Browsing by Author "Gunathilaka, AMLN"

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item: Conference-Full-text
Analysis and design of telecommunication towers for earthquake loading in Sri Lanka for sustainability
(2013-11-12) Gunathilaka, AMLN; Lewanagamage, CS; Jayasinghe, MTR
Large number of telecommunication towers has been constructed in Sri Lanka during last few decades with the rapid development of telecommunication sector in the country. These towers play a significant role especially in wireless communication and failure of such tower in a disaster like an earthquake is major concern mainly in two ways. One is the failure of communication facilities will become a major setback to carry out rescue operations during disaster while failure of tower will itself cause a considerable economic loss as well as damages to human life in most of the cases. Therefore, design of telecommunication towers considering all possible extreme conditions is of utmost importance and a good design can be considered as a step towards a greater degree of sustainability. However, almost all telecommunication towers in this country have not been checked for earthquake loading since most of people believe that earthquake threats are not that much of significance to Sri Lanka until recently. With many tremors recorded in recent past, designers have started to rethink about earthquake design of structures and main objective of this research is assessing the performance of exiting towers (which were not initially designed considering earthquake loading) under possible earthquake loading and find cost effective strategies for retrofitting in case such action has to be effected. Accordingly, behaviour of existing four legged Greenfield towers under seismic loadings appropriate for Sri Lankan conditions were analyzed using equivalent static load method given in ANSI/TIA-222-G. This can be considered as an initiative in this research area under local conditions. Results and conclusions based on this analysis are discussed in this paper.
item: Conference-Abstract
Analysis of four leg telecommunication towers for seismic loading using response spectrum method
Gunathilaka, AMLN; Lewangamage, CS; Jayasinghe, MTR
Telecommunication towers are common sight even in very remote areas of Sri Lanka with the revolutionary development in this sector during last few decades. These towers play a vital role especially in wireless communication. Hence, a failure of such tower in a disaster like an earthquake is a major concern since it hampers communication needs in rescue operations during the disaster. Further, since these are usually tall structures, failure of tower may itself cause a significant damage. However, almost all existing telecommunication towers in this country have not been checked for seismic loading since Sri Lanka was considered as a country free from earthquakes until recently. But, now most of the structural engineers consider seismic effects for their designs of important structure such as high rise buildings, dams, etc. Still, this practice has not been implemented regarding telecommunication tower designs. This paper discuss the structural performance of selected existing four legged Greenfield towers which were analyzed under seismic loadings using Response Spectrum method given in ANSI/TIA-222-G. Approach of analysis and comparison of analytical results under different seismic analytical techniques as well as with results under wind loading are presented in this paper.
item: Conference-Abstract
Earthquake Performance of free Standing four Legged Greenfield Towers
Gunathilaka, AMLN; Lewangamage, CS; Jayasinghe, MTR;
Telecommunication/broadcasting towers play a vital role in telecommunication and broadcasting sectors by facilitating wireless data and signal transmissions. The failure of a tower especially under a disaster situation such as earthquake is a major concern mainly in two ways. One is the failure of communication/broadcasting facilities which will become a major setback to carry out rescue and other essential operations during a disaster while failure of a tower will itself cause a considerable economic loss as well as damages to human life since these are tall giant structures in most of the cases. Presently, a strong dialogue is going on amongst the professionals regarding the seismic condition of our country with the reported earth tremors in recent times. Hence, evaluating the structural performance of existing telecommunication/ broadcasting towers under seismic loads is utmost important since almost all existing towers have not been designed considering seismic forces due to traditional belief that Sri Lanka will not be subjected to earthquakes of appreciable magnitudes. Considering the above situation, assessment of structural performance of existing towers (which were not initially designed considering earthquake loading) under possible earthquake loading with different analytical techniques was selected as main objective of this study. Accordingly, behaviour of existing four legged Greenfield towers under seismic loading using ANSI/TIA-222-G tower design code was studied and results, observations and conclusions based on this analysis are presented.
