Hpi nghi khoa hoc ki thudt md qudc ti - 2010 Cong nghiep mo tien tiin vi sic phat trien bin vung
HIEU QUA CUA BIEN DO GIAM CHAN TRONG VIEC DANH GIA
T R A N G T H A I U r V G S U A T T l / O N G D O I T R O N G V i A T H A N PGS.TS Pilecki Zenon1, Szreder Zbigniew2,
Pilecka E l z b i e t a3, K r o l K r z y s z t o f4
'Hoc V i e n M o - L u y e n K i m Kracop, 2C 6 n g ty M E E P J PAS, Kracop,
3T a p doan than Jastrzebie, 4T 6 n g cue M o N h a nuac C H Ba L a n
Tom tat: Bdo cao trinh bay hieu qua cua viec su dung bien dp giam chan cua song khuc xa -
P a via than trong qua trinh khai thdc md. Doi vdi viec su dung thuc te bien dp giam chan, cdc phep do ddc biet vd phuong phap gidi tich dd duoc chuan bi nhu the nao. Do su suy giam duoc la gid tri tinh toan he so suy giam dua tren viec xac dinh bien dp cua song khuc xa - P. Vi du trong bdi viet nay ve he so suy giam so vdi van toe cua song khuc xa P thay doi trong khu vuc chiu dnh hudng cua via khai thdc d ldp tren ciing nhu khu vuc phay phd dd mo td. Loi ich ciia he so suy giam doi vdi phan tich nhu vay dd duoc nhdn manh do dp nhay ldn cua su thay doi trang thdi img suat vd bien dang trong via than so vdi su thay doi van toe song khuc xa P. Ngudi ta thay rdng he so suy giam cd the Id mot tham sd cd y nghia cho van tdc song khuc xq P de danh gid gid tri di thuong vd pham vi dnh hudng ciia nd trong khai thdc cdc via than cd ung suat tuong doi.
Tir khoa: Khai thdc than dd, img suat vd bien dang, giam dia chan, van tdc song P l.Md dau
Phuang phap xac dinh bien do giam chan bang khuc xa duac sir dung rong rai de danh gia trang thai t u o n g doi cua ung suat trong v i a than ( D u b i n s k i 1989). N o i chung, phuang phap nay cho phep danh gia ve mat k h o i l u o n g , tac dong anh h u o n g cua cac yeu to khac nhau tao ra trang thai ung suat va bien dang. V e nguyen tac, do la mot p h u a n g phap co ban cho phep danh gia tac dong anh h u o n g cua bo khai thac va cho khai thac con lai, cac phay pha, tren he thong chong 16. Phuong phap giai thich va do dac da duoc thiet lap va chung m i n h . N h u n g ket qua dat dugc ve bien do dia chan co l g i ich dac biet trong viec danh gia nguy co buc dat da.
Tir cac thi n g h i e m truoc do v o i bien do dia chan trong v i a than, n g u o i ta biet rang he so suy giam nhay h o n v o i thay doi cua trang thai i m g suat va bien dang so v o i van toe song khuc xa P. T h o n g t i n them ve van de nay co the x e m trong bai viet cua Pilecki va Szreder (2007) va Szreder et al. (2008).
Cac phep do bien do dia chan trong via than chi ra rang xac dinh thay doi cua he so suy giam co l g i the can thiet nay la nhay h o n sir thay doi trang thai u n g suat va bien dang trong via than so v o i su thay doi van toe song khuc xa P. Gia t r i he so suy giam co the thay doi lap di lap lai theo khoang ty le % so v o i thay doi gia t r i van toe song dia chan. V a n de nay thuc te co y nghTa quan trgng trong dieu kien khai thac 6 m u c sau v i sir gia tang van toe song la nho h o n v u n g v o i sir tang ung suat (Szreder et al 2008). T r o n g k h i do sir gia tang he so suy g i a m giam 6 muc do nho k h i u n g suat tang. He so suy giam co the la chi so hieu luc hon ve trang thai cua ung suat va bien dang n h u duoc so sanh v o i van toe song dia chan d u o i cac dieu kien do.
