Civil Engineering

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T E I CAPM T O F AL N U D S /E LAN OC D V RE HC NA EG ON RESER V RIO ES ID M NE TAT OI .N SAC( E FO TEKE EZ RDYH O P O D REW AM)
(Hawassa University, 2016-10-12) T KLEWE NY I T LKE U HAB A
W dehsreta si eredisnoc d ot eb ht e aedi l tinu of r m na ag neme t fo the tan u ar l uoser r sec . Ex oitcart n fo sretaw h de ap r retema s nisu g (GI )S dna esu of lacitamehtam sledom si eht ruc r tne dnert f ro hy lord og ci ev noitaula fo .sdehsretaw lioS noisore si a suoires taerht ni t eh ekeT ze sretaw h .de ofeD r ,noitatse evo rg ar iz ng, dna roop dnal am an tnemeg ca c ele r deta eht ar te fo noisore eud ot ht e tcapmi fo dnal esu dnal revoc ahc n eg . oT leved op evitceffe e noisor lortnoc snalp dna to eveihca snoitcuder ni ,noitatnemides ti si i tnatropm ot uq a itn fy eht tnemides yi dle dna itnedi fy ra e sa aht t era high srotubirtnoc of tnemides ta rcim o- taw re dehs level dna ov re l ra eg ar sae . In siht uts dy SW TA oS( il dna W reta tnemssessA )looT h gniva na ecafretni htiw rA cG SI erawtfos saw desu ot etamitse tnemides yi dle dna itnedi fy laitaps noitubirtsid fo tnemides y dlei ni eht .dehsretaw hT e ledom saw lufsseccus ly detarbilac dna tadilav ed rof derusaem rts e ma wolf dna s dednepsu tnemides noitartnecnoc ta alihceY gauging .snoitats ehT wolf itarbilac on dna noitadilav luser t dewohs taht edom l ep rfo cnamr e lave u noita scitsitats oc e tneiciff of d mrete i noitan R( 2 ) dna N hsa - effilctuS ledom ffe i neic cy (E ))SN we er ni eht ac elbatpec range R( 2 ni the ar nge 98.0 dna 8.0 7, SNE ni ht e egnar fo 38.0 dna )47.0 . oslA eht dednepsus tnemides noitartnecnoc ta lihceY a gauging snoitats R2 68.0 dna 8.0 4, SNE of 8.0 2 dna .0 78 rof oitarbilac n dna v .noitadila sihT setacidni taht eht bo s re v de seulav ohs w g doo agr tnemee htiw detalumis v eula of r b hto wolf dna tnemides y .dlei The om d le noitciderp re stlus detacidni taht tuoba 50.21 % fo eht aw t dehsre ra e sa ev ry es v ere ly edore d wi ht unna la tnemides aol d ar nging f mor 2 .9 54 ot 3 63.3 ah/senot /yr na d tuoba .42 67% fo the wa dehsret a er a sah es ver le y e noisor tiw h nna u la tnemides daol ar nging 24. 79 ot 29 5. 3 t ah/ /yr. T eh launna eva ar ge tnemides yi dle fo ht e taw e hsr ed saw 71 53. ah/t /yr of r eht dnal su e dnal evoc r pam fo 0102 . ehT tluser fo eht uts dy dluoc pleh d nereffi t dlohekats e sr ot ppa tnemelpmi dna nalp r taw dna lios etairpo e c r o tarts noitavresn eg ni sei t sretaw eh h .
