Vikas Garg - Professor in Civil Engineering, Petroleum University, Dehradun,
Baldev Setia - Professor, Civil Engg. Deptt, National Institute of Technology, Kurukshetra – ۱۳۶ ۱۱۹ Haryana
D.V. S. Verma - Professor, Civil Engg. Deptt, C R University, Murthal (Sonepat)– Haryana

This study based on the laboratory work, analyzes the protection by passive device around circular and oblong bridge pier. A delta wing like passive device referred henceforth as a passive device, which is attached to cylindrical or oblong pier, has its origin from Aerodynamics. Suitable delta wings like plate attached to upstream nose of a pier can hydro dynamically modify the primary horse shoe vortex. Passive device as scour countermeasure devices was tested in laboratory through extensive experimentation. The maximum scour depth around bridge pier in protected and unprotected conditions were compared. The passive device with optimum dimensions can reduce scour up to around 49% and 64% for point contact and semicircular contact respectively, with respect to an unprotected cylindrical pier under uniform flow conditions for 300 minutes durational run.