAL HIGHWAY: A CASE STUDY ALONG SHASHEMENE - WOLAYTA SODO AND SHASHEMENE - ASELA ROAD SEGMENTS
    (Hawassa University, 2019-10-10) ALEMAYEHU AYELE
    Design consistency is the conformance of highway’s geometric and operational features with driver’s expectancy. Techniques to evaluate consistency of a design are change in operating speed and change of vehicle stability along the horizontal alignment. To use operating speed and vehicle stability as the consistency tools requires the ability to accurately predict speed as a function of the horizontal roadway geometry. The current Ethiopian road Authority geometric design manual is based on design speed. However, due to the constraints resulting from roadway elements, right of way, and environmental features, inconsistency in operating speed based and vehicle stability based cannot be guaranteed. In order to make informed decisions to ensure highway geometric design consistency, the consistency evaluation of horizontal geometric design of operating speed and vehicle stability on simple curve and tangent section was studied. Forty five sections for both of horizontal curve and tangent section were selected from Shashemene to Wolayta Sodo and Shashemene to Asela. Roadway geometric design variables were obtained from design documents and through field measurements. The speeds of passenger cars, buses, and trucks were measured on each curve and its approaching tangent, under dry day time condition. This study focused on two major issues, in evaluating the horizontal geometric design consistency of selected alignments and developing operating speed predicting models for selected section. Therefore, the results obtained from consistency evaluation of change operating speed between simple curve and tangent section shows that twenty sections were in poor conditions, between design speed and operating speed shows that nine section in simple curves and thirty one sections in tangents sections were in poor conditions. Whereas, consistency evaluation between changes of side friction assumed and side friction demanded shows that twenty seven section in horizontal curves were in poor condition. Finally, both two models were found for horizontal curves and tangents. Model found for horizontal curve and tangents were governed by the combination of grade, super elevation and tangent length. This study would provide information about the improvement design manual for the existing level of design inconsistency and to develop guidelines that designers can use to improve the geometric design consistency of roadway features on high-speed of two-lane rural highway road.
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    SURFACE IRRIGATION POTENTIAL ASSESSMENT OF BONKOKA RIVER CATCHMENT FOR IRRIGATION SCHEME DEVELOPMENT IN DARA WOREDA, SIDAMA ZONE SOUTHERN REGION
    (Hawassa University, 2019-03-12) ABRAHAM AMENU ANEBO
    Surface irrigation potential assessment is very important for maximizing agricultural production by using surface irrigation method. The objective of this study was to assess surface irrigation potential of Bonkoka river catchment for surface irrigation schemes development in Dara Woreda, Sidama Zone Southern Nation Nationalities Peoples’ Regional State. Surface water irrigation potential assessment was undertaken by using ARCGIS10.3 software application, by using soil data, land slope data and land cover or land use data of study area were used in order to identify suitability of river catchment with respect to soil, land slope, land use or land cover and overlay analysis of soil suitability, slope suitability and land use or land cover suitability were undertaken. And also un-gauge Bonkoka River surface water potential discharge were estimated by using runoff coefficient of gauged Kolla river catchment which had similar soil type, land slope and land use or land cover. Water requirement of crops in the study area was estimated by using Cropwat8.0 software application and the Cropwat8.0 software estimates Reference Evapo-transpiration on monthly basis, Crop Evapo-transpiration, Potential Evapo-transpiration, Crop water requirement. Surface irrigation land suitability analysis result with respect to soil show that 100% of soil (covering an area 2,186 ha) are suitable and suitability analysis result with respect to slope 9% of slope in the study area (covering area 198.52 ha) are in the range of highly suitable to marginal suitable for surface irrigation application. Considering suitability analysis result with respect land cover or land use, land covered by agroforestry covering 28% or 606 ha area and 59% cultivated land (covering area 1,300ha) and remaining 13% grass land (covering area 280 ha) are suitable for surface irrigation application. From overlay analysis of suitability of surface irrigation with respect to soil, slope and land cover or land use result show that 31% of Bonkoka catchment (covering area 676ha) is suitable for surface irrigation.