Bridge Engineering

A: Option A would give slow geometry change without the sharp shear cracks at the piers, Option C shifts internal forces but doesn't spike pier reactions overnight, Option D stays local at the deck ends, while Option B explains restrained thermal expansion driving compressive forces into piers and cracking them while forcing midspan deflection.

A: Option A worsens vibration amplitudes and chews up fatigue life, Option B changes boundary conditions and invalidates correlation, Option C avoids the symptom without learning the cause, while Option D controls excitation and lets you compare measured dynamics to code load models.

A: Option A breaks contractual compliance and can trigger rework claims, Option B mixes limit states and partial factors inconsistently, Option D overreaches if the annex isn't cited, while Option C aligns with contract law and controlled change under MOC.

A: Option A is directly mitigated by the kerb geometry, Option C comes from hydraulic action not rolling stock, Option D affects maintenance not life safety, while Option B remains because containment doesn't stop a derailed train slamming into substructure.