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
DISTRIBUTION ANALYSIS OF FLUORIDE IN GROUNDWATER OF HAWASSA ZURIA WOREDA, SIDAMA ZONE
(Hawassa Inversity, 2017-10-13) IYASU MARKOS CHICHOLA
As per the Woreda Water Supply Office‘s study, the water source from the ground and surface water is polluted in Hawassa Zuria Woreda but their distribution and extent of pollution is not well understood.The main aim of this study is to determine the distribution of the fluoride ion concentration levels in Hawassa Zuria Woreda in the groundwater. The collected primary data were used to assess the distribution of the fluoride concentration levels in all groundwater sources. Fluoride concentration from twenty-three Kebeles was analyzed at laboratory of Fluorides in this research area. The delineation and mapping of Fluorides were carried out using GIS software, based on sampling at random bore holes during 2016/17 year of seasons. Areas of particularly high or low fluoride levels were identified. High fluoride greater than 6mg/l concentrations were found in Kajma Umbulo, Sama Ejersa, Jara Damuwa and Jara Karara provinces. Those provinces need for partial de-fluoridation and this must receive serious consideration since the water from those sources is currently being used for drinking purpose. From temporal distribution high fluoride distribution expected to occur during wet season which shows the best cares during this season than the others
Assessment of causes of delay on selected asphalt road Projects in the Southern Region of Ethiopi
(Hawassa University, 2017-10-18) Mengistu G/kirosGesesew
PERFORMANCE EVALUATION OF ANBESSA CITY BUS SERVICE ENTERPRISE TRANSPORT SERVICE: THE CASE OF ADDIS ABABA-BISHOFTU CORRIDOR
(Hawassa University, 2018-03-25) TAMRAT BERARA GETU
Providing and improving public transport service is becoming highly important to meet the demand of rapidly growing mass mobility due to high population growth and galloping urbanization in and around the city of Addis Ababa. Performance measurement is a popular activity in the transportation sector. Various studies on the performance of transportation systems with the utilization of data analysis have been common. In Addis Ababa-Bishoftu corridor public transport problem related to limited numbers of buses, insufficiency of bus routes, inadequacy of bus stops and operational deficiency are common. This research evaluate the performance of public transport service provided by Anbessa City Bus Service Enterprise (ACBSE) in the selected corridor. The study uses GIS techniques and Statistical (descriptive, correlation, factor and regression) analysis to assess the route network, travel speed, dwell time and passenger carrying capacity of the transport service. It has identified that there is route network gap for the town of Bishoftu and the current transport service in this corridor is poor. In addition to this the study assess the level of satisfaction of customers about the transport service provision of ACBSE in related to selected performance indicators such as frequency, travel speed, price, security, bus comfort, seat availability, vehicle overcrowding, punctuality and safety of the transport service. The study indicates that in the selected corridor there is very limited number of buses, there is high breakdown of buses and existing buses are not operating as per the schedule. Therefore, the service is found not reliable for travelers. Excessive waiting time and long walking distance to reach the service make it inconvenient. Moreover, high overcrowding and lack of seat inside the bus makes it uncomfortable. Correspondingly, the quality of the service is poor and customers are not satisfied about the transport service of ACBSE. In terms of LOS in most case the transport service operates at LOS D and lower. Thus to improve ACBSE transport service for Addis Ababa-Bishoftu corridor this research suggest that the extension of route network coverage for the town of Bishoftu, increase frequency of the transport service, upgrading the ticketing procedure, improving treatment of customers by bus operators and bus priority measures for high traffic congestion areas
PREDICTIVE MODEL OF UNCONFINED COMPRESSIVE STRENGTH FROM INDEX PROPERTY OF LATERITIC SOILS. (CASE OF DILLA TOWN)
(Hawassa University, 2018-04-14) SAMUEL ABAYNEH
In Dilla large buildings and important infrastructures are often supported by lateritic soils. Lateritic soils are anisotropic and heterogeneous. Geotechnical engineers concerned on lateritic soils are attempting to develop specific empirical equations to predict more reliable results needed for the design. As this study is one avenue towards developing specific predictive models, lateritic soil samples were taken and laboratory tests were conducted to meet its objective. Twenty disturbed and twenty undisturbed samples were taken from ten different randomly selected borrow pits having four-meter depth with in the town and various laboratory tests including Atterberg’s limits, natural moisture contents, in-place unit weight, specific gravity and unconfined compressive strength were performed on the soil samples. Regression analysis have been done and various linear relationships between unconfined compressive strength and index properties were investigated and predictive equations estimating unconfined compressive strength from index properties were developed. Among the developed models, two comparatively better models having determination coefficients of 0.866 and 0.927 with standard error of less than 0.0005 are selected and validated. A model with 0.866 determination coefficient is given by qu = -421.843- 4.191wn + 40.870γins. While, a model with 0.927 determination coefficient, qu= 1.1𝑒 0.282𝛾𝑖𝑛𝑠 is exponential and got a better accuracy on prediction during validation using control test result. The equations are valid for a natural moisture content in a range of 19% to 35% and in-situ unit weight in a range of 12 kN/m3 to 20.6 kN/m3 .
