Published December 2016
This guidance is written for mechanically excavated unsupported trial pits and trenches used for geotechnical and geoenvironmental investigations.
Deep trial pits and trenches or those which require person entry should be planned, designed and excavated in accordance with The Construction (Design and Management) Regulations 2015, 22 (Excavations)
Trial pits and trial trenches can be used for making a rapid check of the condition of the ground. They permit examination of both horizontal and vertical faces exposed as the pit is dug/advanced.
All trial pitting activities including site preparation, excavation, sampling, logging and backfilling must be planned and a suitable and sufficient site specific method statement and risk assessment produced. In most situations, CDM Regulations will apply.
All site personnel including the machine driver, the supervisor, the person responsible for logging and other ground specialists shall have sufficient knowledge of the specific tasks and sufficient experience and ability to carry out their duties.