TRIAL PIT & BOREHOLE

TRIAL PIT AND BOREHOLE

• 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.

• To identify whether the site is suitable for the proposed work.

TRIAL PITTRIAL PIT• Shallow excavations to a depth no greater

6m.

• Support use are timbering, steel frames with hydraulic jack, battered or tapered side.

• Suitable for most low rise developments. • Suitable for the investigation of all types of

land.

Depth Excavation Method

0-2m By Hand

2-4m Wheeled Back Hoe

4-6m Hydraulic Excavator

ADVANTAGES DISADVANTAGES

•Preferred for

cohesive soil and soft

rock.

•Easy dug / excavated

using diggers.

•Showing clear land

strata to facilitate

rough inspections.

•Depth is limited.

•Deeper excavation will

require the human

energy.

HYDRAULIC EXCAVATOR

WHEELED BACK HOE

BOREHOLEBOREHOLE

• Excavations to a depth above 6m depth.

• Excavation method using drilling rig machine.

• Common method of site investigation.

ADVANTAGES DISADVANTAGES

•Can extract mineral

resources.

•Work becomes easier

and faster.

•Can excavated soils

to a depth above 6m.

• Require skilled

workers to do the work

of drilling.

•Labor cost expensive.

•Noise that interferes

with public.

Drilling rig machine