8 Design of river and canal structures 1 2 3 4 5 6 7 8 9 10 CIRIA C683 965 8 Design of river and canal structures CHAPTER 8 CONTENTS 8.1 Introduction. 970 8.1.1 Context . 970 8.1.2 Types of structures and functions. 971 8.1.3 Design methodolology. 973 8.1.3.1 Approach to the design . 973 8.1.3.2 Functional requirements . 974 8.1.3.3 Detailed design . 975 8.1.3.4 Economic considerations . 975 8.1.3.5 Environmental and social considerations . 976 8.1.3.6 Physical conditions . 976 8.1.3.7 Materials related considerations. 977 8.1.3.8 Construction related considerations . 979 8.1.3.9 Operation and maintenance related considerations . 980 8.2 River training works . 980 8.2.1 Erosion processes . 980 8.2.2 Types of river training structures . 982 8.2.2.1 Revetments . 983 8.2.2.2 Spur-dikes and hard points . 984 8.2.2.3 Guide banks . 985 8.2.2.4 Works to improve navigation . 986 8.2.2.5 Flood protection . 986 8.2.2.6 Selection of the appropriate solution. 987 8.2.3 Data collection . 988 8.2.4 Determination of the loadings . 988 8.2.4.1 Hydraulic loads. 988 8.2.4.2 Other types of loads . 989 8.2.5 Plan layout . 989 8.2.5.1 General points. 989 8.2.5.2 Bank protection . 990 8.2.5.3 Spur-dikes . 992 8.2.5.4 Longitudinal dikes or guide banks . 993 8.2.6 Cross-section design . 994 8.2.6.1 Design considerations for selection of the cross-section . 994 8.2.6.2 Cross-section design and typical cross-sections . 1000 8.2.7 Structural details . 1004 8.2.7.1 Head and berm of spur-dikes or guide bunds . 1004 8.2.7.2 Crest level and width of spur and longitudinal dikes . 1005 8.2.7.3 Stability of revetment toes . 1005 8.2.7.4 Falling aprons . 1007 8.2.7.5 Flexible open revetment. 1009 8.2.7.6 Transitions. 1013 8.2.8 Materials issues that influence design. 1020 8.2.8.1 Materials availability . 1020 8.2.8.2 Materials supply and transport . 1021 966 CIRIA C683 Contents 8.2.9 Construction issues that influence design . 1022 1 8.2.9.1 Approaches to construction . 1022 8.2.9.2 Construction situations. 1022 8.2.10 Maintenance issues that influence design. 1024 8.2.11 Repair and upgrading. 1025 2 8.3 Navigation and water conveyance canals. 1026 8.3.1 Introduction . 1026 8.3.2 Types of structures and functions. 1026 8.3.2.1 Navigation canals . 1026 8.3.2.2 Water conveyance canals . 1027 3 8.3.3 Plan layout and overall concept . 1027 8.3.4 Cross-section design . 1028 8.3.4.1 General . 1028 8.3.4.2 Navigation canals . 1028 8.3.4.3 Water conveyance canals . 1030 4 8.3.5 Structural details . 1030 8.3.5.1 General . 1030 8.3.5.2 Calculation of ship-induced hydraulic loads . 1031 8.3.5.3 Design of the cover layer against waves. 1034 8.3.5.4 Design of the filter layer. 1035 5 8.3.6 Issues that influence design . 1035 8.3.6.1 Construction issues . 1035 8.3.6.2 Maintenance issues . 1035 8.3.6.3 Repair and upgrading . 1036 6 8.4 Rock works in small rivers . 1036 8.4.1 Types of structure and functions . 1037 8.4.2 Plan layout and overall concept . 1038 8.4.3 Cross-section design . 1039 8.4.3.1 General . 1039 7 8.4.3.2 Forms of revetment using stone. 1041 8.4.3.3 River restoration . 1041 8.4.4 Issues that influence design . 1043 8.4.4.1 Materials aspects . 1043 8.4.4.2 Construction aspects . 1043 8 8.4.4.3 Maintenance aspects . 1045 8.5 Special structures . 1045 8.5.1 General . 1045 8.5.1.1 Water levels . 1045 8.5.1.2 Current velocities . 1046 9 8.5.2 Fishways. ..