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Hdi nghi khoa hoc kT thudt md qudc te - 2010 Cdng nghiep md tien tien vi su phat triin bin vung
2. C o so* p h u o n g p h a p l u a n cua b i e n d a n g suy g i a m v a v a n toe song k h u c xa t a i v i a t h a n t r o n g q u a t r i n h k h a i t h a c m o h a m 16.
T h o n g so co ban duoc sir dung trong p h u o n g phap b i l n dang dia chan la van toe cua song khuc xa P. D o la van toe song truyen theo qua t r i n h khai thac tai k h u vuc ben canh dan hoi, v u n g tiep giap v o i k h u vuc m e m . Ranh g i o i giua k h u v u c dan h o i va k h u vuc m e m co the m i n h hoa bang viec sir dung m o h i n h Ladanyi (1974) ( H i n h 2.1) d u o i cac dieu kien tac dong lau dai ciia sir chong 16 k h i khai thac bang k h o i da.
CJ3 = hang so
y/.'/.y.'/.'/r.' i - " -""/•
Khu vuc mem eon lai Khu vuc mem Khu vuc dan hoi
Hinh 2.1. Md hinh dien biin ddi han cua khoi ddxung quanh khu vuc khai thdc tren co so Ladanyi (1974)
al - ung suat chinh Ion nhat, o3 - ung suat chinh nhd nhat, ad - ung suat tiep tuyen, or - ung suat hudng tdm, el - bien dang chinh ldn nhat, po - ung suat ban ddu, pi - tdi trgng ciia vi chong Gia tri cue dai ciia irng suat tiep tuyen xay ra tai khu vuc dan hoi 6 vung bien voi khu
vuc m e m ( H i n h 2.1). Gia d i n h rang trong phan k h u vuc dan h o i nay xuat hien dieu kien thuan l o i nhat cho sir truyen song khuc xa ( H i n h 2.2). T r e n thirc te, v u n g bien giua khu vuc dan hoi va k h u vuc deo co dac t i n h chuyen tiep va sir truyen song dia chan la phirc tap hon.
M o t dac diem phiic tap cua t r u o n g song la co the n h i n thay tren ban ghi dia chan (Hinh 2.3). A n h h u o n g dang ke den sir bien dang cua h i n h anh la co chieu rong bien doi manh cua k h u vuc khai thac m e m doc theo qua t r i n h khai thac ( H i n h 2.3). V i e c xac dinh qua trinh xam nhap song khuc xa va bien do cua no l u o n phiic tap theo cac dieu kien nay.
Thong t h u o n g , ket qua k h o n g thuc te ciia m o h i n h dao n g u o c quan sat duoc 6 qua trinh dich cac phep do bien dang dia chan
chiing m i n h dieu do.
Tir each n h i n nhan chung, quan sat cac phep do dia chan ciia suy giam bien do song v o i sir tang len o cho uon cong co lien quan den truyen song va v o i t o n that nang l u o n g dia chan la ket qua cua sir hap thu va tieu tan. Co the gia d i n h rang suy giam bien do song la tong so hieu
ung cua sir hap t h u va tieu tan nang ^ * a x[m]
luong dia c h i n ya l u y thira trong ham so m n h 2.2'Ddc'diim cua van toe song P theo khoang each d o i v o i song phang trong ham so khoang each tie hdng lb khai thdc via than: (Szreder et al. 2008)
Hoi nghi khoa hoc kT thuat md quoc te - 2010 r r Cong nghiep md tien tien vi su phat trien ben vung
A(r) = A0 e-ar (3.2) Trong do:
A - bien do khoang each " r " tir nguon, Ao - bien do nguon,
a - he so suy g i a m (suy g i a m la 1/m).