THE EFFECT OF CLIMATE CHANGE ON URAN DRAINGE: CASE OF BISHOFTU CITY DRAINAGE
(Hawassa University, 2018-07-14) ABREHAM AMDE GEBRESELASSIE
Climate change is a reality that planners and designers of drainage infrastructures must consider. Therefore, the risk should be investigated and quantified properly. The objective of this thesis is to investigate the effect of climate change on Urban Drainage having the case of Bishoftu city drainage. Projection of the future climate is done by using CMIP5 climate model outputs of RCP4.5 and RCP8.5 scenarios and downscaled daily rainfall and temperature data of CMIP5. The future climate projection analysis was done by partitioning the coming 50 years in two periods which are (2020-2040) and (2051-2070) and the 1994-2013 is taken as the base line period. These climate scenarios data were bias corrected for serving as input to the SCS for impact analysis. Using Easy fit software, the rain fall data was fitted to Gumball distribution for the quantile estimation. The quantile estimation of 2, 5, 10, 25, 50 and 100 years return period for the site were found to be 47.818, 60.043, 68.137, 78.363, 85.95, 93.481, 110.884 and 118.365. Respectively. The study area which are Kalhiwet church area and the market area water shed area of the drainage design was done. The hydrologic analysis of rain fall run off is computed by using modified SCS method and the hydraulics parameter is computed by 4.2 Hydraulic tool box software for the two catchment area with RCP4.5 and RCP 8.5 Scenarios of the two time horizon of 2030s and 2060s. Finally the design discharge amount is change in Market area by RCP 4.5 in 2060 is change by 63.3% and Minimum 18.64% in RCP 4.5Average design discharge, channel width and depth will increase up to 60.8% Max and 16.9% Min , 29.9% Max and 6.05% Min, and 20.21% Max and 6.7% Min depth is changed in KHC respectively. And for the design discharge of market area Max 63.3% and Min 18.64%, the width of channel is changed by 31.16% Max and 8.17% Min, and also the depth of the channel 32.22% Max and 9.09% Min also change. Therefore, the consideration of climate change on drainage is important
INVESTIGATING SITE LAYOUT PLANNING AND IMPLEMENTATION PRACTICE IN BUILDING CONSTRUCTION PROJECTS
(Hawassa University, 2018-07-14) SISAY TEMESGEN
Building projects in SNNPRS experience challenges of meeting project objectives due to an improper initial work management plan, which includes a site layout planning. Lack of proper site layout planning contributes to cost and time overruns in projects of the Region. Site layout planning utilization has implications for project safety, construction efficiency, scheduling, and budgetary performance of a project. The main purpose of this research was to investigate site layout planning and implementation practice in building construction projects in SNNPRS. The objectives of this study were identifying effects of poor site layout planning in building construction activities, identifying the key factors which contribute to achieving an effective site layout planning, and studying site layout plan utilization practice in building construction projects in SNNPRS and finally to provide practical procedure that can be referenced when developing site layout plan. The main approaches used in collecting information for the study were through a questionnaire survey, and personal observations of some major construction sites in SNNPRS in case of selected towns. The questionnaire survey was distributed to 40 respondents and a total of 36 responses were received. For the analysis of the data, statistical analysis by using mean score ranking and descriptive statistics were employed. The finding of the research indicated that the main impacts of poor site layout planning in building construction activities were a decrease in the output from labour and machinery, construction materials lost and damage, and increased travel distance on site. Availability of access and exit road to the construction site, location of