What is the minimum number of tests a competent person must perform to classify the soil at an excavation site?

To classify the soil at an excavation site, the requirement is for a competent person to perform a minimum of two tests. This is crucial because a single test may not provide a comprehensive understanding of the soil's properties and behavior, which can vary significantly across a site. With two tests, a competent person can gather enough data to make a more informed and reliable classification of the soil type, ensuring that proper safety measures are implemented based on its characteristics. This practice supports a thorough evaluation of the soil, helping to identify potential hazards such as collapse or instability during excavation work.