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Unformatted text preview: ; MPa/cm = & kgf/cm?/cm where P = load intensity
1.25 mm. corresponding to settlement Alternatively,
the K-value may be defined
( 0.70 kgf/cma ) divided by the corresponding
a standard 75 cm diameter steel bearing plate
3 100 kgf, say ET= d
Ii- = 0.70 -;T-kgf /cm*/cm where
d = settlement 2.4 Stiffening
for stiffening Plates - of plate of as a pressure of 0.07 MPa
That is when
is subjected to a load of 1 in cm.
Nest of plates stacked on the bearing test plate it. I
*Glossary of terms and symbols refating to soil engineering 4 (firsf w&ion ). 0 o-5 1;o l-5 SETTLEMENT FIG. 1 2-o 2.5 3.0 OF PLATE-mm RESULTOF PLATE BEARING
TEST ON NATURALSUBGRADE 3. APPARATUS - ( see Fig. 2 ), 3.1 Bearing Plates - It is a circular mild steel plate of 75 cm diameter
and 25 mm thickness. Smaller bearing plates of 45, 40 or 30 cm may also
3.2 Loading Attachment
- Loads are applied by means of a hydraulic
jack or a screw jack working against a reaction frame through bearing
plates. The loading attachment should have a capacity of at least 150 kN
( 15 000 kgf) equipped with ball and socket joint between the test load
The device should have an arrangeand the jack to avoid eccentricity.
ment for attaching to a truck, trailer, truss or any other equipment load
3.3 Jacks - Hydraulic or screw jack of 150 kN ( 15 OCOkgf ) capacity. 3.4 Proving Ring - One calibrated proving ring of capacity, 150 kN
( 15 000 kgf) with dial gauge to read to an accuracy of 0.002 mm. The
proving ring should have an accuracy of one-half percent of the load
5 6000kg min. 6000 kg min. PROVING RING BALL AN0 SOCKET STEEL JOIN1 CRIBDING
75cm NOTE - Support
FIG. 2 for load reaction shall DIA DIA SUPPORT PLATE PLATE be 210 cm minimum from bearing plates. SCHEMATIC DIAGRAM OF PLATE BEARING TEST 3.5 Loading Reaction -- The reaction for jacking can be provided by a
truck, trailer or anchor frame such that its reaction
shall be at least
2.5 m away from the centre of the bearing plates.
When the test is to bc
conducted on granular subgrades, a reaction of at least 150 kN ( 15 000 kgf )
will be required.
For cohesive soils a 50 kN ( 5 000 kgf) reaction
applied loads will be measured
by at least three Gal gauges uniformly
sp .tced 120” apart, preferably four uniformly placed at 90” apart, and placed
at about 10 mm away from the rim of 75-cm plate.
The gauges will be
6 1Sr 9214-1979
supported by an independent datum bar such that their positions are
These supports should be at least
unaffected by the loading operations.
2.4 m from the plates and the wheels. The settlement of the plate is taken
as the average of the readings of the dial gauges used for the purpose.
Gauges tifith an accuracy of 0.002 mm are desirable; however, gauges
with an accuracy of 0.01 mm may be - sed if time-reading; are made.
3.7 Jack-Pads - Due to variation ia the depth of test points some distance pieces, for example, spacers, will be required between jack and
proving ring. These can be solid cylindrical pieces of aluminium alloy or
any other suitable material to withstand and help in transferring heavy
loads on to the bearing plate. These spacers should be at least 15, ‘20
and 30 cm long. The exact requirement of these jack pads will vary from
one test point to another according to depth of test point below ground
3.8 Stiffening Plates -These
: diameter and 25 mm thickness. are mild steel plates of 60, 45 and 30...
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This note was uploaded on 03/14/2014 for the course CE 684 taught by Professor Prof.deepankarchoudhury during the Spring '13 term at IIT Bombay.
- Spring '13