Preliminary Design Report

Common Bridge #1234
over
Raging River

Anytown, Maine

02050800
WIN 10000.00

Maine Department of Transportation
Bridge Program

Table Of Contents

Background Information	3

Existing Bridge Synopsis	4

Bridge Recommendation Form	5

Environmental Summary	7

Summary of Preliminary Design	8

Hydrology Report	9

Hydraulic Report	10

Preliminary Plans	Appendix

Photographs	Appendix

Hydraulics Data	Appendix

Miscellaneous Information	Appendix

Traffic and Accident Data	Appendix

Preliminary Cost Estimates	Appendix

Background Information

TOWN	Anytown	WIN	10000.00	BRIDGE NO.	1234

Bridge	Common Bridge	ROAD	Route 9

Funding:	Choose an item

PROGRAM SCOPE:	Choose an item

PROGRAM DESCRIPTION:	Common Bridge (#1234) over Raging River, located 0.16 of a mile easterly of Route 9. This bridge is over 20’ in length.

PROJECT BACKGROUND:	This bridge was constructed in 1930 and was widened in 1960 along with a deck replacement. It is currently in poor condition and in need of complete replacement. Preconstruction engineering was funded in the 12/13 BCWP.

JURISDICTION	State Highway	NHS	Yes

FUNCTIONAL CLASSIFICATION	Choose an item	CORRIDOR PRIORITY	3

URBAN/RURAL	Rural	FHWA SUFFICIENCY RATING	35.9

LOAD POSTING	15 tons	POSTED SPEED	45 mph

TRAFFIC:	2013	AADT	1,000	ACCIDENT DATA, CRF	1.0

2033	AADT	1,200	DHV	200

Existing Bridge Synopsis

Year Built	1936	Span Lengths	60'-60'	Curb to Curb Width	24'

Type of structure: Two-span continuous structure with painted steel beams, composite cast-in-place deck, bituminous wearing surface and membrane waterproofing, and concrete bridge rail.

General Condition: Steel beams are in fair condition with minor section loss along with rusting and extensive failing paint. Concrete deck is in fair condition with some spalling and leakage on the bottom. Wearing surface is in poor condition with extensive cracking and patching. Bridge rail is in very poor condition with much cracking and patching.

Load Ratings:	Operating	Inventory

HL-93	40 Tons	30 Tons

Rating Factor	1.00	1.00

Legal Loads

Controlling Configuration: 1	40 Tons

Rating Factor	1.00

Controlling Member:	Interior floor beam in flexure

See Appendix F for load rating summary

STRUCTURALLY DEFICIENT	Choose an item.	FUNCTIONALLY OBSOLETE	N/A

Maintenance Problems: Cracking of bituminous wearing surface. Cracking, spalling, and vehicular damage of concrete bridge rail.

Maintenance Work: Repeated patching of wearing surface and repair of bridge rail.

Previous Structure: A timber covered bridge on granite abutments.

Other Comments: This is a non-historic bridge located in a historic district.

Bridge Recommendation Form

WIN	10000.00	TOWN	Anytown

BRIDGE NO.	1234	BRIDGE	Common Bridge

Project Manager	Name

DESIGNED BY	ABC	DATE	Click here to enter a date.

Approved by	Date

Approved by	DATE

Project: Bridge Replacement with 800’ of approaches, including transitions.

Alignment Description: Tangent on bridge with two 1000’ horizontal curves located on each end of the project to match into existing curves. A 600’ sag vertical curve with a finished grade about 1.5’ higher than the existing bridge. New centerline located approximately 4.5’ downstream of existing bridge centerline.

Approach Section: Two 11’ lanes with 4’ shoulders. 1:2 sideslopes with standard steel guardrail and 1:3 sideslopes without guardrail.

Spans	70’-70’	Skew	30° ahead on left

Loading	HL-93 modified for Strength 1	Design Speed	45mph

structure: Precast, prestressed concrete butted box beams with a non-composite leveling slab and a 3” bituminous wearing surface on ¼” membrane waterproofing. 30’ curb-to-curb with standard 2-bar steel bridge rail and a 2% normal crown. Beams made continuous for live load.

Total Opening	Existing	72 SF	Proposed	96 SF

Available Soils Information: Existing plans and preliminary borings show ledge to be present at about 30’-50’ below streambed. For more information, please refer to the Geotechnical Report.

Additional Design Features: Begin transition @ STA 100+00, begin project @ STA 100+50, end project @ STA 800+50, end transition @ STA 900+00. A 3’ tall garden retaining wall will be constructed between STA 200+00 and 200+25 on the north side.

Complete Streets: Click or tap here to enter text.

Maintenance of Traffic: Maintain two-way traffic on a one-lane temporary bridge located on the upstream side.

Construction Schedule: One construction season with landscaping the following spring.

Advertising Date: January 2014

Preliminary Engineering	Right of Way	Construction	Construction Engineering	Total
Estimated Project Cost	$0	$0	$0	$0	$0
Available Funds	$0	$0	$0	$0	$0
Shortfall/Surplus	$0	$0	$0	$0	$0

Additional Borings Required? No

Additional Geotechnical Evaluations Required: No

Approved Design Exceptions: Bridge width is less than State Standards in order to match existing corridor width.

