PERMFILE52862

• Permit No: M1997054
• IBM Index Class Name: Permit File
• Section_Exhibit Name: EXHIBIT D MINING PLAN
• Media Type: D
• Archive: No

~) D 2664
itl two circumferential (horizontal) gages similarly located
ound the circumference, but in the direction perpendicular
the axial gages.
4.5 Flexible Membrane-A flexible membrane of suitable
aterial to exclude the confining fluid from the specimen,
id that shall not significantly extrude into abmpt stu{ace
recs. It should be suf5ciently long.to eicund well onto the
atcns and when slightly stretched be of the same diameter
the rock specimen.
Nore 2-Neoprene rubbu robing of tArin. (1.588-mm) wall thick-
rs and of 40 to 60 Durometer hardness, Shore Type A or various sizes
trityrJe inner tubing, have txen found generally suitable for this
egtrirot~• SsmP~g
c time S.1 The specimen shall be selected from the cons to
t resent a true average of the type of rock under consider-
I in ttie 'on. This tan be achieved by visual observations of mineral
eonstituenu, grain sins and shape, P8r[ings and defects such
pump pons and fisstrra.
dty.td
)ben is
nexpw-
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tus in
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which
105 in.
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.High-
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within
range,
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orma-
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:fly to
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a will
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Rinl
erimens
>fe Gom
yti. Tat Specimens
~c.6.1 Preparation-The test specimens shall be prepared in
Taccordance with Practice D 4543. -
h 6.2 Moisture condition of the specimen at the time of tat
'can have a significant effect upon the indicated strength of
the rock. Good practice generally dictates that laboratory
tuts be made upon specimens representative of field condi-
tions. Thus it follows that the field moisture condition of the
specimen should be preserved until the time of test. On the
other hand, there may be reasons for rating specimens at
other moisture contenu, including urn. In any case the
moisture content of the test specimen should be tailored to
the problem at hand and reported in accordance with 9.1.6.
7. Procedure
7.1 Place the lower platen on the base. Wipe clean the
bearing faces of the upper and lower platens and of the test
specimen, and place the test specimen on the lower platen.
Place the upper platen on the specimen and align properly.
Fit the Flexible membrane over the specimen and platen and
install rubber or neoprene O-rings to seal the specimen from
the confining Ouid. Place the cylinder over the specimen,
ensuring proper seal with the base, and connect the hydraulic
pressure ling. Position the deformation meazuring device
and fill the chamber with hydraulic Fluid. Apply a slight axial
load, approximately 25 lbf (110 N), to the triaxial compres-
sion chamber by means of the loading device in order to
properly seat the bearing parts of the apparatus. Take an
initial reading on the deformation device. Slowly raise the
lateral Fluid pressure to the predetermined tat level and at
the same time apply Sufi-icient axial load to prevent the
deformation measuring device from deviating from the
initial reading. When the predetermined test level of Fluid
pressure is reached note and record the axial load registered
by the loading device. Consider this load to be the zero or
starting load for the test.
7.2 Apply the axial load continuously and without shock
until the load become constant, or reduces, or a predeter-
mined amount of strain is achieved. Apply the load in such a
manner az to produce a strain rate az constant az feasible
throughout the test. Do not permit the strain rate at any
Sven time to deviate by more than 10 % from that selected.
The strain rate selected should be that which will produce
failtue of a similar test specimen in unconfined compression,
in a test time of between 2 and 15 min. The selected strain
rate Cor a given rock type shall be adhered to for all tau in a
given series of investigation (Note 3). Maintain constant the
predetermined confining pressure throughout the tat and
observe and record readings of deformation az required.
Nort¢ 3-Raulu of tats by other investigators have shown that
strain rata wihin this range will provide rircogth values that are
reasonably free from rapid loading elfecu and reprodudble within
acceptable toteanca.
7.3 To make sure that no testing fluid has penetrated into
the specimen, the specimen membrane shall be carefully
checked Cor fissures or punetura at the completion of each
triaxial test. If in question, weigh the spetamen before and
after the test.
8. Calculations
8.1 Make the following calculations and graphical plow:
8.1. I Conswct a stress difference versus axial strain curve
(Note 5). Stress difference is defined az the maximum
principal axial stress, ot, minus the lateral pressure, oa.
Indicate the value of the laurel presstrre, off, on the curve.
Nora 4-1f the specimen diameter is not the same as the piston
diameter through rho chamber, a correction mutt be applied m the
measured load to account for differcnoa in atu bttweCn the SpCGIDeo
and the loading Diston where it passes through the seals inm We
chamber.
No're 5-If the total deformation tr txorded during the test, suitable
alibrauoo (or apparatus deformation must be made. This may be
accomplished by inxrting into the apparatus a rieel cylinder having
known elastic propenia and obxrving differrnra in deformation
between the assembly and rieel cylinder throughout the loading range.
The appaatus deformation is then subtracted from the toW deforma-
tion at each increment of load in order to arrive at specimen deforma-
tion from which the axial strain otth specimen is computed
8.1.2 Construct the Mohr stress circle on an arithmetic
plot with shear stresses az ordinates and normal stresses az
abscissas. Make at least three triaxial compression tesu, each
at a different confining pressure, on the same material to
define the envelope to the Mohr stress circles.
Nor¢ 6-Beaux o(ihe heterogeneous nature of rock and the saner
is raulu often cocouotered, it rs coavdered good praetia to make at
least three tau of esxntially idential specimens at each confining
pressure or single tests at nine dilfercm confining ptessura covering the
ange investigated. Individual riress cucla shall be plotted and consid-
ered io drawing the envelope.
8.1.3 Draw a "best-fit," smooth curve (the Mohr enve-
lope) approximately tangent to the Mohr circles az in Fig 1.
The figure shall also include a brief note indicating whether a
pronounced failure plane was or waz riot developed during
the test and the inclination of this plane with reference to the
plane oC major principal stress.
Nore 7-If the envelope is a straight line, the angle the Gne makes
with the horizontal shall be reported as the angle of interval friction, b
(or the slope of the line as tan ~ depending upon preference) and the
intercept of this line at the venial axis reported as the cohesion
intercept, C. If the tovelope is not a straight Gne, values of ~ (or tea ¢)
should be determined by conrimeting a tangent to the Mohr eurle for
ach wnfioing stress at the point of contact with the envelope and the
corresponding cohesion intercept noted.
233