The Mackintosh Probe is a lightweight penetrometer that is faster and cheaper than boring equipment, especially for moderate depths in soft or loose soils. It consists of 16mm steel rods connected by couplings that prevent buckling during driving with a 5kg hammer from 30cm above. The number of blows to penetrate 30cm is recorded and used to evaluate soil consistency, density, and parameters. It allows disturbed soil sampling and subsurface stratigraphy identification. Advantages include being light, easy to use, economical, and faster than other tools, while disadvantages include potential for human error, limited depth, and inability to penetrate medium-strength soils. The procedure involves assembling the probe, driving it with blows counted for 30cm intervals, until 15
3. JKR/ MACKINTOSH PROBE
•The Mackintosh Probe is a
lightweight and portable
penetrometer. It is a considerably
faster and cheaper tool than boring
equipment especially when the
depth of exploration is moderate and
the soils under investigation are soft
or loose
• Mackintosh Probe which has 30°
cone penetrometer while JKR Probes
has 60° cone penetrometer.
4. • 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.
6. 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:
7. Collecting a disturbed soil sample for
grain size analysis and soil classification.
Determine the sub-surface stratigraphy
and identify materials present.
Evaluate soil density and in-situ stress
condition.
Estimate geotechnical parameters.
8. ADVANTAGES
• Light and easy user.
• Does not need skill worker.
• Economical.
• Provides a disturbed soil sample for moisture
content determination.
• Faster and cheaper tools
9. 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.
11. 1. Equipments for the test are assembled. The
cone diameter is measured in SI unit.
2. The boring rods and hammer are joint using the
rod coupling. Grease is sweep up for an easy
dissembles later.
3. Distance of 0.3 m is measured and marked on
the 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 the
maximum. The hammer is dropped freely to
driven the cone into the soils.
6. The sum of the number of blows for penetration
of 0.3 m is recorded in the data sheet.
12. 7. The hammer is taken off on the last 0.3 m of each rod and
joined 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 m
8. Pull the rods using lifting tools after the penetration reached
the requirement.
9. The equipment is dissembled and cleaned before storing.