Seismic Behavior of Concrete Bridge Piers Reinforced with Steel or GFRP Bars

Acknowledgments

Notation

A_b

nominal area of reinforcement bar (mm²);

d_b

longitudinal reinforcement diameter (mm);

d_t

transverse reinforcement diameter (mm);

E_acc,u

accumulative energy dissipation at ultimate drift (kNm);

E_b

modulus of elasticity of reinforcement (GPa);

E_i

energy dissipated in one hysteretic cycle (kNm);

F

lateral force resisted by specimen (kN);

F_A

force measured in horizontal actuator (kN);

F_max

maximum experimental lateral force (kN);

f ′_c

average compressive concrete cylinder stress (MPa);

f_u

ultimate strength of GFRP reinforcement (MPa);

f_y

yield strength of steel reinforcement (MPa);

K_BM

effective stiffness of the benchmark specimen (kN/m);

K_e

effective stiffness (kN/m);

L_md

length from actuator to center of most-damaged region (mm);

L_p

average length of concrete damage (mm);

L_tot

total height of the column and footing (mm);

M

moment at the critical section (kNm);

M_max

maximum experimental flexural resistance (kNm);

P

axial load applied to the specimen (kN);

P_o

nominal axial load capacity specimen (kN);

p_i

displacement of linear potentiometer (mm);

s

center-to-center spacing of transverse reinforcement (mm);

Δ

adjusted tip displacement of the specimen (mm);

Δ_act

horizontal actuator displacement (mm);

Δ_base

lateral deformation of steel footing (mm);

Δ_e

effective yield displacement (mm);

Δ_foot

tip displacement due to lateral deformation of steel footing (mm);

Δ_u

ultimate displacement when lateral resistance reduces to 80% (mm);

Δ_uplift

tip displacement due to uplift in the steel footing (mm);

${\epsilon }_u$

strain at reinforcement rupture (%);

$\theta$

lateral drift of specimen (%);

${\theta }_{\mathrm{base}}$

rotation at base of specimen due to uplift (%);

${\theta }_{r,\mathrm{ULS}}$

residual drift at ULS displacement (%);

${\theta }_u$

ultimate drift when lateral resistance reduces to 80% (%);

${\theta }_v$

inclination of vertical actuators (rad);

${\theta }_y$

drift at first yield of longitudinal reinforcement (%);

μ_u

displacement ductility factor;

${\mu }_{\varphi }$

curvature ductility factor;

ρ_l

longitudinal reinforcement ratio (%);

ρ_v

transverse reinforcement ratio (%);

ϕ

curvature at the critical section (1/m);

ϕ_e

effective yield curvature (1/m); and

ϕ_u

ultimate curvature at the critical section (1/m).

References