the sellwood bridge · pdf fileas part of multnomah county’s outreach efforts for the...

The New Sellwood Bridge Open to the Public in 2015!

Activity Book &

Curriculum Guide

The Sellwood Bridge Project

The Sellwood Bridge Project Goes to School!

K-8 Lessons & Activity Sheets

Final

Table of Contents

Introduction···································································································1

Bridge Glossary······························································································2

Project Description·························································································3

Did You Know?

Bridge Facts & History············································································4

Detour & Stages of Construction ·························································5-6

Curriculum Guide—In-class Activities

Bats ································································································9-12

Bridges & Applied Loads··································································13-14

Gumdrop Bridges············································································19-22

What is a Watershed & Why does Pollution Matter?····························22-23

Arches, Buttresses , Abutments & Piers···············································25-28

Exploring Civic Engagement &

The Role of Government in Public Works Projects··················· ············29-33

Careers in Planning, Design & Construction········································34-37

Student Activity Sheets & Glossary······························································38-42

i

Sellwood Bridge—Activity Book & Curriculum Guide


1

Introduction

As part of Multnomah County’s outreach efforts for the Sellwood Bridge

Project, Lois D. Cohen Associates (LDC) developed and implemented a

School-based Outreach Program to engage students in this exciting local

project through:

Providing A Functional Curriculum: Members of the Sellwood Bridge

Project Team led in-class activities to explore the connection

between what students are already learning, such as math, science

and civics, and real world problem solving.

Presenting a Variety of Career Paths: Increasing students’ understanding

of career possibilities by introducing them to technical experts ranging

from engineers and environmental consultants to contractors and

communications professionals.

Exploring All Aspects of Bridge Building: Hands-on activities and in-class

projects allow students to look beyond the bridge to consider

environmental impacts, materials sources and selection, and find

design solutions that meet required standards and aesthetics while also

meeting all users’ needs.

This Activity Book and Curriculum Guide is meant to serve as a resource for

teachers. You will find supplemental classroom materials (both in-class

curricula and student activity sheets) that are engaging for students, easy to

implement for you, and applicable and relevant to the benefits of the new

Sellwood Bridge.


2

Glossary—Bridge Terms:

Approach spans: Short spans over land leading to the main spans.

Beam: Thin, horizontal members of the bridge that support the deck.

Bent: Vertical support elements of the bridge; may be a column, pier, or abutment.

Chords: In a truss, the upper and lower horizontal (or arched) members of the frame.

Cross-bracing: Diagonal bracing that resists wind, earthquakes or other forces on

beams and trusses.

Dead load: Self-weight of bridge that must be considered during design.

Deck: Slab of concrete or steel that rests on the floor support system that is supported

by beams. Traffic moves on the deck.

Floor beams: Deck support beams perpendicular to the centerline of the roadway.

Footing: Support element at the bottom of a column or bent.

Foundation: The underground base that supports the bridge columns, e.g. footings,

drilled shafts, and piles.

Frame: A structural skeleton designed to resist collapse.

Girder: A type of beam. Refer to ‘beam’ definition.

Grade: Rate of change in elevation of road surface.

Horizontal curve: Left or right curve in the roadway.

Live load: Weight of traffic on the bridge, e.g. trucks, buses, cars, pedestrians.

Median: An area in roadway or barrier between opposing travel lanes; minimizes

head-on collisions.

Members: Structural pieces that compose a bridge such as beams, columns, and

girders.

Model: Mathematical representation of a real world problem for analysis purposes or a

physical representation of a structure.

Multi-use path: For use by bicyclists and pedestrians; may be two-way for traffic.

Pier: Similar to bent or column when it is located in water.

Seismic: Forces pertaining to earthquakes and earth vibrations.

Spans: Numbered segments of the bridge between vertical supports (bents, piers and

columns).

Superstructure: Part of bridge that rests on supports, e.g. beams, truss, deck, sidewalks.

Truss: Jointed open structure; the frame is divided into a series of triangular figures for

rigidity and strength.

Project Description

The Sellwood Bridge Project involves

replacing the 87-year-old (built in 1925)

Willamette River crossing with a new,

seismically-sound structure that offers

upgraded facilities for all users, including

wider vehicular travel lanes, bicycle lanes,

wider sidewalks, lighting, and pedestrian

seating areas. Additionally, the bridge is

being built to accommodate potential

streetcar construction in the future.

The project team is using an innovative detour solution while the new bridge is being

constructed. The existing bridge has been moved to the north, approximately 50

feet, and utilized as the detour bridge while the new bridge is being constructed.

The team placed temporary piers (supports) adjacent to the current bridge

location and slid the existing bridge (truss and deck) onto the temporary

supports.

Users:

Due to the lack of other river crossings in the southern metro region, and its close

proximity to the Multnomah/Clackamas County line, the Sellwood Bridge serves a

diverse group of users. The bridge is a primary east-west connection for residents

and businesses in west Portland/Washington County and those in Sellwood,

Milwaukie, and Clackamas County.

Many bridge users are commuters who live in Clackamas County. In fact,

83 percent of Sellwood Bridge trips begin or end outside the Portland city limits. Prior

to the reduction of weight limits in 2004, the bridge was an important secondary

freight route, especially for local deliveries. Weight limits prevent many delivery

trucks and TriMet buses from using the bridge, forcing out-of-direction travel that

adds to congestion on other routes and increases costs to businesses and

consumers.

3


4

Did You Know?

Facts:

The Sellwood Bridge was built in 1925.

The steel continuous truss is one of the only known 4-span continuous truss bridges in

the country.

How much traffic can it carry?

Today it serves about 31,000 vehicles per day. It is the first Willamette bridge in

Portland that was constructed without any trolley tracks. Notably, the new bridge is

being built to accommodate future streetcar tracks!

How long did it take to build the bridge?

It took one year to build the old bridge (January-December 1925). It will take four

years to build the new bridge.

What materials were used?

Steel and concrete.

