# Presentation: 238692

## Woodrow Wilson Bridge Scour

-  Model Testing

- J. Sterling Jones
- FHWA TFHRC

**Eastern/Southern Resource Center**
**Hydraulic Engineer’s Conference**
- Orlando, FL             July 2000

## Slide 2

## Slide 3

## Small Scale Tests at FHWA’s TFHRC Lab

## Large Scale Test at USGS BRD  LAB in Mass.

## Preparation of Large Scale Test for M1

**Preparation of Large Scale Test for M1**

## Large scale M1 w/ Dolphins

**Large scale M1 w/ Dolphins**

## GEOMETRIC SCALING

**GEOMETRIC SCALING**
**by The Froude Law**

## GEOMETRIC SCALING (CONT’D)

**GEOMETRIC SCALING (CONT’D)**

** ****INHERENT ASSUMPTIONS**

** ****1.  “Near max” scour occurs at the critical**
**       ****uncipient motion velocity, v****c****, in the**
**       ****approach flow **** **

** ****2.  The scour depth scales as a length dimension**

- y

- y

- L

- s

-  m

- s

-  prototype

- r

- 

## Slide 10

## Univ of Fl Scaling Concept

## Univ of Fl. Scour Function at U=UC

**Univ of Fl. Scour Function at U=U****C**

## Univ of Florida Scour Function at U=UC

## Slide 14

## Slide 15

## Univ of Fl. Scour Function at U=UPB

**Univ of Fl. Scour Function at U=U****PB**

## Univ. of Florida Scour Function at U=UPB

## Slide 18

## Velocity at Transition to the Plain-Bed

-  Sediment Transport Regime (after N.S. Snamenskaya, 1969)

## Geometric Length ratio Scaling

## U. FL. COMPLEX PIER SCALING

## ADJUSTING SCOUR DEPTHS FOR

**ADJUSTING SCOUR DEPTHS FOR**
**DESIGN VELOCITY & DEPTHS**

**PROBLEMS:  Recommended design velocities **
**                          ****changed during study period.**
**                          ****Interested in Q****100**** and  Q****500**** scour**
**                          ****depths. That meant two sets of design**
**                          ****depths and velocities for each model. **

## Adjusting Scour Depths (cont’d)

**Adjusting Scour Depths (cont’d)**

## Run 12: M1, 56’ CAP, 1:100 scale  

**Run 12: M1, 56’ CAP, 1:100 scale  **
**Scour Depths : 27’(Q****100****), 30’(Q****500****)**

## Run 1: M1,  56’ CAP ,  w/ 3-45’ dolphins 

**Run 1: M1,  56’ CAP ,  w/ 3-45’ dolphins **
**Scour Depths : 53’(Q****100****), 59’(Q****500****)**

## Run 4: M1,  56’ CAP ,  w/ 3-30’ dolphins 

**Run 4: M1,  56’ CAP ,  w/ 3-30’ dolphins **
**Scour Depths : 37’(Q****100****), 41’(Q****500****)**

## Run 22: M1,  56’ CAP w/ 1-45’ dolphin  

**Run 22: M1,  56’ CAP w/ 1-45’ dolphin  **
**Scour Depths : 21’(Q****100****), 23’(Q****500****)**

## Run 9: M1, 56’ CAP and E1,  w/ 3-45’ dolphins 

**Run 9: M1, 56’ CAP and E1,  w/ 3-45’ dolphins **
**Scour Depths : 41’(Q****100****), 45’(Q****500****)**

## Run 63, 64: M3 w/ Tremie-Seal, Channel Change  

**Run 63, 64: M3 w/ Tremie-Seal, Channel Change  **
**Scour Depths : 38’(Q****100****), 43’(Q****500****)**

## Run 58: M9 w/ Tremie-Seal  

**Run 58: M9 w/ Tremie-Seal  **
**Scour Depths : 26’(Q****100****), 30’(Q****500****)**

## Run 48, 49, 50: M1, 96’ CAP, w/ 3-45’ dolphins  

**Run 48, 49, 50: M1, 96’ CAP, w/ 3-45’ dolphins  **
**Scour Depths : 68’(Q****100****), 76’(Q****500****)**

## Run 61: M1,  96’ CAP w/ Fender ring   

**Run 61: M1,  96’ CAP w/ Fender ring   **
**Scour Depths : 29’(Q****100****), 32’(Q****500****)**

## ys  =  ys pier +  ys ps + ys pg 

**y****s  ****=  y****s pier**** +  y****s ps**** + y****s pg**** **

## Slide 34

## Slide 35

## Slide 36

## Slide 37

## CONCLUSION

**CONCLUSION**

## Run 21: E27 & E28 

**Run 21: E27 & E28 **
**Scour Depths :7’(Q****100****), 8’(Q****500****)**

## Run 33, 34: M1,  56’ CAP , 1 :40 scale  

**Run 33, 34: M1,  56’ CAP , 1 :40 scale  **
**Scour Depths : 34’(Q****100****), 38’(Q****500****)**

## Scour Depths : 29’(Q100), 32’(Q500)

**Scour Depths : 29’(Q****100****), 32’(Q****500****)**
**c.f. Run 46 M1 w/out Fender ring**
**Scour Depths : 40’(Q****100****), 45’(Q****500****)**