Log Book Week 1 - Antigone Gougoussis 641138

A01

LOGBOOK

CONSTRUCTING ENVIRONMENTS (ENVS10003)

ANTIGONE GOUGOUSSIS (641138)

2

WEEK 1

E-LEARNING AND READINGS

The e-learning and Ching readings this week introduced the concepts of loads and load

paths (including static, dynamic, wind and earthquake loads), basic structural forces and

materiality. Diagram 1.1 (below) shows the interrelatedness of loads, forces and materiality.

LOADS

Structural Systems of buildings need to support 2 types of loads:

1. Static – applied slowly to a structure without fluctuating rapidly in magnitude or

position, where structure responds slowly to deformation

2. Dynamic – applied suddenly to a structure, usually with rapid changes in magnitude

and developing inertial forces in relation to mass

Diagram 1.1 Loads, Forces and Materiality

3

Load Paths applied loads take the

most direct route in order to reach

the ground, where the reaction

force is equal in magnitude and

opposite in direction in order for a

structure to remain stable.

INTRODUCTION TO MATERIALITY

When deciding which material to use in construction, things to consider include strength,

stiffness, material behaviours, shape, economy/budget and sustainability.

STEEL – Strong in both tension and compression, but more expensive than timber.

WOOD – Much weaker in tension and compression than steel, but more readily

available in Australia.

BRICK/CONCRETE – Very strong under compression, but weak under tension (needs

steel reinforcement if it going to be used in construction and put under tension

forces).

(Left to right) Steel, concrete and timber

Diagram 1.2 Load Path Diagram

4

TENSION AND COMPRESSION

Tension

– forces that stretch/elongate a

material (when an external

load pulls on a structural

member)

– depends on stiffness of

material, C.S.A. (cross sectional

area) and magnitude of the

load

Compression

– forces that push/compress a

material

– opposes tension force

STUDIO SESSION ACTIVITY REPORT: “COMPRESSION”

TASK: In the first studio session, we were places into groups and asked to construct a tower

from wooden building blocks in order to help us understand the behaviour of mass

construction and the ways in which loads are transferred through the structural members in

compression structures.

PROCESS AND DISCUSSION:

1. My group decided on our first layout

of placing the blocks vertically as

columns to help achieve height with

our tower. Soon we discovered that

this structure was extremely

unstable as the loads of the applied

blocks were being unevenly

distributed through the structural

members.

Diagram 1.3 Compression and Tension

5

2. Structural members placed in different ways

as tower construction was rushed while

attempting to curve the walls of the

structure. This led to loads being unevenly

distributed through the structure and

instability of the tower. Therefore, we

changed our design concept.

3. New attempt was made with curved walls and new design layout of blocks in order

to distribute the applied load of the blocks as equally as possible through the

structural members.

Diagram 1.4 Initial Tower Structure

6

4. Our final tower design allowed for all loads to be distributed equally through

structural members. Although our final tower attempt wasn’t as high as we had

hoped for, we managed to create a tower able to withstand compressive forces

created by applied loads. We tested the strength and sturdiness of our tower by

placing heavy objects on top of its roof, which it was easily able to carry.

Diagram 1.5 Final Tower Structure

7

5. By applying loads on top of the structure, this

allowed for structural members to be under compression

and tension forces. The roof of our structure was hurried

and did not follow the base and main body of our tower’s

structure.

6. However, the layout of our tower allowed for the

loads causing these forces to be transferred equally

throughout the structural members, therefore reducing

the magnitude of the compressive forces on each block.

This allowed for a strong and sturdy final structure.

Diagram 1.6 Forces on each block for Final Tower

8

GLOSSARY

Anisotropic: different physical properties in different directions (e.g. wood – stronger along the grain)

Beam: rigid structural members, carry and transfer transverse loads across to supporting elements

Compression: forces that push/compress a material

Couple: a force system of two equal, parallel forces acting in opposite directions and tending to produce rotation but

not translation

Dynamic loads: loads applied suddenly to a structure with rapid changes in magnitude e.g. earthquake and wind loads

Earthquake loads: longitudinal and transverse vibrations induced in the earth’s crust resulting from the movement of

plates along fault lines (weak spots)

Impact loads: kinetic loads of short duration e.g. from moving vehicles and machinery (static load)

Isotropic: Same physical properties in different directions

Lateral load: the force acting on a structural member in the horizontal direction, the forces working against a structure

e.g. wind pressure against a building

Live loads: moving or moveable loads on a structure e.g. collected snow, water or moving equipment

Load: the overall force which a structure is subjected to, including mass or weight, externally applied forces (snow, rain,

equipment, etc.)

Load path: the path in which a load (applied) will pass through structural members of a structure in order to reach the

ground

Masonry: building structures using brickwork and stonework

Moment: the tendency of a force to produce rotation of a body about a point (clockwise or anti-clockwise direction)

Point load: a load applied on a certain point of a beam (load concentrated on a small area of a structural member)

Reaction force: forces that are equal and opposite in reaction to the applied forces in order for the structure to remain

stable

Settlement loads: loads resulting from the subsidence of soil and causing movements in the foundations

Static load: loads applied slowly to a structure until it reaches peak value, allowing the structure to respond slowly to

deformation

Tension: forces that stretch/elongate a material (pulls on structural member)

Wind loads: the forces exerted by kinetic energy of a moving mass of air (assumed to come from any horizontal

direction)

9

References:

Ching, F 2008, Building Construction Illustrated, 4th edn, John Wiley & Sons, Hoboken, New Jersey.

Gregory La Vardera Architect 2006, Steel Beam, image,

<http://blog.lamidesign.com/2006/03/6030-house-floor-beam-day.html>.

Kandla Timber Directory 2014, Timber Beams, image, < http://kandlatimberdirectory.com/>.

Newton, C 2014, W01 m1 Introduction to Materials,

<http://www.youtube.com/watch?v=s4CJ8o_lJbg&feature=youtu.be>.

Newton, C 2014, W01 s1 Load Path Diagrams,

http://www.youtube.com/watch?v=y__V15j3IX4&feature=youtu.be>.

Online Architecture and Design Exhibition 2014, Concrete Beam, image, <

http://www.archiexpo.com/prod/prestasi-concrete-sdn-bhd/prestressed-concrete-i-beams-56829-

126838.html>.