Key differences between the old and new bridges:

Old Bridge New Bridge

Truss

Narrow vehicular lanes

One narrow sidewalk

Structure damaged by landslide on

the west bank

No streetcar tracks

Buildings underneath

Arch

Wider travel lanes

Wide sidewalks in both directions (on

both sides)

New structure includes landslide

mitigation to prevent damage

Built to accommodate future streetcar

track installation

No buildings underneath


Detour Bridge

How will we travel across the river while the new bridge is being built?

Instead of building the new bridge in two phases, Multnomah County used the “Shoofly”

method to move the old bridge (approximately 50 feet north of its existing location). Until

the new bridge is built, the old bridge will serve as a detour bridge.

First, temporary piers were built to the north of the existing bridge piers and then the entire

steel deck truss was slid onto the temporary piers using hydraulic jacks. Temporary ap-

proach spans were installed prior to the truss move at the east and west ends of the bridge

to link the bridge to SE Tacoma Street and Hwy 43.

5


ACE Academy students built a to-scale model of the old and

new Sellwood Bridges, part of their senior project.

Using the old bridge as a detour bridge offers several advantages over building the new

bridge in stages:

The temporary detour structure will be as strong as, if not stronger, than the

old bridge.

The new bridge will be built entirely in one phase.

Cost savings are estimated at $5 to $10 million.

Saves up to a year in construction time.

Safety benefit by separating construction workers from vehicles crossing the bridge.

Requires fewer temporary work bridges with less impacts to the river’s ecosystem (plant

and animal).

Stages of Construction

Float in

Main Span

1

2

3

4

5

6

7

8

9

10


6


Curriculum Guide


9

Bat Boxes

Grade Level:

4-8

Subject Areas:

Environmental Science, Earth Science, Life

Science, Fine Arts

Durations:

Prep Time: 3 hrs

Activity Time: 1:30 -2 hrs

(warm up: 20 minutes, activity: 40-60

minutes, wrap up: 20 minutes)

Setting:

Classroom

Skills:

Analyze, Apply, Create, Demonstrate,

Describe

Summary:

Students will explore what types of animals,

such as bats, make the Sellwood Bridge their

home. This activity will engage students in

thinking about different opportunities the

bridge site offers, such as how the shade

from the bridge could provide ideal living

conditions for various plant species; shelter

provided by the bridge deck could be a

good place for various birds and bat species

to nest or roost.

Objective:

Students will gain an understanding of the

local bats in the area. Students then build

and decorate their bat boxes. Additional

research can be done by students to

understand best areas to hang or mount

their bat boxes, and colors that attract the

most bats in the region.

Some of the bat boxes created in year one

of the Sellwood Bridge School-Based

Outreach Program will be mounted

underneath the new bridge to provide new

roosts for Oregon’s bat population.

Note:

There are several bat box assembly kits

available for purchase online. You can also

assemble a bat box from scratch. On the

following page is a list of instructions, from Bat

Conservation International, about building

your own bat box.


There are 15 species of bats in Oregon.

Bats are good for the economy! In our region, they eat

insects that harm farmer’s crops, and bat droppings

(called guano) make great and cheap fertilizer.

Wings make bats look larger than they really are. The big-

gest bat in Oregon is the Hoary bat, which weighs about

an ounce, or about the same as five quarters.

Many species of bats have a sonar system called echolo-

cation; they emit high-pitched (ultrasonic) sounds

through their mouth or nose (depending on species) and

listen for the returning echo.

Bats use echolocation to navigate, avoid obstacles and

chase down juicy moths and crunchy beetles.

Bat wings are supported by long finger bones covered

with two thin layers of skin, like the webbing between

your thumb and first finger. Bats can use the wing and tail

membranes to scoop insects.

Bats have small, moveable thumbs on the top of their

wings for grasping and climbing. Their back feet are used

for hanging.

While bats can fly 20 to 30 miles per hour, their average

hunting speed is about 10 miles per hour. Bats can ma-

neuver better than most birds.

Bats sleep during the day, and rest during the night, in

roosts.

Most of Oregon’s bats hibernate during the winter.

Hoary, Silver-haired and Mexican free-tailed bats migrate

south for the winter.

Bats have few natural enemies (owls are one). Many may

live as long as 30 years.

These facts and more can be found at:

http://www.dfw.state.or.us/wildlife/living_with/bats.asp

Bat Facts

Bats in Oregon:

Big Brown

California Myotis

Western Small-footed Myotis

Long-eared Myotis

Little Brown Myotis

Long-legged Myotis

Yuma Myotis

Fringed Myotis

Western Small-footed Myotis

Hoary

Pallid

Silver-haired

Townsend’s big-eared

Western Pipistrelle

Spotted Bat

Bats are the only flying

mammals.

Like all mammals, bats are

warm blooded and feed their

young with milk.

Bats are covered with fur.

Bats eat insects.

A bat can catch up to 600

insects in an hour.

Hoary Bat

11

12


Bats have lost many of their natural roosting sites in old trees, snags and caves as a result of

human activity. Some species can roost in man-made structures. Conservation includes

protecting natural sites and encouraging bats to roost in bridges, culverts and mines where

their activity does not interfere with human use of these structures.

Getting Along With Bats

In winter, avoid places where bats

hibernate, because awakening a bat

depletes energy reserves. A bat can

lose 10 to 30 days worth of fat re-

serves from being awakened and

then is at risk of starvation before

spring arrives. Support protecting

caves from human use when bats

are present.

In summer, avoid disturbing nursery

caves or roosts. Frightened mother

bats may drop or abandon their ba-

bies.

Bats need open water. Support ef-

forts to preserve, create and en-

hance marshes and wetlands.

Never touch or pick up a bat. It may

bite in self-defense like any other wild

animal. A bat you or your pet can

catch outside is probably sick and

should be left alone. Do not handle

dead bats.

Do not use pesticides near bat roosts

or open water.

If you own or manage forested

property, preserve snags and cavity

nesting trees for birds, bats and

mammals that call these trees home.

