Civil Engineering

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

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Start date: 2016End date: 2019

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    CORRELATION BETWEEN INDEX PROPERTIES WITH SHEAR STRENGTH PARAMETERS FOR HAWASSA SOIL
    (Hawassa University, 2017-04-23) BATAMO BELIHU
    Shear strength parameters (angle of internal friction and cohesion) are the key engineering properties of soil. In every situation finding these parameters by laboratory testing or by using advanced equipment may be uneconomical for clients during the preliminary design phase. So it is a common practice in geotechnical engineering to estimate these parameters by employing empirical equations from easily found engineering properties of soil. Correlations and empirical equations developed are site specific, and a good result will be found using them for soils from which they are developed. In this study an attempt was made to correlate shear strength parameters (angle of internal friction and cohesion) for Hawassa city soil from index properties. Detailed analysis was carried out by randomly taking thirty four samples from seven sub cities of Hawassa city. The sampling pits were dug manually using hand tools with plan area of 1.50 m by 1.50 m at depth of 3.0 m from the ground surface. From laboratory test results, most samples were found to be with very low values of density and no plasticity. The soil was classified as cohesionless soil of fine to medium sized sand with group name silty sand, sandy silt, silty, clayey sand, silty, clayey sand with gravel and well graded sand with gravel consecutively. Due to the nature of the soil, cohesion was exempted from correlation. The Influence of easily found index properties of soil on its shear strength parameter was studied, and a regression carried out for the selection of most influencing variables. This parameters identified as the grain size distribution, density, and water content of the soil
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    EFFECT OF ROAD GEOMETRY AND SPEED ON ROAD SAFFTY AND IDENTIFICATION OF HAZARDOUS ROAD SECTION (CASE STUDY ON THE WUKRO-ADIGRAT-ZALAMBESA ROAD
    (Hawassa University, 2018-10-23) RAHMA AHMED EBRAHIM
    In Ethiopia road traffic crashes are causing heavy loss of human and economic resources with the relatively low road network and motorization level. The risk is increasing with the increase in population, the road network expansion with little consideration of safety, and the increase in motorization with the vehicle fleet generally in poor conditions.This thesis deals with the most essential issue of road traffic accident related to geometric characteristics, flow and speed and identification of hazardous road section on the Eastern Tigray Zone (Wukro-Adigrat Zela'ambesa ) two lane road. The main objective of the study is to develop a prediction model for road traffic crashes occurring on a two lane road and to identify the hazardous road section.The study area has a total length of 96 km. Data such as crash data, traffic flow data, speed data, roadway characteristics and road geometry data was collected from offices and the site. Two models were developed one for the geometric characteristics of the road and flow model, the second for the speed model. The statistical analyses were performed using statistical software package SPSS version 20. The Generalized Linear Model (GLM) with Poisson regression and Negative Binomial (NB) the error structure was used to estimate the model parameters. From the two models the negative binomial model was fit to the data. The results show that number of vertical curve, number of vertical grade, no of horizontal curve, speed, shoulder width, were found to be statistically significant explanatory variables (p < 0.05) for crash involvement and when the crash rate relates to the speed it is statically significant for the crash rate. After calibration the model was validated using data from similar road on Mekelle-AbiAdi road. And the result has shown it is not validate on the similar road. For the identification of hazardous road section Empirical bays method was used. Results indicate that from the total 96 km road sections 25 sections were highly prone to accidents with PI EB values. Possible solutions are using traffic signs, user awareness campaigns, policy revisions, and permanent geometry and pavement modifications.
