Abstract:
Corrugated Soil-Steel Bridges have been used as underpass and drainage structures in the Southern Highway
Project. This design and construction process is novel to the Sri Lankan context. The Ring Compression
theory, which is based on two dimensional plain strain idealizations, has been used in the design of the
structures. However due to the presence of the ring walls, the effect of uneven loading in the longitudinal
direction due to load combinations of HA and HB loads, these assumptions are in question. The maximum and
minimum depths of soil covers have been defined according to the results obtained by the Ring Compression
theory. The effects of depth of cover in Soil-Steel bridges were evaluated using finite element computer
modelling according to the US 5400 The original design results and the results of finite element analysis were
compared. The structural stability of the existing bridges with respect to the different fill heights was
determined. The Ring Compression and Finite Element Methods results are compatible for higher depth of
covers The stresses of the steel structure for defined maximum and minimum depth of cover, at the ultimate
limit state conditions are less than the crushing strength of the steel. Butt further buckling analysis should be
considered because the corrugated steel structure vulnerable to buckling failure
