CERIS - 2012

Permanent URI for this collectionhttp://192.248.9.226/handle/123/18177

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item: Conference-Full-text
Civil Engineering Research for Industry Symposium 2012 (Pre Text)
(Department of Civil Engineering, University of Moratuwa, 2012) de Silva, LIN
item: Conference-Full-text
Study on rebound values on inclined planes
(Department of Civil Engineering, University of Moratuwa, 2012) Baskaran, K; Liyanage, KLDO; Munasinghe, NT; Gunawardana, WWCJ; Nawagamuwa, U; de Silva, LIN
Non-Destructive Testing (NDT) methods parameters like strength and durability of an existing structure. They offer significant advantages of speed, cost and lack of damage in comparison with test methods which require the removal of a sample. But they incorporate various limitations in practical use. This study is focused on the 'Rebound Hammer Test' which is used to assess the compressive strength by surface hardness. The rebound hammer concernedin this case, has been calibrated and charts have been developed to get the readings on vertical and horizontal surfaces only. When the structure to be investigated is consisted of an inclined surface, direct use of these charts may not be possible. During this study, basic formulation to calculate the corresponding horizontal rebound number to represent a rebound value obtained on an inclined plane was derived and verified. Taking readings on inclined surfaces of the cubes placed at different angles was done in order to observe the deviations and then the results were interpreted and analysed to obtain a suitable relationship by applying the derived formula.
item: Conference-Full-text
Study on palmyrah as a reinforcement material
(Department of Civil Engineering, University of Moratuwa, 2012-12) Baskaran, K; Mallikarachchi, HE; Jayasekara, MJPLM; Madushanka, GAT; Nawagamuwa, U; De SIlva, LIN
Most developing countries Abstract: are confronted with acute housing shortage due to their over dependence on expensive, imported building materials. So there is an intense search for innovation of locally available, nature friendly materials.Palmyrah is widely spread all over North East region in Sri Lanka and has found use in many structural applications. This research explores the feasibility of using Palmyrah strips as an alternative for reinforcing steel in short span, lightly loaded slabs and beams.Structure of this research consisted of literature survey, testing mechanical properties of Palmyrah, basic design, construction and testing of Palmyrah reinforced concrete slabs and beams, analysing of results and recommendation.Static bending test, tensile test and compression test were conducted to identify characteristic strength and stiffness properties along with density and moisture content. Water absorption with time was also studied. Slabs and beams with varying reinforcement percentages were constructed and tested.Failure loads, crack loads, mode of failure and crack patterns of test slabs and beams were observed. Flexural capacity of concrete slabs and beams reinforced with Palmyrah strips was evaluated.lt was observed that Palmyrah reinforcement enhanced the failure load of the slab by 107% and failure load of beam by 370%. Experimental failure load of slab and beam averaged 140% and 164% of theoretically predicted value respectively. Both beams and slab had flexural failure by fracture of Palmyrah strips and their failure loads increased with increase of Palmyrah reinforcement.Thus it is concluded that Palmyrah strips has potential to be used as reinforcement in lightly loaded slabs and beams.
item: Conference-Full-text
Indoor air quality (IAQ) inside a hospital theatre
(Department of Civil Engineering, University of Moratuwa, 2012-12) Gunaratne, S; Gunatilake, D; Madushanka, R; Perera, TM; Jayasinghe, C; Perera, A; Rajapaksa, S; Nawagamuwa, U; De Silva, LIN
In this research study, the effect Abstract: of the activities associated with a hospital theatre, on its IAQ has been studied since the theatre staff experience some discomfort while being inside the theatre. In order to evaluate this, variation of Carbon Dioxide (CO:), Carbon Monoxide (CO), Total Volatile Organic Compounds (TVOC) and Particulate Matter less than 2.5 microns (PM25) concentrations inside the theatre were measured and analyzed. Significant variations were observed in the concentrations of CO:, TVOC and CO inside the operation theatre. CO2 concentration inside the room increased at the beginning and end of the surgeries due to high occupant density and also during Laparoscopic surgeries. TVOC concentration was affected by the usage of different chemicals during the surgery. Major effect to the CO concentration was by Diathermy.