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    EVALUATION OF MICRO AND SMALL ENTERPRISES PERFORMANCE IN 20/80 CONDOMINUM HOUSING CONSTRUCTION: THE CASE OF GULELE SUB-CITY, ADDIS ABABA
    (Hawassa University, 2019-10-17) ZERIHUN ALEMAYEHU TEKA
    Ethiopia has embarked on a long term development strategy which aimed at achieving sustainable development with all pre-requisites for a middle income country by the year 2025. The poor and deteriorated state of the construction industry with poor performance has detrimental effects to the developments of the industry. Thus, makes construction industry end product encountered many problems in terms of quality, delivery time and cost. Therefore the aims of this study also evaluation on micro and small enterprises that were engaged in 20/80 condominium housing construction at Addis Ababa in terms of quality, delivery time and cost. To achieve the proposed objectives, data were collected through the case study; questionnaire survey and site observation then making detailed discussion and analysis of problems and constraints that were hampering the performance of them. The finding of this research indicates MSEs on the average 67.6% MSEs couldn‟t delivered their activities on the required time, 75.7% MSEs couldn‟t deliver quality product output and 54.05% housing construction project office saves its cost by participating MSEs than that of contractors. On the other hand, on average according to the respondent 78.37% critical challenges were that hamper the performances of MSEs in 20/80 condominium housing construction projects at Addis Ababa. Factors causing delay in delivery of activities for MSEs are: delay in delivery of materials, contractor improper planning and skill shortage whereas factors which affect their quality include poor project management, low quality of materials and lack of experience. On the other hand major factors that cause cost overrun for MSEs in rendering activities are delay in material supply, poor project management and lack of skill. This study contributes to the advance knowledge in the area of enhancing and improving the performance of micro and small enterprises on 20/80 condominium housing construction. And also, its output will be used as a primary input for the government body during amendment and introducing of the new policies on the issues like, challenges that hampers the performance of MSEs and the solutions to overcome those problems
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    MULTIVARIATE COMPARATIVE ANALYSIS FOR SELECTION OF INTERSECTION CONTROL (CASE STUDY FOR SELECTED UNCONTROLLED INTERSECTIONS IN HAWASSA CITY
    (Hawassa University, 2019-08-12) ZEMENAYHU BORENA BORSAMO
    Uncontrolled intersections that are found on major road carrying a higher traffic volume generally have traffic safety and operational problems. This is due to the crossing and turning movements at this intersection cannot be satisfactorily managed with existing uncontrolled intersection. At major arterial road intersection with medium and high volume roads where grade separation can‟t be justified traffic would generally be controlled by either signal or roundabouts. The main objective of this thesis is to assess and find out optimum intersection control mechanism from roundabout or signalized intersection for existing uncontrolled intersection of shell and Addisu Menhariya in Hawassa city. These intersections are selected because both are found on major road carrying high traffic volumes (AADT) that justify the introduction of roundabout or signalized intersection based on ERA intersection selection criteria. The methodology that is used for selection is multivariate comparative analysis that uses cost, operational performance and safety performance as evaluation criteria. The traffic, geometric, cost, signal and crash data‟s are collected to make Comparison. Operational performance analyses are made using HCM 2010 methodologies incorporated in SIDRA Intersection software 5.1.The safety performances are measured using mean crash rates and causalities for similar intersection types for years from 2014 to 2018 G.C for millions of entering vehicles to intersections. The costs that are used for comparison are estimated initial costs for alternatives based on current market prices of the city and operational costs that are found using SIDRA Intersection software 5.1.The result show that proposed roundabout and signal intersections will serve LOS C and LOC F with existing traffic condition in both intersections respectively. The summary data indicates that the casualty crash exposure rate at roundabouts in Hawassa city is approximately 19% less than the casualty crash exposure rate of signalized intersections, when averaged across all crash types. The fuel costs and operational cost for roundabout intersection are also lesser than alternative signalized intersection. But the initial cost for roundabout is higher than proposed signalized intersection. Roundabout options are finally recommended for existing uncontrolled intersections of shell and Addisu Menhariya in Hawassa city
