VOCABULARY
Horizontal load:
the sum
of horizontal forces
(shear forces) acting on
the elements of a
structure.
P ROC E DUR E
Teacher Preparation
1. You may want to invite an architect, engineer, geologist, or
seismologist to visit your class during Lesson 4 of this unit, when
students will again design model buildings. The guest expert could
initiate the building challenge and help students to understand the
concepts involved.
2. Read the teacher background information on Master 4.1a. 1f
possible, assemble visuals from among those listed in the Unit 1
Resources.
3. Draft a few students to cut the Styrofoam into pieces, or ask the
industrial arts instructor to help. (Styrofoam is easily cut on a band
saw.) Finally, collect the building materials for this lesson and put
them into piles on a table in the front of the room.
Lead:
the sum of vertical force
(gravity) horizontal forces (shear
forces) acting on the mass of a
structure. The overall load is further
broken down into the loads of the
various parts of the building.
Different parts of a building are
designed and constructed to carry
different loads.
Vertical load:
the effect of vertical
force (gravity) acting on the elements
of a structure.
TEACHING CLUES AND CUES
Cut more Styrofoam
than you will need for
this lesson—about 35
strips per group—since
A. Introduction
Set the stage by asking students to tell what they know about the effect
of earthquakes on buildings and other structures, both from personal
experience and from reading, television, movies, or other sources. Be
protective of their right to say what they remember, even if it may
sound exaggerated to other students. If you have pictures or slides of
earthquake damage, show them now.
B. Lesson Development
1. Divide the class into cooperative working groups of three to five
students each. Explain that throughout this unit the groups will be
known as seismic engineering teams, or SETs. Encourage each SET to
choose a name.
2. Ask the groups to collect materials and build the strongest structures
they can with the materials and the time allotted. Do not direct or
criticize their efforts. This activity is for fun. When students try again
in Lesson 4, they will be able to apply what they have learned in this
unit.
3. After 20 to 30 minutes, call a halt to construction. Have a
spokesperson for each group bring its structure to the materials table
in the front of the room and describe the structure to the class. Ask
students to explain why they built what they did.
4. With all the structures on one table, ask the class what would
happen if you were to place a brick on top of each structure. Have the
brick in hand, but do not actually crush any structure. Explain to the
students that the brick is simulating the static force of gravity (vertical
load) that every structure must carry. In this case, the Styrofoam is
quite strong for its weight, so the brick can also represent the weight
of all the nonstructural elements of a building, such as floors, wall
coverings, and electrical wiring. Expect the students to protest because
they were not told their structures had to support a brick. Explain that
this activity was only an introduction and a chance to discover the
physical properties of the materials.
you will also use these strips in
Lesson 4. If some of the strips are
less than uniform, use them now,
saving the best ones for Lesson 4.
A G U
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F E M A
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