In India, some bridge engineers have doubts on point of application of horizontal load. Some people consider the point of application of longitudinal and transverse load at the bearing level.
Longitudinal force :
The longitudinal forces shall be considered as acting horizontally through the knuckle pins in case of bearings having rocking arrangement or through girder seats in case of sliding, elastomeric or PTFE bearings for the design of bearings and substructure.
The force is to be applied at the top of the bearings for the earthquake in the longitudinal direction.
Point of application
at the level of bearing (Ref. cl. 220.127.116.11 of IRS Bridge Rule & Clause 219.5, Annexure D of IRC: 6-2016)
Transverse force :
The horizontal force is required to be applied at the centre of mass of the superstructure horizontal deflection at the top of the pier/ abutment for the earthquake in the transverse direction.
Point of application:
The centre of mass of the superstructure (Ref. cl. 18.104.22.168 of IRS Bridge Rule & Clause 219.5, Annexure D of IRC: 6-2016)
What are the load on bridges?
The dead load, superimposed dead load, Full live load (without any reduction), live load on a footpath, earthquake load, earth pressure, erection load such as cranes, machines etc, prestressing load, hydrodynamic load, buoyancy load, shrinkage load, creep load, temperature load etc.