Civil Engineering Commons^™

A Conceptual Approach To Water Resources Management For A Catchment In Tanzania, F Mwanuzi

Tanzania Journal of Engineering and Technology (TJET)

In hydrology/Water resources, normally rainfall data are available for longer periods than runoff data. Many attempts have been made to extend these runoff data by using system approach and conceptual models. The conceptual approach to simulate runoff at the outlet ofa catchment is based on the physical processes involved in the transformation of rainfall into runoff (river flow). In this paper a conceptual model, (SEAMOD) has been used. This model has a limited number of parameters to optimize when compared to other models like the sacramental model. Also it requires less input data. The model assumes that the storage is …

Effect Of Reduced Plate Width On The Structural Behaviour Of A Triangularly Folded Plate Barrel Vault, S Manyele

Tanzania Journal of Engineering and Technology (TJET)

Various methods of analysis have been employed to predict the  structural behaviour of the Triangularly Folded Plate Barrel  Vault, with conflicting results. A review of past analytical  and experimental investigations carried out on the structure  show that theoretical analysis based on a smaller effective  width rather than the overall plate width is capable of closely  predicting the deflection behaviour of the structure.  This paper presents an experimental study of the behaviour of  a triangularly folded plate barrel vault with physically reduced  plate width.  It is found that physical reduction of the plate width to  correspond to ‘theoretical’ effective width weakens …

Evaluation Of Wind Data Records To Predict Extreme Extreme Wind Speeds In Tanzania, L Lwambuka

Tanzania Journal of Engineering and Technology (TJET)

The progress made towards evaluation of local wind data records to pred ict extreme values of wind speeds in Tanzania is being presented . Records of wind data, stored continuously since 18 years, have been compiled and statistically processed. Extreme value theory of Fisher —Tippet Type I has been fitted into the data to abstract extreme values of wind speeds for locations at which the wind data records were obtained. A reliable wind map of Tanzania containing basic wind speeds at 18 locations across the country has been produced. The basic wind speeds are being recommended for des ign against …

Hydrodynamic Stability Of The Breakwater Extension At Rrviksand, Norway, Alfonse Dubi

Tanzania Journal of Engineering and Technology (TJET)

The fishing port of Årviksand in Norway, which is situated on an open coast, is artificially harboured by breakwaters. The northern and southern breakwaters which were built in 1930—ies and 1950—ies respecti vely have been on several occasions damaged by heavy storms. This resul ted in the need for further protection by extending the northern breakwater. This paper describes one of the hydrodynamic tests on the breakwater extension. The breakwater, with a berm breakwater concept design, is subjected to the joint probability of sea level elevation and wave heights (in other 'fatigue" test). words , It is found that cover …

Optimization Of Dispersed Flor Pond For Bacterial Removal, Mayo A. W

Tanzania Journal of Engineering and Technology (TJET)

The design of waste stabilization ponds is seldom done with consideration of optimum pond dimensions. The analysis of pond dimensions within practical limits in dispersed flow ponds on the basis of minimum cost for the predetermined bacterial remova) ef ficiency, with the aid of computer is presented. The data collected in the pilot and full scale waste stabilization ponds at the University of Dar es Salaam Was used as input to the computer program. The results shows that pond configuration and climatic conditions which have influence on bacterial mortality rate have a re:narkable influence on pond cost

The Performance Of A Horizontal Flow Roughing Filter/Slow Sand Filter Water Treatment Plant In Tanzania, Mbwette T. A

Tanzania Journal of Engineering and Technology (TJET)

The performance of a water treatment plant comprising of the Horizontal f Iow Roughing F i Iter (HRF) / Slow Sand Filter (SSF) System was evaluated by monitoring the water quality of the inlet water and the plant filtrates for a Improper operational procedures and period of two months. the absence of adequate maintenance of the plant was found to have resulted to relatively Iow removal efficiency. This subsequently improved as a result of plant rehabilitation and introduction of new operational procedures and became comparable to the performance of HRE/SSF plants documented in literature. For example, as a result of …

The Hydraulic Performance Of A Vortex Tube Foector, F Mtaro

Tanzania Journal of Engineering and Technology (TJET)

The vorle.r tube silt exrrac/or consists of a pipe, rhe crest of which has a slit and lies flush across lhe canal bed.With minimal warer loss, I.oe bedload is extracted through lhe slil settling canal back ro the river, thus reducing or eliminating the bedload transported in main canal. Ihe resulting swirling flow phenomena is of complex nature and depends on sc conirol paramerers, as a result of which previous empirical design approaches have yielded conflicting guidelines. By means Of a simplified hydraulic system, the flow mechanism and energy in rhe can be determined.

