Abstract:
Highway system makes the crucial contribution to the economic development of any nation.
Road network not only connects people but also provides access to the employment, social
stability, health and educational services. Motorways are the cornerstone of the road network
of any country and their maintenance is pivotal for carrying ever increasing vehicle volumes.
The main objective of this research is to carry out detailed analysis of the pavement drainage
facility provided at super elevated segment of a motorway to check the adequacy of drainage
inlets and underground drainage lines (pipes). Data for present study were obtained from
detailed design drawings including curve details, rainfall data and data on drainage structures.
We determined pipe capacity, number and size of pipes and time required for removal of rain
water from super elevated road surface. Rainfall intensity was compute using FAA (Federal
Aviation Authority) method. For determining pipe sizes, Manning’s formula was adopted. The
pipes’ sizes so calculated were utilized to perform analysis to check adequacy of designed
pipes. Software based analysis was also performed using AutoCAD Civil 3D and Storm and
Sanitary Analysis. Our analysis revealed that presently sub-surface drainage infrastructure is
being designed with low factor of safety (one). Since sub-surface drainage infrastructure is
not only difficult to maintain/ replace, but also very costly, therefore a minimum factor of
safety between 3-4 is recommended.
