Abstract:
Abstract: Large monumental constructions were a prominent feature in ancient Sri Lanka. Construction materials
and techniques used in the past can be of significant interest to the modern engineer. The evolution of brick sizes
during four ancient periods of Sri Lanka spanning from 375 B.C to 1350 A.D. was studied by using recorded data of
bricks found on ancient construction sites. The calculated ratios and the relationships indicate that the length was
relatively significant in the reduction of the brick sizes while breadth and thickness changed roughly in proportion to
the length at a lower rate. The effect of ground condition, i.e. rock, strong soil and weak soil; and the effect of pedestals
on a solid hemispherical dome type Stupa were analysed using SAP2000. It was found that a stupa, if unrestrained
along its horizontal directions, could experience tension being developed at the centre when built on a weak soil.
Also, when constructed on poor ground conditions a pedestal reduces the compressive stresses at the base. However,
the pedestal causes higher hoop and radial tensile stresses closer to the top and bottom of the outer surface of the
dome. Vaulted structures in Sri Lanka exhibit approximately similar span to wall thickness ratios, thus indicating the
possibility of the design being governed by the geometry of the structure. Also the development of stresses in vaulted
structures indicates that the maximum vertical stress is compressive at the base, while the maximum tensile stress is
at the crown intrados.