Viec xac d i n h he so suy g i a m a trong m o i t r u o n g k h o n g dong nhat la kho khan do truong song phirc tap trong k h u vuc m e m gan hong 16 khai thac. T r o n g dieu k i e n n h u vay, co the tao ra nhieu loai song: true tiep, phan xa, nhieu xa, khuc xa doc theo noc va nen v i a than hoac song kenh. Theo p h u o n g co hoc va l y hoc de t i n h toan he so suy g i a m a, bien do song P khuc xa trong v i a than co the duoc lam sang to.
a ) b )
thdi gian [ms]
10 20 30
Diem n6 Lo dpc via
' 7 gig V
10 Khoang each[m 20 15
25
y I N . v j
• - H - ; «•
A A A A*A S 6 ne p l r^c li^P
v V v \
Song P khuc xa
Hinh 2.3. Bien dang cua dia chan doc theo hdng lb khai thdc (Szreder et al. 2008).
(a) truyen song khuc xa; (b) do thi song lam mau 3. P h u o n g p h a p gia d i n h b i e n d a n g g i a m c h a n
3 . 1 . P h u o n g p h a p do
T u y thuoc vao dieu k i e n lan truyen song khuc xa P trong v i a than, do dai lan truyen cua 24 may dia a m co the dat t o i 115 met k h i dieu chinh nang l u o n g cua nguon song.
Khoang each cua may dia am dupe gia d i n h la 2-5 met tuy thuoc vao kha nang nhan dang song khuc xa P. Song dia chan b i k i c h t h i c h b o i va dap bang bua ta. B e cai thien t i n hieu va ty so tieng on, can ap dung it nhat 7 lan xep chong. Cac ban g h i dia chan de dpc ngay ca trong truong hop m u c dp on d i n h dia chan thap va dp khuech dai cao cua thiet b i thir nghiem tren lOOdB. M a y dia am co the dupe cai dat theo m o t each khac, ngoai ra, tiep xuc voi khoi da la de bao d a m sir rieng biet va sir x a m lan khong b i bien dang cua song khuc xa. M a y dia am dupe de co d i n h , tai cac thanh neo dai khoang 4 0 c m tai k h o i da khong b i rod ra dam bao arm cua song de co the dich dupe. T h o i gian g h i va m a u t i n hieu l u o n l u o n dupe thir nghiem tai hien t r u o n g khao sat rieng. Co m o t so g o i y de lira chon khoang t h o i gian lay mau la 0,125ms va dp dai g h i la 0,5s tren co so cac thir n g h i e m truoc do.
3.2. P h u o n g p h a p t i n h
T i n h toan he so suy g i a m bao g o m :
• Xac d i n h gia t r i cue dai cua bien dp song khuc xa tren bang g h i lien tiep 6 vung bien dang lira chon dupe g o i la v u n g tham chieu. Tren co so k i n h n g h i e m , bien dp t i n h toan
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Hdi nghi khoa hoc ki thudt md quoc ti - 2010 Cong nghiep md tien tiin vi su phat triin bin vung
co the gia d i n h la v i i n g t h a m chieu co chieu dai den 15m tir d i e m n g u o n song, loai trir diem ghi nam gan nguon song nhat,
• Chuan hoa cac b i e n do co lien quan den gia t r i APmax I o n n h i t - gan v o i nguon song,
• T r i n h bay dir l i e u 6 dang do t h i duoc bo t r i theo ham logarit t u nhien cua bien do tieu chuan hoa ciia song khuc xa Ap theo ham so khoang each tir n g u o n , v i d u \n(AP/APmax),
f i f r %
• T i n h toan he so do nghieng ciia d u o n g thang la ket qua ciia phep xap x i cac diem khao sat la he so suy g i a m a,
• Gan gia t r i he so suy g i a m a da t i n h toan v o i trung d i e m ciia v i i n g tham chieu Gia t r i t i n h toan ciia he so suy g i a m doc theo toan bo chieu dai bien dang doi v o i tirng d i e m nguon song duoc the hien d u o i dang do t h i la thuan l o i nhat v o i sai so cho phep cac he so khai thac va dia chat co kha nang l a m xao t r o n trang thai u n g suat va bien dang tai hien t r u o n g khao sat.