Bat Box—built and decorated by students at

Llewellyn Elementary


13

Bridges & Applied Loads

Grade Level:

4-6

Subject Areas:

Science, Math

Durations:

Prep Time: 30 minutes

Activity Time: 1 hr

(Warm up: 15 minutes, activity: 30 minutes,

wrap up: 15 minutes)

Setting:

Classroom

Skills:

Analyze, Apply, Demonstrate

Vocabulary:

Dead Load, Live Load, Seismic Load, Stress,

Wind Load, Environmental Stress/Load,

Compression, Tension, Torsion and Shear

Summary:

Students will use a model to discover the

effect of a load on a beam bridge at varying

distances.

This involves determining the proportionality of

force relative to a given distance from a

prescribed point. A bridge must be able to

withstand a certain amount of load given its

intended use.

Objective:

Students will learn that bridges must be able to

resist and overcome associated loads and

stresses such as dead load, live (static and dy-

namic) load, and environmental stress/load.

Students will also learn how structures can fail

and explore methods used for strengthening

and reinforcement.

Students will understand the need for an

experimental design that includes fair testing

and how to work as a team.

A practical demonstration could incorporate

the use of two scales or spring balances. A

“beam” will bridge the two balances topped

by a sliding weight.

As the weight slides along the beam, the bal-

ances are checked to record the change in

force relative to the distances moved.

1. The students will construct a bridge using

available materials, such as cardboard or

foam.

2. They will be expected to construct models

of the intended load.

3. They will be expected to compare

different designs and identify their

advantages and disadvantages.

Forces that act on a bridge:

Demonstrated with popsicle sticks

Compression is a pushing (compressing) force. The

shorter a piece of wood the more compression it can

hold. The longer a piece of wood the less compression

it can hold. When you compress a long stick of wood

you will notice that it starts to bend. When a piece of

wood breaks because of compression, we say it failed

from buckling. Typically the top of a bridge, including

model bridges, will be in compression. Different truss

designs spread out the force so that various internal

parts will be in compression as well.

Tension is a pulling force. Wood has the ability to re-

sist a lot of tension. It would be hard to break a pop-

sicle stick if you held both ends and pulled apart. Ten-

sion may be applied parallel to the grain of the wood,

but should be avoided perpendicular to the grain.

Wood is very strong in tension parallel to the grain, but

much weaker in tension perpendicular to the grain.

Also, unlike in compression, the ability of wood to resist

tension does not change with its length. A shorter

piece of wood should hold the same amount of ten-

sion as a longer piece.

Torsion is a twisting force. When you wring out a

cloth, you are applying torsion to the cloth. If you take

a stick pretzel, twist one end and hold the other end

still, it will break very easily. If you do that with a base-

ball bat, it will not break. However, if you take a piece

of licorice and apply torsion to it, the licorice will twist

around several times before it breaks. Each of these

materials has a different way of responding to torsion.

Bridge designers must watch for torsion and try to re-

duce it as much as possible.

Sheer is an interesting force. It happens when there

are two opposing forces acting on the same point. If

you hold a piece of wood with both hands next to

each other, and push up with one hand and down

with the other, you are applying shear to that piece of

wood. Shear usually occurs horizontally, and not verti-

cally.


14


15

Types of Forces on a Structure

Note: College students planning on becoming engineers study the following loads and how

they impact structures. Professionally, structural engineers design structures to withstand

these loads.

Dead load: The force exerted by a bridge as a result of its own weight.

Live load: The force exerted on a bridge as a result of the traffic moving across the bridge.

Dynamic load: Loads that change over time; wind gusts to pounding objects create

vibrations that can become bigger and more dangerous over time.

Earthquake load: Earthquake; shaking and rattling.

Fatigue: Cause of structural deficiencies, always due to repetitive loading over time.

Force: Any action that tends to maintain or alter the position of a structure.

Environmental loads: Temporary loads that act on a bridge and are due to weather or

other environmental influences, such as wind from hurricanes, tornadoes or high gusts; snow

and ice; and earthquakes. Rainwater collecting might also be a factor if proper

drainage is not provided.

Seismic loading is one of the basic concepts of earthquake engineering which means

application of an earthquake-generated agitation to a structure. It happens at contact

surfaces of a structure either with the ground, or with adjacent structures, or with gravity

waves from a tsunami.

Wind load: When wind blows on a structure; wind pushes horizontally on a structure.

Thermal load: When a structure expands or shrinks with the temperature; causes beams and

columns to change shape and push and pull on other parts of the structure.

Settlement load: When soil beneath a structure settles unevenly; the structure will sink and

change load.

Example of settlement

load

Can you make a paper bridge that can

support 100 pennies?

Materials Needed:

piece of 8 1/2" x 11" paper

6 books

100 pennies

ruler

Instructions :

1. Do you think that by using just one piece

of paper you can make a bridge that

holds a lot of pennies?

2. Make two stacks of books of equal height.

Put them 6 inches apart.

3. Make a bridge by putting a sheet of

paper across the books.

4. Put some pennies on the bridge. How

many pennies can the bridge support

before it collapses? What happens if the

pennies are in the center of the bridge or

spread across the bridge?

5. How can you make the bridge stronger?

Try bending, folding, or tearing the paper.

6. Test your bridge again by adding pennies

one at a time. How many pennies can

your bridge support?

Can you change the design of your bridge to

support more pennies?

How can you make a weak material like

paper strong enough to support a load of

pennies? One way is to change its shape, like

rolling it in a tube, crumpling it, or folding it

like an accordion.

16

Can you make a bridge out of straws that

can support 100 pennies?

Materials Needed:

straws

straight pins

scissors

thimbles

100 pennies

small cup

Instructions:

1. Your mission is to build a bridge, using

straws and pins, that can support 100

pennies in a cup.

2. When you finish building your bridge,

place the cup with the pennies on top.

Can your bridge hold the pennies?

Once you find a structure that will support

the pennies, you can test which parts are

needed and which parts aren't needed. To

test this, use the scissors to carefully snip

away at the bridge.