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    UTILIZATION OF BASALTIC QUARRY DUST AS A PARTIAL REPLACEMENT OF CEMENT IN HOLLOW CONCRETE BLOCK PRODUCTION IN THE CITY OF ADDIS ABABA (THE CASE OF KALITY AGGREGATE PRODUCTION SITE)
    (Hawassa University, 2019-10-16) YOHANNIS LEMMA ALEMU
    Crusher dust is a byproduct from crushing of coarse aggregate during quarrying activities. The utilization of this materials as a manufactured sand is controversial due to excessive fine particles in it and the disposal of fine materials is causing environmental problem. On other hand, the use of hollow concrete blocks as a walling material has been increased following the boosting of building construction activity in the country. This resulted in shortage of construction materials, especially the cement, creating price escalation. Furthermore, the sustainability problem related with the production of cement is a major issue of the globe. This research was, therefore, conducted to examine the potential of basaltic crusher dust as partial replacement for Portland pozzolana cement in hollow concrete block production. In doing so, Some units of cement pastes and concrete hollow blocks of different classes, i.e. A, B and C, were produced by partially replacing the cement content with 10%, 20%, 30% and 40% by weight of basaltic crusher dust using vibrating block molding machine. The units without basaltic crusher dust serve as a control. The cement pastes were examined for consistency and setting time, and the blocks produced were tested to determine their compressive strength, water absorption rate and density. Furthermore, the possible cost advantages of using basaltic crusher dust as partial replacement of cement in hollow concrete block were analyzed. The result indicates that the experimental HCB of class A and C surpassed the required standard of compressive strength, water absorption and density specified by the Ethiopian standard ES 596:2001; whereas, the compressive strength of class B fails at 40% cement replacement. It was concluded that concrete hollow blocks of class A and C with up to 40% replacement and class B with up to 30% replacement can be used for load bearing walls and save costs of block with comparable properties
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    NEGATIVE ENVIRONMENTAL IMPACTS OF CONSTRUCTION ACTIVITIES IN SNNPRS: (THE CASE OF BUILDING CONSTRUCTION PROJECTS IN SELECTED TOWNS
    (Hawassa University, 2019-10-10) YIDNEKACHEW ESAYAS
    Construction activities affect the environment throughout the life cycle of development. Even though the construction period is comparatively shorter in relation to the other stages of a building’s life, it has diverse significant effects on the environment. This study was carried out to identify the major environmental impacts of construction activities on building construction projects of selected towns in SNNPRS and to propose measures for their mitigation. Eleven site activities adversely affecting the environment; thirty-three possible environmental impacts of construction activities; and four groups of people likely to be affected by construction site activities were identified from literature. The 33 impacts were further categorized into nine major groups. The main approaches used in collecting data for the study were through questionnaire survey, and personal observations of some major construction sites in selected towns. Questionnaires were distributed to a total of 174 purposively selected respondents consisting of 58 contractors, 58 consultants and 58 nearby residents on 58 active building construction projects in selected towns. The respondents were asked to identify the most important item from the listed. The relative importance of the items identified were calculated and ranked by the relative importance index. According to the results of the study, the respondents agreed that concrete vibration; concrete batching, mixing and placement; and excavation are the main site activities having adverse environmental impacts in selected towns. Also resource consumption group impacts ranked highest among the major environmental impacts of construction activities in selected towns. The resource consumption group impacts were raw materials consumption, electricity consumption, water consumption and fuel consumption. Local issues impacts was second followed by transport issues impacts. Noise and vibration generation from local issues impacts group was ranked highest of all environmental impacts of construction activities. The respondents also agreed that site workers, nearby residents, and people in schools and hospitals are most likely to be adversely affected by construction site activities. The results of this study will be useful to support the implementation of environmental management systems in construction companies by providing guidance for construction practitioners. The paper recommends that stakeholders in the construction industry should start working with new methods and technologies following sustainable construction techniques to reduce environmental impacts
