Unlike dead loads and super dead loads, live loads are not fixed, and can vary with position and magnitude. In this article, we will explain a few basic points about
What are Live Loads?
As mentioned above,
Live loads are usually specified in units of kN/m2 or N/mm2
From the Japanese Building Code
Japanese Building Law stipulates a set of minimum design loads as shown below:
| Occupancy | Slabs, Secondary Beams | Girders, Columns and foundations (架構用) | For seismic design | ||
| N/mm2 | |||||
| a | Residential living areas | 1800 | 1300 | 600 | |
| b | Office | 2900 | 1800 | 800 | |
| c | Classroom | 2300 | 1800 | 800 | |
| d | Department stores / shop floors | 2900 | 2400 | 1100 | |
| e | Theaters, cinemas, performance halls, assembly halls, etc. | Fixed seating | 2900 | 2600 | 1600 |
| f | Buildings used by many people, for meeting or lots of seating | Other | 3500 | 3200 | 2100 |
| g | Car parking and car passageways | 5400 | 3900 | 2000 | |
| h | Corridors, entrances, stairs | Same as (f) when connecting to occupancies (c), (d) or (e) | |||
| i | Rooftop terraces or balconies | As per (a). However, in buildings used for schools / department stores, follow (d). | |||
In contrast to most other international building standards, live loads in Japanese design practice are separated based on the structural element being considered. As you can see, the live loads for a single occupancy, say office, are higher for slabs compared to girders. This is because there is a higher probability of the slab being heavily loaded locally compared to girders which support a larger tributary area.
Other Details to Consider
- Tributary Areas for Live Loading: Explained
- Reducible and Non-Reducible Live Loads
- Live Load Considerations for Seismic/Wind Loading