General Construction Aspects: Plan of Building

1. Plan of Building

a) Symmetry: The building, as a whole or its individual blocks, shall be planned to be as close to symmetrical as possible.

b) Regularity: Buildings with simple rectangular shapes behave better in earthquakes than irregular buildings with projections. To avoid torsional effects which are pronounced in long narrow rectangular blocks, length of a block shall not be greater than three times its width. If longer lengths are required, it should be divided into two (or more if the length desires so) separate blocks with sufficient separation.

Figure 5-1: Plan of building blocks (P)

c) Separation of Blocks: Separation of a large building into several blocks may be required so as to obtain symmetry and regularity of each block. For preventing hammering or pounding damage between blocks a physical separation of 40 to 50mm shall be provided throughout the height of the building above the plinth level.

The separation can be treated just like an expansion joint or it may be filled or covered with a weak material which would easily crush and crumble during earthquake shaking.

d) Simplicity: Ornamentation involving large cornices, vertical or horizontal cantilever projections, facia stones, etc. where used must be reinforced with steel, which shall be properly embedded or tied into the main structure of the building.

Source: Nepal National Building Code, NBC 202:2015, Government of Nepal.