Domain: Engineering — Geotechnical Engineering
Target concept: Differential settlement of twin columns due to uneven foundation compaction

Video generation prompt: Two identical model piles support a rigid beam, each located in separate soil boxes: the left one is compacted dense soil, and the right one is loose soil; a heavy object is placed at the center of the beam.

Evaluation guide:
(i) Target concept: Differential settlement of twin columns due to contrast in soil compaction state (dense vs loose), resulting in rigid-beam rotation.
Minimum mechanism: Soil must behave as a deformable particulate medium; columns must transfer load vertically to soil; beam must be rigid and continuous; no slippage or detachment at interfaces; settlement must be irreversible and monotonic under sustained load.
(ii)Storyline: Frame 0–2: Static setup. Twin columns upright in side-by-side soil boxes, beam resting level on both, heavy object not yet placed. Frame 3–4: Loading event. Heavy object appears at beam center with no positional drift. Frame 5–10: Response phase. Right column descends continuously while left column holds position; beam rotates clockwise as a rigid body; soil surface deforms only locally beneath right column base; all motion is smooth, bounded, and confined to vertical displacement and rotational tilt; fixed frontal viewpoint ensures side-by-side comparison remains visible throughout.

Manual:
Experimental Procedure
1. Place two identical model piles vertically into two separate soil boxes side-by-side.
2. Compact left soil box thoroughly; leave right soil box loose/uncompacted.
3. Mount a rigid beam across both pile tops.
4. Place heavy object at exact center of beam.
Observation of Experimental Phenomena
Right pile sinks downward visibly more than left pile; beam tilts downward on right side; left pile remains nearly stationary; soil surface around right pile shows local subsidence, left shows none.
Summary of Experimental Principles
Differential settlement occurs because loose soil has lower bearing capacity and higher compressibility than dense soil—under identical load, the right pile settles more, inducing rotation of the rigid beam.

Prompt Grounding rubric:
level_1: The scene is missing the basic geotechnical setup: no twin columns, no rigid beam spanning them, no two separate soil boxes, or no heavy object placed on the beam. At least three of these core elements are absent, mislabeled, or the two soil containers are not shown as distinct side-by-side boxes.
level_2: Twin columns and a rigid beam appear, but the setup is misconfigured: for instance the columns are not aligned under the beam's ends, the beam is not level before loading, one of the two soil boxes is missing or oddly shaped, the heavy object is absent or off-center, or the two soil boxes are stacked or overlapping rather than placed beside each other.
level_3: Two identical vertical columns support a single rigid horizontal beam resting on both column tops; two separate soil boxes sit side by side, each holding one column; a heavy object rests at the beam's center; all these elements are visible together from one fixed camera angle.
level_4: Everything from the 3-point level holds, and in addition the left soil box visibly reads as compacted (smooth, uniform surface with no gaps) while the right box visibly reads as loose (grainy, uneven surface with visible voids); the beam shows no bending before loading; and the two columns match each other in shape, color, and size.
level_5: Everything from the 4-point level holds, and additionally the compaction contrast is unmistakable (the left box's surface stays smooth and tightly packed while the right box's surface looks loose with exposed grains and slight subsidence around its column), the columns start upright and unrotated, the beam starts perfectly horizontal and remains unbroken and unbent throughout, and no stray objects, text labels, or overlays appear in the shot.

Scientific and Causal Correctness rubric:
level_1: Loading the beam produces no visible difference between the two columns (either both columns sink by the same amount, neither sinks at all, or the beam stays level throughout), so there is no evidence that the loose right-side soil settles more than the compacted left-side soil.
level_2: Only one column moves while the two soil boxes still look identical to each other (no visible dense-vs-loose contrast), or both columns sink by the same amount in the same direction, or the beam tilts without either column visibly moving, or settlement begins before the heavy object is placed on the beam.
level_3: After the heavy object is placed, the right column (in the loose soil) sinks visibly lower than the left column (in the compacted soil), the beam tilts down on the right side, the left column stays at its original height or sinks noticeably less, and the two soil boxes keep looking distinctly different (dense vs loose) before and after loading.
level_4: Everything from the 3-point level holds, and additionally the beam tilts only toward the right/loose side with no rightward-then-leftward reversal, no moment where both columns sink to the same depth, and the beam never separates from either column top.
level_5: Everything from the 4-point level holds, and additionally the right column keeps sinking steadily after loading with no pause or sudden rebound, the left column shows essentially no vertical movement for the whole sequence, the beam's tilt grows smoothly without wobbling or snapping to a new angle, and the ground dimples more visibly around the right column's base than around the left column's, matching the loose-vs-dense soil contrast.

Spatiotemporal Consistency rubric:
level_1: A column disappears and reappears at a different height instead of sinking continuously, the beam breaks apart or vanishes partway through, a soil box's position or orientation jumps abruptly, the scene's lighting switches drastically between one moment and the next, shadows vanish entirely or flip direction with no matching change in the light source, or the camera itself jumps or zooms without a smooth transition.
level_2: At least two of the following occur: a column visibly bends, buckles, or rotates instead of staying rigid; the beam's motion skips positions or freezes for a stretch instead of moving smoothly; the soil surface behaves like a liquid, flowing or cracking in physically impossible ways; a column momentarily separates from the beam above it or the soil below it.
level_3: The columns, beam, and soil boxes keep their shapes and relative arrangement throughout: the columns stay attached to both the beam above and the soil below, the beam moves as one rigid piece, and the soil boxes don't drift from their positions; the motion proceeds without frame drops or stutters, though minor timing imperfections may remain.
level_4: Everything from the 3-point level holds, and additionally any column-height change is purely vertical (no sideways drift or axis tilt of the column itself), the beam rotates smoothly about roughly its center without stretching or shearing, the soil surface deforms only in the small area right under each column base (no wholesale collapse or spreading), and no column visibly passes through the soil or the beam.
level_5: Everything from the 4-point level holds, and additionally the right column's downward movement is continuous and never reverses direction from start to finish, the left column's height visibly stays the same for the whole sequence, the beam's tilt angle increases steadily frame to frame without ever snapping back, and the local soil dimple appears only around the right column's base while the left box's surface stays undisturbed.