PERMFILE57196

• Permit No: M1999002
• IBM Index Class Name: Permit File
• Doc Date: 6/18/1999
• Doc Name: OBJECTORS EXHIBIT
• Media Type: D
• Archive: No

Sheariu~ u( Rnrl. alau :d Ucplh
l'u cuu clalr l~l )IL rellcrtiulrolclliricnl .unllliludr :uul luck-s Wlla nurve-
ntcnls at the depths of 4ti m ;Ind (r6 m (Icu;Iliuns of Iwo open cods), relations
drvclopcd Gum prcviuusly oblainrd I:Ihur:dnry d:Ita o•ctc uliliccd 'flx•sc
Iclaliuns arc mnnm:uirrd lium plcvunlsly uulrpurlyd Icsls tonduacd b}•
him (I'lti'1) anJ 1'clcnuu (1991).
As shmvn in fig. ti, cablr; length signifirandy influences the signature.
Variation of tcflcction tucllicicnl wish disl:utrr :dunl; the rabic is shown in
I•ig. ;{ (Rim 19X9). I'rtersun (1991) showed Ihal it the shc;u xunc thickness
is ]n the range of 5 Iu 411 nun Iltc magnihulc ul the (hick ncss hats little af(ccl
on the atrrcl:uion hchvccn rcflcclirnt angtlitudc and shc;Ir displaccntcnl.
Since rock shc:uing nnrm:llly lakes plan :dung :1 nmu6ct ul sc pn roc, Ihiu
shear h:nuh ar plink (GuuJm:m 19X9). Ilex 16irkncss cllrtt dixusscJ by
1'clcrsun i> tluhlght nut lu he as iugxnt;uu :n ihr ethic-length cfira.
La rgcr-di:uncltl tables rryuilc pcalcr dclnrnlariun lu pnrducc a given
rcllcclinn :unlrliRalc (!)nwduy, rl al. 19XX). "I ~hr r.ll rlr 16:uuclcl lot the Bala
in Pig. X is 12.7 nun, which is smallu Ihan the Z2?-nun diameter aeRt:dh'
used. -thus, shear defonuationa occunin,e in Iltc field arc probably largrr
Ih:m Ihosc indic:ucd iu Pig. ti in curve (a). lltctcful c. shearing dcfuunalinns
+ee K• colilltaitd +cilll col ve (b) Iu aeeuunl fur n•dut'liun in sr utiilivlly due
to both increased cable length ;uul diantcler as indlraled by the initi:d 19XS
study.
Cungtarisau of [lurizonl:d hluvcmentcnl at Dcplh and tiur(acc
Ilurinyntal displaccntcnis at the surlacc ul the cable collar (nunnuucm
66) and at depths uI 4V m and G6 m :dung the cable arc cnngrucd in Pig.
'). Ilorirom:d displacemem al the sw lace is uMainrd ducal}' bum nptied
sulvcy uteasnrr ntcw ul xtn lacr uwnunlcul nlovrnlcW (Iirnucll cl :d. I'/')2).
+vhilc those ;d +lcplhs of 4ti and 66 m ;Ire amvrucd +vilh relations (a) and
(b) in Pig. X. Ax c:m he scrn in Pig. 9(.I). Ihr rani-wrsl cum punent :d the
sm(atc was nntsis(auly gr rater Ih:ul the nullh-south cnnyurnrnl al Ihr
center of the lungwall subsidence trough.
Cvcn more important th:m the lino lag bctwccn displaccnteul ;u rlcplh
:utd ai Ihr surface is the distance al which early subsurface direction uicun
Izo - -------- ---_ .. .. _ . .. -- - -- - -
ouuuu Im
su-+i rxm
JoJJO Nam cl:,
L t~ 't},Ler 59 m1.(IV lx.i mmd~+ '
E ~~.~ Lvmrvlhuxmm a••.I„I~.I~n -
~ 80
v ;. "
D / ,
v
o /^ ~ci
U in : " > ,;
p "° - ,emu %% / n
~u % rJ•~-'G ri
ar ~ i. ~ ~' - o-t
7~I ',R.•x~y ~l ~
0 2 4 6 J 9 f0
Shear Deformation (mm)
FIG. 8. Reduction in Rellectlon Coetlicienl Sensitivity to Shear Deformation for
Increasing Length of Cable (Kim 1989)
1420
no >t ~) Sminm Sorvay
\\\lllll xet
so ~ sws
11~n IM,oniJ C,ma•~.
no I c.w ua,~..~a r...,,r.,..•
• taJ lwlsne a.a.o.~,
sw.W.s
20 o nMrte,..e
el In S.unL+M1 a.l • row. e
E /u..w.a~nrW.lo
E o ~ -- - - ----.___--
~) -a6 m TDIt
y 60
E
no
v°i ~ I
0 zo ''
i0 ~
yrM1 n.~0 _ _. __
~ o _ ..- ~-
H d~GLm1U11
= GO
i
40 I ~
zo ~" " ,-
o.l-._~-..- -----
~zo o zo ao so eo too tzo Ino
Distance to Face (m)
FIG. 9. Comparison of Horizontal Surface Displacement and Shearing Dclorma-
tion al Depths of AD and GG m whh Distance bclwccn Cable and Mlne Face Shows
Early Detection of Movement at Depltt by TDR
as shown in Digs. 6 :uul 9. Muventrnls al a depth of GG m began when the
(ace was hchvccn 125 m anti G4 m from the cable whcscas they did not
begin ai a depth n(48 m until (hc face was 23 m from the cable. Significant
su r(acc nxwcmcnl was not tlctcctcd until the lace was within 15 m.
Simple gamtclric priuci pies dictate that Mal horizottal sur[:ICC rlisplace-
nu•nl at a palti~ular lints (ur distance to the face) should be equal to the
sum of all the relative horizontal displacements (or in Ibis case, shear dc-
fonu:diuns) produced along the veritcal lint (or in This cast, cable) from
the mining fact to the ground surface. This comparison hchvccn total Itor-
itontal displaccmcnt al the surface and the sum o[ horizontal, relative shear-
ing deformation is illustrated SCIICIIIaIICally in Pig. 10. The illuslratiun in
big. 10 assumes that the direction of shearing deformation underground is
additive ur Ihal it occurs in the s:uuc direction. Comparison is made at an
instant when the distance bclwccn the fact and cable is 3 m (10 (t), which
is the last time for which complete subsurface cable and surface survey data
arc available. Currclations bclwccn rc(lccliun cocf(icicnl and shear defor-
mation marAcd as (a) and (b) in Pig. 3 were employed to produce a range
of possible cable tlefonualinns to account far the difference in cable lengths
and diantclcr :durcntcntiuncd.
Ati Calt OC til'CIt Itt pig. Ill ant( Table 1, the total horizontal displaccmcnt
al dtc surface as optically survcyctl was 49.5 mm and sums u( shearing
dcforntalions ;dung Ihr; cable were 32.5 non and 55A nun fur relations (:Q
and (b), respcdivcly. While the agrecutcul in these measures v( surface
displaccmcnt :Ind cable deformation may be fnrhtitous, it ncvcrthclcss fur-
1421