Which action is NOT permissible for excavation below support system members?

The action of excavating without evaluating soil conditions is not permissible because proper evaluation of the soil is critical for ensuring safety and stability during excavation operations. Understanding soil conditions helps determine the risk of collapse and informs the necessary precautions that must be taken. Excavations can be inherently dangerous, and factors such as soil type, moisture content, and the presence of groundwater must be thoroughly assessed before proceeding.

Evaluating soil conditions allows operators to implement appropriate protective measures, such as shoring or sloping, and to ensure that the excavation will not undermine support systems or adjacent structures. Neglecting this essential evaluation increases the risk of structural failure, which can lead to serious accidents or injuries. Therefore, conducting a thorough soil evaluation is a fundamental requirement for safe excavation practices.