Permanent and Transient loads
Permanent loads remains in the bridge for an extended period of time, usually for the entire service life. Loads like self-weight of girders, deck, wearing surface, curbs, parapets, railings, utilities, luminaries, and pressures from earth retainments.
Transients loads are like gravity loads due to vehicular, railways, pedestrian traffic, wind, water, earthquake, fire, ice floes, ships and vehicular collisions and temperature fluctuations.
AASTHO used permanent loads:
- Dead load of structural components and non structural attachments (DC)
- Dead load of wearing surfaces and utilities (DW)
- Dead load of earth fill (EV)
- Earth presure load (EH)
- Earth surcharge load (ES)
- Locked-in erection stresses (EL)
- Downdrag (DD)