$1 Bridges


Can you make a paper bridge that can support the weight of

pennies and starbursts?

Materials Needed:

piece of 8 1/2" x 11" paper

6 books

Pennies

Starbursts

ruler

Instructions :

1. Do you think that by using just one piece of paper you can make a bridge that

holds a lot of pennies?

2. Make two stacks of books of equal height. Put them 6 inches apart.

3. Make a bridge by putting a sheet of paper across the books.

4. Put some pennies on the bridge. How many pennies can the bridge

support? What happens if the pennies are in the center of the bridge or spread

across the bridge?

5. How can you make the bridge stronger? Try folding, rolling, and bending it.

6. Test your bridge again by adding pennies one at a time. How many

pennies can your bridge support?

Paper Bridge Beam Challenge


17

(Cars)

(Trucks)

Total Pennies ÷ 2

+ Total Starbursts =

Total Trucks

How many trucks can your bridge hold?

1 Starburst = 1 truck

1 Penny = 1 car = 1/2 truck

1. Count the pennies you have on your bridge.

2. Count the Starbursts you have on your bridge.

3. In the chart below, write down how many of each you have.

4. Divide your total number of pennies by 2.

5. Add your total number of Starbursts to that total.

6. Record the total number of trucks you have.


18


19

Gumdrop Bridges

Grade Level:

4-8

Subject Areas:

Math, Science, Fine Arts...

Durations:

Prep Time: 1 hrs

Activity Time: 1:20 hrs

(warm up: 15 minutes, activity: 45

minutes, wrap up: 20 minutes)

Setting:

Classroom

Skills:


Describe, Critical Thinking, Geometry

Vocabulary:

Reinforce, strengthen, diagonal, stable,

unstable, framework, lattice, truss, section,

square section, ties, strut, beam, horizontal,

vertical, model, load and weight, chord

Summary:

Students will construct truss bridges out of

gumdrops, saltine crackers and toothpicks

using real bridge “plans.” Optional to print

and decorate mock roadway for it to stand

on. (Design cut-out on following pages)

Objective:

Students are given a project design plan

sheet and tasked with building a bridge.

Students will learn the basics of bridge truss

structures.

Teacher’s Guide:

Print one project design plan (pg. 20-22) per

group of 3-4 students.

Material Materials per Bridge

Gumdrops 14

Crackers 3

Round Toothpicks 29


23

Grade Level:

4-6

Subject Areas:

Environment, Science, Earth Science, Life

Science

Durations:

Prep Time: 1 hr

Activity Time: 1 hr

(Warm up: 15 minutes, activity: 30 min-

utes, wrap up: 15 minutes)

Setting:

Classroom

Skills:


Describe

Vocabulary:

Watershed, infiltration, runoff, erosion,

bioswales, headwaters, hydrology,

non-point source pollution, point source

pollution, pollutant, public water system,

riparian area, sub-watershed, tributary.

Summary:

You will create your own topographic map

representing the Willamette River Basin and the

Portland Metropolitan area watershed to identify

the local watersheds we rely on for our water

sources. While participating in this activity, you will

learn how pollution from streams, rivers, human

and animal usage, and surrounding watersheds

affect the local watersheds.

Creating a Watershed Materials needed:

• 2 pieces of plain scrap paper (8.5 X 11)

Spray bottle

• Water

• Water-based markers (blue, brown, and black)

Activity:

1. Crumple up the piece of paper and then smooth it

back out most of the way. It should still be a bit crum-

pled, showing small ridges (high points) and valleys (low

points).

2. Imagine that this paper is a section of land, and find

the ridgelines (the tops of the fold-lines).

3. Use a washable blue marker to color along the

ridgelines on your “land.”

Some questions to consider:

1. What do you think will happen to your land when it

“rains?”

2. What will happen to the blue

ridge lines you colored?

3. Where will the “rainwater”

travel?

Next:

1. Use a spray bottle of water to

create a “rainstorm” over your

land. You want to create gentle

sprays of mist.

2. Observe what happens after

every misting.

3. As your “rainfall” accumulates,

observe the pathways where the

excess “rainfall” travels.


24

Willamette River Facts: The Willamette River Basin is one of

the largest watersheds in Oregon, covering more than 11,500

square miles. Thirteen major tributaries join the Willamette

River as it stretches nearly 300 miles from its headwaters at

Waldo Lake in the Cascade Mountains southeast of Eugene

to the confluence with the Columbia River at Kelley Point in

Portland.

The Willamette River flows through 9 counties and 19 cities

and provides ports for commercial barges and oceangoing ships, irrigation for crops sold

worldwide, and abundant fishery, and recreational opportunities.

Fun Fact: The Willamette River is one of the few major rivers in the United States that flows

primarily North!

What is a watershed?

A watershed is the area of land that catches rain and snow and drains (or seeps) into a

marsh, stream, river, lake or groundwater. Homes, farms, ranches, forests, small towns, big

cities and more can make up watersheds. Some even cross county, state, and international

borders. Watersheds come in all shapes and sizes. Some are millions of square miles, others

are just a few acres. Just as creeks drain into rivers, watersheds are nearly

always part of a larger watershed. Create a mental image: picture a tree.

When it rains on the tree, the water will trickle down from branch to branch

until it seeps into the ground below, only to be absorbed by the tree’s roots.

Did you know that you are sitting in a watershed right now?

That’s right! You are sitting in the Willamette River Basin.


Grade Level:

4-6

Subject Areas:

Science, Math

Durations:


Activity Time: 1 hr

(Warm up: 15 minutes, activity: 30 min-

utes, wrap up: 15 minutes)

Setting:

Classroom

Skills:

Analyze, Apply, Demonstrate

Vocabulary:

Arch Bridge, Beam Bridge, Compression,

Equilibrium, Force, Impending Motion,

Mass, Tension, Weight, Buttress,

Abutment, Pier

25

Arches, Buttresses, Abutments & Piers

Summary:

Students will construct a simple bridge and

use proportion models of intended loads to

identify areas of weaknesses and strength in

their structure, and the shapes that create a

stronger structure.