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    ANALYSIS OF TRANSPORTATION MODE CHOICE OF THE PASSENGERS USING MULTINOMIAL LOGIT MODEL FOR WORK AND SCHOOL TRIPS: A CASE STUDY IN HAWASSA CITY
    (Hawassa University, 2019-10-19) YESHITLA DENEKE
    The urbanization and urban sprawl of the city are becoming expanded in Ethiopia. People migrated to urban centers like Hawassa city in order to work, trade, and learn. Due to this, the transportation planners and engineers are always encountering a problem on how to provide adequate transportation services and facilities within the city because of the various mode choice behavior of the travelers. Hence, this study focused on identifying factors affecting mode choice behavior, analyzing the work and school trip makers’ mode choice behavior in Hawassa city using the Multinomial Logit Model by determining and forecasting the current and future mode share respectively. The transport modeling process as a travel demand forecasting tool used in the analysis of probable market shares of different motorized modes. The model developed with questionnaires distributed for this purpose by using workplace and school survey in the seven sub-cities of the Hawassa city. The primary data, like total waiting time were collected through site investigation at different major station of the city. Likewise, the secondary data like travel cost within each station gathered from the Hawassa City Road and Transportation Bureau. SPSS Software was used to process data for a Multinomial Logit Model (MNL) and to explain the travel patterns and mode choice of employees and students. The model was made with mode used in a trip as dependent variable and out of the vehicle travel time, in vehicle travel time, travel cost, income and comfort as an independent variables. Results indicated that the factors that significantly affect the choice of transport modes were average monthly income, in-vehicle travel time, out of the vehicle travel time, total travel cost and comfort during journey. The prediction level of the developed model was 79.5% for the employees and 82.9% for the students. The employee’s current probabilities of the modal split for city bus, damas, Bajaj and motorcycle were 28.83%, 25.4%, 6.2% and 39.58% while for the students were 35.92%, 29.74%, 19.79% and 14.53% respectively. The validation and verification of the developed model was done by testing the reasonableness of the sign of the parameters and by examining it with the three fundamental properties of the MLM. The estimations of the model might also be valuable to policy-makers and transport planners, who can estimate possibilities for various modes and determine the impact of unique policy modifications on the need for trip makers
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    FLOOD HAZARD ASSESSMENT AND MAPPING OF FLOOD INUNDATION AREA OF LOKA-ABAYA WOREDA OF SIDAMA ZONE IN S/N/N/P/R/S ETHIOPIA
    (Hawassa University, 2019-07-14) YEHUALASHET MULAT TEKABE
    Loka-Abaya woreda is found in S/N/N/P/R/S Rift Valley, surrounded by Bilate catchment. The area is dominated by undulating terrain with relatively steep to moderately steep and flatter slopes in the downstream of the catchment. This flood plain has been vulnerable to high flooding from rainfall during rainy season. This study focuses on estimation of flooding of the woreda due to the out-braking of Bilate River. The data used for generating the peak discharge for different return period related to the hydro metrological data of past events, and geometrical characteristics of the river channel and the reach boundary conditions are prepared in SCS method, HEC-RAS and HEC-GeoRAS models and Arc GIS environment. It was found that simulation result for return period of 5, 10, 25, 50 and 100-yearflood discharges of magnitude are 405.38, 551.48, 707.20, 745.37 and 898.12 in m3 /s respectively. The maximum flood hazard and flow depth for the return periods are found to be 3699.3 and 3.42; 3851.4 and 5.52; 4011.2 and 6.18; 4067.0 and 6.29; and 4224.5 hectare and 6.78 m respectively with a maximum velocity of 5.6m/s. The percentages of area inundated by floods are found increasing from 18.6 (3699.3ha) for 5 years to 21.3 (4224.5 ha) 100-year return period. Billate erisha lemat, Billate chricho, Thinbaho erisha lemat, Billate Eta and Boro shebela Keble of the woreda is found as flood prone area. It is observed that the findings of the research lead to key inputs in the designing of sustainable mitigation measures to minimize the impact of floods and the associated risks; it supports policy and decision makers to decide about how to allocate resources, flood forecasting, ecological studies, and significant land use planning in
