What are the advantages of assigning the central pier and the abutment as fixed piers?

Abutment pier to be assigned as fixed pier while the bridge is quite long, the longitudinal loads due to earthquake are quite large.

Central pier to be selected as the fixed pier, the bridge deck is allowed to move starting from the central pier to the end of the bridge. However, if the fixed pier is located at the abutment, the amount of movement to be incorporated in each bearing due to temperature

1. Actually they are more safe than the suspensioned.

2. During the aggression attacks a small part of the structure can be affected comparing to the the suspended which'll get total collapse.

3. The central pier is easier in execution than else.

The advantges are :

1- fixed pries not allow the horizantl force in both way X.Y

2- More fixed for structure system in horizantal direction 

3- NO free movalble for piers in fixed case and resist the shear force 

Thanks for your invitation

Agreed with colleagues answers..

It is advantage for long span bridge. It used to carry high value of longitudinal loads or earthquake loads that causes bending stress. The fixed piers should be large and massive to resist the large value of earthquake loads

Thank you for the invitation

Agreed with colleagues

For abutment pier to be assigned as fixed pier while the bridge is quite long, the longitudinal loads due to earthquake are quite large. As the earthquake loads are resisted by fixed piers, the size of fixed piers will be large and massive. In this connection, for better aesthetic appearance, the selection of abutment as fixed piers could accommodate the large size and massiveness of piers. Normally abutments are relatively short in height and for the same horizontal force, the bending moment…

(i) For abutment pier to be assigned as fixed pier while the bridge is quite long, the longitudinal loads due to earthquake are quite large. As the earthquake loads are resisted by fixed piers, the size of fixed piers will be large and massive. In this connection, for better aesthetic appearance, the selection of abutment as fixed piers could accommodate the large size and massiveness of piers. Normally abutments are relatively short in height and for the same horizontal force, the bending moment induced is smaller.

(ii) For the central pier to be selected as the fixed pier, the bridge deck is allowed to move starting from the central pier to the end of the bridge. However, if the fixed pier is located at the abutment, the amount of movement to be incorporated in each bearing due to temperature variation, shrinkage, etc. is more than that when the fixed pier is located at central pier. Therefore, the size of movement joints can be reduced significantly.