plant and equipment, and positioning of temporary facilities were the major key factors which were found to be contributing to achieving an effective site layout planning. In the research, site layout plan utilization practice in building construction projects was also studied which led to development of a procedure describing an approach of site layout plan in construction projects. The procedure incorporates important aspects associated with project constraint identification, plan necessity, data acquisition, plan development, communication, implementation and enforcement, monitoring and evaluating, and documentation. This research contributes by providing information (factors) that one has to examine in order to have an effective and efficient site layout planning and also by bringing practical procedures and recommendations that can be referenced when developing site layout plan on the construction site
NON - LANA RAENIL Y FO SIS S ITLUM DECARB LEET - NIER YROTS F CNOC DECRO R TE E FRA S
(Hawassa University, 2018-07-18) A EYABM AP U S
ehT noitavitom ot poleved se cimsi r se i tnats serutcurts ets sm fr mo the laitnatsbus cimonoce sessol taht can eb esuac d by earthquake .egamad enO dohtem fo iveihca ng ies s cim re lis i ycne is to gised n bu gnidli s ac p elba of ser i gnits etal r la e tra hquake ,sdaol gnitapissid ,ygrene dna gniziminim ingis f aci nt larutcurts .egamad In siht yduts a luger ar ,net evlewt dna txis e ne yrots htiw ruof yab bu sgnidli ra e de dengis rof gr ytiva sdaol and dezylana rof es i ims c lo da sac e .s ehT gnicarb s evah neeb id detubirts ta the elddim and ruof renroc yrehpirep fo eht fo rts u erutc revo eht hgieh t ht ne non raenil mit e h tsi o yr sisylana saw ofrep rmed. effiD r tne sdnik fo st lee gnicarb s w ere used rof maxe ple rc o ss ,gnicarb rvehc on V( ,)gnicarb V 001 ,cirtnecce V 005 ec ec ,cirtn V 0001 ,cirtnecce dna V 0051 ec ec .cirtn ehT srebmun detpircsbus ped ict ht e ec icirtnec ty pr oisivo n in ch rve on br ica n sg ta eht pit ni temillim e .sr roF ereht si sorc s s lanoitce dna enffits ss noitairav ni itsiser ng laretal daol s neewteb b ,sgnicar ti aw s t eir d ot e etauq eht s it f ssenf eb twe ne orc ss carb i sgn sgnicarb fo tser eht ot cnamrofrep ehT.deiduts e fo ht e erutcurts w t no pu devorpmi sa he fo noisulcni s et el gnicarb s . ivorp naht retteB d carb gni i gn s oc eht ta r lddim yrehpirep ren e sgnicarb eyalpsid d a si ng tnacifi aretal l dr fi t r de u itc no . A noitcuder of umixam m aretal l yerots lpsid a tnemec of tuoba 36,%85 % %94, saw devresbo rof eht 01 , 21 and 61 - erots y elddim sorc s ecarb d b nidliu gs pser e evitc ly, co derapm to the as-bui tl on .e ehT ffe e tc fo gnidulcni yticirtnecce in sgnicarb smretni of l lareta alpsid cement and ni t yrotsre rd i tf w sa sid c essu d. lareneG l ,y m elddi yab carb ed dliub i sgn id s deyalp ecuder d laretal alpsid c me e tn dna yrotsretni tfird sa ew edivorp ce cen icirt ty. gninrutrevO emom nt ser i ecnats aercni ses htiw cni noisul fo ste le gnicarb eud ot ercni a es in eht o llarev its ffness of the rts u erutc aicepse lly nehw nisu g c sor s carb i .sgn gnisU sorc s gnicarb sah a etteb r l lareta alpsid c neme t gnicarb tser eht naht yticapac noitcuder s s idut e d i iht n s repap . ti yduts siht nI a saw l p taht detartsnomed os e airetirc ecnamrofr ac n b pmi e l etneme d not ylno rof gnittiforter wen nidliub gs tub also of r the de ngis fo new bu idli n sg thro hgu suoroger snoitareti rof a de engis r ed t re m ni ed ofrep r ecnam el ve .l In siht ts udy it w sa ed s ht ot deri mi e m de i l ecnamrofrep ycnapucco deta e ev l
COMPUTER PROGRAM FOR ANALYSIS AND DESIGN OF REINFORCED CONCRETE BEAM SECTIONS
(Hawassa University, 2018-10-10) MIKIYAS JABIR
