Assertion: trench | /r/HasProperty | open of possible loss of soil
Facets:
Source sentences:
text: Earth excavation to a depth of 2 ft (0.61 m) below the shield is permitted, but only if the shield is designed to resist the forces calculated for the full depth of the trench and there are no indications while the trench is open of possible loss of soil from behind or below the bottom of the support system.