2. Objectives……
The objectives of this lecture is to
understand and learn the
rational terms of differential
movement design to resist
rational phenomena and meet
user needs
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4. WHY????
◦ Fewer activities requires us to be outside
◦ We need shelter from sun, wind, rain, and snow. We
need dry, level platforms for our activities.
◦ We need to stack these platforms to multiply available
ground space.
◦ On these platforms, and within our shelter, we need air
that is warmer or cooler, more or less humid, than
outdoors.
◦ We need less light by day, and more light by night,
than is offered by the natural world.
◦ We need services that provide energy, communications
and water and disposal of wastes.
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5. So we gather materials and assemble them
into the constructions we call BUILDINGS
to satisfy these needs.
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6. How can the building resist from the
natural disaster????
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earthquake?
flooding?
tsunami?
landslide?
7. Building Loads
The design, selection of materials
for and construction of building
structures is based on the expected
loads, use(s) of the building and the
acceptable risk of failure.
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8. ◦ The loading of a building structure can take on a wide
variety of forms. In many cases the exact loading will not
fit neatly into a specific category. Yet, loads can usually be
considered to be either Primary or Secondary.
◦ Primary loading generally includes the materials from
which the structure was built, the occupants, their
furniture, the direct influence of various typical weather
conditions, as well as unique loading conditions
experienced during construction, extreme weather and
natural catastrophes.
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9. Structures Are Subject To
Complex Loads ….
a) Forces from different directions
b) Different intensities of forces
c) Different frequencies
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11. 4 Common Types of Loads
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Dead
Wind
Snow
Live
12. Dead Load
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Dead load is the weight of the building
materials.
Dead loads will vary depending on the
type of construction and materials used.
13. Live Load
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Materials that are being moved. Vibration from equipment
Any load that will change during normal use of the
building.
Live loads are estimated on a pound per
square foot basis for structural calculations.
Equipment
People
14. Wind Loads
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The effect of wind on a
building is not consistent.
On the up wind side of a
building, wall and roof
panels experience a positive
pressure, while on the down
wind side there is a negative
pressure or suction load.
The dashed line represents
the “racking” forces caused
by wind.
15. JK/BSB552/2012
Wind can have multiple effects
on buildings.
How does the effect of wind influence
building design and construction?
16. Wind effects…
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As the wind blows over
and around the
building, eddy currents
are formed which exert
varying negative
pressures in those
areas.
The destructive power of
wind is dramatically
increased when you include
water and/or hail.
17. Snow Loads
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1. Added load from sliding snow
2. Increased load for lower roof.
3. Drift load behind obstruction
4. Increased load in valleys
5. Unbalanced snow load
6. Balanced snow load
7. Increased load because of change in slope
18. JK/BSB552/2012
Secondary loads are those loads due to temperature
changes, construction eccentricities, shrinkage of
structural materials, settlement of foundations, or
other such loads.
