Gilson HM-380D User manual

1
INTRODUCTION
The Gilson model HM-380D Dead-Weight Direct Shear
Machine is a motorized unit for direct and direct/residu-
al shear testing of soil samples and uses a 10:1 dead-
weight beam loading system to apply vertical conning
pressures. These compact, self-contained units are
built for harsh laboratory environments and require lit-
tle oor space.
This Direct Shear Unit has a strain rate of 0.0001 –
0.3 in/min (0.0025 – 7.62 mm/min) with a maximum
shear displacement of 0.8in (20.3mm) and the travel
speed is set with the thumbwheels on the left side of
the unit. The residual shear force is determined by a
load cell while real time load settings and peak load are
displayed on the digital readout. Vertical load capacity
is 1,411lbs (640kg) and the maximum horizontal shear
force is 1,500lbf (6.67kN). Consolidation and shear
displacement are measured with Displacement Trans-
ducers and displayed on a digital readout.
Shear boxes and weight sets are required and sold
separately.
FEATURES
• Total shear capacity of 1,500lbf (6.67kN)
• Stepper motor controls strain rates to +/- 1% from
0.0001 – 0.3in/min (0.0025 – 7.62mm/min)
• Teon coated anodized aluminum water chamber
with drainage port included.
• Meets requirements for ASTM D3080 and AASHTO
T 236
REQUIRED ACCESSORIES (purchased separately)
Direct shear boxes are sold separately and are avail-
able in a wide range of inch and metric sizes with round
or square shapes. See all options at www.globalgilson.
com and in the chart.
Direct Shear Boxes & Accessories
Description Shear Box Cutters Extruders
Porous
Stones
Round Direct Shear Boxes
50mm (1.97in) Diameter
2.0in (50.8mm) Diameter
60mm (2.36in) Diameter
2.42in (61.4mm) Diameter
2.5in (63.5mm) Diameter
100mm (3.94in) Diameter
4in (101.6mm) Diameter
HMA-733M
HMA-733
HMA-734M
HMA-734
HMA-735
HMA-737
HMA-736
HMA-743M
HMA-743
HMA-744M
HMA-744
HMA-745
HMA-747
HMA-746
HMA-763M
HMA-763
HMA-764M
HMA-764
HMA-765
HMA-767
HMA-766
GSA-208
GSA-210
GSA-213
GSA-217
GSA-219
GSA-231
GSA-232
Square Direct Shear Boxes
50mm (1.97in) Square
2.0in (50.8mm) Square
60mm (2.36in) Square
2.42in (61.4mm) Square
2.5in (63.5mm) Square
100mm (3.94in) Square
4in (101.6mm) Square
HMA-733MS
HMA-733S
HMA-734MS
HMA-734SA
HMA-735S
HMA-737S
HMA-736S
HMA-743MS
HMA-743S
HMA-744MS
HMA-744SA
HMA-745S
HMA-747S
HMA-746S
HMA-763MS
HMA-763S
HMA-764MS
HMA-764SA
HMA-765S
HMA-767S
HMA-766S
GSA-208S
GSA-210S
GSA-213S
GSA-217S
GSA-219S
GSA-231S
GSA-232S
Rev: 07/2020
HM-380D Digital Direct Shear
Machine, Dead-Weight
Dead-Weight Direct Shear Machine with Linear Variable
Displacement Transducers, Four-channel Data Readout and
Shear Box shown (Shear Box sold separately)
OPERATING MANUAL
PHONE: [phone] P.O. Box 200, Lewis Center, Ohio 43035-0200
740-548-7298 E-mail: [e-mail] Product Web Page: www.globalgilson.com
FAX: [phone]
740-548-5314

2
UNPACKING & SETUP
• Inspect your Direct Shear Machine for damage,
remove from the pallet.
• Review connections section and install necessary
components.
• Assemble the dead weight lever arm. Remove all
packing material from arm and adjusting screw sup-
port bracket. Reposition the arm above the support
bracket holes and reinstall the support bracket. Next
install the 3.5in diameter counterbalance weight and
the weight platform.
