Domain: Engineering — Geotechnical Engineering
Target concept: Simulation Experiment on Vacuum Preloading Accelerating the Consolidation of Soft Soil

Video generation prompt: Two transparent containers filled with clay were used. Container A was open, while Container B was sealed and connected to a vacuum pump for evacuation. The settlement state and surface smoothness of the clay in both containers were observed and compared.

Evaluation guide:
(i) Target concept: Vacuum-induced consolidation of saturated soft clay via effective stress increase.
Minimum mechanism: Clay must be saturated (pore water present), vacuum must be applied to sealed system (no air inflow), and consolidation must manifest as irreversible downward settlement and surface densification (not drainage, evaporation, or mechanical compression).
(ii)Storyline: Frame opens on static wide shot showing two identical transparent containers side-by-side, both filled with homogeneous clay. Container A is clearly open (no lid, no tubing). Container B has sealed lid with visible tubing leading off-screen to vacuum pump (or pump visible). Vacuum pump activates (audible hum or indicator light optional but not required for visual scoring). Over time, Container B clay visibly lowers in height and its surface becomes progressively smoother and less fissured, while Container A clay remains unchanged in height and retains coarse, cracked texture. Entire sequence maintains fixed viewpoint, consistent lighting, and uninterrupted visibility of both clay surfaces.

Manual:
Experimental Procedure
1. Place two identical transparent containers side-by-side.
2. Fill both with identical saturated clay.
3. Leave Container A open to atmosphere.
4. Seal Container B and connect tubing to vacuum pump.
5. Activate the vacuum pump and continue observing as consolidation proceeds; note that on a real bench-scale sample this settling and surface-smoothing unfolds over minutes to hours as pore water pressure dissipates, so the sequence depicted here compresses/dramatizes that longer process rather than showing a literal few-second outcome.
Observation of Experimental Phenomena
- Container A clay: minimal settlement, rough and cracked surface.
- Container B clay: visible settlement (lower height), smoother and less cracked surface.
Summary of Experimental Principles
Vacuum preloading increases effective stress in saturated clay by reducing pore water pressure, accelerating consolidation and improving surface uniformity.

Prompt Grounding rubric:
level_1: No transparent containers appear; no clay is visible; no vacuum pump or tubing appears; the two containers are never shown together in the same shot; there is no way to compare settlement or surface texture between them.
level_2: Only one transparent container appears on screen, or the two are never shown in the same frame together; the vacuum pump and its tubing are missing or clearly not connected to anything; there is no visible difference set up between an open container and a sealed one.
level_3: Two transparent containers holding clay-like material appear together in the same shot; Container A has no lid or tubing; Container B has tubing that visibly runs to a vacuum pump (or a sealed lid); the clay surface and fill level in both containers can be clearly seen, not blurred or blocked.
level_4: Everything in the 3-point description holds, plus Container A stays clearly and continuously open the whole time (it never gains a lid or tubing), Container B's seal and tubing connection stay intact and visibly attached to the pump, both containers stay in the same relative position on screen throughout, and neither container is swapped out or moved mid-clip.
level_5: Everything in the 4-point description holds, plus Container A never becomes sealed even briefly, Container B's tubing never detaches even briefly, both clay surfaces stay fully visible for the entire clip, and the camera never pans, zooms, or cuts in a way that takes both containers out of frame at the same time.

Scientific and Causal Correctness rubric:
level_1: Container A and Container B's clay end up looking identical (same height, same amount of cracking), with no sign that turning on the vacuum pump did anything to Container B's clay specifically.
level_2: Container B's clay changes only slightly (e.g., a few grains shift), but it does not visibly sink lower or get any smoother than Container A's clay; the pump is clearly running, yet its clay's height and surface look about the same as the untouched Container A.
level_3: Container B's clay ends up noticeably lower (more settled) and visibly smoother or less cracked than Container A's clay, and this difference stays visible rather than flickering in and out.
level_4: Everything in the 3-point description holds, plus Container B's settling is straight downward with no bulging out the sides or rising up, its surface ends up fairly flat rather than lumpy, Container A's clay keeps its rough, cracked look throughout, and nothing unexplained happens (no bubbling, no water squirting out, no sudden collapse).
level_5: Everything in the 4-point description holds, plus Container B's clay keeps sinking and smoothing gradually and continuously, never rising back up or un-smoothing, Container A's clay never changes height or texture at all, and neither container shows pooling water, separated layers, or the clay turning soupy, all consistent with the vacuum drawing water out of the clay's pores rather than some other cause.

Spatiotemporal Consistency rubric:
level_1: One or both containers suddenly jump to a different spot or vanish between frames; the clay inside appears or disappears without being poured; the tubing on Container B detaches and reattaches with no hand or motion causing it; the picture flashes dark and light instantly for no reason; a container's walls bend or warp unnaturally.
level_2: A container shifts position or rotates slightly between frames without anything pushing it; the clay's surface blinks out of view for a moment and comes back; the tubing seems to disconnect and reconnect on its own; a bright highlight on the clay jumps instantly from one side to the other; a container's edge looks broken or jagged instead of smooth.
level_3: Both containers stay put in the same spots relative to each other; the clay surfaces in both stay visible the whole time; the tubing stays visibly attached to Container B without ever coming loose; neither container's shape stretches, bends, or overlaps with the other; any settling motion in Container B's clay is gradual and moves consistently downward, not jerky or reversing.
level_4: Everything in the 3-point description holds, plus the camera viewpoint itself never pans, tilts, or zooms; the room's lighting stays the same brightness and comes from the same direction the whole time, so the shadows the containers and clay cast keep the same shape and fall the same way throughout; there's no stutter or repeated frame, and Container B's settling proceeds steadily downward without pausing or bouncing back up.
level_5: Everything in the 4-point description holds, plus all motion (camera, settling, any pump vibration) looks smooth with no sudden jumps in speed; Container B's clay surface changes shape gradually with no tearing, floating chunks, or patches that seem to slide independently; the transparent container walls look optically consistent throughout with no flickering reflections or color fringing; and the settling motion never flickers or strobes.