APPENDIX "J"

PRELIMINARY SCOUR CALCULATIONS

COMP BY: GJK DATE: 2/1/2007 SHEET 1 OF 1

CHKD. BY: DATE: ENGINEERS - SRVEYORS - PLANNERS JOB NO.

PROJECT STRUCTURE

RIP-RAP SIZE SELECTION

REFERENCES:PENNDOT PUBLICATION NO. 15, DESIGN MANUAL 4 "STRUCTURES",

PART A: CHAPTER 7 DRAINAGE STRUCTURES, SCOUR AND CULVERTSPENNDOT PUBLICATION 218 "STANDARDS FOR BRIDGE DESIGN" (BD-600 SERIES)PENNDOT PUBLICATION 408 "ROADWAY SPECIFICATIONS"

In determining the rock size for protection of the substructures it is recommended in PENNDOTDesign Manual 4, Chapter 7 (PP A.7-5) to use the Federal Highway Administration Formula listed below for determining the average required diameter of the stone (D50). The minimum rock size is R-6.

A correction factor is applied to the velocity depending on the placement location of the rock:1.5 times the Velocity is used at the pier locations and1.8 times the Velocity is used at the abutment and wingwall locations

For SR 194, Rip-rap will be placed past the wingwalls at a distance of 5'-0". The velocity shown below is at the outlet of the proposed culvert extension.

D50 = 0.692 V*2

(S-1) (2g)

Where:

D50 = Average Stone Diameter in ft

S = Specific Gravity = 2.65

g = acceleration of gravity = 32.2 ft / sec2

V = Velocity in Channel = 12.23 ft / sec V = 100 year storm

V*= Velocity*1.8 = 22.014 ft / sec

Therefore D50 = 3.1560 ft = 37.87 inches R8

FROM PENNDOT PUBLICATION BD-632M

USE R- 8

NOMINAL PLACEMENT THICKNESS = 4.0 FT OK

Rock

According to PP (A.7.1) - No Scour Analysis for a box culvert is required. Refer to BD-632M for scour

protection details for box culverts

According to BD-632 Sheet 5 of 9 the detail for a culvert with endwall states : Minimum of 2'-0" thick

rock protection Class R-6 minimum [See 850.2 (a)] (Each End), 5'-0" - From end of apron or wingwall.

alfred benesch & company

Rip-Rap Size Selection Box Culvert

8661.01

SR194 Over the Spring Run

HEC-RAS STATION 372

File: Racetrackscour calc.xls.xls; RipRapBox

COMP BY: GJK DATE: 2/7/2007 SHEET 1 OF 1

CHKD. BY: DATE: ENGINEERS - SRVEYORS - PLANNERS JOB NO.

PROJECT STRUCTURE

RIP-RAP SIZE SELECTION

REFERENCES:PENNDOT PUBLICATION NO. 15, DESIGN MANUAL 4 "STRUCTURES",

PART A: CHAPTER 7 DRAINAGE STRUCTURES, SCOUR AND CULVERTSPENNDOT PUBLICATION 218 "STANDARDS FOR BRIDGE DESIGN" (BD-600 SERIES)PENNDOT PUBLICATION 408 "ROADWAY SPECIFICATIONS"

In determining the rock size for protection of the substructures it is recommended in PENNDOTDesign Manual 4, Chapter 7 (PP A.7-5) to use the Federal Highway Administration Formula listed below for determining the average required diameter of the stone (D50). The minimum rock size is R-6.

A correction factor is applied to the velocity depending on the placement location of the rock:1.5 times the Velocity is used at the pier locations and1.8 times the Velocity is used at the abutment and wingwall locations

For SR 194, Rip-rap will be placed past the wingwalls at a distance of 5'-0". The velocity shown below is at the outlet of the proposed culvert extension.

D50 = 0.692 V*2

(S-1) (2g)

Where:

D50 = Average Stone Diameter in ft

S = Specific Gravity = 2.65

g = acceleration of gravity = 32.2 ft / sec2

V = Velocity in Channel = 17.09 ft / sec V = 100 year storm

V*= Velocity*1.8 = 30.762 ft / sec

Therefore D50 = 6.1626 ft = 73.95 inches R8

FROM PENNDOT PUBLICATION BD-632M

USE R- 8

NOMINAL PLACEMENT THICKNESS = 4.0 FT

alfred benesch & company

Rip-Rap Size Selection Box Culvert

8455.09

SR194 Over Unnamed Tributary to Spring Run

CONCRETE APRON

Rock

According to PP (A.7.1) - No Scour Analysis for a box culvert is required. Refer to BD-632M for scour

protection details for box culverts

According to BD-632 Sheet 5 of 9 the detail for a culvert with endwall states : Minimum of 2'-0" thick

rock protection Class R-6 minimum [See 850.2 (a)] (Each End), 5'-0" - From end of apron or wingwall.

File: GreenSpringsscour calc.xls.xls; RipRapBox