CONNECTIONS
Vertical Displacement Transducer Rod – Screws
into the top platform to the right of the rear pull-down
rod.
Vertical Displacement Transducer Clamping Arm –
Attach to the above rod.
Vertical Displacement Transducer – Consolidation –
Attach to the clamping arm with the screw provided.
Connection is made at the rear of the readout box.
Horizontal Displacement Transducer – Shear – At-
tach to the threaded rod on the angle bracket-top plat-
form, right front. Connection is made at the rear of the
readout box.
Air Line – A constant supply of air is required. The air
inlet air pressure should not exceed 200 psi, nor should
it ever be less than 20 psi higher than the highest pres-
sure setting. The connection is a ¼” Swagelok, located
in the rear of the cabinet. Insert the tubing into the t-
ting until it bottoms out. With the nut nger tight, tighten
the tting 1 ¼ turns with a wrench. Do not over tighten.
Load Cell – Connect the load cell to the support cast-
ing at the right end of the direct shear using the two
knobs. Adjust the knobs so that the load cell is as far
to the right as possible. This will allow room for assem-
bling the water chamber and the shear rings with min-
imum interference. Connection is made at the rear of
the readout box.
Mini USB 2.0 Port – Connection is made at the rear of
the readout box to a computer.
Water Chamber – Special care should be taken to
see that the four (4) roller bearings between the water
chamber and the base slide tracks are properly cleaned
and contain a slight amount of oil during and after use.
We advise using a cover over the direct shear after
use to eliminate dust from entering the precision slide
assembly. The main drive shaft should be at its home
position. This will place the sample load pad in the cen-
ter of the crossarm for consolidation.
Shear Boxes (sold separately) – The shear rings are
held together with (2) stainless steel screws boxes.
There are also (4) screws for adjusting the gap be-
tween the rings once consolidation has been reached.
The gap is adjusted by turning the screws clockwise
from the nger tight position. One full turn will give
.031” gap. There is a line scribed on the adjusting knob
for determining how much gap each screw has provid-
ed. The screws should be turned evenly to maintain
a proper gap. At the bottom of each screw is a nylon
glide which keeps the top shear ring from dropping
during the test.
FRONT PANEL CONTROLS
The strain rate is controlled from the front panel thumb-
wheels. Machine must be plugged in to a properly wired
grounded receptacle with appropriate electrical current.
PANEL CONTROLS — POWER & SHEAR RATE
Power Switch – An indicator light is present when
power is turned on.
Strain Rate Selector – The strain rate is set with
thumbwheel selectors. The switches are direct reading
in inches/minute with an implied leading decimal point.
Weight Sets are required to apply the consolidation load and are available in both Pound and Kilogram sets.
Pound Weight Sets
Model Total Mass
Total Load at 10:1
Beam Ratio¹
Included Weight Sets
0.852lb (1/8tsf) 1.704lb (1/4tsf) 3.409lb (1/2tsf) 6.818lb (1tsf) 13.635lb (2tsf) 27.270lb (4tsf)
HMA-727
HMA-732
HMA-729
54.5lb
109.1lb
218.2lb
545lbf (8tsf)
1,091lbf (16tsf)
2,182lbf (32tsf)
2
2
2
1
1
1
1
1
1
1
1
1
1
1
1
1
3
7
¹tsf values indicate force applied to a 2.50in diameter specimen using a 10:1 beam ratio.
Kilogram Weight Sets
Model Total Mass
Total Load at 10:1
Beam Ratio
Included Weight Sets
1kg 4kg 8kg
HMA-730
HMA-725
HMA-731
32kg
64gk
88kg
320kg
640kg
880kg
4
4
4
3
5
5
2
5
8

3
Once the rate is set and the test is started, the switch
setting is ignored until the stop switch is pressed or a
limit switch is tripped.
Limit Switches – These switches are located on the
platform behind the water chamber.
Adjustment of these switches is made by loosening the
Phillips-head screws and moving the limit switch as-
sembly in the direction desired. The home position has
been set so that the load crossarm is in the middle of
the shear rings.
