Thong tin khoa hpc cong ngh$ m 6
Sir DUNG BUA SCHMIDT XAC DjNH NHANH do ben cua dd tram tich tqi hien trudng
So far, the quick determination of the rock mechanical strength at the drifts has been paid much attention to.
Under the different geological conditions, the same rock provides its different toughness with the utilization of different equipment. The paper refers to the utilization of the Schmidt hammer for the quick determination of the sedimentary rock toughness in situ
Tinh chat co* hpc cua d^ ^nh huo-ng d^n qua trinh cong nghp va ch6ng giu khi thi cong cac duo'ng 16 trong I6ng d^t.
Su hinh thanh cac tr^m tich la nguyen nhan tao nen cac tinh chat ca hpc cua da khac nhau, khi tac dpng vao chung theo cac huo'ng khac nhau. Qua trinh tram tich la qua trinh thanh tao 16'p theo kich thuo'c cac CO' hat nhu: hat mjn, hat trung. hat tho tuo'ng ung vo'i cac loai nhu: than, set, bpt, cat, san, cupi k§t. Su thanh tao cac 16'P khong nhu-ng chi theo khoi 16'n, ma ngay trong cung mpt loai da cung c6 su khac nhau, khong nhung ve cau tao hgt ma c6n khac bi?t ve tinh ch^t CO' hpc ma dac trung nhat la dp ben nen doc true. Khi nen mpt mSu da theo hudng vuong g6c vo'i 16'P va dpc theo i6'p da cho th^y su khac biet ro rang giija dp ben nen vuong g6c Iu6n 16'n hen so vo'i dpc theo 16'p. Ngoai ra, v6'i cung mot logi da, nhung tai m6i vj tri khac nhau (dp sau, hay 6" g4n cac phay, uon n^p, kho hay ngap nu6'c v.v...) d4u th^ hien dp ben khac nhau.
Qua trinh dao 16 la qua trinh tac dpng co* hpc (khoan, no hay cIt) d l pha vo" da. Qua trinh pha da c6 t h i gop phan giu cho da xung quanh duo'ng
TS. PHAM MINH OU'C TS. u i VAN CdNG KS. TAO VAN NGAN Vi^n khoa hgc Cdng ngh^ t/ld-Vinacomin
16 khdng bj giSm dang k l muc dO 6n dinh hay tac dOng mgnh lam cho kh6i 6k bj nut ne do c6ng ngh^ lam mJit 6n djnh.
Trong qu^ trinh thilt k l , thi cong duo'ng 16 mo, mpt s6 dgc tinh ve dp b i n v l c^u true da dup'c quan tam d6 la dp b i n nen dpc trgc, m6dun dan h i i hay SM' nut ne, phan 16'p, goc doc cua 16'P da v.v...
Den nay, hau het cac tinh chSt CO- ly cua da deu dM'a vao k i t qua nen thu cac m l u lay t u cac 16 khoan trong qua trinh khoan tham d6. Song cac k i t qua xac d|nh trong qu^ trinh khao sat, thSm d6 c6 tinh dgi dj$n khdng cao, do khoang each giij'a c^c Id khoan r i t 16'n.
MIt khac, do cac I5i khoan t u tren m l t dat xuIng nen cac loi khong vuong g6c v6'i 16'p da, do do, khi nen, lye nen khong the vuong goc hay song song v6i 16'P da.
Trong thi cong, d l c6 nhung quyit djnh nhanh, chinh xac ve dp b i n ca hpc cua da c i n c6 s6 li?u nhanh. Trong khi do, de xac djnh dp ben trpng khi thi nghiem can r i t nhieu nguyen cpng t u g i a cong mlu,eat got mai phing mgt m l u , nen mlu... d6i hoi phai co thd"! gian dai. Do d6, bi$n phap xac i^nh
nhanh tgi hi$n trud'ng (in situ) IS bi$n phdp huu hi$u nhit.
Hi$n nay dang t i n tgi mot s6 bi$n ph^p xiie djnh nhanh va chinh x^c cdc ehi tidu ca hpc da tgi hi^n truang, do la si>
dgng bua d^p nly Schmidt (phuang phap khong phA huy) va xac djnh tren may nen mlu khong d|nh hinh {BU-39) (pha huy mlu).