4. V i d u ve b i e n d<j> suy g i a m v a v a n toe song k h u c x a - P 4 . 1 . V i t r i v a p h a m v i n g h i e n c u u
Mat cdt A-A' - Id chp- 22 tqi via 505/2
Khao sat dia chan tai cac d u o n g 16 tai 16 chp 22 tai v i a 505/2 6 do sau khoang 750m da dupe tien hanh tai m o than Jas-Mos. M a t cat A - A ' co chieu dai 150m nam tai v i t r i anh huong cua b o khai thac phia tren 6 v i a than 505/1 theo khoang each thang d u n g la 8-12m.
M u c dich co ban ciia khao sat dia chan la de nhan biet va xac d i n h so l u p n g anh huong ciia bo v i a 505/1 tren he) k h o i da - chong g i u 16 cua 16 chp 22 tai v i a 505/2.
Mat cdt B-B'- lb clip 2-Z2 tqi via 510/2
Khao sat dia chan tai cac d u o n g 16 tai 16 chp 2-Z2 tai v i a 510/2 6 dp sau 820m da dupe tien hanh tai m o than Jas-Mos. M a t cat B - B ' co chieu dai 198m nam tai v i t r i anh huong cua b o khai thac phia tren 6 v i a than 510/1 theo khoang each thang dung la 30m va vung phay pha tai v i a than 510/2. M u c d i c h co ban cua khao sat dia chan la de nhan biet va xac dinh so l u p n g anh h u o n g cua cac he so nay tren tren he k h o i da - chong g i u 16 cua 16 chp 2-Z2 tai v i a 510/2.
4.2. D i e u k i e n d i a c h a t t a i h i e n t r u o n g Mat cdt A-A' - Id chp 22 tai via 505/2
• • •
V i a than 505/2 co chieu day thay d o i khoang 1,7 den 4 m . D p ben nen don true (uniaxial compressive strength) U C S trung b i n h cua v i a than 505/2 la Rc = 10,1 MPa. Lop da set day 4 m va dp ben nen d o n true Rc = 51,6 M p a xuat hien o noc 16 true tiep cua via than 505/2. T r u e tiep tai noc 16 xay ra hien t u p n g cue bp cat ket chuyen thanh da bun co dp ben nen d o n true Rc = 76,1 M p a . C) day v i a than 505/2 xuat h i e n set ket co dp ben nen don true Rc = 36,6 M p a va trong khoang each tir 2 - 4 m phia d u o i xuat hien v i a than 505/3. Dp doc cua cac l o p vao khoang 10° den 2 0 ° theo h u o n g D o n g Bac.
Mat cdt B-B' - Id chp 2-Z2 tqi via 510/2
V i a than 510/2 co chieu day thay d l i khoang 1,6 to 3,4m. D p ben nen d o n true cua via than 510/2 la Rc = 7,3 - 18,4 M P a . L o p cat k i t day 3 3 m va dp ben nen d o n true Rc = 44 - 100 M P a xuat hien 6* noc 16 true t i l p cua v i a than 505/2. T r u e tiep tai noc 16 xay ra hien tupng cue bp set ket c h u y l n thanh da b u n co dp ben nen Rc = 39 M P a . O day v i a than
r t
Hdi nghi khoa hoc kT thuat md quoc te - 2010 Cong nghiep md tien tien vi su phat trien ben viing 510/2 xuat hien set ket co do bin nen Rc = 24.7 - 49.2 Mpa va trong khoang each tir 2-4m
phia d u o i xuat hien v i a than 505/3.
Cac v u n g khai thac tai cac v i a phia tren nam trong k h u v u c khao sat. Gan v o i v i a than 510/2 tren b o v i a 510/1 trong pham v i 30m. V i a than 510/2 co u o n nep va phay pha.
Do doc cua cac l o p vao khoang 5° den 15° theo h u o n g D o n g Bac.
4.3. K e t q u a b i e n do d i a c h a n va p h a n t i c h
V i t r i khao sat bien dang dia chan tai cac b o v i a phia tren trong k h u v u c 16 cho 22 tai via than 505/2 va 16 cho 2-Z2 tai v i a than 510/2 6 m o than Jas-Mos duoc trinh bay trong Hinh 4 . 1 .