The purpose of this study is to develop a computer program that can be used for analysis and design of a reinforced concrete beam sections based on the new Ethiopian building code, and also that can optimize double reinforced rectangular beam section. The computer program is developed in MATLAB programming language and graphical user interface is incorporated in the program by following procedures reuired for design problem by satisfying design criteria set by the code (ES EN 1992-1-1:2015). The program incorporate simple interface for section analysis and design of reinforced concrete rectangular, T or inverted L and trapezoidal beams for flexure and rectangular beam with vertical and inclined stirrup for shear, torsion and combined effect of shear with torsion that will help the designers to save time, minmize effort and avoid calculation error that commonly occur. A graphical user interface developed for flexure is programed for a particular beam cross-section dimensions and material properties satisfiying stress-strain compatibility and equilibrium on the basis of rectangular-parapolic stress distibuiton for rectangular beam and on the basis of equivalent rectangular stress distribution for T or inverted L and trapezoidal beam section. Finally, the moment resistance (MRd) and area of reinforcement required to resist a design moment are determined. The two graphical user interface; for shear programmed based on truss model and for torsion programmed by considering beam as equivalent thin-walled sections. Using this interface design shear resistance of concrete (VRd,c), design shear resistance (VRd), design torsion resistance of concrete (TRd,c) and design torsion resistance (TRd) for rectangular reinforced concrete beam section with vertical or inclined stirrup is determined. Using graphical user interface combined effect of shear with torsion is also checked for rectangular beam with vertical and inclined stirrup. Dimensions of beam cross section, area of reinforcement, size of stirrup and spacing of stirrup are selected by satisfying design criteria for shear, torsion and combined effect respectively. Finally, application of the user interface is demonstrated with example for analysis and design of reinforced concrete beam section for flexure, shear, torsion and combined effect of shear with torsion
COMPARATIVE ASSESSMENT OF CONVENTIONAL VERSUS REMOTE SENSING BASED APPROACH FOR LAKE EVAPORATION ESTIMATION: THE CASE OF LAKE HAWASSA, ETHIOPIA
(Hawassa University, 2018-10-11) GIRUM FIKADE WOLDE SENBET
Evaporation is the major component of the water and energy budget of the water bodies. The Evaporation process needs special attention for a better allocation and management of water resources. The main objective of this study was to compare evaporation estimates based on conventional and Remote Sensing approach. Different methods have been developed and implemented to estimate total evaporation, including meteorological ground-based point data, field measurements and spatially explicit remotely sensed data. Surface Energy Balance System (SEBS) was employed to estimate the Lake Hawassa evaporation and other energy balance components. The SEBS results were compared with meteorological methods results (Debruine Keigeman, BREB method, and Penman), using Pan Evaporation as a reference. Nash-Sutcliffe, efficiency coefficient (E), Wilmott‟s index (dr) for evaporation estimates, and Root Mean Square Deviation (RMSD) were used as a statistical performance measures for energy balance component estimates. The SEBS results indicate that the Lake Hawassa average evaporation estimate is 1.16 mm/day in September and 5.2 mm/day in February. Using Pan Evaporation measurements as a tool; evaporation estimates of SEBS perform better than any other metrological method, with Nash-Sutcliffe, efficiency coefficient (E) = 0.48 and Wilmott‟s index (dr) = 0.48 as well. Penman and BREB methods perform poor in evaporation estimation from Lake Hawassa. SEBS heat fluxes RMSD from the meteorological based estimation were 15.01W/m2 for Net Radiation (Rn), 13.7 W/m2 for Stored Heat Flux (G0), and 11.54 W/m2 for Sensible Heat Flux (H). Generally it was concluded that the SEBS remote sensing algorithm is applicable for evaporation and other energy balance components estimation on Lake Hawassa.
