Factors Affecting the Weight of a Steel Hall (Soole)
1. Span Width:
Increasing the span width directly increases the length of roof beams, which leads to an increase in the overall weight of the structure. In steel halls with spans exceeding 20 meters, this weight increase becomes exponential. For spans greater than 30 meters, the use of plate girders for roof beams without intermediate columns is not recommended, as it significantly increases the structural weight.
2. Height of the Steel Hall:
An increase in height means taller columns and consequently more structural weight. Additionally, greater height leads to higher exposure to wind loads, which further contributes to an increase in weight.
3. Length of the Hall:
Although the hall length does not directly influence the total weight, it improves the weight-to-area ratio. This is because as the number of frames increases (and therefore the overall weight), the covered area also increases. It is important to note that certain structural elements like bracings are constant and do not depend on hall length. Thus, increasing the length improves the structural efficiency by reducing the relative weight per square meter of coverage.
4. Snow Load in the Region:
One of the most critical factors affecting steel hall weight is the regional snow load. For regions with snow loads of 200 kg/m² or more, the weight per square meter of the structure rarely drops below 40 kg/m². Additionally, wider spans (over 20 meters) further amplify the snow load’s impact, causing a rapid increase in structural weight.
5. Other Applied Loads:
Generally, the more varied and heavier the loads, the heavier the steel hall will be. One common load to consider is the crane load. The presence of a crane and the dynamic loads it imposes on columns significantly increase the required section sizes and thus the overall structural weight. This effect becomes more severe with cranes of 10 tons or more. Additionally, wider spans exacerbate the crane's impact on columns, further increasing the weight.
Another load factor is the presence of mezzanine floors. Not all halls include mezzanines, but those that do are significantly heavier than typical single-level halls. The weight difference between mezzanined and non-mezzanined halls can reach up to 50%. While these structures use more materials, they offer the advantage of increased usable space, especially valuable for projects with limited site area. Given both the added weight and functional floor space, careful consideration must be given by the client when deciding whether or not to include mezzanines.
6. Construction of Twin or Multi-Bay Halls:
When multiple halls are to be constructed for a single project and the site layout allows, it is beneficial to build the halls adjacent to one another rather than leaving gaps between them. This approach enables the use of a shared column between two halls, reducing steel consumption and lowering structural weight. It also enhances resistance against lateral loads such as wind. However, this method is most effective in areas with snow loads below 200 kg/m². In regions with heavy snow, snow accumulation between adjacent roofs may negate the weight-saving benefits of this approach.