This educational application supplements, but does not replace, the official AASHTO LRFD Bridge Design Specifications, applicable state DOT manuals, project specifications, and professional engineering judgment.
Graded quiz
Chapter 15 — Seismic Design of Bridges (8 questions)
Chapter 15 — Seismic Design of Bridges (8 questions)
8 questions · PE-exam format · 70% to pass · attempts save to your progress record when signed in.
Work each item to the requested precision. Use the Show clue button only after an honest attempt — hints reveal the AASHTO section and setup, not the answer.
- Q1AASHTO's Seismic Design Category (SDC) is determined by:
- Q2Single-mode base shear. W = 3000 kip, T = 0.9 s, C_sm = S_D1/T with S_D1 = 0.40. Compute C_sm and V = C_sm·W (kip). Use response modification R = 3.kip
- Q3The response modification factor R = 3 for a multi-column bent implies:
- Q4Confinement steel (SDC D). Spiral D_c = 30 in, f'_c = 4 ksi, f_yh = 60 ksi. Compute ρ_s,min = 0.12·f'_c/f_yh for spirals in the plastic hinge (AASHTO Guide Spec §8.6.2).-
- Q5Capacity-protected foundations under the Guide Spec are sized for:
- Q6Displacement demand (single-mode). T = 0.9 s, S_D1 = 0.40, S_DS = 1.0. If T ≥ T_S = S_D1/S_DS, S_a = S_D1/T. Compute spectral displacement S_d = S_a·(T/(2π))²·g (in). Use g = 386.4 in/s².in
- Q7The design response spectrum per AASHTO §3.10 uses which soil site classes?
- Q8Seismic isolation shifts the fundamental period to typically:
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