1. Gim thi^u bua dap nay Schmidt
Bua dap nay Schmidt la loai thilt bj thi nghipm hign truorig, dup'c SCP dgng chu yeu d l xac djnh dp b i n nen cua betong, c i u tao cua bua dup'e t h i hien tren hinh 1.
Phy thuOc vao logi va dg b i n cua betdng nhu betong liln khoi, betSng due san.
betong phun hay betong sieu ngng, betong ngng, betong nh?
hay betong x6p v.v... Mpt so hang san xuat thilt bj nhu PROCEQ, DRC hay TEC- NOTESTv.v... da san xuat mpt so loai bua va du^c phan loai nhu sau:
Loai N
Tren thj truang dang pho b i i n hai logi thiet bj, logi hien s6 tren thang do khong ty ghi (N) v a t y ghi (NR). Log! N, vo'i nang lup'ng dap 2,207Nm,
KHCNM SO 6/2012* CNKT H A M L 6
Thong tin khoa hoc cony nghe m o
1- D^u dap. 2- Qua dap. 3- Ld xo nen. 4-Ch6t khoi Id xo. 5- Ld so ndn iao krc dip. 6- Thanh d§n hu'&ng, 7- DJa ham. 8- Bang chi thi tn so tan sual dap. hoac bang chi thi dien tu. 9- Tam che bang hien s6 doi v&i
may khong tu ghi. 10- Kho^ ham qua dap. 11-V6bua. 12 - Cliot ham 16 xo dap Hinh 1- Cau tao bua Schmidt
du'p'c SU' d u n g kha p h o bien trong viec xac dinh do ben nen dpc true cua betdng lien khoi t u 10 - 7 0 N / m m ' (10 - 7 0 M P a ) Loai NR t u ghi (R - r e c o r d ) (D1GI S c h m i d t ) , cac so lieu du'O'c truyen den bp n h o tren bua va truyen den may in, su' dung cho cac loai b e t o n g co do ben t u 10 - TON/mm-^, n a n g lu'ong dap cua bua - 2 . 2 0 7 N m . Hinh anh bua S c h m i d t loai N.
t u ghi, tren hinh 2, d a c t i n h ky thuat cua biia S c h m i d t loai N giai thieu tai bang 1.
Loai L
Bua S c h m i d t loai L la loai thiet bj nhe, d i i n g t r o n g viec xac d m h dp b i n cua cac t a m betong co chieu day tu' 50 den 1 0 0 m m , c u n g co hai loai,
Bang 1. Dac tinh ky thuat cua bus Schmidt loai N Hang san xuat
Nang luong dap Pham VI do Lu'u so lieu Kich thu'O'C Trong luong
TECNOTEST 2,207Nm 10 - 70N/mm-
khong tu gh 55x55x250mm
1,2kg
PROCEQ 2,207Nm 1 0 - 7 0 N / m m '
khong tu gh 55x55x250inm
1,6kg
DRC 2,207Nm 10-120N/mm'
tu ghi 90x55x250mm
3,2kg khong tU' ghi (LB) va ghi lu'u so
lieu do (LR). Hinh anh bua S c h m i d t loai L tren hinh 3, dac t i n h ky thuat cua bua loai L duo'c gio'i thieu trong bang 2,
Loai LB. vol n a n g lu'ang d a p 0 , 7 3 5 N m , s u dung de xac d m h do ben betong tu' 10 - 7 0 N / m m ' , chu y&u de xac dinh do b i n cua betong nhe, betong xop va vQ'a
Loai LR la loai t u ghi so lieu va truyen so lieu d i n may m, co
Hinh 3. Biia Schmidt loai L dac t i n h t u ' c n g t u nhu' loai khong tu' ghi de xac dinh do b i n betong t u 10 - 70N/mm^
Bang 2. Dac tinh ky thuat cua bua Schmidt loai L
Hinh 2. Bua Schmidt loai N
Hang san xuat Loai Nang lu'Ong dap Pham VI do Luu so lieu Kich thu'oc Trong iuo'ng
PROCEQ SILVERSCHIUIIDT-L
0,735Nm 1 0 - 7 0 N ; m m '
khong tu gh 55x55x250(h)mm
600g
PROCEQ SILVERSCHMlDT-L
0.735NrT 10-70N/mhl^
tti ghi 55x55x260(h)mm
600g
KHCNM S 6 6;2012» CNKT H^M L 6
^•.•;^r^^ie,*^iiisgs^
Thong tin khoa hoc cong nghe mo
Nang lu'cng dap cua bua 0,735Nm
Loai M
Bua Schmidt loai M la loai thiet b! nang, voi nang luong dap Ion, d i n 29.5Nm, duo'c su dung de xac dmh do ben ciia betong mat duang, san bay.