item: Conference-Full-text
Investigation on uplift capacity of shallow foundations on cohesionless soil
(Department of Civil Engineering, University of Moratuwa, 2012-12) Koorala, SKDCP; Kumara, MKSN; Edirisinghe, EAL.; de Silva, LIN; Nawagamuwa, U; de Silva, LIN
Shallow foundations are Abstract: commonly used in Sri Lanka for communication towers, power transmission towers and towers for wind turbines. The design of these foundations is based on several assumptions and therefore, a large factor of safety is imposed on estimated ultimate uplift capacity. In view of the above, the uplift capacity of shallow foundations on dry sand was determined ill the present research by conducting laboratory model tests on circular and square foundation models. The results were compared with the uplift capacities obtained from analytical solutions for both circular and square flat foundations. Two foundation models (circular and square) at three different depths in dry sand were tested and the uplift force and upward displacement of each model were investigated. Uplift force versus upward displacement characteristics obtained from experimental analysis was compared with the uplift capacity obtained from analytical solutions. From both experimental and theoretical results, it can be concluded that the uplifting capacity of square foundation is higher than circular foundation at each depth. Also the uplifting capacity is increased with embedded depth of foundation for both types of foundations. Another important conclusion is that, the angle between the vertical plane and the failure plane is nearly half of the friction angle of the soil.
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Study of ground vibration due to rock blasting of metal quarry: a case study
(Department of Civil Engineering, University of Moratuwa, 2012-12) Madanayaka, TA; de Silva, LIN; Dharmarathne, PGR; Nawagamuwa, U; De Silva, LIN
This study was carried out to compare vertical and horizontal bench blast(s) at a granitic gneiss rock quarry located in Colombo, Sri Lanka and predict the resulting peak particle velocities of ground vibration levels. To achieve these objectives, particle velocities and frequencies of 38 and 35 blasts respectively were measured in three perpendicular directions for horizontal and vertical bench blasts respectively with the use of Instantel Blastmate II seismographs. In the blasts, Ammonium Nitrate (ANFO)(blasting agent) primed by a Gelatine Dynamite primer were electrically initiated. Scaled distance parameters (Maximum charge weight per delay and distance between blasting points to monitoring location) were also recorded. The extensively used equation for seismic low of propagation proposed by Devine (1962) and Devine and Duvall (1963) was used for the prediction of peak particle velocities. Points were plotted with Peak Particle Velocity (PPV) in Y- axis against Scaled Distance (D/Q03) in X- axis. Regression analysis was performed to define the line of best fit. At the end of statistical analysis, an empirical relationship with good correlation was established for prediction of peak particle velocity. Frequency analysis was also done for dominant frequency and Zero crossing frequency to identify the effect of frequency of ground vibration to structural damages and defining the most suitable type of frequency analysis to define the single frequency value for ground vibration. The established relationship, frequency analysis and result obtained are presented.
item: Conference-Full-text
Evaluation of soil liquefaction in Sri Lanka - a dynamic approach using geotechnical investigation data
(Department of Civil Engineering, University of Moratuwa, Sri Lanka., 2012-12) Kumarasiri, C; de Silva, N; Abayakoon, S; Nawagamuwa, U; De Silva, LIN
Soil Liquefaction is a process, where granular soils below the ground water table temporary lose its strength and behaved as a viscous fluid rather than a solid. The porewater pressure is suddenly increased during an earthquake due to the cyclic loading. The increased porewater pressure is forced the soil particles to suspend in water. As a result, the buildings, utility services, natural substances and other structures are collapsed causing severe damage to the people and the nature. In Sri Lanka, it is rare to find the historical data of liquefaction or related incidents. Recent studies demonstrated that there is a potential for liquefaction in some places of the island. It could be evaluated by using the basic geotechnical investigation data, according to the simplified procedure proposed by Seed and Idriss (1971). This paper is intended to evaluate the liquefaction potential in Sri Lanka by identifying the liquefiable layer thickness, using an extensive geotechnical investigation data base. As per the analysis 384 locations were identified as susceptible for liquefaction with various layer thicknesses out of 3282 locations analysed. Further, the analysis has extended for varied ground water table.
