The study looked at how water pressure in wet sand changes when it's squeezed repeatedly. They found that when the stress on the sand goes above a certain point, the water pressure keeps rising until it matches the pressure on the sand. This weakens the sand's strength. Below that point, the water pressure stops increasing no matter how many times it's squeezed. The water pressure jumps up when the squeezing direction changes, causing the sand to shrink. The water pressure doesn't always go up with the squeezing, and it goes down when the sand changes shape. This helps us understand how wet sand behaves under pressure.