item: Thesis-Abstract
Optimized roof top tower design
Gunathilaka, AMLN; Hettiarachchi, MTP
Errection of Telecommunication towers has become one of the key elements in any network expansion project in telecommunication industry at present days. Roof top towers play a dominant role in this context especially in urban and suburban areas since the possibility of erecting green field towers is limited in these areas due to factors like scarcity of lands, social factors, economic factors, etc. But, a proper scientific research on rooftop towers or effects that are caused by the tower installation on existing buildings ha<; not been carried out yet in Sri Lanka. Even in world context, a very few researches have been done in this regard. Hence, this topic was selected for my MEng(structural) research with the main objectiv{; of find ways to optimizing cost for roof top towers and identification or structural effects 011 existing structures on which roof top towers arc installed.A comprehensive scientific study was carried out within the so1pe of this work and finally it has reached to some important conclusions that can be practically adopted for the betterment of this roof top tower design and construction field. Also, 1 hope this report will be a motivator to the practicing engineers in this field to carry out more and more research in this field for the betterment of the industry
item: Article-Full-text
Seismic Analysis of Guyed Mast Towers in Sri Lanka
(2015-12-29) Kogul, S; Gunathilaka, AMLN; Lewanagamage, CS; Jayasinghe, MTR
With the rapid development of the telecommunication sector in the country, telecommunication/broadcasting towers play a vital role in telecommunication and broadcasting sectors. There are many structural forms available for towers and guyed mast is one such type commonly seen in country sides of Sri Lanka where land is available for cheaper price. Moreover, in the case of very tall tower is needed, guyed mast is more economical solution than self-supporting towers. The failure of a guyed tower especially under a disaster situation such as earthquake is a major concern in many ways. One is the failure of communication/broadcasting may hamper the communication needs to carry out rescue and other essential operations. Further, failure of a tower may itself cause a considerable economic loss as well as damages to human life. Therefore, checking of structural performance tower under seismic and other extreme weather effects is quite vital. Even though, Sri Lanka was believed to have no seismic threats, presently a strong argument is going on amongst the professionals regarding the seismic condition of our country with the reported earth tremors in recent times. Hence, evaluating the structural performance of existing telecommunication/ broadcasting towers under seismic loads is utmost important since almost all existing towers have not been designed considering seismic forces due to traditional belief that Sri Lanka will not be subjected to earthquakes of appreciable magnitudes. Considering the above situation, assessment of structural performance of exiting Guyed mast towers (which were not initially designed considering earthquake loading) under possible earthquake loading was selected as the objective of this study. Accordingly, behavior of existing Guyed mast towers under seismic loading using ANSI/TIA-222-G tower design code was studied and results, observations and conclusions based on this analysis are presented
item: Conference-Full-text
Seismic Analysis of Guyed Mast Towers in Sri Lanka
(2016-04-26) Kogul, S; Gunathilaka, AMLN; Lewanagamage, CS; Jayasinghe, MTR
With the rapid development of the telecommunication sector in the country, telecommunication/broadcasting towers play a vital role in telecommunication and broadcasting sectors. There are many structural forms available for towers and guyed mast is one such type commonly seen in country sides of Sri Lanka where land is available for cheaper price. Moreover, in the case of very tall tower is needed, guyed mast is more economical solution than self-supporting towers. The failure of a guyed tower especially under a disaster situation such as earthquake is a major concern in many ways. One is the failure of communication/broadcasting may hamper the communication needs to carry out rescue and other essential operations. Further, failure of a tower may itself cause a considerable economic loss as well as damages to human life. Therefore, checking of structural performance tower under seismic and other extreme weather effects is quite vital. Even though, Sri Lanka was believed to have no seismic threats, presently a strong argument is going on amongst the professionals regarding the seismic condition of our country with the reported earth tremors in recent times. Hence, evaluating the structural performance of existing telecommunication/ broadcasting towers under seismic loads is utmost important since almost all existing towers have not been designed considering seismic forces due to traditional belief that Sri Lanka will not be subjected to earthquakes of appreciable magnitudes. Considering the above situation, assessment of structural performance of exiting Guyed mast towers (which were not initially designed considering earthquake loading) under possible earthquake loading was selected as the objective of this study. Accordingly, behavior of existing Guyed mast towers under seismic loading using ANSI/TIA-222-G tower design code was studied and results, observations and conclusions based on this analysis are presented.
item: Conference-Abstract
Seismic analysis of three legged lattice telecommunication towers for Sri Lanka conditions
Desmond, JA; Gunathilaka, AMLN; Lewangamage, CS
Mobile communication is feeing an exponential growth and thousands of telecommunication towers have been constructed in Sri Lanka to accommodate the current demand. Failure of communication tower in a disaster like an earthquake is of major concern as this can hinder the communication needs, especially in case of rescue operation. It also causes property damage to itself and adjacent structures. Hence, design of telecommunication towers considering all possible extreme conditions are essential Sri Lanka is considered earthquake free as it is fer away from earthquake prone regions and almost all local telecommunication towers were not checked against earthquake. However designers have started to think about earthquake design of structures as frequent tremors are recorded in recent past due to intra plate earthquakes. Objective of this research is assessing the performance of existing three leg self-supporting towers which were not designed for seismic loadings and find strategies for retrofitting in case of significant adverse effect This paper presents the analytical results of three legged lattice telecommunication towers in different heights under seismic loading for local conditions. Such results indicate that structural actions under local seismic loading condition are comparatively insignificant when compared with same under wind loads for the selected telecommunication towers.