▁of ▁a ▁bridge ▁with ▁vertical ▁pi ers . ▁ ▁However , ▁this ▁system ▁is ▁less ▁commonly ▁used ▁in ▁rig id ▁frame ▁brid ges ▁because ▁the ▁pi ers ▁need ▁to ▁be ▁approximately ▁centered ▁under ▁the ▁bridge . ▁ ▁O ften ▁the ▁brid ges ▁span ▁over ▁road ways ▁or ▁water ways ▁and ▁construction ▁of ▁pi ers ▁in ▁those ▁cases ▁can ▁be ▁cost ly ▁and ▁challeng ing . ▁ ▁B atter - post ▁ ▁B atter - post ▁rig id ▁frame ▁brid ges ▁are ▁defined ▁by ▁their ▁supports ▁that ▁run ▁from ▁the ▁deck ▁to ▁the ▁ab ut ments ▁at ▁an ▁angle . ▁This ▁design ▁supports ▁the ▁deck ▁in ▁a ▁similar ▁way ▁to ▁v - sh aped ▁pi ers ▁but ▁diff ers ▁in ▁how ▁the ▁found ations ▁must ▁be ▁built . ▁The ▁pi ers ▁bear ▁on ▁or ▁next ▁to ▁the ▁ab ut ments , ▁elimin ating ▁the ▁need ▁for ▁found ations ▁directly ▁beneath ▁the ▁bridge . ▁This ▁is ▁particularly ▁advantage ous ▁when ▁the ▁bridge ▁cross es ▁a ▁river ▁and ▁construct ing ▁a ▁foundation ▁in ▁the ▁water ▁is ▁challeng ing . ▁As ▁a ▁result , ▁either ▁the ▁ab ut ments ▁have ▁to ▁be ▁made ▁larger ▁or ▁additional ▁found ations ▁must ▁be ▁placed ▁next ▁to ▁the ▁ab ut ments . ▁ ▁Rec ent ▁adv ances ▁In ▁the ▁past ▁few ▁years , ▁most ▁research ▁on ▁rig id ▁frame ▁brid ges ▁is ▁related ▁to ▁retro f itting ▁existing ▁structures ▁to ▁meet ▁new ▁se ism ic ▁specific ations . ▁This ▁research ▁often ▁finds ▁that ▁the ▁amount ▁of ▁rein for cing ▁required ▁at