TERRAIN CONDITIONS AND ITS INFLUENCE ON SUBDRAINAGE SYSTEMS FOR ROADS

High water table, seepage zones and infiltration of surface runoff can drastically alter the behavior of highway pavements, resulting in early distress and costly maintenance. The need for subsurface drainage systems should be identified whenever possible in the design of roadways. Case histories are presented to illustrate terrain conditions where subsurface drainage installations are effective and several cases where they would be ineffective because of roadway design and construction deficiencies. For the covering abstract see ITRD E108441.