Design of a Pedestrian Bridge Presentation to the Village of Tivoli, NY

May 14, 2015

Overview of Team

Presentation Overview● Site Overview &

Proposed Bridge Layout

● Code & Clearance Requirements

● Structural Design○ Piers○ Roof○ Stairs○ Handicap Ramp and

Lift System

● Structural Analysis○ Design Loads○ Truss Member Sizing○ Stress and Deflections

● Geotechnical Summary○ Sheet Piles○ Footing Design

● Cost & Maintenance

● Future Plans

Site overview

● Limited on east side by adjoining property

● Limited on west side by riverbank

● Narrow package of land in which to satisfy clearance requirements

Existing Property Lines

View Looking South from Diana StExisting Zoning Map

Comparison of Bridge Layout with Stairs and Ramp

Footprint of Bridge with Stairs Footprint of Bridge with Ramps

Working Design for Pedestrian Bridge

Vertical Clearance

Horizontal Clearance

Bridge Materials

Timber Steel

Structural System

Arch

Pratt Truss

Burr Truss

Bridge Piers

Material: Steel

Member Section

Vertical Column HSS6x6x1/2

Horizontal Bracing L3x3x1/2

Diagonal Bracing (interior, lower) L6x6x1/2

Diagonal Bracing (all others) L5x5x1/2

Bridge Pier Alternatives

Concrete Timber

Primary Roof Design

Bridge Roof Alternative Designs

Option #1

Option #2

Option #3

Stair Design

Stair Design (cont.)

10’-6”

10’-6”

52’

42’

80’ 25’

Stairway Columns

Ramp Design

Inclined Handicap Lift

GSL Artira Inclined Platform Lift

GSL Atira Specifications and Design Features (cont.)

GSL Artira Specifications and Design Features

Technical Specifications Cont’d

Kayak Lift Theory

B

BA

C DC

D

A

Design Loads

Load Name Load Type Calculated Design Load

Reference

Dead Load (DL) Gravity 60 psf -

Live Load (LL) Gravity 90 psf AASHTO Pedestrian Bridge Design Guide

Snow Load (SL) Gravity 30 psf ASCE 7

Wind Load (WL) Lateral 85 psf ASCE 7

Earthquake Load (E) Lateral 2.8 kips ASCE 7 & USGS

Truss Structural System

Gravity Load Trusses Lateral Load Trusses Complete BridgeStructural SystemDL + LL + SL WL + E

Member SizingTop Chord HSS 10x10x1/2

Bottom Chord HSS 10x10x1/2

Diagonals (2)-7x7 Parallams

Verticals 7x7 Parallam

Top Chord HSS 10x10x1/2

Bottom Chord HSS 10x10x1/2

Diagonals L 5x5x3/8

Verticals 3.5x11.875 Parallam

Bottom Chord Diagonal

Vertical Top Chord

STEEL

TIMBER

SAP2000 Stress Ratios

Gravity Load Analysis Lateral Load Analysis

WL

DL + LL + SL

Truss Member Max. Axial Force

Top Chord (G) 34 kips (C)

Bottom Chord (G) 34 kips (T)

Vertical (G) 25 kips (C)

Diagonal (G) 33 kips (C)

Top/Bot Chord (L) 50 kips (C or T)

Vertical (L) 11 kips (C or T)

Diagonal (L) 17 kips (C or T)

Stress and Deflections

(G) - Gravity

(L) - Lateral

(C) - Compression

(T) - Tension

GRAVITY LOAD CASE (G) LATERAL LOAD CASE (L)

0.44” Max Deflection0.92” Max Deflection

Details● Driftwood railings● Copper-plated caging● Gutters● Stair treads● Roofing materials

Sheetpile

River Slope

Spread Footing

Location of Footings

Cost Estimate

Geotechnical Estimate

Truss Estimate (Quoted from ExcelBridge)

Bridge Pier Estimate

Inclined Lift Estimate: TBD

Maintenance$$$ Repainting Steel

$$$ Retreating Timber

$$ Snow/Ice Removal

$$ Deck Repair/Replacement

$$ Cleaning/Lubricating Bearings

$ Clearing Drains

Possible Observation Platform

Plans for future work

● Soil studies● Solar energy● Bring to an engineering firm

Questions?