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3. The reinforcement of structural elements 3.1 Columns

The above column has an overall dimension of 30/30 which is the smallest dimensions
that can be used for columns in an earthquake resistant building, according to common
building regulations. This column is rarely used nowadays but is selected because of
its simplicity in order to explain the several different reinforcement options and charac-
teristics. This column is reinforced with four (4) steel bars and one simple stirrup.
The height of the column’s body is 2,70m and the height of the node area is 0,5m (it is
equal to the height of the adjacent beam). The transverse reinforcement is common
stirrups with Ø10 diameter. The longitudinal reinforcement consists of four (4) steel
bars with Ø20 diameter. The covering of reinforcement is 2.5cm.
In general, columns are the most important earthquake resistant structural elements in
a building and the stirrups are the most important characteristic of a column. The col-
umn’s body is divided into the critical areas (due to the influence of earthquakes), the
intermediate area and the node areas (which is the common area of the column and
the adjacent beam).

Abstracts from the book of Apostolos Konstandinideis called ‘EARTHQUAKE RESISTANT BUILDINGS’, Volume A,
chapter 3.1, published in low resolution in the site of pi-SYSTEMS International S.A. www.pi.gr 101
COLUMN 30 x 30cm (1
st


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In this method we assume that the entire height of the column is considered critical and
is reinforced with Ø10 stirrups for every 10cm. For the total height of 2.70m we need 27
stirrups, thus the onomatology of the reinforcement will be 27Ø10/10.
The node area is covered with 5 Ø10 stirrups for every 10cm. This is displayed in the
drawings as 5Ø10/10.
Abstracts from the book of Apostolos Konstandinideis called ‘EARTHQUAKE RESISTANT BUILDINGS’, Volume A,
chapter 3.1, published in low resolution in the site of pi-SYSTEMS International S.A. www.pi.gr