Objective:

Students will construct two bridges – a beam

and an arch – out of cardboard to compare

the stability of the shapes by standing them

up and applying pressure. Students will inves-

tigate which bridge can span the greater dis-

tance without additional supports.

1. How much weight can be applied before

a collapse?

2. How can they reinforce each bridge?

1. Have two students form an arch by placing their palms together and leaning toward

each other, sliding their feet as far back as they can. Caution them not to lose their bal-

ance. Ask: Where do you feel a push or a pull? (pushing on their hands)

2. Have a third student gently pull down on the top of the arch to test its strength. Ask: How

difficult is it to break the arch? (not difficult)

3. Have the group brainstorm ways for two more students to join the arch and make it

stronger, but without breaking up the space beneath the arch. Guide them to the idea of

adding buttresses by asking the arch-makers how stable their legs feel. Then repeat Step 2

and compare the results. (The buttresses exert an

inward force on the sides of the arch that balances

the outward force created by the load pressing

down on the top of the arch.)


26

What is an Arch?

An arch is a curved structure that spans a

space and supports a load.

What is a Buttress?

A buttress is an architectural structure built against or projecting from

a wall which serves to support or reinforce the wall, the way book-

ends keep books on a shelf from sliding sideways.

What is a Pier? The main support for a bridge,

upon which the bridge superstructure rests;

constructed of masonry, steel, timber, or con-

crete founded on firm ground below river.

What is an Abutment?

An abutment is generally the point where two

structures or objects meet. This word comes

from the verb abut, which means adjoin or

having common boundary.

An abutment is an engineering term that

describes a structure located at the ends of a

bridge, where the bridge deck adjoins the

approaching roadway. Basically, an abutment

is the point where two structures or objects

meet.

Buttress

protruding

from a wall

Foundation

Arch bridges

Arch bridges are one of the oldest types of bridges and have been around for thousands of

years. Arch bridges have great natural strength.

They were originally built of stone or brick but these days are built of reinforced concrete or

steel. The introduction of these new materials allows arch bridges to be longer with a lower

number of spans.

Instead of pushing straight down, the load of an arch bridge is carried outward along the

curve of the arch to the supports at each end. The weight is transferred to the supports at

either end.

These supports, called the abutments, carry the load and keep the ends of the bridge from

spreading.

The load at the top of the key stone makes each stone on the arch

of the bridge press on the one next to it. This happens until the push

is applied to the end supports or abutments, which are embedded

in the ground.

The ground around the abutments is squeezed and pushes back

on the abutments. Engineers study the strength of the surrounding

soil to know how much load can be carried by the bridge in

balance with the soil (earth).

For every action there is an equal and opposite reaction. The

ground which pushes back on the abutments creates a resistance

which is passed from stone to stone, until it is eventually pushing on

the key stone which is supporting the load.


27

Keystone


How do the abutments support an arch bridge? Activity

1. Get a 2- inch by 12- inch strip of cardboard. Bend the strip gently, forming an arch.

2. Place both ends on a table in the fashion of an inverted U.

3. Press down gently on the top of the arch and notice the effect on the ends. (The likely

outcome is the spreading outward of the ends of the arch.)

4. Place two stacks of books about six inches apart (the stacks must be lower than the

height of the arch).

5. Place the arched strip between the stacks of book in the inverted U fashion.

6. Apply a gentle force to the top of the arch and notice how the stacks of books act as

abutments, preventing the ends of the arch from spreading apart.

Whenever the arch bridge is supporting its dead load (its own weight) and the load of the

traffic crossing the bridge (the live load) every part of the arch is under compression. Given

this situation, arch bridges must be constructed from materials which can withstand

considerable compression force.

Steel and pre-stressed concrete makes it possible to construct longer and more elegant

arches. Generally, modern arches span a distance of 200-800 feet.

28

Load Compression in arch

distributes load to piers

Vertical arch

load supported

by pier

29


Exploring Civic Engagement &

The Role of Government in Public Works

Grade Level:

6-8

Subject Areas:

Social Studies

Durations:


Activity Time: 1 hr

(Warm up: 15 minutes, activity: 30 minutes,

wrap up: 15 minutes)

Setting:

Classroom

Skills:

Critical Thinking, Analyze, Apply, Debate

Vocabulary:

Civic Engagement, Public Works, Public

Involvement, Potentially Affected Interests

Summary:

Students will participate in a role-playing

activity that aims to increase their

understanding of the roles of government,

community, business, and various interest

groups in public works projects.

Objective:

Students will explore the roles of government,

community relations, spending tax dollars

(budget), and local and regional impacts of

public works projects.

How wide of a bridge do we build?

How do we accommodate all user groups’

needs and stay within budget?

What is the best way to fund infrastructure

projects? Who should pay? How much?

**Turn to page 45 for a more comprehensive activity outline.

**

30


Divide students into 8 groups representing each of the following stakeholders: truckers, local

businesses, parents with small children, recreational travelers, commuters, local

government, and bicyclists. Pose the same question to each group, and have them

consider the answers from the perspective of each of the interest groups.

Students will be given a budget and hypothetical costs to build a bridge addressing the

following question: “How wide of a bridge do we build?”

The bridge must be 1900 feet long. Students will be given a construction cost per linear foot.

Bridge elements to consider:

Travel lanes—narrow (9 feet wide); standard (10 feet wide); wide (11 feet wide)

Sidewalks—narrow (5 feet wide); standard (8 feet wide); multi-use/wide (10 feet wide)

Bike lanes—narrow (5 feet wide); standard (6 feet wide); wide (8 feet wide)

The student group representing the local government will be given the parameter in which

they have to work to accommodate different groups’ needs and interests to create a cross

section for the bridge that fits the budget.

