TRIAL PITS AND HAND AUGER HOLES

Purpose ~ primarily to obtain subsoil samples for identification, classification and ascertaining the subsoil's characteristics and properties. Trial pits and augered holes may also be used to establish the presence of any geological faults and the upper or lower limits of the water table.

TRIAL PITS

General use ~ dry ground which requires little or no temporary support to sides of excavation.

Subsidiary use~ to expose and/or locate underground services.

Advantages ~ subsoil can be visually examined in-situ † both disturbed and undisturbed samples can be obtained.

HAND AUGER HOLES

General use ~ dry ground but liner tubes could be used if required to extract subsoil samples at a depth beyond the economic limit of trial holes.

Advantages ~ generally a cheaper and simpler method of obtaining subsoil samples than the trial pit method.

Trial pits and holes should be sited so that the subsoil samples will be representative but not interfering with works.