Trial Pits :

A trial pit is an excavation of ground in order to study or sample the composition and structure of the subsurface, usually dug during a site investigation, a soil survey or a geological survey. Trial pits are dug before the construction. They are dug to determine the geology and the water table of that site. Trial pits are usually between 1 and 4 metres deep, and are dug either by hand or using a mechanical digger.

Field Density Test (FDT) :

In this test, the density of soil in-place is determined by using two methods :

1. The Drive-Cylinder Method ( according to ASTM D2937 ).
2. The Sand-Cone Method ( according to ASTM D1556 )