Browsing by Author "Ratnayake, KC"

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item: Conference-Extended-Abstract
A comprehensive study of serviceability behaviour of slabs on grade
(2006) Weeraseka, IRA; Rowel, WDNP; Dassanayake, CI; Ratnayake, KC; Wickramaratne, PVL
A slab on grade is simply a slab constructed on earth or ground. Often these types of slabs are encountered in the industrial practice. There are several types of slabs on grade commonly used such as pavement slabs found in footpaths, walk ways, airport runways, highways, basement floors and bottom slab of swimming pools. The observed behaviour of these slabs is such that most of them are cracked due to serviceability problems or construction defects. This study is aimed at investigating the time dependent behaviour both at short term and long term conditions due to creep, shrinkage of concrete and relaxation of steel.
item: Thesis-Abstract
Design methods for apartment buildings with thin concrete shear walls
Ratnayake, KC; Jayasinghe, MTR
Economizing the construction cost is a strict demand of the current economic environment. Many structural engineers, practicing and academics; are actively involved in finding a favourable solution for this problem through experiments and researches. Many countries like Chile, Malaysia etc. have obtained good results. Thin concrete shear wall structures shade some light on this as most apartments for low and medium income groups should have symmetrical arrangement of lateral walls. This system is somewhat new to Sri Lanka but, could be very useful. Properly designed and detailed buildings with shear walls have shown overwhelming performance in past earthquakes occurred in different parts of the world. Shear walls in high seismic regions require special detailing. However, in past earthquakes, even buildings with sufficient amount of walls that have not been specially detailed for seismic performance (but had enough well distributed reinforcements), had saved from collapse. Shear walls are easy to construct; reinforcement detailing is relatively straight forward; repetitive construction; therefore shear walls are efficient both in terms of construction cost and effectiveness in minimizing earthquake damage in structural and non-structural elements. The objectives of the thesis are to assess the suitability of thin concrete shear wall structures for medium and 'low income group apartments, to check the feasibility with respect to economy, to optimize the thickness of shear walls, to assess ongoing building projects, and to check the suitability of thin shear wall structures in case of seismic (earthquake) loads. Methodology to achieve these objectives is the use of detailed literature survey, assessing code provisions, cost implications, establishing a finite element model, structural designs to British Standards, and comparison with other forms. It is concluded that apartment buildings with thin concrete shear walls are comparatively economical with other forms.