Civil Engineering

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

Browse

Search Results

Now showing 1 - 10 of 106
  • No Thumbnail Available
    Item
    PERFORMANCE OF HOLLOW CONCRETE BLOCKS WITH CRUSHED WASTE GLASS AS PARTIAL REPLACEMENT OF FINE AGGREGATE
    (Hawassa University, 2020-10-23) YOSEF KUMA AYANA
    Construction is booming in developing countries like Ethiopia. As construction is increasing, demand and price of the construction materials are increasing. Among building construction components hollow concrete block is being widely used. From concrete block making materials fine aggregate is higher constituent. The uses of river sand as fine aggregate leads to exploitation of natural resources and also environmental concerns related to the disposal of various waste materials have escalated to a worrying level, among those: crushed wastes glass is one of them. Therefore, to make the construction industry sustainable, the use of waste materials in place of natural resources is one of the recommended. The main objectives of this study was to investigate the performance of class C hollow concrete blocks with crushed waste glass as partial replacement of fine aggregate and to determine the replacement percentages at which crushed waste glass can be effectively put into service and also compare the cost of crushed waste glass partially replaced in hollow concrete block with the conventional ones. The method used was experimental study. The crushed waste glass partial replaced fine aggregate with 10%, 20% and 30% by volume and the control mix was prepared. The compressive strength test was carried out at the 7th, 14th and 28th days, whereas the density and water absorption tests were carried out on the 28th day. As per the finding, the control mix compared with the replacement specimen, the density is decreased as the proportion of crushed waste glass increases and decreases by 5.6% at a 30% replacement, the water absorption decreases as crushed waste glass content increases and it decreased by 2.5% at a 30% replacement, the compressive strength with up to 20% replacement increases by 59.72%, but after that, it starts decreasing for 30% replacement by 10.64%, results showed that replacement of 20% fine aggregate by crushed waste glass was found to have optimal compressive strength, and also the production of block using 20% crushed waste glass saves cost compared to the conventional once by 2.06% in 1m2 area.
  • No Thumbnail Available
    Item
    EVALUTION OF THE CONTRIBUTION OF GEOMETRIC DESIGN OF THE ROAD INTERSECTION IN ALLEVIATING TRAFFIC ACCIDENT IN SHASHEMENE TOWN
    (Hawassa University, 2020-08-18) YASIN ASSEFA MOSSA
    Efficiency of intersections contributes significantly towards the efficiency of urban road networks. Whereas intersections constitute a very small part of the entire transportation network, more than 50% of all motor vehicle accidents occur at intersections. Because of the overrepresentation of intersection-accidents, intersections require special attention in the planning and designing of road networks. Thus, the main aim of this research study is the evaluation of the contribution of geometric design of the road intersections in alleviating traffic accident in the Shashemene town. Abosto and Kudus Mikael signalized intersections while Tekliye, Semaniyaand (81), arada Sefer, Gibrna, Zero Amst (05) and Mobile non signalized intersections were chosen for this thesis. These intersections were selected for the study from different locations within the town. They have more traffic accident than any other similar junctions do in Shashemene town. The geometric, traffic and accident data were collected during the morning and afternoon peak time periods using site observation, field measurement and video camera in each of the selected junctions. The study use four distinct scientific principles namely: accident frequency, accident rate, empirical Bayesian and critical accident method to identify black spot locations at selected intersections. Out of the methods, empirical Bayesian proved superiority so that much of the conclusion was based on this method. Log linear Poisson regression and Negative binomial regression model was used to investigate the effect of road geometric design elements on the road crash occurrence in the selected junctions.The results of paper proved that road junction Semaniyand, Tekliye, Kudus Mikael and Abosto were highly prone to accidents than other road junctions in Shashemene town with adjusted accident frequency values of 27.85, 26.54, 25.25 and 22.65 respectively. And also the result of this study shows, there is a strong correlation between road geometric design elements and road crash occurrence. The modeling result indicated that the explanatory variables such as lane width, super elevation, gradient, and intersection sight distance, shoulder width, median type, and median width, angle of intersection, side walk width and curves radius had significant effects on the occurrence of road traffic crashes
  • No Thumbnail Available
    Item
    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
  • No Thumbnail Available
    Item
    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.
  • No Thumbnail Available
    Item
    PERFORMANCE EVALUATION OF OFF-STREET PARKING IN ADDIS ABABA CITY (A CASE STUDY IN SELECTED CENTRAL BUSINESS DISTRICTS)
