Browsing by Author "Gamage, DE"

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item: Conference-Abstract
Cost effective roughness computation method using smart phones
(Department of Civil Engineering, University of Moratuwa., 2016-08) Gamage, DE; Pasindu, HR; Bandara, JMSJ; Pasindu, HR
Road roughness is a representation of its surface condition and is resulted of the irregularities in the pavement surface such as potholes, depressions, cracking, rutting, ravelling etc. International Roughness Index (IRI) is the globally accepted indicator to measure the road surface condition. The main problem- associated with low volume roads in Sri Lanka is lack of funding for maintenance and resources. Unfortunately in many developing countries like Sri Lanka planning decisions on maintenance are mostly taken based on subjective judgment/ad-hoc decisions without a consistent objective basis due to significant political and other interferences. Fund allocation can be optimized if the decision making can be supported by up to date information of the road network condition. Road Roughness information is very useful for road agencies because it can be used to assess the road condition and be used in decision making process for maintenance planning and programming. In addition, the information is very important for road users because using such information, road users can avoid the bad roads ahead. But existing measurement technologies used in Sri Lanka like Profilometer are very expensive. It also has limitations in accessing narrow roads though it can provide accurate information. Therefore it is necessary to investigate low cost, practical methods to evaluate roughness which can be used in maintainence planning and programming of low volume roads. Today smart phones have the capability of collecting information related to variation in road surface level which can be converted to road roughness measured as IRI (International Roughness Index). - number of smart phone applications are available but it is necessary to calibrate such models to suit local condition and vehicle used for data collection. The results of these can be considered as adequate for comparison of relative levels of road roughness which will be useful for maintainence decision making In this research regression analysis was used to - find a relationship between roughness value (IRI) obtained from profilometer and resultant accleration obtained from an android application called Androsensor. Engineers can use that relationship to estimate road surface condition based on accelerometer readings. It can be expected to have more than 60% savings by using this smart phone application for roughness computation of roads.
item: Thesis-Full-text
Framework for selecting pavement types for low volume provincial roads
(2018) Gamage, DE; Bandara, JMSJ
Low volume Roads are those that serve the daily social and economic needs of the locality. In developing countries, the main problem with low volume roads which are managed by local authorities is the lack of funding for maintenance and resources. The funds allocated to local authorities are largely insufficient to maintain low volume road network at good condition. Fund allocation can be optimized to achieve better overall network performance if the decision making can be supported by up to date information of the road network condition. Road roughness information is very useful for road agencies because it can be used to assess the road condition and be used in decision making process for maintenance planning and programming. But existing measurement technologies to measure road roughness like profilometer are very expensive and difficult to use with the prevailing constraints in the local road agencies. The development of smartphones with 3-Axis accelerometer allows it to take acceleration measurements in m/s2 along each of x, y, z axes. In this research regression analysis was used to two find a relationship between roughness value (IRI) obtained from profilometer and resultant acceleration obtained from an android application called Androsensor. According to the results Resultant acceleration has a linear relationship with road roughness (IRI) and Engineers can use this relationship to estimate road surface condition based on accelerometer readings. In developing countries planning decisions on maintenance and decisions on selecting pavement type are mostly taken based on feedback from local communities and subjective judgement made by the authority due to significant political and other interferences. Therefore it has been become the trend in the recent past in Sri Lanka to pave low volume roads in asphalt all over the country regardless of the traffic volume and the required condition of the road. Although asphalt roads has it’s many advantages in the point of view of the road user, when analysing the effective cost comparisons of life cycle cost this may not be the most suitable method available for some roads considering the limited funds available. Therefore suitable framework should be developed as a primary step to providing the context and a methodology by which pavement options may be assessed and selected for low volume roads. This research presents a methodology to select suitable pavement type for low volume roads in Sri Lanka. The main factors considered for framework are Traffic volume, Traffic composition, Land use, connectivity, terrain and weather.
item: Conference-Full-text
Framework for selecting pavement types for low volume roads
(Department of Civil Engineering, University of Moratuwa, 2015-10) Gamage, DE; Bandara, JMSJ; Hettiarachchi, MTP
Low volume roads, have remained the least attended roads in Sri Lanka, although over 72% of the entire road network in Sri Lanka are low volume roads. The funds allocated by local authorities are insufficient to maintain at least 50% of existing low volume roads in good condition. It has been become the trend in the recent past to pave low volume roads in asphalt all over the country regardless of the traffic volume and the required condition of the road. Although asphalt roads have many advantages from the point of view of the road user, when analyzing the effective cost comparisons of life cycle cost this may not be the most suitable method available for some roads considering the limited funds available. A structured questionnaire was used to identify several issues associated with different road surfacing methods. Life cycle cost analysis was done to find the most suitable paving type for by using Net Present Value technique (NPV). According to that gravel has the highest NPV for 20 year design period while concrete block pavement has the lowest NPV. For a 10 year design period asphalt has the highest NPV.