IMPACTS OF ROAD CONSTRUCTION DELAY ON TRANSPORT COST AND BENEFIT A CASE STUDY ON HAGEREMARIAM -YABELO ROAD CONSTRUCTION PROJECT
(Hawassa Unversity, 2018-10-11) SELAMAWIT KIFTAGA NAMAGA
Completion of a project is considered as the most important factor of successes of road projects which helps to decrease problems for all concerned parties and give new chances to a county's economy. Delays in completion of road projects will result in significant loss of benefits for all road users. Accordingly, this research is carried out with the view of evaluating the impacts of road construction delays on transport costs and benefit considering Hageremariam-Yabelo Road. Questionnaire surveys were used to collect data on causes of delays and impact of delay on vehicle operating cost as well as an analysis was conducted by using the Likert Scale with mean score value. A total of 35 responded questionnaires from the client, consultants and contractors were collected. In addition, pertinent data were collected from vehicle operators on Hageremariam Yabelo Road project. Respondents identified twenty-seven (27) causes of delays and nine (9) impacts. The most important causes of delays were: delays to furnish and deliver the site (right of-way problem) and lack of possession of the site in various locations; variation of order (additional works not considered during the first time); and late site mobilization. The most common impacts of delays regarding vehicle operating cost were identified as; working hours per year (frequency of journey per day); tire consumption / tier-wear and average vehicle service life. This research also used the Highway Development and Management (HDM-4) tool in quantifying additional costs due to delays in respect of road agency and road user costs with the total loss of benefits. Using the Model, results were generated in the case of both alternatives (with delay and without delay) of the subject construction project. Overall, the 'with delay' alternative was compared with the 'without delay' alternative and the total transport costs increased by Birr 674.22 million. The amount of lost benefits from vehicle operating cost savings, travel time cost savings and accident cost reduction that resulted in the case of 'with delay' alternative was calculated at Birr 17.49 million. It is believed that these findings will guide to improve the performance of the construction industry of Ethiopia in the future
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
COMPARISON OF TIES CONFIGURATION FOR COLUMN UNDER COMPRESSIVE LOAD
(Hawassa University, 2018-10-16) Henok Shiferaw
A tied column in the reinforced concrete structure is the one in which longitudinal bars are tied together with smaller diameter bars at intervals up the column. In Ethiopia most building in the seismic area have tied column. Ties should confine core concrete properly. One way to enhance confinement is using proper detailing, seismic hook. However, installation (bending) of confining reinforcement with a 135-degree hook (seismic hook) is not easy. Therefore, in practice, many construction workers in most part of our country with high seismic zones: Zone 3 and Zone 4 apply a confining reinforcement with a 90-degree hook (fixed by wire mesh) .But most of the building codes recommend using a 135-degree hook, especially in this seismic zones. In the present study, a comparison of two type of ties configuration by taking 150x150x465(mm) reinforced concrete specimens made. This study proposed two different type of ties configuration Introduced category 3 (IC3) and Introduced category 4 (IC4) and compared with 900 ties configuration under peak load and load-deformation behaviors. Three samples cast for each ties configurations having 8mm ties and three plain concrete with the same size. Additionally, two samples with similar geometry for 900 and 1350 compared having 6mm ties. Concentric axial compression load applied with the universal testing machine and average axial deformation were measured using linear voltage displacement transducer. The strain gauge was placed in ties at mid-height of the column. From observed experimental program ties with 900 configurations got the least performance for both diameter ties, its peak axial strength was 23.24% lower than seismic hook configuration for 8 mm ties. Introduced configuration 3 (IC3) was in good proximity with standard 1350 hook; axial peak load reduction of IC3 was 8.33% from 1350 hook. But IC4 result was similar to 900 ties configuration. In addition to experimental study analytical and nonlinear finite element model for 8mm formulated and the result was in good agreement with a standard hoo
