Domain: Engineering — Geotechnical Engineering
Target concept: Comparison of the Effects of Impact Compaction and Static Compaction

Video generation prompt: Use two sandboxes filled with loose sand. A static pressure (weight of X) is applied to sandbox A, while a shock pressure of the same weight X is applied to sandbox B. Observe and compare the density and height of the sand in both sandboxes.

Evaluation guide:
(i) Target concept: Granular soil densification under dynamic vs. static loading.
Minimum mechanism: Sand must behave as a cohesionless, frictional granular solid; impact must deliver transient kinetic energy sufficient to overcome inter-particle friction and induce rearrangement; static load must apply only sustained normal stress without acceleration-induced mobilization.
(ii)Storyline: [Frame 0–1] Two labeled sandboxes with loose sand at equal initial height, fully visible in fixed side-by-side view. [Frame 2–3] Weight lifted above sandbox A and lowered steadily into contact, then held immobile. [Frame 4–5] Same weight lifted to identical height above sandbox B and released: contact occurs, brief surface deformation visible, weight rebounds/retracts. [Frame 6–9] Both sand surfaces settle; final state shows B uniformly lower and smoother than A. Perspective: frontal, eye-level, full-container framing; no obstructions; sand surface always in focus and evenly illuminated.

Manual:
Experimental Procedure
1. Place two identical transparent sandboxes side-by-side, each filled with same volume of loose dry sand.
2. Gently place identical weight X onto center of sandbox A and hold still.
3. Drop identical weight X from short height onto center of sandbox B.
Observation of Experimental Phenomena
- Sandbox A: sand compresses slightly, retains visible grain separation and slight surface mound.
- Sandbox B: sand compresses significantly, surface becomes flatter and denser, final height lower than A.
Summary of Experimental Principles
Impact compaction produces greater density increase than static compaction under equal force due to energy transfer inducing particle rearrangement and void reduction.

Prompt Grounding rubric:
level_1: No sandboxes appear, no weight object appears, and no static-versus-shock action is shown; the clip shows unrelated content or a blank scene with nothing to compare in sand height or density.
level_2: Two containers appear, but they are not both clearly filled with sand or not clearly labeled A and B; only one weight object is applied to only one container, with nothing showing what static loading versus shock loading looks like; the two containers are not shown together in a way that lets a viewer compare them.
level_3: Sandbox A and sandbox B, each filled with loose sand at a matching starting height, sit next to each other in the same shot; two matching weight objects appear; the weight on sandbox A is set down gently and stays in place (static loading); the weight on sandbox B makes contact and then lifts away again (shock loading); both sand surfaces are visible before and after each action.
level_4: All elements of score 3 are present, and the two weight objects look identical to each other in shape, color, and size; the labels A and B stay legible next to their respective sandboxes; the shock action on sandbox B clearly shows a distinct impact-then-rebound motion rather than a smooth placement; both sand surfaces stay fully visible with nothing blocking the view of either one.
level_5: All elements of score 4 are present, and the shock action on sandbox B happens as one unbroken motion (contact, brief surface dip, rebound) without pausing or repositioning the weight partway through; the static weight on sandbox A stays completely still after being set down; both sand surfaces sit at the same height in frame and are lit evenly enough to compare directly; nothing obscures the texture or outline of either sand surface.

Scientific and Causal Correctness rubric:
level_1: There is no visible difference between sandbox A and sandbox B after the actions, or sandbox B (shock) ends up taller or looser-looking than sandbox A (static); the sand behaves like a liquid or a dust cloud rather than a granular solid that holds a surface shape.
level_2: Only one of the two sandboxes shows any height change, or both end up at the same height and surface appearance; the impact on sandbox B throws sand out of the container or carves a crater, which is more violent than a low-energy compaction; or the static weight on sandbox A keeps sinking without the sand ever settling into a stable surface.
level_3: Sandbox B's final sand surface sits visibly lower than sandbox A's; both sandboxes still look like solid sand, with no liquid-like flow, dust cloud, or flying grains; the lower surface in sandbox B is even across the whole box rather than lower in just one spot; no sand spills over either container's edge.
level_4: All elements of score 3 are present, and sandbox B's surface looks flatter overall than sandbox A's, with no small hills or loose mounds remaining in B; sandbox A's surface keeps a visible mound or uneven texture where the weight was set down; neither surface shows cracking or caving in; the height difference between A and B stays visible for the rest of the clip.
level_5: All elements of score 4 are present, and sandbox B's surface is uniformly level and smooth from edge to edge with no dimples or high spots; sandbox A's surface clearly keeps its looser, slightly mounded shape where the static weight sat; the height and surface-flatness difference between A and B never reverses or flickers back and forth once it is established.

Spatiotemporal Consistency rubric:
level_1: The weight or the sand jumps instantly from one position or shape to another with no motion in between; the overall scene brightness changes abruptly partway through the clip; a sandbox's position jumps to a different spot in the frame; the sand surface tears or warps instead of deforming smoothly; a weight object appears or disappears without ever being seen moving into place.
level_2: The weight's path from being lifted to making contact skips visible steps, as if parts of the motion are missing; the sand surface flickers or breaks up visually during the impact or placement; one sandbox is briefly blocked from view and then reappears at a different height with no visible cause for the change.
level_3: Both sandboxes and both weights stay in the same place relative to the frame throughout; the weight's motion toward each sandbox is smooth with no jumps or freezes; the sand surface in sandbox B deforms smoothly during impact and settles without snapping or tearing; the scene's overall brightness and light direction stay the same from start to finish; neither container nor the sand structurally tears or bends unnaturally.
level_4: All elements of score 3 are present, and the camera holds one fixed framing with no pan, tilt, or zoom for the whole clip; the weight travels straight down, centered over its sandbox, rather than at an angle; the sand deformation in sandbox B spreads out evenly from the point of impact rather than bunching to one side; no blurring or double-imaging obscures the weight or sand at any point.
level_5: All elements of score 4 are present, and the moment the weight lands in sandbox B lines up naturally with sandbox A already sitting still, with no jarring cut or mismatch in timing between the two; no part of the dropping or placing motion repeats or skips a beat; every motion looks physically grounded, with no floating pause before the drop and no unnatural bounce; the edges of both sandboxes stay sharp and steady throughout.