Flood Analysis and Hydraulic Competence of Drainage Structures along Addis Ababa Light Rail Transit (A Case Study on Mesualekia-Nefas Silk2 Stretch)
| dc.contributor.advisor | Yilma, Sileshi (PhD) | |
| dc.contributor.author | Kiwanuka, Moses | |
| dc.date.accessioned | 2022-03-09T04:56:20Z | |
| dc.date.accessioned | 2023-11-04T15:17:37Z | |
| dc.date.available | 2022-03-09T04:56:20Z | |
| dc.date.available | 2023-11-04T15:17:37Z | |
| dc.date.issued | 2019-07 | |
| dc.description.abstract | This study is on flood analysis and hydraulic competence of the existing drainage structures on some roads of Addis Ababa City after an integration of Roads and Addis Ababa Light Rail Transit Drainage Systems. Flooding in any circumstance causes major stresses on the economic, social and environmental regimes of the affected area. Addis Ababa has a pronounced rainfall peak which is common during the summer time months of July to August. Flooding is a major problem for Addis Ababa city roads. Therefore, this study was carried out in-order to assess the flood analysis and hydraulic competence of drainage structures along Mesualekia - Nefas silk2 stretch for the different rainfall intensities corresponding to different return periods. The existing side drains and cross drainage structure located within the study area were inspected and assessed in order to ascertain different aspects relating to their performance. The hydrological analysis was assessed in-order to determine the different watershed contributing to the flows. This was done by use of Geo spatial tools like ARCGIS, ARCSWAT, and HEC GEOHMS. The flows were obtained by using the rational method for areas less than 0.5km2 and HEC HMS for areas greater than 0.5km2. Rational method was used to obtain different design flows for watershed 1 to 4, including flow from the carriageway runoff and the following were obtained as 2.66, 0.08, 3.23, 6.20, 2.12, 0.08, 0.08, 0.08 m3/s corresponding to a 10-year ARI. HEC HMS was used to obtain a design flow of 29.52 m3/s corresponding to watershed 5. A design flow of 46.3m3/s was used for assessing the cross culvert which was the summation of all the flows from side drains and carriageway runoff. The hydraulic analysis was carried out using HY-8 for the culvert and Hydraulic tool box for existing side drains. From field survey and measurements, it was discovered that the existing side drain of 900mm circular pipe couldn’t convey a flow of 6.2 m3/s. The existing box culvert comprised of one barrel of 4000mm x 3300mm, which was sufficient in conveying the designed flow because its headwater elevation was lower than that of the roadway elevation. However, observations like presence of accumulated silt, debris within most side drains and an undersized side drain reduced its hydraulic competence. Based on the findings, recommendations were made including regular desilting, screens at inlets of side drains and at some distance before the entrance of the culverts, periodic maintenance of the existing drainage structures and widening of the pipe conduits for the side drains to about 1200mm for easy maintenance. There is also need to monitor performance of existing side drains and culverts, that, basing on field data assessed, might have resulted in under- or overdesigns. Regarding the on-track drainage network, this research provided for aggregate drains of size 400mm and the existing longitudinal drains were efficient to convey the flow. | en_US |
| dc.identifier.uri | http://etd.aau.edu.et/handle/123456789/30514 | |
| dc.language.iso | en_US | en_US |
| dc.publisher | Addis Ababa University | en_US |
| dc.subject | Lancha | en_US |
| dc.subject | Circular side drains | en_US |
| dc.subject | Box culverts | en_US |
| dc.subject | headwater and roadway elevations | en_US |
| dc.subject | Hydraulic tool box software | en_US |
| dc.subject | HY-8 software | en_US |
| dc.subject | Design flow | en_US |
| dc.subject | Aggregate drains | en_US |
| dc.title | Flood Analysis and Hydraulic Competence of Drainage Structures along Addis Ababa Light Rail Transit (A Case Study on Mesualekia-Nefas Silk2 Stretch) | en_US |
| dc.type | Thesis | en_US |