Local

Business

Parents with

Small

Children

Recreational

Travelers

Truckers

Commuters

Neighbors

who live near

bridge

Bicyclists

Local Government

Bridge Stakeholder

Groups

Student Role Play Activity—All About Trade-Offs

Bridge Owner

Bridge Elements

Narrow travel lane—9’ wide

Standard travel lane—10’ wide

Wide travel lane—11’ wide

Narrow sidewalk—5’

Standard sidewalk—8’

Multi-use/wide sidewalk—10’

Narrow bike lane—5’

Standard bike lane—6’

Wide bike lane—8’

Hypothetical Cost

$10

$15

$20

$10

$15

$25

$5

$10

$15

Scenario 1

You have $100 to build your bridge and it must be no less than 50-feet in width. You must be

able to accommodate all 8 stakeholder groups by listening to their concerns.

Bicyclists are concerned about not having enough room to pass other bicyclists in the same

lane without needing to swerve out of the bike lane.

Commuters are concerned about traffic and traffic accidents. When there is an accident,

there needs to be a wide enough shoulder so those involved in the accident can pull over

and out of the traffic lane.

Considering both the bicyclists and the commuters, how will you make sure both groups of

stakeholders are satisfied with the width of the driving lanes and the width of the bike lanes?


Hypothetical Cost and Scenario

31

Middle School Lesson #4

Public Involvement/Community Engagement

What is community engagement/public involvement?

Why is it important to involve the community in bridge building projects?

When should you incorporate public involvement into project activities?

Who do you involve?

How do you do this?

How much decision-making influence is it appropriate to give to community members? Why?

How much influence is too much to give to community members? Why?

What could happen if you don’t engage the community?

What happens if you engage the community?

What do you do when things go wrong with Public Outreach? Can you think of examples?

What does success look like?

What skills does a successful Public Involvement practitioner need to have?

32


33


5 Responsibility Objectives:

Establish the legitimacy of your organization and your project

Maintain the legitimacy of your organization and your project

Establish the legitimacy of your process, your problem-solving and decision making

processes

Maintain the legitimacy of your process

Establish and maintain the legitimacy of relevant earlier decisions and assumptions

5 Responsiveness Objectives:

Get to know all the Potentially Affected Interests (PAI’s)

Get to see your project, organization and team through their eyes

Help identify all relevant problems, including the ones you are creating for the PAI’s

Help identify all the potential solutions and partial solutions

Explain and clarify the key issues

5 Effectiveness Objectives:

Build and protect your credibility

Have all the information that you need to communicate to your PAI’s received and under-

stood by them

Receive and understand all the information provided to you by PAI’s

Find common ground among opposing interests

Mediate between PAI’s who take opposing positions on your projects

*Taken from Institute for Participatory Management & Planning, www.ipmp-bleiker.com

15 Citizen Participation Objectives*


34

Careers in Planning, Design & Construction

What are the various job types involved in bridge design and construction?

There are a broad range of career opportunities on the Sellwood Bridge Project—

involving many jobs related directly to design and construction and some that you

might not associate with construction projects.

Construction

Pile Driving and Drilling

Steel Fabrication

Concrete Forming, Supply and

Placement

Traffic Control

Landscaping

Excavation and Embankment

(digging in the dirt)

Bridge Building

Roadway Paving

Pipe Laying for Storm Drains

Financial Experts

Project Managers

Estimators/Accountants

Carpenters

Electricians

Government

Federal Highway Officials

County Commissioners

Portland Mayor

State Officials

Lawyers

Accountants

Engineering and Design

Engineers

Architects

Managers

Biologists

Community Relations Experts

Right–of-Way Agents

Utility Coordinators

Lighting Designers

Landscape Architects

Surveyors

Environmental

Biologists

Hydrologists

Compliance Engineers

Tug-boats and Barges

Crane Operators

Demolition Experts

Divers (to work underwater)

Career Examples

Architect

An architect is a professional trained and licensed in the planning, design and oversight of construction projects. Architects create the plans (blueprints) that the contractor uses to build the project. An architect's decisions affect public safety, and thus an architect must undergo specialized training consisting of advanced education and hands-on training.

Landscape architect

A landscape architect plans and designs outdoor spaces, landscapes and garden.


35

Carpenter

Carpenters build or remodel almost every kind of structure, including houses and commercial buildings, bridges, churches, factories and highways. They work with power and hand tools to build wood framing for houses, roofs, stairs, decks and sheaths, and forms for concrete. They read blueprints, measure accurately and calculate dimensions.

Cement Mason

Cement masons prepare and repair concrete, including pouring and finishing slabs, steps, wall tops, curbs and gutters, sidewalks, and paving. They work with a variety of materials including terrazzo, magnasite, epoxy, polymer and other plastic materials for topping repair and injection.

Construction Lineman

Construction electrical lineworkers erect electric transmission and distribution lines for residential, commercial, industrial and agricultural customers. They assemble and erect steel towers, frame and erect wood poles, install hardware insulators, conductors, and secondary and primary cable, set poles, trim trees, and replace transformers and string conductors. Work is done under and above ground.

Electrician, Sign Fabricator

Sign fabricators craft signs by hand from a variety of materials including metal, plastic and glass. Tools used include state‐of‐the‐art equipment such as computerized numerical control (CNC) cutting machines and computer driven plotters, as well as traditional equipment such as hydraulic cranes for installations and repairs.

Estimator

An estimator is a professional that calculates materials, labor and the associated costs needed to bid and complete design and construction projects. Estimating is used in almost all forms of construction including residential, commercial and civil works.

Ironworker

Ironworkers erect the structural framework for high rise buildings, bridges, power plants and towers. They place reinforcing steel in concrete forms for roadways, foundations and structures and erect the aluminum fascia on high rise window walls.

Laborer

Laborers may be skilled or unskilled workers with duties as varied as clearing timber and brush, removing demolished materials from a job site, placing and vibrating concrete, landscaping, installing pipe, handling the materials for other trades workers or using explosives to demolish buildings.

Laborers are needed on all types of construction projects such as highways, bridges, tunnels, large build-ings, sanitation, and residential and perform work for the duration of the project. A laborer must know how to work with his or her hands and with power tools run by gasoline, electricity and compressed air.

