105
5
Structures
Once we are clear about the steps which we have to follow, the
project specifications and the solutions to any issues arising from
the tasks, we are ready to start thinking about our first ideas and
sketches.
It is necessary to bear in mind that throughout the unit there are
different activities, indicated by the project symbol, which will
help us to achieve a better result at the end of the project.
Web link (virtual tour):
NEW BRIDGE IN THE TAJO DE
RONDA (MALAGA)
Using the Google Maps tool, students can get a panoramic view
of this.
Answer key
1.
How wide should the bridge be?
Total width of the bridge: two lanes of vehicular traffic 3 m
x 2 m = 6 m; two for bicycles of 1.5 m x 2 m = 3 m; 3 m of
pavement for pedestrians, 12 m in width.
2.
What will the distance be between the supports on
your scale model?
On a scale of 1:100 and measuring 50 m on the ground, the
distance between the supports on the model will be 50 cm.
3.
What should the minimum length of the model bridge
be so that it is strong enough at each end?
As a minimum and depending on the type of bridge that
will be built, it needs to be 10 cm for each side in the
supports.
4.
What should the minimal height of the bridge be? And
of the model on a scale of 1:100?
The bridge must have a minimum height of 4.5 m. On the
model that will be 4.5 cm.
5.
What will the total area of the bridge’s deck be?
The area between the supports on the deck will be 12 m x
50 m = 600 m
2
.
6.
Calculate the load that the bridge has to support for road
traffic, bearing in mind that the aforementioned load is
20 kN/m
2
, what is the total weight which it must bear?
600 m
2
x 20 kN/m
2
= 12000 kN
7.
For the purpose of testing our model bridge, let us take
a specific load in the middle of the arch which is equal to
the total of the previous question divided by 400000. How
much weight will we have to put on the on the bridge?
12000 x 1000 N / 400000 = 30 kN, which amounts to an
approximate weight of 3 kg or three milk cartons of 1 L each.
OXFORD PROJECTS
First of all there is an introduction to the unit. Some initial
questions are asked and the task of the investigation which has
to be solved by the end of the activities is set. The task presents
a practical problem which requires students to draw on any
acquired knowledge and their own investigation in order to solve
it. It’s important to convey the idea that they will be learning
concepts and/or methods which they will be using later to solve
a practical problem.