Hinh 4.1. V\ tri khdo sat bien dqng dia chan tqi cdc bd via phia tren trong khu vuc lb chp- 22 tqi via than 505/2 (a) vd lb chp 2-Z2 tqi via than 510/2 (b) d md than Jas-Mos Mqt cdt A-A' - Id chp 22 tqi via 505/2 (Hinh 4.2a)
H? so suy g i a m cua song dia chan thay d l i tir 0,12 m"1 d i n 0,20 m "1. B i l n dong t u o n g doi cac gia t r i trong v u n g anh h u o n g cua bo via 505/1 trong mat cat. la 6 2 m . V a n t i c song khuc xa P thay d o i tir 2270 m/s d i n 2450 m/s. B i l n dpng t u o n g d l i cac gia t r i cua van t i c do dupe la Av' = 1 1 % . V a n toe song dia chan duy t r i cac gia t r i cao nhat trong v o n g anh huong cua b o v i a 505/1 va cac gia t r i thap nhat d u o i k h u vuc da khai thac cua v i a than do.
Trong ca hai t r u o n g hop van toe song va he so suy g i a m , c h i u su thay d o i t u o n g d l i dpt ngpt dp doc cua gia t r i trong v u n g anh h u o n g cua b o via. C h i l u rong cua v i i n g nay la khoang 3 8 m trong k h u vuc khoang 40 len d i n 7 8 m .
Mat cdt B-B' - lb chp 2-Z2 tqi via 510/2 (Hinh 4.2b)
Dac d i e m thay d o i cua van toe song khuc xa P va he so suy g i a m la t u o n g t u nhau nhu trong mat cat B - B ' , n h u n g b i xao tron b o i su anh h u o n g cua k h u vuc phay pha. B i l n thien h? so suy g i a m dao dpng tir 0,13 m"1 d i n 0,18 m"1 ( AA
2 = 4 5 % ) tai k h u vuc anh huong cua b o v i a va b i xao t r o n cua k h u vuc phay pha. T r o n g k h u vuc phay pha, he s i suy giam thay d o i tir 0,12 m "1 d i n 0,17 m"1 ( AA
3 = 5 1 % ) . T r o n g t r u o n g hop van t i c song, sir bien thien xao t r o n manh trong k h u vuc anh h u o n g b o v i a cua k h u v u c phay pha. T r o n g khu vuc phay pha, van t i c thay d l i tir 2070m/s d i n 2270m/s ( Av
3 = 9 % ) . Pham v i anh
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Hdi nghi khoa hoc ki thudt md qudc ti - 2010 Cdng nghiep md tien tien vi sir phat triin bin viing
huong cua v u n g b i e n la k h o xac d i n h do anh h u o n g ciia v u n g phay pha, t r o n g k h i do pham v i dupe uoc t i n h vao khoang 7 0 m .
T o m l a i , k h u v u c anh h u d n g ciia b o v i a gay ra su thay d o i dot ngdt gia t r i van toe song va he so suy g i a m . K e t qua dat dupe cho thay rang he so suy g i a m duy t r i t u o n g doi d miic thap trong dieu k i e n u n g suat ciia b d v i a phia tren. V a n tdc song dia chan P se tang len trong dieu kien nay. D p ddc cua su thay d d i nay l d n h o n d d i v d i he sd suy giam. N o cung phu thuoc vao dp l d n cua tai trong t i n h tir b d lien quan den n h i e u thdng sd nhu: khoang each tir v i a than tien hanh khao sat, chieu day v i a " c d b o " va khoang t h d i gian tir k h i khai thac hoac t i n h chat dp ben va bien dang ciia k h d i da. X a c d i n h gia t r i bat thuong va pham v i trong k h u vuc anh h u d n g ciia b d v i a than se dupe nhan biet qua cac tac nhan gay xao tron n h u k h u vuc phay pha.
a ) 20 I 10 0
2500 2400 I
£.2300 2200
Via 505/1 8-12m Via 505/2
seam I
2100 0 A
*- —* — •- m. \ m Av.'=11%
Aa.'»68% m
— —• — <
v — 3 m
*—
" T -
10 20 30 40 50
[m] 60 70 80
0.25 0.2 0.15 90 0.1 A '
b ) 40 r 20 0
2400 2300
w"
1.2200
>*
2100 2000 J
Via 505/1 seam S10/1 (30m Via 505/2
seam S10/2 /
Khu \yic phay pha
fault zone / r
Av.2=11V^V
f \ > t \
—=^ —. . Av.2=11V^V
f \ > t \ " f — \ —=^ —. .
