EMBANKMENT PROTECTION AT RIVER CONSTRICTIONS

THE EXTENT TO WHICH RIPRAP IS NECESSARY TO PROTECT A FLOW-CONSTRICTING STRUCTURE AT A RIVER---IN THIS CASE AN EMBANKMENT---IS CONSIDERED FROM THE STANDPOINTS OF ANALYTICAL MODELS AND LABORATORY EXPERIMENTS. THE ANALYTICAL MODEL IS W. G. FIELD'S EQUIVALENT NOZZLE CONCEPT, WHICH IS MODIFIED TO PLACE THE NOZZLE ALONG THE INTERSECTION OF THE WATER SURFACE WITH THE UPSTREAM SLOPE, RESULTING IN SMALLER TIP VELOCITIES, AND TO ADJUST ITS LENGTH SO THAT THE BOUNDARY OF THE JET ISSUING FROM IT COINCIDES WITH THE CURVATURE OF THE WATER SURFACE INTERSECTION AROUND THE EMBANKMENT NOSE. MODEL BRIDGE EMBANKMENTS WITH THE SLOPE PROTECTED BY RIPRAP WERE CONSTRUCTED IN THE 6 X 80 FT FLUME AND 20 X 180 FT OUTDOOR FACILITY OF THE ENGINEERING RESEARCH CENTER AT COLORADO STATE UNIVERSITY. THE OBSERVATIONS FROM TESTS CONDUCTED AT THE CENTER WERE COMBINED WITH THE MODIFIED ANALYTIC MODEL TO DESIGN RIPRAP PROTECTION FOR BRIDGE EMBANKMENTS. FIELD'S SUGGESTIONS FOR TREATING BACKWATER AND SCOUR ARE DISCUSSED AT LENGTH. VARIOUS TYPES OF SCOUR ARE DEFINED AND REPRESENTED MATHEMATICALLY. THE EFFECTS OF BENDS AND SPUR DISKS ARE CONSIDERED BRIEFLY. QUANTITATIVE ESTIMATES OF THE VARIOUS FACTORS ARE MADE TO THE EXTENT PERMISSIBLY BY THE CURRENT STATE OF KNOWLEDGE.

• Supplemental Notes:
  • pp 160-206, 26 FIG, 3 TAB, PHOTS, 27 REF, 2 APP
• Authors:
  • Simons, D B
  • Lewis, G L
  • Field, W G
• Conference:
  • Colo State Univ, Bridge Eng Conf
• Publication Date: 1970

Subject/Index Terms

• TRT Terms: Backwaters; Bridges; Constrictions; Design; Embankments; Flow; Mathematical models; Protection; Quantitative analysis; Riprap; Rivers; Scour
• Uncontrolled Terms: Model tests; Models
• Subject Areas: Bridges and other structures; Design; Highways; Marine Transportation; Security and Emergencies;

Filing Info

• Accession Number: 00209520
• Record Type: Publication
• Files: TRIS
• Created Date: Dec 20 1971 12:00AM