In-Situ Stress

Model: EKE 220

For measuring in-situ rock stress close to the surface of excavation. The method consists of cutting a slot, thereby relieving the stresses perpendicular to the slot, resulting in the deformation of the slot, which is measured. Flat Jack is then embedded in the slot and grouted. Hydraulic Pressure is applied through the flat jack until the displacements which took place on slot cutting are reduced and finally canceled. By measuring the cancellation pressure in two mutually perpendicular directions, the in-situ stress close to the rock surface can be assessed approximately.

Flat Jack Outfit
The equipment comprises the following:

• EKE 22001 Flat Jack, 30 cm x 30 cm 1 No.
• EKE 22002 Hydraulic Pump, hand operated, with 15 cm dial Pressure Gauge of 70 kg/cm² capacity with flexible Pressure Pipe of 1 m length 1 No.
• EKE 22003 Deformeter, consisting of a Dial Gauge having 10 mm travel and 0.002 mm least count, and two interchangeable Stems for 150 mm and 250 mm gauge length 1 Set
• EKE 22004 Standard Bar 1 No.
• EKE 22005 Reference Pins 6 Nos.

Note: Flat Jacks of other sizes and capacities can also be manufactured on request.