What condition can make soil hard for the HYEX to excavate?

The correct answer, which refers to weather-hardened conditions, highlights a state of soil that has become compacted and solidified due to exposure to elements such as sun and wind over time. This process can transform the soil into a hard and dense material, making it significantly more challenging for a hydraulic excavator to dig through.

When soil is weather-hardened, its structure is tightly bonded, which means that the excavator's bucket may struggle to penetrate and loosen it effectively. Consequently, this can result in reduced efficiency and increased wear on the equipment.

In contrast, wet conditions can typically make soil easier to excavate, while loose soil conditions generally allow for simpler digging, as the soil particles are not tightly bound. Dry, sandy conditions might present challenges concerning stability, but they do not generally exhibit the same level of hardness as weather-hardened soil.