    (Hawassa University, 2020-10-21) ALEMSEGED ESHETE TEKLEWOLD
    Car-parking sector has always been of great importance in terms of urban mobility, since it is a fundamental element in achieving a high level of accessibility in the city centers. Central Business Districts (CBD) are areas of dense traffic which result in parking problems. Addis Ababa, the administrative and financial capital of Ethiopia, is experiencing continued growth and change. But due to the fact that more than 60% of the vehicles in the country are operated in this city, parking problem is crucial. Parking plays an important role in mobility, access and the economic development of Addis Ababa. The space that parking requires can be problematic in any city, but it poses particular problem in Central Business Districts (CBD). Due to the absence of clearly designated areas of parking in Ethiopia, shortage of parking facilities has been a long standing problem in the country. Especially cities with greater economic activities, greatly faced to traffic congestion and delay problems. The general objective of this research is to evaluate the efficiency of off-street car parking in the Central Business District area of Addis Ababa City. Depending upon their greater demand requirement for a parking facilities, three central business districts of the capital (i.e. ‘Megenagna’, ‘Bole’ and ‘Merkato’) were chosen for detailed analysis. From the stated locations; 11, 13 and 11 off-street parking sites were selected for further analysis respectively. For data collection in and out data collection technique were used. Data was collected from May to September 2019 during the interval of time 8 am-6 pm. From the accumulation graph, peak hour for the demand was selected. The performance analysis result shows that off-street parking’s in the central business district of the city is over their capacity. Demand study was also made to ‘Megenagna’ site by using land use analysis method. From the demand analysis 2,454 additional parking spaces were required to afford the existing demand. In addition to this, structured interview was made to the users of the parking facilities to strengthen the analysis. The research conclude that the main problem of parking in the areas is lack of enough off-street parking space supplies, lack of parking policy and management system, absence of parking signs and marks which results in confusion for finding available parking spaces and lack of knowledge of users for parking usage and shared parking strategies
  • No Thumbnail Available
    Item
    SEISMIC PERFORMANCE EVALUATION OF REINFORCED HCB FULLY GROUTED MASONRY WALLS AND ITS PERFORMANCE COMPARING WITH UNREINFORCED FULLY GROUTED MASONRY WALLS
    (Hawassa University, 2021-10-22) ZERIHUN TALE BIZUNEH
    A reinforced hollow concrete block masonry walls constructed by assembling masonry units, and it was the key structural element widely used to resist lateral loads in masonry buildings. Unreinforced hollow concrete block Masonry wall rapidly fails because of lateral load like an earthquake. Hence this study attempts to evaluate responses of a reinforced and unreinforced fully grouted hollow concrete block masonry wall, select the best walls based on differing their aspect (H/L) ratio, horizontal and vertical reinforcement ratio, and spacing. Also, know the behavior of reinforced and unreinforced fully grouted hollow concrete block masonry wall under lateral load and determine its percentage effectiveness. The study was conducted using finite element ABAQUS software for which a total of 24 masonry wall models were considered. For validation of the finite element method, reinforced masonry walls experimentally worked by M. Hany (2016), and the experimental results compared with the numerically modeled. The comparison of the results indicated that both experimental and numerical results agreed very well. After the validation, the effect of seismic load on reinforced and unreinforced fully grouted hollow concrete block masonry walls investigated by the quasi-static method. The comparison for ultimate load carrying capacity, stiffness degradation, and displacement ductility of each investigation parameter are carried out from the comparative analysis. It was found that the aspect ratio 1.39 wall vertical reinforcement ratio increases from 0.26% to 0.36%, the ultimate strength increase by 15.344% for push and 14.578% for pull direction. And also, the vertical reinforcement spacing increases the Ultimate strength of the wall decrease. The Ultimate shear resistance of the wall is reduced by 17.21% for push and 14.25% for pull direction for in-plane load when the spacing of Ø16 vertical reinforcement increases from 200mm to 400mm. The aspect H/L ratio increase from 1.39 to 1.95 the ultimate strength decrease by 38.15% for push direction and 41.89% for pull direction. Generally, aspect ratio, vertical reinforcement spacing, and vertical reinforcement ratio variation highly influence hollow concrete masonry wall seismic performance relative to horizontal reinforcement
  • No Thumbnail Available
    Item
    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
  • No Thumbnail Available
    Item
    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
  • No Thumbnail Available
    Item
    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
  • No Thumbnail Available
    Item
    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