Flood Forecasting In Tanzanian Catchments, Omari Rumambo

Tanzania Journal of Engineering and Technology (TJET)

Floods are still a problem to many countries in the world todate. Floods do cause damages to property and sometimes loss to human life. Flood control measures by structural and non—structural methods are avail able in the literature . However , structural flood control measures are financially infeasible in most developing countries today. Flood forecasting is a non—structural measure for reducing flood damages. It is a means of providing early The Li near f 1 ood warnings to flood prone areas . Perturbation Model has been appl ied for real time flood The Linear forecasting in Tan zanian catchments . …

Experimental Investigations On The Behaviour Of Wood In Transverse Compression, A Mrema

Tanzania Journal of Engineering and Technology (TJET)

Experimental investigations were done to study the behaviour of wood in transverse compress ion. Three key variables were incorporated in the experiments to study their influence on the •nriables were the orthotropic ratio of the behav iour. These material, the geometry of loading and that of the specimen . Deformation measurements were made at selected locations on test specimens by means of strain—gage based clip gages. Results from the experimental measurements were compared to previous deformation predictions made by a finite element analysis (9) . There is a very good agreement between measured values and those obtained trom the finite …

The Stability And Sate Dimensioning Of Circular Masonry Arches, A Mrema

Tanzania Journal of Engineering and Technology (TJET)

An analysis of masonry arches where collapse is assumed to occur by the hinging of voussoirs upon each other is made. The behaviour of the arch material is assumed to be such that the plastic theory is valid. Certain aspects related to the properties So far the approach by of the line of thrust are clarif led. writers has been based on the conventional view that the 1 ine of It is shown that pressure is tangential to the line of thrust. this is not the case in general. Definitions are given on what is meant by "line of thrust" …

Parking Demand And Supply In The Central Business District Of Dar Es Salaam City, Theophil Rwebangira

Tanzania Journal of Engineering and Technology (TJET)

The Central Business District (CBD) Of Dar es Salaam city is currently experiencing severe congestion. Among the major causes of this condition is lack cf enough parking facilities. Obstructions due to vehicles parked on the roadway and increased vehicle circulation by drivers looking for a mace to park This paper reports on a recent study are major contributors to congestion. which evaluated the demand and supply as vell as usage of parking spaces in the CED. The f indings indicate that there is currently an acute shortage Of parking spaces, especially of off—street parking spaces. For the existing facilities, there …

Carrying Capacity And Cracking Resistance At The Of Halving Joints In Reinforced Concrete Beams, S Mpinzire;

Tanzania Journal of Engineering and Technology (TJET)

Results are presented from tests on 3 beams having discont inuous support zones. All Of them had web and diagonal shear reinforcement. TWO out Of the three represented beams, their test results have been analysed in a paper designated part I which appeared in the Uhandisi Journal , Vol. I December 1989. They have been presented in this paper for compar ison purposes. The third beam has been made to invest i gate the effect of anchoring diagonal shear reinforcement by spot Welding method. The third beam was tested With two concentrated loads in the span. In all beams several …

Design, Operation And Maintenance Considerations Of Iiorizontal Flow Roughing Filters Preceding Slow Sand Filters, T Mbwette,

Tanzania Journal of Engineering and Technology (TJET)

The paper mentions some of the reported uses of Horizontal Flow Roughing Filters (IIRF) in drinking water treatment plants in Europe before briefly reviewing research activities carried out in the use of IIRF prior to Slow Sand Filters. Design, operation and maintenance aspects Of HRF are reviewed on the basis of the laboratory and field tests carried out in Tanzania and Switzerland, respectively in addition to experience gained in operation of a number of plants already built to date. Design aspects are introduced from the point of view Of its philosophy and optimization strategies before design guidelines are given. Important …

A Finite Element Analysis Of Wood In Transverse Compression, A Mrema

Tanzania Journal of Engineering and Technology (TJET)

A two dimensional finite element analysis is utilized to predict the stress and strain distributions for wood in transverse compression. Important key var iables are incorporated into the ana lysis to define their influence on the stress and strain distributions. These variables are geometry of loading, geometry of specimen and the orthotropic ratio of the material. Based on the finite element analysis results, relationships are arising stress from developed relat ing maximum stress concentrations to the above three variables. possible appl ications of the results from this study relate to the development of more efficient design of connections such as …

Force Displacement Relationship For The Prediction Of Structural Fluttering, Ladislaus Lwambuka

Tanzania Journal of Engineering and Technology (TJET)

A new presentation of force displacement relationship for the prediction of structural fluttering is discussed in this paper. This topic is limited to a detailed discussion of the derivation of the equations of motion for the rigid streamlined airfoil/flat plate system of three degrees of freedom, which yields expressions for aerodynamic resultant forces due to a steady air flow. The equations of motion presented herein are derived from the conventional classical complex presentation transformed into real matrix equations. This new presentation of the equations of motion constitutes the foundation for the latest state-of-the-art of predicting critical wind loads on the …

Transport Matrices Of Finite Beams Resting On Elastic Foundations, M. W. Giger

Tanzania Journal of Engineering and Technology (TJET)

A method of derivation of the coefficients of the transport matrix for a finite element resting on one and two-parameter elastic foundation soils is outlined. The coefficients are summarized for both the Bernoulli–Euler and the Timoshenko beam model in tabular form, for general reference. In addition, bounds on the parameters describing beam/soil flexure, beam and soil shear, which govern the validity of the two-parameter elastic solutions are provided in graphical form.

