Cause of Poor Drainage Condition and Its Effect on Pavement Performance, Jimma City Hermata Kebele

Abstract

Poor drainage condition is one of the major challenges facing developing country. Poor drainage causes early pavement distresses leading to structural failures of road as pointed out by several researchers. In Jimma, new constructed roads were informed to fail rapidly after opened to traffic.Hermata Kebele is found in jimma town which are affected by poor drainage condition. The Objectives of this study are to assess the existing condition of drainage, cause of poor drainage and to evaluate its effects on pavement. An exploratory and descriptive type of methods was used to describe and explore the existing condition of drainage and pavement. Data collection methods were carried out using both primary and secondary data sources, the secondary data source was only relevant to support the primary data, which was accomplished with the help of topographic map and design data. The collected data were analyzed and presented using Microsoft-excel, tables, graphs, picture and percentages. The result of this study, it was found that most roads in the kebele suffered from people awareness, construction problem, absent of routine maintenance and poor management system are causes for poor drainage condition. Based on respondent survey data, 80% had responded for poor condition, about 16% of the respondents for fair and only 4% thinks the drainage system is good. Result from cause of poor drainage condition occurred 69% due to people awareness and absent of routine maintenance, 19% due to construction problem of drainage structure, and 12% are due to cross slope difficult. This all problem lead to have low drainage inlet, the evaluation shows that the efficiency of inlets is 40.36%. Due to surface water, debris and silt back to roadway, pavement distresses occurred. Based on the result conclude that, poor drainage condition and its contributing to the early deterioration of pavements, the existing drainage conditions inadequate to carry the flow. Absent of routine maintenance, people awareness and poor management systems are also the main cause for inlet not to work properly and failure of pavement. The study recommends that, to minimize early pavement failures, it is better to provide adequate drainage system alert people to use efficient drainage, improve routine maintenance ability, attention during construction and it helpful to increasing the service life of pavement