Javad Sudagari - Assistant Profeddor

UnHighway engineers generally believe that is there is their enemy. While it is absolutely true that water is the source of life, but when it comes to the road it is one of the main causes of damage to pavement integrity and durability . when water is on the surface of the road causes the traffic to slow down and in extreme condition under complex situations can cause danger to travelers due to for example generation of spray, slipperiness and when its level in high can bring traffic to a half. In this paper the important of providing a drainage system functioning both as surface and subsurface type in investigated and the use of such a system designed and implemented at a water logged underpass on Tehran – Qom motorway which has this problem for 25 years in referred to. This locations under the motorway is in an arid or semi arid region of the country, but the water nuisance for the passing traffic was the worst during spring and summer time. The problem had been so severe that is had caused difficulties in road maintenance , maintaining safe passage of traffic and an acceptable level of service and at times the underpass would be closed for long times. The road maintenance division of Tehran province Highway Agency had been under very high public pressure for the condition over this section of the road network. A limited call for solution was made and the author’s proposal put forward was selected on its merits to solve the problem by designing and implementing a surface and subsurface drainage system to get rid of the ever standing water on the surface of the road using geotextile and an intelligent pumping. Sontrol system as described in this paper. The main advantages of the system are that it is flexible, easy and quick to construct , very cost effective about one tenth of other proposals and free from legal implications and safety problems associates with other proposals.

Underpass , Geotextile , Gravel filter materical , Catch - pit manhole , Electric pump and intelligent control automatic system