Journal of Civil and Environmental Engineering

Now a day’s irrigation practice in Ethiopia has given more attention to struggle poverty and increase prosperity in the country. To do so, assessments of the irrigation water quality is one of the crucial parameter for successful irrigation implementation. The researchers try to make an assessment on Gurage zone, Cheha Wereda for two periods of sampling time Pre Monsoon (PRM) starting from November up to February, 2022 and Post Monsoon (POM) starting from April up to Jun, 2022. A representative sample borehole has been identified and samples had been taken for the physic-chemistry analysis by laboratory tests in order to check their suitability for irrigation water quality assessments. For the classification of different physiochemical parameters laboratory results irrigation water quality (WHO 2008) and irrigation water quality standards (US Regional Salinity Laboratory and FAO) standards had been used. After analysis of groundwater samples from the study area, the PH of water indicates that acidic character with a PH ranging from 6.63 to 6.8 in PRM and 6.84 to 7 in POM. Accordingly the result shows that 81.92% the water quality index parameters indicates that the water in the study area is suitable for irrigation and the rest 18.18 % of water quality index parameters the water is not suitable for irrigation. Based on the analyzed result the following water quality indexes SSP, EC, Na, Cl, NO₃, MAR, SAR, PI, and KI result indicates that the water is suitable for using irrigation purpose both in rainy (POM) and dry (PRM). Whereas the TH and RSC WQI result shows that the water is not suitable for irrigation purpose.

Railway transportation is nowadays becoming one of the most preferred mode of transport due to its safety, capacity and reliability; the capital cost for the construction of the railway infrastructure is however very high and is characterized by high rigidity as the track layout is fixed; therefore there is need to optimally use the available infrastructure. Minor delays arising from a simple disruptions or even a single train failure can have massive impacts in terms of overall delays for subsequent trains using the track facility if not solved amicably. Disruptions can be attributed to power outages, mechanical failures, derailments, accidents or even environmental factors.

In a case of multiple uncertain perturbations happening in a busy complex railway network, where there are many trains requesting to use the available track resources concurrently, there will be massive delays which has a lot of negative operational and economic implications as well as passengers’ dissatisfaction. A mathematical model that is; a mixed integer linear programming formulation is modelled to minimize total time delays in case of a set of multiple disruptions occurring on a busy track section i.e. bottleneck section, the model is formulated with consideration of sets of constraints factoring in feasible routes and safety margins and other operational dynamics such as dwell times to achieve optimal use of the available infrastructure.

A number of numerical experiments based on arbitrary data and real network data are carried out to verify the effectiveness and efficiency of the proposed model. Performance of the designed model is evaluated and results are validated, the results obtained shows that the model offers an efficient rescheduled trains operation plan during disruptions, furthermore the performance of Fmincon solver and Genetic Algorithms (GA) are compared and their robustness evaluated, GA shows better performance during multiple disruption scenarios.

Microplastics (MPs) pollution is a most burning concern as they pose threats to marine organisms and their ecosystem. However, there is limited information for MPs availability in the marine environment, especially in Pakistan. The current study was conducted with the objective of investigating microplastic number, shape and color in the water and sediments of Ras Zarrin, Ras Juddi, Pasni Creek and Ormara beach and Astola Island. Comparisn of MPs contamination in the first marine protected area (Astola Island) and other coastal areas of Balochistan. Our results demonstrated that greater concentration of microplastics in the sediments as compared to water samples. According to this study, the most polluted areas in the following order Astola Island>Ras Juddi>Ormara beach>Pasni creek>Ras zarrin. In water samples the number of micro plastics investigated 9 items/100 L as compared to sediments 103 items/10 g. The dominant colors were black, blue, green, red and white. Size ranges (1 mm to 5 mm) and has shape of fibers and fragments mostly. This research study highlights the need of proper plastic waste management system and should be create awareness to the local residents, tourists and stakeholders about plastic pollution catastrophes in these areas.