Municipal/State Agreement Required? Specify type of agreement if required

Comments by Engineer of Design:

Environmental Summary

[paste table here]

Summary of Preliminary Design

Background

[Background Description]

Purpose and Need

[Purpose and Need Description]

Maintenance of Traffic

[Maintenance of Traffic Alternative Analysis]

Conclusion: Option 1 – Bridge Closure.

Utilities

[Maintenance of Utilities]

Right of Way

[Right of Way Description]

Summary of Alternatives

The following alternatives were considered:

Do nothing

Single span steel welded plate girder

Two span concrete box beams

Alternative 1:

[Alternatives Analysis]

Conclusion: Option 2 – Single span steel welded plate girder

Proposed Alternative

[Recommendation Description]

The preliminary cost estimate of this replacement is $1,800,000. For more information please see Appendix C.

Hydrology Report

Watershed Description

[any significant features like wetlands or topography]

Previous Hydrologic Studies

[data from FEMA or previous PDRs]

Current Data

[a basic description will usually follow one of these templates:]

Flow data was calculated by the Maine DOT Environmental Office Hydrology Section using the USGS regression equations for Maine (Hodgkins 1999).

Flow data was calculated by the Maine DOT Environmental Office Hydrology Section using a combination of the data from the [identify] USGS flow gage and the USGS regression equations for Maine (Hodgkins 1999). The gage data estimate was adjusted for the difference in watersheds between the bridge and gage site and combined with the regression equation estimate using the weighting method recommended by Hodgkins.

Summary

Drainage Area	326	mi2
Q1.1	4,100	ft3/s
Q10	7,400	ft3/s
Q50	12,000	ft3/s
Q100	14,300	ft3/s
Q500	21,100	ft3/s

Reported by: Some Engineer

Date: Click here to enter a date.

Note: All elevations based on North American Vertical Datum (NAVD) of 1988.

Hydraulic Report

Existing Structure

Information Sources Reviewed:

☒ Flood Insurance Study	☐ FEMA Maps	☐ FEMA Other: Click or tap here to enter text.

☐ USGS Gage Data	☐ Storm Report	☐ Previous PDR Dated: Date

☐ On-Site Inspection	☐ Other: Click or tap here to enter text.

Structure Type:	Choose an item.

Existing Conditions

Roadway Overtops:	☐ Never	☐ Rarely	☐ Regularly	☐ Annually	☐ Unknown

Ice Issues:	☐ Never	☐ Rarely	☐ Regularly	☐ Annually	☐ Unknown

Debris Issues:	☐ Never	☐ Rarely	☐ Regularly	☐ Annually	☐ Unknown

Erosion/Scour Issues:	☐ Never	☐ Rarely	☐ Regularly	☐ Annually	☐ Unknown

Other:	Click or tap here to enter text.

Comments:	Click or tap here to enter text.

Model Type/Software:

Boundary Condition:

☐ Normal Depth	☐ Critical Depth	☐ Rating Curve	☐ Known Water Surface Elevation

☐ Other:	Click or tap here to enter text.

Model Calibration:

Click or tap here to enter text.

Model Sensitivity:

Click or tap here to enter text.

HW/D: Fill in or N/A	Q50 Freeboard: Fill in or N/A	Q100 Freeboard: Fill in or N/A

Proposed Structure

Structure Type: Click or tap here to enter text.

HW/D: Fill in or N/A	Q50 Freeboard: Fill in or N/A	Q100 Freeboard: Fill in or N/A

Foundation Type: Click or tap here to enter text.

Scour Analysis

Click or tap here to enter text.

Summary

Existing Structure	Recommended Structure	230', 2-Span Continuous Steel
210' Span through Truss	150' Single Span Steel
Total Area of Waterway Opening	ft2	2380	1925	2650
Headwater elevation @ Q1.1	ft	92.92	93.91	94.64
Headwater elevation @ Q10	ft	97.56	97.45	98.13
Headwater elevation @ Q25	ft	98.12	97.92	98.59
Headwater elevation @ Q50	ft	98.82	98.53	99.15
Headwater elevation @ Q100	ft	99.17	98.88	99.46
Headwater elevation @ Q500	ft	99.5	99.2	99.77
Flood of Record [year]	ft
Freeboard @ Q50	ft	8.65	9.47	8.85
Freeboard @ Q100	ft	8.29	9.12	8.54
Outlet Velocity @ Q1.1	ft/s	2.15	2.16	1.89
Outlet Velocity @ Q10	ft/s	2.97	2.97	2.65
Outlet Velocity @ Q25	ft/s	3.08	3.09	2.75
Outlet Velocity @ Q50	ft/s	3.19	3.21	2.84
Outlet Velocity @ Q100	ft/s	3.21	3.23	2.86
Outlet Velocity @ Q500	ft/s	3.21	3.24	2.87

Reported by: Some Engineer

Date: Click here to enter a date.

Note: All elevations based on North American Vertical Datum (NAVD) of 1988.