2002-1 the roman oval

8/7/2019 2002-1 The Roman Oval

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F. ESCRIG 1

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THE ROMAN OVAL.

F.ESCRIG, Prof. of the School of Architecture of Sevilla. Spain.J.SNCHEZ, Prof. of the School of Architecture of Sevilla. Spain.J.P.VALCARCEL, Prof. of the School of Architecture of La Corua. Spain.V. COMPAN, Prof. of the School of Architecture of Sevilla. Spain.

SUMMARY:

In 1999 we received the commitment of covering a velodrome pavilion till this momentuncovered and needed not only to bicycle races but any other kind of performances. The sizewas of 145x114 m and 3000 seats around a reglamented path. Our first proposal by which ourteam was selected was a complex cap sustained by only four piers. This proposal wascompleted with a retractable solution that at last was rejected. The similitude with the RomanColiseum was clear and the proportion very similar although we used a rigid greed instead ofa hanged fabric as it was usual in the ancient times. The construction is now in a veryadvanced period and after it a lateral wall will be installed that at first not was considered inthe proposal.

This paper includes only the design process as well as the analytical considerations. Somepictures of the site in its actual situation are also included.

PRELIMINARY DESIGN.The Fig. 1 shows the preliminary design approved by the Town Council. The problem ofcovering an oval was complex. While the sphere segments develop stresses in a uniform way,the ellipsoid segments stresses are variable and very different between them. We ruled out aninflate or tensile textile fabric because the client preferred a rigid one. Then we decided to usea grid of steel pipes in the way of some Japanese designs. We always have avoided the use oftriangulated girders because are more expensive than Vierendeel beams. The only problems isthat is more difficult of mounting for great roofs. In the Fig. 2 we show a retractablealternative that moved on an horizontal rail.

Fig. 1 Preliminary design.


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Fig. 2 Retractable roofOther consideration done in the preliminary design was how to connect the new roof to theactual building. Our option was not mix old and new works an this obliged to us to putoutside the supports, that we decided to be only four piers, separated 91 m. (Fig. 3).

91m.

91

m.

Fig. 3 Oval on a 91 m square edge. Fig. 4 Generation of the roof.

Our choice for the roof was to intersect two cylinder as it is presented in the Fig. 4 and to cutthe border as a projection of the oval. The borders then could be relatively discharged becausethe lines of stress could be oriented like it is shown in the Fig. 5.

Fig. 5. Main stresses on the roof oriented. Fig.6. The arches which transmit the roof weight


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As the curvature of the roof is small, the horizontal forces are high. The supports then aresubjected to important bending moments. We decided to use piers with great dimensions in ascheme like shown in the Fig. 7. that took the form shown in Fig. 8 when completely

designed.

Fig. 7. Scheme of the piers. Fig.8. Design of the piers.

FINAL DESIGN.

These piers where oriented in the direction of the line of intersection of the two cylindrical

shells and connected to the box girder that solve the spatial curve of this intersection. (Fig. 9).The box girder, whit a section of 3 m height and 2m. wide is designed to pass in trough and isshown in the Fig. 10. together with the border girder, that is similar although it is notnecessary as we said before.

Fig. 9. The grid of the roof.


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Fig. 10 The box girders

Fig. 11. Encounter between the grid and the box girders.

The Fig. 11. shows the encounter between the grid and the box girders. It is sure that we couldmaintain the image of the preliminary design in which the box of the border are not necessary

but for us the aspect of the whole and the necessity of galleries to the maintenance of lights,loudspeakers an other devices was preferable.

Other consideration was to decide what kind of greed to use. As we have said , the rigid jointswhere preferable for us than pined ones and not triangulated beams better than usual girders.If we compare in the Fig. 12 a plane beam with a span similar to the central beam of ourdesign, the difference is obvious. The triangulated one is better and the Vierendeel beam has

poor results. Nevertheless if we plan the same with an arch, the results are different. Thetriangulated beam is worst if we attend to the weight. In all cases we have considered the


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joints rigid and the pipes the maximum needed for each case dimensioned to the elastic limit.(Fig. 13.)

LONG. TOTAL:

LONG. TOTAL:

200x8

PESO PROPIO:37.8 Kp/ml

Uds:T

TOTAL: 9,327 T

ULTIMATE ELASTIC LIMIT

PESO PROPIO:165 Kp/ml

Uds:T

28,400 TTOTAL:

252.1m

172.1m

DEFLECTION


355.6x20

DEFLECTION

Fig. 12. Comparison between results of Vierendeel and triangulated girder.

200x8

LONG. TOTAL:

Uds:T

PESO PROPIO: 37.8 Kp/ml TOTAL: 9,652 T 255.5m

LONG. TOTAL:


PESO PROPIO:24.0 Kp/ml

Uds:T

TOTAL:4,212 T


200x5

175.5m

DEFLECTION

DEFLECTION

Fig. 13. Comparison between a Vierendeel and a triangulated arch.

