CHAPTER 1- Introduction to Structure

CHAPTER 1:CHAPTER 1:INTRODUCTION TO INTRODUCTION TO

STRUCTURESTRUCTURE

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The conceptual understanding of structural behaviour.1.What is the function of a structure?• To carry loads

• A structure is a system for transferring loads from one place to another.

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The conceptual understanding of structural behaviour.2. What are the loads and the load paths?

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The conceptual understanding of structural behaviour.

3. How does the structure transfer loads?

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Basic Structural Systems

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Roof

Upper Floor

Ground Floor

Stump

Pile cap

Pile

Roof Truss

Roof Beam

Column

Floor Beam

Column

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Roof truss support the weight of roof sheet/tiles and anything on top

Wall plate tie the roof truss to the roof beam

Roof beam support the weight of roof structure

The upper column take the load from the beams above and transfer them to the column below

The column pass the load to the stump then to pile cap and pass them to the piles foundation

below

Eventually the soil support the entire load throughFrictional force or otherwise partly distributed to the

hard strata (bedrock) below

The conceptual understanding of structural behaviour.

4. What are the forces in the structural elements?

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CompressionA compressive force tends to condense material.

Compression

Compression in natureCompression in

architecture8

TensionA tensile force tends to stretch material.

Tension in natureTension in architecture

Tension

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ShearA shearing force tends to divide an object along a plane parallel with the opposing external forces.

Shear Shear in nature10

TorqueTorque is the result of forces which tend to twist an object, resulting in a shearing stress.

Torque

Torque in a beam

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BendingBending is the result of forces which tend to deflect a manner by inducing tension, compression and shear.

Bending

Bending in a beam

Bending in nature12

The conceptual understanding of structural behaviour.

5. Does the structure have overall stability?

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Settlement occurs due to compression of the Settlement occurs due to compression of the soil under the foundations. soil under the foundations. 14

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Differential settlement occurs due to uneven bearing Differential settlement occurs due to uneven bearing capacity of the soil or to uneven loadingcapacity of the soil or to uneven loading

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Earthquake give rise to horizontal ground Earthquake give rise to horizontal ground movement and can also be the cause of movement and can also be the cause of settlement due to ground compaction.settlement due to ground compaction.

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Effect of Differential settlement on wall 18

Effect of Differential Settlement on wall siding (finishes)19

• The collapse of Highland Towers Condominium in Hulu Kelang, Selangor on December 11th. 1993, where 48 people were killed.

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Bukit Antarabangsa

The conceptual understanding of structural behaviour.

6. Is any element too slender?

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Rules of Thumbs for Approximates Structural Sizes

The size of the cross-section must allow the internal forces determined in the analysis to be carried without overloading the structural material and without occurrence of excessive deflection.

Each element is considered individuallyThe area of cross section determined which will

maintain the stress at an acceptable level in response to the peak internal forces.

If the element-sizing procedures yield cross-sections which are considered unsuitable, modification of the overall form of structure will be undertaken, the whole cycle of analysis and element-sizing calculation must be repeated.

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