Domain: Engineering — Structural Engineering
Target concept: Effect of Basic Form on Seismic Response

Video generation prompt: Two miniature building structure models with different foundation forms are presented side by side on the test platform. The left model features a strip foundation, while the right model has a raft foundation. Both are subjected to the same simulated seismic vibration.

Evaluation guide:
(i) Target concept: Foundation geometry governs global structural stiffness and dynamic response under base excitation.
Minimum mechanism: The raft foundation must act as a rigid diaphragm coupling all columns, suppressing differential settlement and rocking; the strip foundation permits independent rotation of individual supports, enabling greater free rocking motion under identical base acceleration.
(ii)Storyline: Frame 0–2: Static shot showing two identical buildings on shared platform, clearly labeled or visually distinguished as left (strip) and right (raft); Frame 3–4: Vibration initiates synchronously at platform base; Frame 5–8: Strip model immediately develops pronounced rocking motion around its longitudinal axis, while the raft model (its columns tied together by one continuous rigid slab) moves nearly in unison with the platform, showing markedly smaller sway and rocking amplitude; Frame 9–10: The contrast in sway amplitude between the two models remains stable and unambiguous until the end, with both models continuing to cycle at the same rate as the driving vibration. No recovery, collapse, or stabilization phase required. Perspective: Fixed frontal view, centered on platform, capturing full height of both models and full width of foundations; no obstructions; lighting front-diffuse to avoid glare and preserve shape legibility.

Manual:
Experimental Procedure
1. Place two identical miniature building models side-by-side on a rigid test platform.
2. Attach left model to a strip foundation; attach right model to a raft foundation.
3. Activate synchronized horizontal seismic vibration of the platform.
Observation of Experimental Phenomena
During vibration, the strip-foundation model exhibits larger lateral sway and more pronounced rocking about its longitudinal axis; the raft-foundation model shows smaller sway and moves nearly rigidly with the platform, its columns tied together by the continuous slab — both models cycle at the same rate as the driving vibration, and both remain upright and attached.
Summary of Experimental Principles
Strip foundations concentrate load on narrow bearing strips, offering lower stiffness and higher flexibility under lateral seismic forces; raft foundations distribute load over a large area, increasing system stiffness and damping, thereby reducing dynamic amplification and improving stability.

Prompt Grounding rubric:
level_1: No pair of miniature building models is visible on a test platform at all (either both models are missing or only a single model appears), so neither the strip-foundation building nor the raft-foundation building can be identified, and there is no evidence of a shaking-table setup.
level_2: Both a strip-foundation model and a raft-foundation model appear, but they are not shown together on one shared test platform (e.g., one appears in a separate shot, or the two overlap or stack on top of each other rather than standing apart); or one of the two foundation types is not visibly rendered (its base looks generic rather than a recognizable strip or raft); or the platform never visibly vibrates.
level_3: A strip-foundation building and a raft-foundation building sit side by side on one visible shaking-table platform; the left model's foundation reads as a long, narrow strip running under its columns, while the right model's foundation reads as one broad continuous slab spanning its whole footprint; the platform is vibrating and both models are being shaken at the same time.
level_4: Everything required for score 3 holds, and in addition the strip foundation is clearly narrower and more elongated than the raft slab, which clearly spans the entire footprint of its building; both foundations are properly attached beneath their respective buildings with no floating or gap between foundation and superstructure; the vibration is being applied to the whole platform rather than to just one of the two models.
level_5: Everything required for score 4 holds, and in addition the strip-foundation model occupies the left half of the frame and the raft-foundation model occupies the right half for the entire clip with no swapping or repositioning; both buildings share the same height, scale, and superstructure design so the foundation is the only visible difference between them; nothing occludes or distorts the side-by-side view; and the platform's vibration reaches both models simultaneously, without one starting before the other.

Scientific and Causal Correctness rubric:
level_1: During vibration the strip-foundation model and the raft-foundation model move in an essentially identical way (same sway amplitude, same rocking pattern), or either model tips over, detaches from the platform, or otherwise fails structurally, none of which reflects the expected difference between a narrow strip foundation and a full-footprint raft foundation.
level_2: A difference in motion is visible, but it runs backward from what strip vs. raft foundations predict: the strip-foundation model sways less than the raft-foundation model, or the raft model rocks and tips more than the strip model, or the raft model's slab visibly buckles or cracks while the strip model stays rigid. None of this matches how a narrow strip foundation (which lets each column rock somewhat independently) compares to a raft slab that ties all columns together.
level_3: Under the same driving vibration, the strip-foundation model visibly sways back and forth with larger lateral amplitude and more pronounced rocking about its long axis than the raft-foundation model, whose broad continuous slab keeps its columns moving together with markedly smaller relative sway; both models complete every cycle of the input vibration at the same rate as the platform (their oscillation frequency does not diverge from one another), and both stay upright and attached to the platform throughout.
level_4: Everything required for score 3 holds, and in addition the amplitude gap between the two models is present for the entire vibration interval (not just a momentary spike), no foundation separates from its building or from the platform on either model, and the raft model's smaller sway is visibly explained by its columns all moving together as one rigid unit rather than by any ambiguous or unrelated cause.
level_5: Everything required for score 4 holds, and in addition the contrast stays clear and sustained for the whole clip: the strip model keeps rocking prominently about its longitudinal axis with visibly larger excursions at its roofline, while the raft model's roofline sways only slightly and stays closely in phase with the platform's own motion, matching the expected kinematic difference between a flexible strip-founded structure and a stiff, raft-founded structure under the same base shaking.

Spatiotemporal Consistency rubric:
level_1: One of the two models (or the platform itself) vanishes and reappears between frames, jumps to a different spot on the platform, or the camera cuts to a visibly different framing mid-sequence; a foundation or column visibly detaches and reappears somewhere else without any physical cause; the lighting on the platform abruptly flips between bright and dark, or the shadows reverse direction, with no visible cause; or the shaking motion is so jerky that more than three visible frame freezes or skips interrupt the vibration cycle.
level_2: The strip model and raft model drift out of their original left/right positions relative to each other between frames (e.g., one appears to slide sideways on the platform with no mechanical cause); a foundation-to-building joint visibly separates and then reconnects; the platform's vibration abruptly starts, stops, or restarts without a corresponding change in the input; or the shadow cast by either model flips direction or intensity with no accompanying change in the lighting.
level_3: Both models stay fixed in their original left (strip) and right (raft) positions on the platform for the whole clip; the platform's shaking is continuous with no sudden starts, stops, or freezes; every structural piece (columns, foundations, floor slabs) keeps the same spatial relationship to the rest of its own building throughout, with no piece drifting apart from or merging into another.
level_4: Everything required for score 3 holds, and in addition each model's sway and rocking motion changes speed and direction smoothly frame to frame, with no sudden jump in velocity; neither building nor its foundation warps, stretches, or bends in an unnatural way; the two models never visually overlap or pass through each other or through the platform.
level_5: Everything required for score 4 holds, and in addition the camera holds one fixed framing with no pan, tilt, or zoom for the entire clip; the relative size and front-to-back layering of the strip model, raft model, and platform never shifts as they sway; and the sequence shows smooth, continuous motion of both models with no strobing, ghosting, or motion blur that would hide how each foundation is actually moving.