Operating Engineer

Operating and Technical Engineers operate construction equipment such as heavy‐duty trucks, cranes, bulldozers, pavers, rollers, trench excavators and many other kinds of equipment used in constructing buildings, dams, airports and highways.

Painter

Painters apply paints and prepare surfaces for painting. Preparation is the most important part of painting and all sorts of surfaces, including wood, metal, masonry and sheet rock must be prepared. Painters also apply other types of wall coverings besides paint, such as vinyl, fabric and aluminum. Traffic control painters paint striping on roads.

Pile Driver

Pile drivers work with pile‐driving rigs that drive metal, concrete or wood piling into the earth during the early stages of construction. They drive metal sheet piling to hold back dirt during excavations, drive concrete, metal and wood pilings as part of the foundation system for skyscrapers and drive wood and concrete pilings to hold up docks, wharves and bridges.

Plumber

Plumbers assemble, install and repair pipes, fittings, medical gas systems and fixtures of heating, water and drainage systems, such as sinks, commodes, bathtubs, water heaters, hot water tanks, garbage dis-posal units, dishwashers and water according to specifications and plumbing codes. Plumbers also bend pipe using a pipe‐bending machine or by placing pipe over a block and bending it by hand, assemble and install valves, pipe fittings and pipes composed of various metals or glass, vitrified clay, and plastic.

Professional Engineer (P.E.)

A Professional Engineer, P.E., is a licensed engineer authorized to provide professional services to the public. Only a licensed engineer can sign, seal or stamp technical documents including drawings and calculations, estimates, design plans and reports. To become a Professional Engineer you must complete an undergraduate engineering program, gain experience in the field of engineering, and complete the Fundamentals of Engineering (FE) test, as well as the Principles and Practice of Engineering (PE) test.

Project Engineer

A project Engineer is typically responsible for schedule preparation and resource forecasting for technical activities relating to construction projects. Project Engineers may also be in charge of performance management of subcontractors. They assure the accuracy of project costs and schedules, and ensure projects are completed according to project plans. The Project Engineer typically works closely with the project manager and the project superintendent.

Project Manager

A project manager is a professional in the field of project management that typically has the responsibility of planning, executing and closing projects. Key project management responsibilities include managing teams, creating clear and attainable project objectives, building the project requirements, and managing the constraints of the project including cost controls, scheduling, scope and quality.

A project manager often acts as a client representative and has to determine and implement the exact needs of the client, based on knowledge of the firm they are representing. Project managers are utilized in the construction and architecture industry, among others.

Sheet Metal Worker

Sheet metal workers fabricate and install fittings and duct work used in construction or industry for heating, ventilation and air‐conditioning systems in residential, commercial and industrial applications. They set up and operate shears, press brakes, hand brakes, bending rolls, welding machines and other equipment to cut, form and attach metal together for applications such as metal roofing and stainless steel work for restaurants, kitchens and hospitals. They prepare shop and field drawings manually and with computer programs.

Superintendent

A construction superintendent typically runs the day-to-day operations on a construction site and controls the short-term schedule. Superintendents’ responsibilities also include quality control and subcontractor coordination. On larger projects, he/she is often assisted by a Project Engineer.


36


37

Middle School Activity Sheet

Careers Related to Planning, Designing and Building Bridges

Which Career Matches Which Category?

Write the number of the Category next to the Career that it matches.

Example: 1 Roadway Paving

CAREER CATEGORIES: 1 Construction Careers

2 Tug-boats and Barges Careers

3 Engineering and Design Careers

4 Government Careers

5 Environmental Careers

_____ Excavators

_____ Elected Officials

_____ Utility Coordinators

_____ Architects

_____ Lighting Designers

_____ Accountants

_____ Surveyors

_____ Road Design & Construction

_____ Lawyers

_____ Pipe Fitters

_____ Crane Operators

_____ Demolition Experts

_____ Underwater Diving

_____ Carpenters

_____ Hydrologists

_____ Demolition

_____ Pile Driving and Drilling

_____ Biologists

_____ Project Managers

_____ Electricians

_____ Landscape Architects

_____ Right–of-Way Agents

_____ Engineers

_____ Steel Fabricators

_____ Concrete Workers

_____ Federal Highway Officials

_____ Community Relations Professionals

_____ Traffic Controllers

_____ Landscapers

Water, Soil & Roads

Can you define these terms?

Watershed:

Bioswale:

Hydrology:

In-Water Work:

Habitat:

What is geology and why is it important when building a bridge? Can you define these

geologic terms?

Geology:

Volcano:

Glaciers:

Weathering:

Earthquake:

Landslide:

39


Did You Know???

Prior to the construction of the existing Sellwood Bridge people used the

Spokane Street Ferry to cross the river!

1. The existing Sellwood Bridge was made of recycled girders from which Portland bridge?

a) Hawthorne Bridge c) Fremont Bridge

b) Macadam Bridge d) Burnside Bridge

2. Sixteen jacks were evenly distributed to lift the existing bridge. If the bridge weighs five

million pounds, what lifting force was required by each jack?

a) 250,500 lbs or 125.25 tons c) 375,500 lbs or 187.75 tons

b) 312,500 lbs or 156.25 tons d) 210,750 lbs or 105.38 tons

3. What is the maximum depth below the riverbed the contractor will need to drill to install

drilled shafts?

a) 155 ft. c) 150 ft.

b) 130 ft. d) 145 ft.

4. The new bridge is approximately 1780 ft. long. How long is the bridge in inches?

a) 23,450 c) 21,360.

b) 22,850 d) 30,250

40


DID YOU KNOW???

Oregon is a geology sandwich that started

out as underwater volcanoes, weathered in

place, and then got covered by gravel and

soil.

The snow you see on Mt. Hood in the summer

time is actually a glacier.

There is a cinder cone (popcorn) volcano in

Gresham!

The oldest things ever found on earth are

rocks in the Grand Canyon that are over a

billion years old!

The last big earthquake in Oregon was seen

as big waves in Japan in the year 1700. That

is over 300 years ago!