To investigate the spatio-temporal expansion of the town and its impact on the livelihood of urban fringe agricultural community, the study was made on land transformation analysis in between 1984 and 2015. The main objective of the study was to assess the impact of urban expansion on livelihood of urban fringe of Ambo town as a result of land use change in pre urban area of the town. The 1984 and 2011 administrative boundary maps of the town were used to analyze the extent of area expansion of the town. During this period the town was expanded from 1020.220 ha to 8421.75 ha indicating that the net expansion of the town over the study years was about 7351.1062 ha with about 237 ha increment yearly within 31 years. This boundary expansion of the town directly or indirectly affecting the livelihood of the urban fringe agricultural community of the town. Predominantly at the expense of croplands in the hinterlands, built-up area was increased from 307.44 ha (in 1984) to 913.05 (in 2015). Beside to this, the productive farmland of the urban fringe of the town was decreased from 6651.65 ha (in1984) to 5625.75 ha in 2015. Land cover transformation analysis in between 1984 and 2000 the built-up area expansion was contributed by 451.6675 ha and 60.75 ha conversion of cropland and vegetation area respectively while cropland and vegetation area was negatively affected by 176.085 and 173.9703 ha respectively from its previous area coverage. A household survey was conducted on 146 households with different demographic composition through systematic and purposive sampling techniques. The data were collected from both primary and secondary data sources and analyzed using descriptive statistics and had arrived at conclusion that horizontal urban expansion has adverse impact on livelihood of urban fringe farming community. The analyzed information also indicates that the possession assets and hence annual income of dislocated farmers were declined due to declining their asset possession they had. The evidence from the sampled house hold shown that the majority (82.90%) of household heads’ annual income was below 5000 ETB indicating that majority of the affected community’s livelihood is not beyond subsistence way of life. This indicated that the intervention of governmental and non-governmental organizations should be needed to support the dislocated households financially and technically to make sustainable life and adaptive strategies with the change occurred.

In this study, the effect of silicon dioxide nano particle and fly-ash on the permeability of sand were investigated. For this purpose, various combinations of fly ash and sand were investigated to examine the impact of mixing of fly with sand. We can make a least permeable mass by mixing 80% of fly ash with 20% sand. According to specific gravity of sand, fly ash, nano silica and weight of the mould with a porosity of 0.4 these materials has been mixed manually. Fly ash is mixed with the fine sand in increasing proportions of 5%, 15%, 25%, 35%, 45%, 55%, 65%, 75%, 85%, 100%. According to the results of present study, 80% fly ash mixed with 20% sand provides the least permeable combination compared to the rest. The percentage-mix of fly ash and sand is taken different from previous study but least combination was achieved with a similar combination of 80% fly ash and 20% sand which was also reported by Gupta and Alam 2004. To make the least permeable sample to almost impermeable, nano silica mixed with least permeable sample in increasing percentage by 5%, 7.5%, 10% and 12.5%. A falling head and constant head method was used to test all samples for hydraulic conductivity.

Results of present study revealed that when 20% of sand mixed with 80% of fly ash gives value of permeability (6 × 10^-05 cm/s) which are 86 times lower than the permeability of sand.

It was observed that a mixture of 20% sand and 80% fly ash mixed with 12.5% of nano silica gives a permeability (2.20 × 10^-06 cm/s) i.e in the range of clay which is 2340 times lower than the permeability of sand.

The permeability property was found to be highly improved on addition of fly ash and nano particles to sand.

Comprehensive results proving the improvement in the permeability properties have been obtained in the specimen containing 12.5% nano silica with least permeable sample of fly ash–sand mixture.

The lack of level land in slope territory has driven the construction of building on slope Slant. Due to the slope of the land, structures in hilly terrain have unique structural configurations that use varying foundation levels. The asymmetry and irregularity of the building's vertical and horizontal directions provides a noticeable dynamic feature in the shape of the structure on the slope.

On sloping terrain, set-back, step-back, and step-back set-back buildings are the most common building configurations to be seen. In current research work, step-back set-back building are used alongside flat-slab buildings with drop-panel and perimetric beams on sloping land with different gradients. The drop panels are provided to prevent punching shear failure and perimetric beams are provided to reduce the displacement. The different models of G+9 storey building that are considered in the present study are as follows; model M1-structure resting on 0° slope, 2) Model M2-structure resting on 15° slope, 3) Model M3-structure resting on 30° slope in seismic zone V. The building models and characteristics as such storey shear, storey displacement, storey drift, storey stiffness and torsional irregularity are examined while doing the static, dynamic, and time history analysis. In the present study, the storey displacement is found maximum for model M1 and with the increase in slope the storey displacement gets reduced. The storey drift ratio is found more in model M1 and with the increase in slope, the drift decrease. The storey shear is more prevalent in model M1 when compared to other two models. Also there is an irregular variation in storey shear for models M2 and M3. During the design inspection, the short-column effect is observed in columns with restricted height owing to the slope of the ground. The torsional irregularity in all the building models is found to be within safe permissible limits as per IS-1893 2016. The tabular findings and a graphical comparison of the results are provided.