STABILIZATION OF EXPANSIVE SOIL BY USING COFFEE HUSK ASH
(Hawassa University, 2018-10-18) REHMA MELKIE ALEMAYEHU
Expansive soils have high potential for swelling and shrinking as a result of change in moisture content and they are one of the major soil deposits in Ethiopia. Road constructed on an expansive soil needs special attention during the design and construction stages. This study investigates the feasibility of using coffee husk ash as an expansive soil stabilizer. Coffee husk is a byproduct of coffee beans: when coffee husk is burnt under controlled condition (muffle furnace) at 550 oC for 4 hour the resulting ash is coffee husk ash (CHA). To investigate the effect of adding CHA to an expansive soil, laboratory experiments such as atterberg limit tests, free swell index tests, Proctor density, CBR test and unconfined compressive strength (UCS) tests were performed for different percentages of coffee husk ash (CHA). Standard Procter testes were conduct to evaluate the compaction behavior and unconfined compressive tests were performed on samples of 3.6 cm diameter and 7.8 cm height for uncured, 7 and 14 days of curing. The soil was stabilized with CHA in stepped concentration of 5%, 10%, 15% up to 30% by dry weight of the soil for different laboratory tests. Also the effect of curing period was evaluated over a period of 7 to 14 days for UCS and CBR tests. Analysis of the results shows improvement on the geotechnical properties of CHA stabilized soil. CHA reduces plasticity index by 68% up to 25% of CHA content, swelling ratio by 76% up to 20% CHA content and OMC decreased from 47% to 30% at 15% CHA content with an increase in MDD from 1.22 g/cm3 to 1.384 g/cm3. The UCS is also increased from 35.73kPa to314kPa and the un soaked and soaked CBR values increased from 16.2% to 21.5% and from 1.62 to 5.1% respectively after 14 day of curing and with the addition of 15% CHA content. After the addition of the optimum amount of the CHA the value of the laboratory tests are changed. From this investigation CHA is an alternative expansive soil stabilizing material sa it has changed and for further investigation use another stabilizing agent in addition to CHA to change the soil property from medium plastic to low plastic.
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
DEVELOPMENT OF PASSENGER CAR EQUIVALENT FOR SIGNALIZED INTERSECTIONS (BASED ON A STUDY CONDUCTED AT SELECTED FOUR SIGLALISED INTERESECTIONS OF HAWASSA CITY, ETHIOPIA
(Hawassa Unversity, 2018-10-22) THOMAS BEZABIH BASHE
The number of passenger cars displaced in a traffic flow by a truck or a bus, under the prevailing roadway and traffic conditions is called Passenger Car Equivalent, Highway Capacity Manual (2010), where estimating it was the basic objective of this dissertation with all other vehicle categories available at signalized intersection of Hawassa City, Ethiopia. Data was collected from four signalized intersections using digital video recorder which is followed by extraction of the time headway. An analytical model was developed to simulate headway values based on total travel time and vehicle type. This model was used to estimate headways of Motorcycle, Auto rickshaw, Passenger cars, Light Duty Vehicle and Heavy Vehicles which are then used to estimated PCE of each vehicle group. Time headway ratio method was chosen for the analysis and estimation of PCE, for it was found to be utilizing such a dynamic characteristic of traffic stream (i.e. headway) which is able to explain driver behavior, roadway surroundings, traffic volume and speed characteristics through a single parameter. The PCE factors of Motorcycle, Auto rickshaw, Light Duty Vehicle and Heavy Vehicle are found to be 0.552, 0.701, 2.004 and 2.967 respectively. The PCE factor value of Motorcycle used by the local standard book, Ethiopian Road Authority, Geometric Design Manual (2013) is less than half of the calculated finding of the study; similarly, for Auto rickshaw the ERA provision is slightly larger than half of the calculated value of this study. The absence of PCE for Light Duty Vehicle and Heavy Vehicle groups and deviation of PCE factors for the remaining vehicle groups from this study result indicates a significant quantity of calculations involving PCE, such as saturation flow rate and thus influences the design of signalized intersections. Finally, it is suggested that the values obtained in this study can be used as a guideline in the design and analysis of signalized intersections in Hawassa City as well as in Ethiopia
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.
