Important Definitions in Bridge Engineering

35. Afflux : The rise in the flood level of the river immediately on the upstream of a bridge as a result of obstruction to natural flow caused by the construction of bridge and its approaches.
36. Bearing Capacity : The supporting power of a soil / rock expressed as bearing stress is referred to as its bearing capacity.
37. Safe Bearing Capacity : The maximum pressure which the soil can carry safely without  risk of shear failure and it is equal to the net Safe Bearing Capacity plus original overburden pressure.
38. Cofferdam : A structure temporary built for the purpose of excluding water or soil sufficiently to permit construction or proceed without excessive pumping and to support the surrounding ground.
39. Foundation : The part of bridge in direct contact with and transmitting load to the founding strata.
40. Pier : Intermediate supports of the superstructure of a bridge.
41. Abutment Pier : It is designed for a condition that even if one side arch span collapses it would be safe. Generally provided after 3 or 5 spans in multiple span arch bridges.
42. Retaining Wall : A wall designed to resist the pressure of earth filling behind.
43. Return Wall : A wall adjacent to abutment generally parallel to road or flared up to increase width and raised up to the top of road.
44. Toe wall : A wall built at the end of the slope of earthen embankment to prevent slipping of earth and / or pitching on embankment.
45. Wing Wall : A wall adjacent to abutment with its top up to R.T.L. near abutment and sloping down up to ground level or a little above at the other end. This is generally at 45 degrees to the alignment of road or parallel to the river and follows the profile of earthen banks.
46. Substructure : The bridge structure such as pier and abutment above the foundation and supporting the superstructure. It shall include returns and wing walls but exclude bearings.
47. Well foundations : A type of foundation where a part of the structure is hollow, which is generally built in parts and sunk through ground or water to the prescribed depth by removing earth through dredge hole.
48. Tilt of Well : The inclination of the axis of the well from the vertical expressed as the tangent of the angle between the axis of the well and the vertical.
49. Shift of Well : The horizontal displacement of the center of the well at its base in its final position from its designed position.
50. Skew angle of Bridge : It is the angle between the perpendicular to the flow of traffic direction and the flow direction of river.