When you look at a hill side, the oldest mate-

rial is always on the bottom and the young-

est is always on top.

The earth is precious and it

took a long time to make it.

If you take care of the

earth, it will take care of

you!

We are here!

41


Willamette River Facts:

The Willamette River Basin is one of the largest watersheds in the state, covering more than

11,500 square miles. Thirteen major tributaries join the __________________ as it stretches

nearly 300 miles from its headwaters at Waldo Lake in the Cascade Mountains southeast

of Eugene to the confluence with the Columbia River at Kelley Point in Portland! The Wil-

lamette River is one of the few major rivers in the United States that flows primarily

___________!

The Willamette River flows through _____ counties and _____ cities!

The Willamette River provides ports for commercial barges and oceangoing ships, irriga-

tion for crops sold worldwide, an abundant fishery, and recreational opportunities!

Other Fun Water Facts:

Water is millions of years old!

There is the same amount of water on Earth now as there was MILLIONS of years ago!

Nearly 97% of the world’s water is salty or otherwise undrinkable. Another 2% is locked in

ice caps and glaciers.

The average total home water use of each person in

the U.S. is about 50 GALLONS a day!

DID YOU KNOW???

What can you do to

use less water?

42


Geology: The study of rock, soil and

water

Volcano: A cone that shoots out melted

rock, dust, or cinders (like popcorn)

Glacier: Big thick sheet of ice (some are

over 1,000 feet thick) that used to sit on

Oregon and most of the United States

Weathering: When rock turns into soil

Earthquake: When two pieces of the

earth move against each other and

make the ground shake

Landslide: When rocks and soil move

downhill

Watershed: An area of land that drains into

a lake, wetland, stream or river. In Oregon,

no matter where you live, you are in a

watershed

Bioswale: Gently sloped, vegetated

ditches that clean runoff into the sewer

system. The names grassy swale, vegetative

filter, and vegetative infiltration basin

represent different types of bioswales

Hydrology: The scientific study of the

behavior of water in the atmosphere on the

Earth’s surface and underground

Hydrologic Cycle: The natural recycling

process powered by the sun that causes

water to evaporate into the atmosphere,

condense, and return to earth as

precipitation

In-Water Work: Construction-related

activities, such as underwater welding, pile

driving, and excavation, that occur at the

surface or under water

Habitat: An ecological or environmental

area where an animal naturally lives or a

plant naturally grows

Glossary: Water Glossary: Geology

43


44


Answer Key for Did You Know (page 40):

Prior to the construction of the existing Sellwood Bridge people used the

Spokane Street Ferry to cross the river!

1. The existing Sellwood Bridge was made of recycled girders from which Portland bridge?

a) Hawthorne Bridge c) Fremont Bridge

b) Macadam Bridge d) Burnside Bridge

2. Sixteen jacks were evenly distributed to lift the existing bridge. If the bridge weighs five

million pounds, what lifting force was required by each jack?

a) 250,500 lbs or 125.25 tons c) 375,500 lbs or 187.75 tons

b) 312,500 lbs or 156.25 tons d) 210,750 lbs or 105.38 tons

3. What is the maximum depth below the riverbed the contractor will need to drill to install

drilled shafts?

a) 155 ft. c) 150 ft.

b) 130 ft. d) 145 ft.

4. The new bridge is approximately 1780 ft. long. How long is the bridge in inches?

a) 23,450 c) 21,360

b) 22,850 d) 30,250

Activity Outline

Based on the following scenario, you must construct a persuasive argument to present to government officials.

Scenario

A new bridge will be built in your city. The current bridge is 40 feet wide and it is old and falling apart. It is becoming a danger to

those who travel on it. Also, the travel lanes are too narrow for large freight trucks to bring goods into and out of the city. Because

the bridge is too narrow, there is no shoulder for vehicles to park if they are involved in an accident. When there is an accident, it can

sometimes cause traffic jams for up to 2 hours. There are no bike lanes for bicyclists so they must share the one sidewalk with pedes-

trians; however, the sidewalk is too narrow for both bicyclists and pedestrians to pass each other.

Your local government is planning to build a new bridge similar to the old bridge. How can you convince the government to consider

your interest group's concerns while planning the width of the bridge. The government has $100 to build a bridge that aims to accom-

modate all the local interest groups. The new bridge cannot cost over $100 and cannot be less than 50 feet wide.

Some questions to consider

Freight Truck Drivers--How will you deliver goods to the city if the travel lanes of the bridge aren't wide

enough for your truck? How will a decision to widen or not widen the lanes affect you, your business, the

residents of the city, and the business owners? Why should the government widen or not widen the lanes?

Pedestrians and Bicyclists--How will you get across the bridge if there is only

one sidewalk for both pedestrians and bicyclists to share? What should the

government do to make the bridge function effectively for both pedestrians and

bicyclists?

Commuters--How can the government build a bridge to accommodate all the commuters every day? What

can they do to make the bridge more commuter-friendly and lessen traffic jams and commuter time?

Business Owners--What can the government do to consider how people access your business? How can the

government make the needed improvements to the bridge so that people coming into and going out of the city

can do it in a timely and safe manner? Can improvements to the bridge bring in more patrons to your business?

Government--How can you make decisions based on each interest group’s argument? Will you be able to

accommodate each of their requests?


School Engagement Program

Exploring the Sellwood Bridge Project

45

Narrow traffic lane—9’ wide $10

Standard traffic lane—10’ wide

$15

Wide traffic lane—11’ wide

$20

Narrow sidewalk—6’

$10

Standard sidewalk—8’

$15

Multi-use/wide sidewalk—10’ $25

Narrow bike lane—5’ $5

Standard bike lane—6’ $10

Wide bike lane—8’ $15

The local government has $100 to build a bridge that is no less than 50 feet wide and aims to accommodate

the local interest groups.

Bridge Elements *remember, you need 2 of each* Hypothetical Cost


46

Created by: Lois D. Cohen Associates—2013

the sellwood bridge · pdf fileas part of multnomah county’s outreach efforts for the...

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