cau duang. nen mong va cac kit cSu khac Loai nay it xu^t hien tai Viet Nam
Loai P
Bua Schmidt loai P vai nang luang dap nho 0,88 Nm. su' dung de xac dinh do ben cua betong va vat lieu co do ben thap va do cu'ng thap, nhu betong bot, betong bat khi, pham V! do 2 -30 N/mnv Trong do loai PT v6'i pham vi xac djnh dp ben trong khoang 0,2 - 5 N/mm^ va loai PM su dung de xac djnh do b i n cua vua xay va trattuang (hinh 4)
2. Si> dung bua Scfimidt de xac djnh do ben cua da tram tich.
Nhu trinh bay tren, bua dap nay Schmidt su dyng de xac djnh dp ben nen eua betong dua tren dong nang eua qua dap duac gia !ue bo'i 16 xo tai duoi bua, khi qua dgp va ehgm vao mat mlu lap tue bj bat tro' lai, vgt CO dp ben hay dp eung cang cao thi dp nly va tan suit cOa qua dap dao dpng cang 16'n. Bang ehi thi gan tren v6 bua t h i hien chi so dap va dp bat nay cua qua d$p. De xae dinh dup'c dp ben cua vat lieu phai tien hanh it nhat 12 l l n thu cho mpt dilm [7] de tim ra mli lien h$ giOa s6 l l n dap tuang xung vai dp ben cua vat lieu.
De bua Schmidt hoat dpng tot, dam bao tin cay, bua can duac bao quan va kiem tra
Hinh 4 Bun Schmidt lo.ii P
Hinh 5. Kiem tra ho^t d^ng cua bua Schmidt hoat dong sau 1000 l l n si>
dung. De kiem tra hogt dpng cua bua, trong hop dyng bua luon CO kem theo mpt chile de va mpt cue mai (hinh 5) De dup'c dung de bua dap vao khi thu va cue mai de lam nhan be mat vat e i n xae djnh dp b i n .
BOa dap n l y Schmidt lam vipc theo phuang phap nen dilm, cho nen d l be m|t v|it thu t i l p xuc d i u vai d i u d i p , truo'c khi dua bua 6^ thu e I n lam nhan va ISm phang b l m|t.
Ccic chi s6 d i p dup'c ghi ch6p d l xac djnh m l i tuang quan gii^a dp b i n va chT s6 dap, hoac xac dmh m l i lien he giija chi s6 d$p vo-i t i e dp truyin song am. Cap m l u sau khi xae djnh bang bua Schmidt dem nen pha huy d l xae dinh dp b i n thyc t l .
Trong tru6'ng hp'p xae djnh dp ben cua betong liln khii, thi cong tai ch5, hay eua da mo, khong phai luc nao bua eung tac dpng thep huang thang
dCrng t u tren xuong ma co the nIm ngang, hay nghieng so vm be m|t m i u . Do hogt dpng cua bua Schmidt la sy va dip bit nay cua qua d|p nen tan suit d i p eua qua d i p khae nhau theo huo'ng tae dpng. Vi v|y, d l k i t qua xac djnh dp bin b i n g bua Schmidt mot each trung thye, e I n chuyin dii kit qua dp b i n theo phuang tac dpng eua bua (hinh 6).
