The specimen was instrumented across five sensor categories to capture the full response of the soil-DECB-column system, including structural strain, structural acceleration, foundation kinematics, and free-field soil motion. All ETNA2 triaxial accelerometers and CMG-40 broadband seismometers were synchronized to a common GPS time reference. All remaining sensors (Kistler uniaxial accelerometers, Waycon laser displacement sensors, and strain gauges) were recorded independently and are provided in raw and converted format only.

Uniaxial strain gauge (120 ± 0.5 Ω) — measured quantity: axial strain; units: μm/m; total number: 12, distributed across the column flanges and web; recording direction: vertical (z-direction only); location IDs 5.1–5.12; data formats: raw (.xy) and converted.

ETNA2 triaxial accelerometer (Kinemetrics) — measured quantity: acceleration; units: m/s²; total number: 6, of which 2 are mounted on the foundation slab (location IDs 1.1–1.2) and 4 on the concrete top block (location IDs 2.1–2.4); recording directions: north-south, east-west, vertical; sampling frequency: 500 Hz; synchronized to GPS time reference; data formats: raw (.sac), converted, and synchronized.

Kistler uniaxial accelerometer — measured quantity: acceleration; units: m/s²; total number: 6, monitoring vertical accelerations at the grade beams and base plate along both the east-west and north-south directions; location IDs 4.1–4.6; data formats: raw (.xy) and converted.

Waycon laser displacement sensor — measured quantity: displacement; units: mm; total number: 6, of which 4 record vertical displacement of the grade beams and base plate (location IDs 3.1–3.4) and 2 record horizontal displacement of the column and top block (location IDs 3.5–3.6); data formats: raw (.xy) and converted.

CMG-40 triaxial broadband seismometer (Guralp Systems) — measured quantity: velocity; units: m/s; total number: 5, deployed on the soil surface at varying distances from the test specimen along both the east-west and north-south directions; location IDs 0.1–0.5; sampling frequency: 200 Hz; synchronized to GPS time reference; data formats: synchronized only.

Data formats summary: raw recordings are provided as .sac files for ETNA2 instruments and as two-column .xy files for Kistler accelerometers, Waycon lasers, and strain gauges. Converted files (.conv.xy) contain data processed into standard engineering units following baseline correction using the Seismic Analysis Code (SAC) software, applying the rmean (mean removal) and rtrend (linear trend removal) commands. Synchronized files (.sync.xy) contain time-aligned recordings for ETNA2 and CMG-40 instruments only, referenced to a common GPS time zero.

File naming convention: files follow the pattern date (YYYYMMDD), vibration type string (FVA, FVAB, or FVABC), location ID, recording direction (n for north-south, e for east-west, v for vertical), unit type (acc for acceleration in m/s², vel for velocity in m/s, dis for displacement in mm, str for strain in μm/m), and processing stage (raw.sac for ETNA2 raw data, raw.xy for Kistler/Waycon/strain gauge raw data, conv for converted, sync for synchronized). Example filename: 20260514_FVABC_1.1_n_acc_sync.xy.

Known data gaps and quality flags: soil instrument 9085/T4K20 (location 0.3) has no north-south recordings for the FVA experiments. Soil instrument T4K21/9084 (location 0.5) consistently recorded velocity amplitudes substantially higher than those of adjacent seismometers throughout the campaign; the source of this discrepancy was not identified during data processing and users are advised to apply independent quality-control procedures to this channel before use. Waycon laser 4.6 did not provide reliable measurements across multiple tests of the campaign.