摘要: |
This paper describes the design and construction of cost effective bridges for Sri Lankan rural roads.Planning, estimation and design considerations are explained.Most of the rural roads categorized in to class "C" and "D" in Sri Lanka road map are situated in most difficult terrain conditions with hill country and suburbs.During the British colonial era, the roads constructed to access tea plantations are of these roads and the bridges on these roads are with pedestrian cable type or steel structures with no vehicular access.Due to the present development these bridges are to be replaced with bridges that can accommodate vehicles.Considering the difficulty of material transport and terrain conditions, steel concrete composite type cost effective bridges are proposed to rural roads and those are very much suitable for sustainable development on affected areas.Convenience of material transport, erection, use of local material, speed of construction and mostly the cost effectiveness for the projects promoted these types of bridges for rural roads in Sri Lanka.Proper design and detailing, the contractor's ability and technological knowhow and the cooperation with the Client-Contractor in a design and built contract are also explained with a case study.It should be noted that although the methods of analysis outlined in this paper can also be applied to similar type of bridges, but essentially the bearing capacity of the particular foundation,hydrological investigations have to be investigated accordingly. |