Department of Mechanics, Materials and Structures BME

Special load-bearing structures – 7th Practical 27.03.2012.

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Cable structures

The given structure is a spoked cable structure.

The outer diameter is 50 m, the middle ring’s

diameter is 4 m. The height of the middle ring

is 2x5 m.

There are altogether 64 pairs of cables

between the inner and the outer ring. Every

cable connection at the outer ring is supported

vertically with reinforced concrete columns.

The joints of the cable truss are in a parabolic

arch shape. The tangent of these parabolas are

horizontally along the edge of the inner ring.

The vertical load of the structure is uniformly

4 kN/m2. This is the design value of the load.

Questions:

1. How much is the vertical reaction force in one of the columns? What size of cross section

should be used?

2. The value of the pre-tension is 400kN in every cable. What is the maximum force, that

appear in the chords as a result of the load? What type of cable should be used? (Choose

from the FUX, or PFEIFER catalogues can be fined in the internet. The 1/3 of the given

resistance force can be used.)

3. What is the minimum value of the pre-tension of the chords?

4. How much is the force in the outer ring that appear as a result of the pre-tension? How much

is the force caused by the vertical load? What size of cross section should be used?

Department of Mechanics, Materials and Structures BME

Special load-bearing structures – 7th Practical 27.03.2012.

2/5

Department of Mechanics, Materials and Structures BME

Special load-bearing structures – 7th Practical 27.03.2012.

3/5

Department of Mechanics, Materials and Structures BME

Special load-bearing structures – 7th Practical 27.03.2012.

4/5

Department of Mechanics, Materials and Structures BME

Special load-bearing structures – 7th Practical 27.03.2012.

5/5