Improvement in Design Practice of Side Slope Protection of Guide Bunds for Bridges

摘要

Design norms for fide slope protection and apron are given by Bureau of Indian Standards (BIS) in IS 10751 : 1994 and Indian Road Congress (IRC ) in IRC: 89 - 1997. There are certain points not very clear requiring further consideration. The origin of the equation recommended for stone size and weight is not given. The implied assumptions and limitations are therefore not known. The equations for apron stone size and weight recommended by BIS and IRC are significantly different. The slope of launched apron specified for concrete blocks and stone-crates is different from that for stones. Provision for allowance to be made in stone size and weight when flood flow is strongly turbulent, the flow is obligue, current eddies and waves are present is left to the judgement of the designer. These points are discussed and possible improvement suggested in this paper.