STABILIZATION OF EXPANSIVE SOIL WITH WASTE PLASTICS
(Hawassa University, 2018-10-26) TEZETA MOGES ADANE
Expansive soils have high amounts of clay particles and have a special mineralogical characteristic. The presence of considerable amount of montmorillonite clay mineral causes them to swell and shrink when amount of water is changed. Due to successive shrink and swell, this type of soil causes some asphalt distresses like upheaval, roughness, rutting and longitudinal cracking. To other extent, black cotton soils in construction sites do have xiv xv significant influence on planning, structural design, construction & maintenance costs, performance and engineering life of roads. There are many techniques to improve poor engineering properties of expansive soils. One of this is stabilization of expansive soil with waste plastic materials in the form of flexi which was introduced in this specific study. The stabilization of black cotton soil with optimum amount of flexi material decreased plastic index (PI) value by 13.6% and optimum moisture content (OMC) value by 18.5%, increased maximum dry density (MDD) value by 1.9%, increased California bearing ratio (CBR) value by 50.9%, increased Cohesion(C) value by 83.3% and increased both unconfined compressive strength (qu) and un-drained shear strength (Su) value by 10.1%. The flexi material gave better strength and stability by means of replacement of black cotton soil by flexi. Sand also used as a stabilizer material to magnify the effect of flexi stabilizer. In addition, the correlation and regression model was done by the result of the laboratory test results of OMC, MDD, CBR, C, and qu as dependent variables with the independent variables of percent (%) of flexi and PI in a single regression analysis. A good correlation and regression models were developed between percent of flexi and CBR, qu & Su. Coefficient of determination (R2 = 0.79) indicates that CBR has strong relation with % of flexi by having equation of𝐶𝐵𝑅 = (2.9909) − (0.3465 ∗ % 𝑜𝑓𝑓𝑙𝑒𝑥𝑖)
IDENTIFICATION OF COLLAPSIBILITY POTENTIAL OF SOILS ALONG SHASHEMENE – AJE ROAD CORRIDOR: AMBURE SITE
(Hawassa University, 2018-10-27) ASHEBIR TAJEBE BEDADA
Large areas of the earth’s surface are covered by soils that are susceptible to large reduction in bulk volume when they are near to saturation (Knodel, 1992). These soils are termed as collapsing soils and are common in many parts of Ethiopia. This study is concerned with the identification of the collapsibility potential of soil found along Shashemene – Aje road corridor, in particular at Ambure site, Western Arsi zone, Ethiopia. The study was carried out as relatively little is known about the collapse phenomenon in the silty/ fine sands. The aim of the study was achieved through the experimental work which included engineering tests like: one dimensional oedometer testing and direct shear strength testing; and classification tests like: moisture content, bulk dry density, compaction, particle size analysis, and specific gravity tests. To provide a better understanding of the collapse behavior of the soil, classification tests were performed to make indicator analyses and evaluation of collapsibility potential using various empirical correlations. Based on the obtained results, soils from the area of study have a collapse potential values ranges from 3.81% to 5.89% and found moderate to highly collapsible types of soils in nature. From the findings of this study, as the Ethiopian Roads Authority site investigation manual does not consider the significant effects of these types of soils, the author suggests a direction in providing the design and construction specifications of problematic soils of collapsible types.