JKR/ MACKINTOSH PROBE•The Mackintosh Probe is alightweight and portablepenetrometer. It is a considerablyfaster and cheaper tool than boringequipment especially when thedepth of exploration is moderate andthe soils under investigation are softor loose• Mackintosh Probe which has 30°cone penetrometer while JKR Probeshas 60° cone penetrometer.
• Based on the principles stated by HUARSLEV (1948) for drive rods for soundings and sampling and recommended methods for static and dynamics soundings by Europeans groups and subcommittee (1968).• The rods consist of 16mm diameter High Yield Steel each of length approximately 120cm. Then the rods are connected to each other by 25mm outer diameter couplings.Coupling = provide the lateral supports to the rods to prevent buckling during driving the rods.• Driving is performed with a small hammer of 5kg and falling vertically though a fixed height of 30cm along a guide a rod.• The total numbers of blows required for the pointer to penetrate a distance of 30cm is recorded and used as a measure of the consistency of cohesive soil and the packing of granular soil.
For every in-situ or laboratory test that had been carried out must have an aim or an objective. The objectives of the JKR/Machintosh Probe Test are:
Collecting a disturbed soil sample forgrain size analysis and soil classification.Determine the sub-surface stratigraphyand identify materials present.Evaluate soil density and in-situ stresscondition.Estimate geotechnical parameters.
ADVANTAGES• Light and easy user.• Does not need skill worker.• Economical.• Provides a disturbed soil sample for moisture content determination.• Faster and cheaper tools
DISADVANTAGES• Contribute to human error. -wrong counting• Low impact energy. -only can penetrated in shallow soil (limited depth)• Unable to penetrated into medium strength soil and gravelly ground.
1. Equipments for the test are assembled. Thecone diameter is measured in SI unit.2. The boring rods and hammer are joint using therod coupling. Grease is sweep up for an easydissembles later.3. Distance of 0.3 m is measured and marked onthe rod start from the tip of the cone.4. The equipment is set up on the ground.5. The hammer is pulled until it reached themaximum. The hammer is dropped freely todriven the cone into the soils.6. The sum of the number of blows for penetrationof 0.3 m is recorded in the data sheet.
7. The hammer is taken off on the last 0.3 m of each rod andjoined the existing rod with another rod and lastly the hammer.The blow is continued and stopped when:· The blow is more than 400 for 0.3 m penetration· The depth reached 15 m8. Pull the rods using lifting tools after the penetration reachedthe requirement.9. The equipment is dissembled and cleaned before storing.