A Study Of Load Bearing Capacity Of Piles Driven In The Zanzibar Harbour Submarine Soils, A. M. Dubi

Tanzania Journal of Engineering and Technology (TJET)

The rehabilitation of the Zanzibar Port involved, among other things, driving piles into the submarine soils. Pile driving fractures the coral and as a result creates a gap filled with loose fractured coral between the unfractured coral and the pile. Grouting of the external surface of the pile is done to strengthen the fractured coral. In this paper, two grouted working piles (TP6 & TP61), randomly chosen from the pile group, were load tested to twice the design load. The test results indicate adequacy of the bearing capacity of the grouted piles.

Carrying Capacity And Cracking Resistance At The Support Zone Of Halving Joints In Reinforced Concrete Beams, H. W. Chung

Tanzania Journal of Engineering and Technology (TJET)

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Carrying Capacity And Cracking Resistance Of The Bracket, S. Mpinzire

Tanzania Journal of Engineering and Technology (TJET)

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Behavior Of Ductile Materials Under Impulsive Loading, M. Y. Brunner

Tanzania Journal of Engineering and Technology (TJET)

Ductile materials under dynamic loading are known to be able to absorb energy and thereby delay or even prevent structural failure. This paper is concerned with such behaviour in the case of impulsive loads of short duration. It is shown that even when the feared, unstable, labile condition is attained, failure may not necessarily occur. This behaviour is particularly impressive for structures with large mass, because it is essentially the mass which slows down the attainment of the failure strains. If the impulsive load dies away quickly enough, the constant plastic resistance will be adequate to bring the increasing deformations …

Optimal Allocation Of Water Among Industries In Dar Es Salaam City, Tanzania, J. I. Matondo

Tanzania Journal of Engineering and Technology (TJET)

Dar es Salaam is the city with the largest number of industries in Tanzania. However, the water demand for these industries is more than the supply. Therefore, there is a water use competing problem among the industries. Dynamic programming technique has been applied to optimally allocate the available water among the industries with the objective of maximizing the net benefits. Results reveal that, industries with the highest net return per unit of water will get the first priority of being allocated water.

Hydraulic Rams For Rural Water Supply Schemes In Selected Areas In Tanzania, T Mbwette

Tanzania Journal of Engineering and Technology (TJET)

This paper presents one of the many efforts made by the Faculty of Engineering and the Institute of Production Innovation of the University of Dar es Salaam towards the realization of the International Water Supply and Sanitation Decade. Special reference is made to the use of hydraulic rams along with some simple water treatment methods. Besides the account of theoretical and practical work done to-date in the field of water supply, a further evaluation of the theoretical model presented is recommended so as to enable a judgement of the present hydraulic ram designs to be done. Tests on a typical …

Under Pinning And Erosion Protection At The University Road Bridge Dar Es Salaam, F Bucher

Tanzania Journal of Engineering and Technology (TJET)

During the assessment of the manuscript, it was observed that the paper does not include an abstract. The document proceeds directry to the main content without providing a separate abstract that summarize the study's objectives, methodology, key findings and conclusions

Hydrauilc And Structural Design Of The Hydromet Station On Sinza River, E Kasenene

Tanzania Journal of Engineering and Technology (TJET)

During the assessment of the manuscript, it was observed that the paper does not include an abstract. The document proceeds directry to the main content without providing a separate abstract that summarize the study's objectives, methodology, key findings and conclusions

Sisal Fibre Concrete And Its Prospective Applications, A Mawenya

Tanzania Journal of Engineering and Technology (TJET)

During the assessment of the manuscript, it was observed that the paper does not include an abstract. The document proceeds directry to the main content without providing a separate abstract that summarize the study's objectives, methodology, key findings and conclusions

A Systematic Approach To Water Resources Development, P. Widmoser

Tanzania Journal of Engineering and Technology (TJET)

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Technical Problems And Progress In Tanzania, Michael K. Mbwando

Tanzania Journal of Engineering and Technology (TJET)

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Construction Of Kariakoo Market, C. E. M. Mpembeni

Tanzania Journal of Engineering and Technology (TJET)

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Reconstruction Work Upon Solima Pier, K.A. Alibhai

Tanzania Journal of Engineering and Technology (TJET)

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Curriculum In Civil Engineering At The University Of Dar Es Salaam, R. Wagner

Tanzania Journal of Engineering and Technology (TJET)

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