Fourth degree of flexibility

Third degree of flexibility

Second degree of flexibility

First degree of flexibility

Текст C

FLEXIBILITY OF LAYOUT

 

The more extensive use of steel in multi-storey buildings results from the need for convertibility of buildings. It often occurs that the internal layout and facilities originally provided in a building soon prove to be not adequate or at least not completely adequate. A building can obtain a longer useful life if it is flexible in the sense that it can be easily adapted to changing requirements.

Depending on the extent of the conversions involved, the following degrees of flexibility may be distinguished:

The modification of the floor space is altered by changing the arrangement of space-separating elements, for example, folding screens which can be moved by the owners of the building themselves.

In this case, altering the internal layout involves dismantling and re-erecting the partitions. This is possible only if the latter are non-loadbearing. This requirement can only be fulfilled by framed buildings in which the load-bearing and space-enclosing functions are separate and are performed by different sets of components. The columns of a framed building may, however, be a problem to internal changes. Wide column spacings and long floor spans improve the flexibility of layout. Flexibility in altering and rearranging the services is also essential. In a building provided with movable partitions, these must be installed in the floors. Hence it is desirable to provide a floor in which the services can be installed according to the design and when the need occurs modified, as re­quired.

It is necessary to distinguish between the following different types of partition:

· movable prefabricated units;

· demountable walls whose materials can be re-used;

· demountable walls whose materials cannot be re-used.

Modification of the load-bearing structure becomes necessary, for example, in the following circumstances:

· strengthening the structure to carry heavier loads;

· increasing the spans by the removal of internal supports;

· increasing the height with additional storeys;

· extending a building;

· demolishing certain parts of a building.

These modifications can be fulfilled easily, without excessive damage to the existing building if it is steel-framed and not be expensive.

This comprises structures which, except for the foundations, can be completely dismantled and whose components can be re-used for other purposes and in combination with other structures. For this, the space-enclosing elements, as well as the actual structural frame, must be composed of demountable standardised components. Only a number of parts of such a building are dismantled, for example, the roof covering, floor finishes, services, etc. The foundations or basements are either back­filled or used for other structures. Constructional systems which comply with these requirements are available for external and internal walls and for ceilings.