item: Conference-Full-text
Analysis of settlement monitoring data to assess the state of primary and secondary consolidation of soft organic soil deposits
(Department of Civil Engineering, University of Moratuwa, 2012-12) Premalal, RPDS; Jayasinghe, TWASL; Indrachapa, KRTH; Thilakasiri, HS; Nawagamuwa, U; De SIlva, LIN
Organic soil deposits under road embankments may cause consolidation settlement problems during the serviceability stage. It is not feasible to design road traces on such soil deposits using the traditionally used most unfavourable ground conditions. Instead the most probable ground conditions are used in the initial design and this approach is referred to as the observational approach. The risks associated with using most probable soil properties are managed by reviewing the initial design through the analysis of the observational data obtained during the construction stage. In this regards, analysis tools to assess the stability of the embankment during construction stage and the estimation of the degree of consolidation during ground improvement phase are extremely important. Even though there are large number of analytical methods available to use for the data analysis, not much research is done to identify the tools relevant to the organic soft soils found in Sri Lanka. This research is aimed at investigation of the analytical tools that can be used in the analysis of settlement monitoring data obtained during the implementation of the observational approach for construction of the road embankments over the soft soil deposits in Sri Lanka.
item: Conference-Full-text
Methodology to develop a driving cycle for a given mode and traffic corridor; case study for Galle Road, Colombo, Sri Lanka
(Department of Civil Engineering, University of Moratuwa, 2012-12) Gamlath, I; Fernando, C; Galgamuwa, U; Perera, L; Bandara, S; Nawagamuwa, U; de Silva, LIN
A driving cycle is a speed time profile which represents the driving characteristics of a selected area. This can be of use to both legislative and non legislative purposes such as development of emission inventory, determination of fuel consumption etc. As driving cycles are dependent on the traffic constituents, driver behaviour and road conditions established driving cycles cannot be used in Sri Lanka. Hence the objective of this research is to develop a methodology and to constructa driving cycle(s) which represent given set of conditions in Sri Lanka such that it can be use to establish emission inventory in future. To achieve these objectives, it is necessary to collect and analyse the on road speed-time data on selected routes which will represent the driving patterns of urban or rural conditions. Due to the restriction of time and resources, study was limited to one transport corridor, anurban condition and for light vehicles only. A sample driving cycle was developed based on the data collected on the Galle Road, section from Katubedda to Fort using on board method. Cycle was developed using micro trip based cycle construction and computer application was developed to aid this purpose. In this study we observed average speed 21.37km/h, average running speed 25.78km/h, average acceleration 2.03km/h/s and average deceleration 2.02km/h/s with acceleration, deceleration, cruising and idling proportions of 27.37%, 23.70%, 31.43.6 and 17.49% respectively for selected urban condition. This study would facilitate the further studies on development of driving cycles for other conditions and could be of use for traffic engineering studies development.
item: Conference-Full-text
Applicability of HCM 2000 to determine the level of service in urban arterial roads, Sri Lanka
(Department of Civil Engineering, University of Moratuwa, 2012-12) Mampearachchi, WK; Jayasuriya, WWC; Senaratne, SAMANI; Nawagamuwa, U; de Silva, LIN
T16 obJective of this research is to identify the applicability of Highway Capacity Manual (HCM) to determine the Level of service in urban minor arterial roads in Sri Lanka. HCM has been developed by the transport research board, USA. Currently most of the local road eve opment agencies use HCM for capacity analysis of roads. There have been no researches carried out to identify the applicability of HCM to the Sri Lankan condition. To depict the quality of service of the roads quantitative measures of a traffic stream are required. Level of Service (LOS) is a quality measure describing operational conditions within a traffic stream, generally in terms of service measures such as speed and travel time, freedom to maneuver, traffic interruptions and comfort. Six LOS are defined based on service flow rates of roads. Letters designate each level from A to F with LOS A representing the best operating conditions and LOS F the worst. Though the local roads have acceptable LOS, the results obtained from both HCM 2000 andl986 have not reflected it It is required to identify the factors which affect the LOS. For that a sample of two way - two lane roads were selected. For the selected sample flow vs. density curves have been developed by considering traffic data and speed survey data. Based on the literature findings and data collected from the field, six LOS for the urban minor arterial roads have been defined.
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Failure analysis of a DBST road using mechanistic empirical method
(Department of Civil Engineering, University of Moratuwa, 2012-12) Mampearachchi, WK; Marasinghe, DL; Dahigamuwa, RMTM; Wanniarachchi, WDNG; Nawagamuwa, U; De SIlva, LIN
The objective of this research is to analyze a failure of a DBST road section using a Mechanistic - Empirical method. For this analysis, failure of A15- Trincomalee-Batticaloe road was selected.This particular road section was rehabilitated recently by extending the width of the initial road section from both the sides and soon, a large amount pot holes appeared in the newly constructed areas.Empirical methods alone failed to identify the reason behind this failure and therefore a Mechanistic - Empirical approach was used along with the KENLAYER software to analyze the section. Mechanistic approach to pavement design seeks to explain phenomena only by reference to physical causes. Thus it uses stresses, strains and deflections within a pavement structure to analyze the loads and material properties of the pavement. This study would help future engineers to identify the reason behind the failure of road sections. This will promote mechanistic softwares like KENLAYER and increase the usage of it. These softwares will make life easy for road designers and consultants and this may turn a new chapter in road designing of Sri Lanka.