We had an other question to study. Could the depth influence the results of the arch design?The Fig. 14 shows how the single layer is the optimum if we not consider the overall

buckling. But to check this behaviour is complicated and not included in the usual analysis

programs. Then we used to test the general buckling the assimilation to the shell behaviourwith the References 2 and 3.


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being hm the equivalent depth.

If we had used a real depth of 200 cm cr=3594.29 Kg/cm2 , lesser than the Elastic Limit of

the steel.

LONG. TOTAL:PESO PROPIO:

Uds:T

57,8 T/ml TOTAL: 3,757 T 65m

LONG. TOTAL:

LONG. TOTAL:


200x8

PESO PROPIO:Uds:T

37.8 Kp/ml TOTAL: 9,429 T


Uds:T

PESO PROPIO: 37.8 Kp/ml

200x8

TOTAL:5,912 T

DEFLECTION

223m

156.5m

DEFLECTION

Fig. 14. Comparison between different depths of arches.

21

4

9

8

6

= RL

hhE bm

cr

26

31

231

/101,2____10200

10000___

59.29250

12513,6921212

.__

552,0250

213,69)___(

)sec_(

cmKgEdiusCylinderRaR

cylindertheofLenghtL

d

Ih

ModulusInertiaEquivalenth

cmmeshtheofdepth

tionpipe

d

Ah

b

b

m

===

==

=

=

=

=

=

==

2/15.6763 cmkgcr=


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LOADS TO BE CONSIDERED.Load Case 1. Self weight. Done automatically by the analysis Programme (SAP2000).Load Case 2. The weight of the steel sheet and insulation. 20 Kp/sqm.Load Case 3. Snow load and use. 60 Kp/sqm.Load Case 4. Machinery. 40 Kp/sqm.Load Case 5. Wind loads. Tested in wind tunnel (Reference 8) according with the expressionq=150 (cpi - cpe). The figure 15 shows the coefficients cpe.Load Case 6. Dynamic Analysis. We consider only the first five modes.Load Case 7. Thermal changes of +/- 30C.We will combine these cases according the codes of practice. The SAP-2000 Programmechecks local buckling.

Fig. 15. Wind loads coefficients.

PROCES OF CONSTRUCTION.

As we have said the construction was planed to be don without demolish anything of theactual architecture and without connecting with it. Really the old building was of a poorquality and not was capable of support new loads. Once we had finished the piles (Fig.16) we

begun to connect the box girders (Fig. 17) previously assembled on the ground (Fig. 18) ofparts of them (Fig. 19).

Fig 16 . Piles to connect the roof.


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Fig. 17. Confection of box girders to the pile. Fig. 18. Assembling the main box girder.

Fig. 19 Assembling parts of the box girders in site. Fig. 20. View from the box girder.

Fig. 20. General views of the assembling.

Figure 20 shows to states of the assembling. After mounting the central and cantilever boxgirders we begun to install the mesh of the corners to make possible to work always from the

play ground for lift all the structure (Fig. 21).


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Fig. 21. Lifting the corner mesh to its final position.

Fig.22. Lifting the longest Vierendeel arch beam.

Fig. 23. The longest Vierendeel arch beam put in place.

Fig. 24. The perimeter completely encircled.


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THE PERIMETRAL ENCLOSURE.

At this moment, in may 2002 this is the progress of works. But out of the first commitmentwe have received the suggestion of propose a solution to close the inner space totally in sucha way to make possible to control temperature and acoustics. The proposal is to hang someelements containing insulated panels and glasses from the perimeter box girders (Fig. 25).

Fig.25. Proposal of the perimeter wall.

Fig. 4. Lateral view.

7. REFERENCES.1.- Chilton, John Space Grid Structures Architectural Press. 2000.2.- Buchert, Kenneth P. Buckling of Shell & Shell like Structures K. P. Buchert &Associates. 1973.3.- Escrig, Felix Pandeo de Estructuras Publicaciones de la Universidad de Sevilla. 1986.4.-Escrig,F. Snchez,J. Great Space Curved Structures with rigid joints. Theory, Design andRealization of Shell and Spatial Structures. IASS. Nagoya 2000.5.- EUROCODE 1. Basis of Design and Actions on Structures. Part 2-4:Action onStructures: Wind Actions 1995.6.- Ishii, Kazuo. Structural Design of Retractable Roof Structures WIT Press. 2000.7.- Ishii, Kazuo. Membrane Structures in Japan SPS Publishing Company. 1995.8.- Meseguer, J. Aerodinmica de Instalaciones Aeroportuarias. Fundacin Aena. 2000.

2002-1 the roman oval

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