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Hydraulics Lab: 2003-2004

Floating Debris Boom Performance Test

 

Full modeling report

 

MODELING SCOPE

This model study was projected to be capable of providing the best performing draft design of floating booms barriers and their application in existing scaled arroyo models.  The test was composed of the initial design task of a 1:18 scaled model floating boom in a rectangular flume and the application task  of a model in a trapezoidal section arroyo scale model.  The trapezoidal section task is a 1:8 scaled model of the North Pino Arroyo, which is adjacent to the North Diversion Channel located in northeast Albuquerque.  In addition, commercial floating boom barriers were reviewed regarding debris exclusion capability in arroyos.

 

SUMMARY AND RECOMMENDATIONS

With the results of the modeling tests, the floating boom is recommended to be approximately 1.0 ft in diameter of Styrofoam bar covered with fiberglass in the case of a 6 ft deep, 132 ft2 section of trapezoidal arroyo.  Stainless steel connectors will hinge the booms to each other.  Figure 1 shows one of the commercial floating booms and their materials and connections.  For the floating boom setup, a 30° or less boom barrier approach angle and a sloped downstream pier are recommended. 

 

 

 

 

 

 

 

 

    a) Floating boom materials                                     b) Boom hinged connections

 

                                                  Figure 1. Commercial Floating Boom

 

Combinations of the log boom and buoyancy boom are suitable for the storm water debris control in trapezoidal arroyos and drain channels, while the buoyancy boom type is good for sediment detentions or reservoirs.  Length of the log boom shall be match the bed width of arroyo, and couples of the buoyancy booms are good for sidewall because of the better flexibility to follow low and high water depth as shown Figure 2.

                                    Figure 2. Floating Boom Application in Trapezoidal Arroyo

 

 

Off-site Storm Water Quality Facility in North Pino

 

Modeling Report

 

Objectives:         Maximum intake of storm water debris into the detention pond pipe.

                                Safe storm water drainage through channel.

Location:             North Pino, Albuquerque, New Mexico

Proceeding:        1:8 scale physical experiments with three scenarios

·         As-Design Weir Model

·         Sloped Side Wall Model

·         Sloped Side Wall with Step Model

Solutions:           High intake of storm water first flush with floating debris.

                                Streamlined and no splash channel design.

Recommended

Model Designs:

  

As-Design Weir Model

Performance:       Floating debris are just washed away along the channel not inflowing to the culvert.

                                Drains more along the channel than the culvert connected to the detention pond.

Water splash might be at the weir in low flow rate.

Hydraulic jump is occurred different location for each flow rate.

                                Weir structure safety problem due to heavy storm water waste.

 

   

           Culvert entrance at the channel bottom            Debris removing experiment

 

      

Rating curves of channel and culvert

                                                               

 

Hydraulic jump location at 2.0 cfs

 

Sloped Side Wall with Step Model

Performance:       Maximum debris removing capacity among three models.

                                Drains more along the culvert than the channel.

                                No significant water splash and hydraulic jump.

               

   SSWS model at 133 cfs discharge                   Experiment with AMAFCA Engineers

           Rating curves of SSWS model