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Investigation of hydraulic performance of Gabion structures
(Department of Civil Engineering, University of Moratuwa, Sri Lanka., 2012-12) Hettiarachchi, SSL; Samarasekara, RSM; Priyankara, SS; Silva, HAM; Nawagamuwa, U; de Silva, LIN
This paper presents selected results of a detail study of the transmission refeletion performance of gabion structures usued in harbour and costal engineering applications. The performance of the structures is discussed and the results of experimental investigations relating wave reflection and transmission are reviewed and presented in a user friendly format The paper also provided important observations on the response of the design parameters'to varying incident wave
item: Conference-Full-text
Selecting a usability evaluation user group - a case study the development of a hydro-GIS tool aiming urban flood mitigation
(Department of Civil Engineering, University of Moratuwa, Sri Lanka., 2012-12) Pradeep, RMM; Wijesekera, NTS; Nawagamuwa, U; de Silva, LIN
Flash floods which are becoming a common occurrence due to poor planning in the ur an areas nee user friendly tools for land managers to arrive at suitable alternatives. These tools require incorporating spatially distributed assessments performing several maps overlay and hydrologic computations for the evaluation of runoff generation before and after a proposed land eve opment. The most common option for urban flood mitigation is the incorporation of land allotment based detention storages. The land managers need to capture the optimum sizes for these storages. A Hydro-GIS tool development was undertaken to ensure easy user friendly operation with automation of complex hydrologic and GIS computations. The tool with the objective of targeting nontechnical users demands high user friendliness and in order to achieve this, evaluations comparing usability becomes very important. Identification of the right number of users to evaluate usability is a requirement yet to be fulfilled. The present work successfully carried out a Hydro GIS tool development for the management of urban land development, achieving its functionality objectives while testing user friendliness with a user group of 23. Analysis shows that a group of over 13 users would arrive at an on average problem area identification rate of 90% or more.
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Identification of WebGIS development potential and issues - a land and water case study application for Moratuwa, SrI Lanka.
(Department of Civil Engineering, University of Moratuwa, 2012-12) Chandramali, EAG; Wijesekera, NTS; Nawagamuwa, U; de Silva, LIN
Polularity of internet usuing is rapidly incerasing. Hence the demand is high for Web based GIS tools. The need to handle heavy maps and attribute datasets, often increase issues specially with aspect to the time taken to serve maps and to filter user desired information for e very. A WebGIS based land and water information management system was developed for a land extent of approximately 2.5km’- within the Moratuwa DSD of Sri Lanka. Information of roads, buildings were collected as land data while water and stream information were collected using an extensive field survey. The developed WebGIS application integrates digital base maps and feature attribute data of the selected case study area and facilitates operations through a user-interface while offering a variety of querying and reporting options. This application which was named Geoinfo WebGIS, possesses a very high potential to serve the users through i)Map to Map ii) Map to database iii) Database to Map and iv) Database to Database functions. The application was tested and verified through a consideration of user satisfaction and accuracy. Geolnfo WebGIS was developed on MS4W framework, PostgreSQL was used as the database. Non-responsive situations, high time consumption when loading the data layers, map overlaying issues and delay in refreshing the performance issues identified through the application development.
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Is course correction needed for direction of research in concrete
(Department of Civil Engineering, University of Moratuwa, Sri Lanka., 2012-12) Holey, S; Silva, A; Perera, HTP; Wijayakulatilaka, WGMA; Nawagamuwa, U; de Silva, LIN
This paper is an endeavour to highlight importance of realizing potential of research in "value addition' or "making" process of concrete. Authors, based upon their cement manufacturing and construction industry, presented information on data generated in past five years in Sri Lanka for various purposes/studies as well as observations and interaction with concerned from the spectrum of Industry. research in experience as link of The paper, while questioning the overemphasis given to "material" part of concrete, shares the learning, which could benefit the Industry, in ensuring consistent superior quaiitv and economy of concrete and suggest the areas for future research.

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