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    THE CAUSES AND EFFECTS OF RIGHT OF WAY PROBLEM ON THE COST OVERRUN AND TIME OVERRUN OF ETHIOPIAN FEDERAL ROAD PROJECTS. (A CASE STUDY OF ERA WESTERN REGION PROJECTS
    (Hawassa University, 2019-10-18) YEALEM TILAHUN DESALEGN
    Right-of-way acquisition problem is a major obstacle in Ethiopian Federal road projects which significantly affect most projects’ final cost and schedule by creating disruption. Even though some researchers state right-of-way problem as the main reason for delay and cost overrun of projects within the country, only few studies were done to investigate the causes and the effects it brought to the construction industry. Taking this into consideration, this research was carried out to study the root causes of right-of-way obstruction; the effects it brought to the time overrun and cost overrun of Ethiopian Federal Road Project and the mitigation measures to adopt. The research used literature review, questionnaire survey, case study and desk study to collect the necessary data. A total of 39 questionnaires from client, consultants and contractors were collected to see the perspectives of different group of respondents on causes of right-of-way problems on Ethiopian Federal Road projects and the mitigation measures to adopt. 26 causes of right-of-way problems of road projects and 19 mitigation measures to adopt were identified and rated using a four-point Likert scale. A case study was done on 10 Ethiopian Road Authority western region projects to see the practical effects of right-of-way problem on time overrun and cost overrun of projects. According to the total collected survey data analysis, the cause of right of-way problem with the highest importance index of 72.68% was “Insufficient coordination between right-of-way agents and utility authorities” which was resulted from poor employer relationship with the utility authorities. In the same way, the best practice to mitigate right-of way problem with the highest relative important index of 0.90 was “Creating good communication and team work sprit with Utility Authorities”. All of the projects under the case study had both cost overrun and time extension due to many reasons. The extension of time due to right-of-way problem ranges from 4.2% to 58.8 % of the total extension of time and there were no cost claims in relation to right of way problems on projects under the case study. However the desk study shows delay has a major contribution to project completion cost through time related costs
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    ASSESSMENT OF BUILDINGS MAINTENANCE MANAGEMENT PRACTICES: (A CASE OF SELECTED TOWNS IN SOUTHERN NATIONS, NATIONALITIES, AND PEOPLE’S REGIONAL STATE)
    (Hawassa Inversity, 2019-10-29) YACOB BADENGA MINUTA
    Building defect is a failing or shortcoming in the function, performance, statutory or user requirements of a fabric, facilities in a building. Maintenance is an important program for the sustainability of buildings under occupancy. (The present buildings) Observed buildings in this study in SNNPRS were manifesting deterioration that should have been maintained long ago. In the region, defects in public buildings appeared and their impacts had been of high maintenance costs. Material and construction deficiency observed as the main causes of building defect under occupancy stage of buildings (Bedru M. , 2015). This research assessed the defects and maintenance management practices in the occupancy stage of public buildings in selected towns of SNNPRS. At the end, effects of defects and defect reducing measures were investigated. Interview survey, case study and desk study were used and analyzed by SPSS for research work. Thirteen buildings were considered during the interview, case studies and desk study. Building administrators, facility managers and other concerned body were considered in the selected buildings in the region for the interview questions. From the result, the main types of defects were identified; economic, functional and social consequences of defects were investigated; the practices of maintenance management in public buildings were assessed and defect reducing measures were finally recommended for buildings. The frequent types of defects identified in the study were; dampness; peeling of paint; leakage and defects in building service installation. Similarly the average results showed that the most common causes of building defect were construction and material deficiency with corresponding shares of 41.95 % and 37.55 % of the defects respectively. High amount of maintenance cost was consumed in a building in the desk study analysis in one time maintenance for a building defect. This implies there was no preventive mechanisms set for buildings. Before beginning of the actual maintenance work, maintenance directory (report) should be prepared for all defective items in team in order to know the severity of defects which enables to prepare maintenance BoQ for execution. Periodic maintenance shall be recommended for public buildings under occupancy