<simpleType name="ReferenceLengthBasisEnumType">
  <restriction base="string">
    <enumeration value="as_cast">
      <annotation>
        <documentation>The whole element as constructed, from the pile head to the toe.</documentation>
      </annotation>
    </enumeration>
    <enumeration value="embedded">
      <annotation>
        <documentation>The part of the element below the ground surface.</documentation>
      </annotation>
    </enumeration>
    <enumeration value="below_sensor">
      <annotation>
        <documentation>The part of the element from the sensor position down.</documentation>
      </annotation>
    </enumeration>
  </restriction>
</simpleType>