,_ 1 i Aa.3=5 % 3
- V - --w^
mj • * 1 I
i Aa.3=5 % 3 - V - --w^
0.25 0.2 0.15 0 0.1
B
10 20 30 40 50 60 70
[m] 80 90 100 110 120 130
V&n toe s6ng P [m/s] B '
• • - P-wa\ so suy giam a _ - — . . atteni V£n toe bdt thuong
Av. - veloci Suy giam bat thuong Aa. - attenuation anomaly
Hinh 4.2. Bien dang d\a chan su thay ddi cua van toe song khuc xq P vd h? so
noi nghi khoa hoc ki thuat md quoc te - 2010 Cong nghiep md tien tiin vi su phat trien bin vung suy giam trong vung dnh hudng cua bd via than 505/1 tqi cdc dudng id
cua id cho- 23, via 505/2 md than Jas-Mos:
a) bien dang dia chan 1-1', b) bien dang dia chan II-IV
5. Ket luan
Lap h6 so ve bien do ciia song dia chan cung tuong tir nhu van toe song dia chan de
mo ta trang thai t u o n g d o i ciia u n g suat va bien dang tai cac v i a than. T r e n co so k i n h nghiem, chiing t o i thay rang: su bien thien t u o n g d o i ciia he so suy g i a m ro rang I o n h o n su b i l n thien t u o n g d o i ciia van toe song khuc xa P. D i e u nay la do do nhay cao ciia bien do song khuc xa P thay d o i u n g suat va bien dang trong k h o i da so v o i van toe t u o n g d o i ciia song P.
Khao sat d j a chan ve su g i a m bien do d o i h o i phai co quy t r i n h do can than, bao gom lap dat may dia chan tao am sao cho dieu k i e n g h i song dia chan co the so sanh dupe tai tirng diem khao sat.
Trong giai doan phan t i c h he so suy giam, anh h u o n g cua no den k h u v u c gan nguon song nen dupe bo qua. V a n de trinh bay tren doi h o i nghien c i i u sau h o n theo h u o n g thu thap kinh nghiem trong cac dieu k i e n khai thac va dia chat khac nhau./.
Tai lieu tham khao
[1] Dubihski J. 1989: Sejsmiczna metoda wyprzedzajqcej oceny zagrozenia wstrz^sami
gorniczymi w kopalniach w g g l a kamiennego. Prace G I G , Seria dodatkowa. Katowice.
[2] Ladanyi B . 1974: Use o f the long-term strength concept i n the determination o f ground pressure on tunnel linings. Proc. o f the T h i r d Congress o f the Int. Soc. f o r Rock M e c h . , Denver, v o l . I I part B , 1150-1156.
[3] Pilecki Z . , Szreder Z . 2007: M o z l i w o s c i wykorzystania w s p o l c z y n n i k a tlumienia do oceny stanu naprgzenia i d e f o r m a c j i za pomocq p r o f i l o w a h sejsmicznych w warunkach duzych glebokosci. Prace N a u k o w e G I G , N r I V / 2 0 0 7 , wydanie specjalnie, 197-203.
[4] Szreder, Z . , Pilecki, Z . , K l o s i h s k i , J., 2008: E f e k t y w n o s c rozpoznania oddzialywania krawedzi eksploatacyjnych metodami sejsmicznego p r o f i l o w a n i a t l u m i e n i a oraz predkosci w pokladzie 505/2 w K W K Jas-Mos. M i n e r a l Resources Management, Quarterly, V o l . 24, issue 2 / 1 .
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