Note: The limit of travel of the drive shaft is dependent
on the limit switch settings. Do not operate the drive
motor with the water chamber disconnected because
this will make the limit switches inoperable.
Stop Switch – Momentary push button to stop the
motor.
Direction Switch – Momentary (spring loaded) switch.
After setting the desired shear rate, moving the switch
in the desired direction will initiate movement. This
switch will then become inactive until the stop button is
pressed, or a limit switch is activated. The left position
will move the water chamber to the left. It will continue
until the water chamber activates the limit switch. At
this time, the limit indicator light will be lit. The right
switch position will move the shear box to the right until
the home limit switch is made. See above note…
Home & Limit Indicators – Used to indicate the limit
of travel of the shear box.
Fuse – 4 amp SLO BLO fuse located in the cabinet
rear.
OPERATING INSTRUCTIONS
Read all operating instructions before performing a test
and refer to ASTM D3080 or AASHTO T 236 for com-
plete test procedures and calculations.
Set Up
1. Place the shear box into the water chamber and se-
cure the load cell shaft to the top of the shear box.
2. Tighten the two shear ring clamping knobs located
on the left side of the water chamber.
3. Install the counterbalance, Model HMA-735, if nec-
essary.
4. Tare the load cell by pressing the “Tare” button on
the digital readout.
5. Adjust the top cross arm and LVDT so there is 1/8in
gap between the cross arm and loading ball. Align
the cross arm pin so it is above the loading ball.
Make sure the cross arm is level.
6. Adjust the LVDT by raising or lowering the indicator
rod and holder so the tip of the LVDT is resting on
the cross arm pin.
Consolidation
The weight of the consolidation load arm with two up-
right rods lower cross arm and lower weight platform is
11.9lbs. The lever arm on the right side of the device
has been preset to a 10:1 ratio, select a consolida-
tion load and apply the required weights to the weight
hanger. The consolidation result is read on the Digital
Readout Box.
Refer to ASTM D3080 for consolidation calculations.
Direct Shear
1. After consolidation phase is complete, add a small
seating shear load by adjusting the two knurled nuts
on the load cell support.
2. Tare the shear load cell which is displayed on chan-
nel 1 of the digital readout box.
3. Remove the two holding screws on the shear box
to separate the top and bottom sections. Adjust the
four adjusting screws on the shear box to set the
gap between the top and bottom of the shear box.
One full turn of these adjusting screws will give a
0.031in (0.78mm) gap.
4. Set the shear/strain rate with the thumbwheels on
the left side of the machine. Each number is set by
pushing the thumbwheel button, the rate is in inches
per minute (0001 = 0.0001 in/min).
5. Tare the horizontal displacement LVDT on channel
2 of the readout box. To begin shear, switch the DI-
RECTION toggle switch to the left towards the LIMIT
light.
6. The water chamber with shear box will continue to
move at the set rate until the limit switch is activated
or the STOP button is pressed.
7. Load and Shear Displacement will be displayed
on channels 1 and 2 of the digital readout box and
transferred to an Excel le or the Direct Shear Data
Acquisition Software on the users connected com-
puter.

4
8. At the test completion, switch the DIRECTION tog-
gle to the right towards the HOME light. Press the
stop button when Zero load is reached on the load
cell, channel 1 of the readout box.
8A. If Residual Shear values are needed, these can be
determined during this time.
9. Reduce the vertical load to Zero by adjusting the
Fairchild Pressure Regulator until Zero psi is
reached on the digital readout box.
10. The Shear Box can now be removed from the
water chamber and the sample can be inspected.
MAINTENANCE
Special care should be taken to see that the four roll-
er bearings between the water chamber and the base
slide track are properly cleaned and contain a slight
amount of oil during and after use. It is recommended
to cover the Direct Shear machine when not in use to
prevent dust buildup.
Empty the water chamber after each test to prevent soil
and sand buildup inside the chamber. The water can be
drained from the port, or the chamber can be removed
from the Direct Shear Machine for thorough cleaning.
ACCESSORIES
HMA-739 Shear Box Counterbalance
HMA-610 Direct/Residual Shear Data Acquisition
Software