/// Calculates the soil coefficient based on settlement and foundation load.
/// Returns a high value (999_999.0) if settlement is zero or negative to avoid division by zero.
///
/// # Arguments
///
/// * `settlement` - The settlement of the foundation in meters.
/// * `foundation_pressure` - The load on the foundation in tons.
///
/// # Returns
/// * The soil coefficient in tons per cubic meter (t/m³).
/// Calculates the soil coefficient based on bearing capacity.
/// Uses a factor of 400 as specified in empirical design practice.
///
/// # Arguments
///
/// * `bearing_capacity` - The bearing capacity of the soil in tons per square meter (t/m²).
///
/// # Returns
/// * The soil coefficient in tons per cubic meter (t/m³).