trail bridges – a common sense approach to selecting bridge sites presenter: james scott groenier,...

Trail BridgesTrail Bridges – – A Common Sense Approach A Common Sense Approach

to Selecting Bridge Sitesto Selecting Bridge Sites

Presenter:Presenter:

James “Scott” Groenier, P.E.James “Scott” Groenier, P.E.

Project Leader, MTDC, WITProject Leader, MTDC, WIT

Prepared for: NOHVCC ConferencePrepared for: NOHVCC Conference

Ontario, CA Ontario, CA

March 17, 2005March 17, 2005

22

Technology & Development

IntroductionIntroduction Site ReconnaissanceSite Reconnaissance Geomorphology ConcernsGeomorphology Concerns Hydrology and HydraulicsHydrology and Hydraulics AlignmentAlignment Environmental Concerns Environmental Concerns Design LoadsDesign Loads Trail Bridge WebsiteTrail Bridge Website SummarySummary

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Site ReconnaissanceSite Reconnaissance

Site Investigation - simpleSite Investigation - simple

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Site ReconnaissanceSite Reconnaissance Site Investigation - ComplexSite Investigation - Complex

Streambed strata

Floodplain widths

Soil types

Logs in stream

Ice Damage

Drift locations

Etc

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Site ReconnaissanceSite Reconnaissance Site SurveySite Survey

Center of Stream

Edge of water

Bottom of Bank

Top of Bank

Floodplains

Trail

Utilities

Roads

Drift / Ice damage

Etc

Survey upstream and downstream for 300 ft

Survey approaches on both sides 150 ft

Survey top of banks for 30 ft

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Site ReconnaissanceSite Reconnaissance Geotechnical InvestigationGeotechnical Investigation

Bedrock Loam

77


Geomorphology ConcernsGeomorphology Concerns

From Rosgen’s

“Field Guide for

Stream Classification”

88



Stream StabilityStream Stability

Bedrock - Type A Channel

Stable Banks – Type B Channel

Deposition Area – Type C Channel

99



Bank StabilityBank Stability

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Hydrology and HydraulicsHydrology and Hydraulics Waterway AdequacyWaterway Adequacy

HydrologyHydrology +Regression Equations from USGS Reports on Estimating Frequency and Magnitude of Floods

=

Flow (CFS)

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Hydrology and HydraulicsHydrology and Hydraulics Waterway AdequacyWaterway Adequacy

HydraulicsHydraulics

1) Take CFS from Hydrology

2) Take Site Investigation info

3) Take Site Survey

And

Use a computer model such as

HEC-RAS (River Analysis System)

Or

WinXSPRO

And you get this…..

HEC-RAS Example

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Hydrology and HydraulicsHydrology and Hydraulics

Flooding –Spring, Fall or rain on snowFlooding –Spring, Fall or rain on snow

Good or Bad Location?

1313


Hydrology and HydraulicsHydrology and Hydraulics

ScourScour

1414


Hydrology and HydraulicsHydrology and Hydraulics Navigational Navigational

ClearanceClearance

5 ft Minimum Required

1515


AlignmentAlignment HorizontalHorizontal

Straight

90 degree Bend

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AlignmentAlignment VerticalVertical

Slight Grade

Bottom of Sag Curve

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Environmental ConcernsEnvironmental Concerns FisheriesFisheries

Spawning Areas, Fish passageSpawning Areas, Fish passage TES - ClosuresTES - Closures

SalmonSalmon Bull TroutBull Trout Cutthroat TroutCutthroat Trout etcetc

WildlifeWildlife Nesting Trees, Rearing areas, etcNesting Trees, Rearing areas, etc TES - ClosuresTES - Closures

Indiana BatIndiana Bat Bald EaglesBald Eagles Northern GoshawkNorthern Goshawk etcetc

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Environmental ConcernsEnvironmental Concerns Ice FlowIce Flow Floating DebrisFloating Debris Falling TreesFalling Trees Falling RocksFalling Rocks Excessive Snow LoadsExcessive Snow Loads Avalanche ChutesAvalanche Chutes Springs/SeepsSprings/Seeps WetlandsWetlands OthersOthers

1919


Design LoadsDesign Loads

Dead LoadsDead Loads SuperstructureSuperstructure DeckingDecking RailingRailing Wearing SurfaceWearing Surface Miscellaneous Miscellaneous

Utility LinesUtility Lines CoversCovers

2020


Design LoadsDesign Loads

Live LoadLive Load Pedestrian – Pedestrian – 85 psf85 psf

Equestrian Equestrian OHV’sOHV’s SnowmobilesSnowmobiles Mountain BikesMountain Bikes VehiclesVehicles

5,000 width <6 ft5,000 width <6 ft 10,000 6 ft<width<10 ft10,000 6 ft<width<10 ft

2121


Design LoadsDesign Loads Snow Loads – Snow Loads – 0 psf to over 350 psf0 psf to over 350 psf

SNOTEL sites – SNOTEL sites – 550 to 600 in the West550 to 600 in the West

Local Building OfficialsLocal Building Officials http://fsweb.mtdc.wo.fs.fed.us/snow_load/http://fsweb.mtdc.wo.fs.fed.us/snow_load/

Wind LoadsWind Loads OverloadsOverloads

GroomersGroomers 7600# - 18,000#7600# - 18,000#

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Bridge TypesBridge Types

Trail Bridge CatalogTrail Bridge Catalog Forest Service Intranet - Forest Service Intranet -

http://fsweb.mtdc.wo.fs.fed.us/bridges/http://fsweb.mtdc.wo.fs.fed.us/bridges/ Forest Service Internet - Forest Service Internet -

http://www.fs.fed.us/na/wit/WITPages/bridgecatalog/http://www.fs.fed.us/na/wit/WITPages/bridgecatalog/

2323


Bridge Bridge Fabrication/SupplyFabrication/Supply Structure produced by a certified Manufacturer Structure produced by a certified Manufacturer

for the type of material being used.for the type of material being used.- See “Contact Information For Wood and Steel Pedestrian and - See “Contact Information For Wood and Steel Pedestrian and Trail Bridges” at National Wood In Transportation WebsiteTrail Bridges” at National Wood In Transportation Website

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SummarySummary Site ReconnaissanceSite Reconnaissance Geomorphology ConcernsGeomorphology Concerns Hydrology and HydraulicsHydrology and Hydraulics AlignmentAlignment Environmental Concerns Environmental Concerns Design LoadsDesign Loads Trail Bridge WebsiteTrail Bridge Website Questions?Questions?

trail bridges – a common sense approach to selecting bridge sites presenter: james scott groenier,...

Documents

technology development

ft slide

hydraulics hydrology

stream classification

flow cfs slide

hydraulics scour scour

site investigation info

degree bend slide