Cae bang tra k i t qua chi so d | p va tra dp b i n trSn than bua Schmidt vai eae lo^i nhu N. L, P, V.V.. ma eac nha san xuit da giai thi|u d i u dup'c thyc hi0n eho vat lieu chu yeu la bdtong, Nhy v|y, d l su dgng bua Schmidt trong nganh mo e I n phai tien hanh cac thi nghi|m trong ph6ng, vai so luang m l u dgi di|n cho tili-ng vung dja ehat (Quang Ninh, Thai Nguyen, Ngh#An, Quang Nam, D i n g bang spng Hing v,v...) de CO the chuyen dii s6 do t r i n bua thanh so lieu v l dp KHCNM SO 6/2012* CNKT HAM L 6
Thong tin khoa hoc cong nghe m o t m i u . Bang ket qua kilm tra
w
trang cSc cji4u ki?n thm gian va do i m khac nhau Bock S. [3]
Sa dua ra m6i quan h0 giCfa si ben v&i tu6i betong va dq km theo cong thi>c (4):
Hinh 6. Bang tra chuyen doi ket qua do b^n cOa vSt tht>
theo phuvng tic dgng ciJa bua b i n cua cac loai da.
Thi du, d^ s i i dyng bua Schmidt N xac dinh dO b i n betong lien kh6i. Bock &nnk (2005) [3] da lam 57 liln thi nghiem tren m l u betong kich thu'oc 150x150x150 va 30 m l u gach kich thu'dc 65x65x65.
Tru-oc kht nen pha huy, ngu'O'i ta si> dung bua Schmidt N va may do sieu am. Sau do mai nen pha huy tren may nen MTS-810 NEW. Tif k i t qua thu- tac gia da lap moi quan he giu'a do ben nen vo'i ket qua thii nghiem tren bija theo cong thCrc(1)va(2)sau.
Do b i n theo m i u nen;
ftc»t» = 3,95.e°»'«L (1) Do bin theo sieu am;
fccuK = 0,355.e°°°'°»i- (2) Hay ting hp'p ca hai tru'O'ng hop cho k i t qua;
fc»K = 6,79.e»=2i-i°-=
+3,22eW"' (3) Trong do;
fo - Dp ben nen cua m l u betong, MPa;
L - S6 lan dap tren biJa Schmidt, lan;
u - T i c do t^uyln song am, km/giSy.
Dp b i n cua betong hay da mo phu thuoc vao t u l l cua beting cung nhu" do am cua
./,,.„
"(5)
/,=/,.;!'; .C.l,9368.e"'""
Trong do
C - H0 so tu-CTng quan;
fcusi - Dp b i n cua mlu thii;
fc - D | ben lly theo ham (4) tu'cng quan
Trong do. Trong qua trinh xac dinh dp fc - D | b i n n6n cua bgtong, '°^" '^^^ " 9 ' 'i^U' <^° so dilm MPa; x^c dinh Ion, muln s i lipu du'a
Q ' - Chi so s i I4n dSp t h i l^? ""•^ ' " * " l'^"^ 5 . " ^ "'.' hien tai bang tren than bua, lan.
yi - Chi s i phu thupc v^o t u l i cua betdng, bang 3;
72 - Chi s i phu thupc vao dp am cua betpng, bang 4;
C - H0 sp tu'ang quan, tinh theo ccng thu-c (5).
dien [7] c i n phai tiin hanh xir ly k i t qua thij theo trinh t y sau;
1- Op b i n trung binh, tinh thep (6).
J:,=-^ .UPa • w
2 - Xac dinh dp Idch vl do
Bang 3. Gia trf it va tuoi cua Tuoi b6t6ng
yi 10 1,20
20 1,04
28-100 1,00
betong 150 0,92
200 0,86
300 0,78
360 0,75
500 0,70
>1000 0,60 Bing 4. Gia trj r> va dd am cua betong
0 6 am betong
)^
BSo ho^ nwCfc 1,12
Nua kho 1,00
Khd hoan toan 0,96 Bing 5. Ket qua xac djnh 6d ben cOa mot soda tram tich [1]
Tic gia
'\ u f m u t h (1973) Cargill&Shako or (1990)
Deere &
Miller(1966)
Kidybinski (1980) Yilmaz &
Sendir (2002)
Him tucng quan
<r, =0,33.(R,./9)'•"
£, = 491 1,84.(«, .pf ( T , = 3 , 3 2 . e ' ° - ° " ' " "
CT,=18,17.e«""i ff,=9,97.e'°'°"'""
B, = 0 , 1 9 . ^ , . p ' - 7 , 8 7
cr,=0,52.e<°-''"''*"
<T,=2,27.e"''»'«''
£, =3,15.e'°-°'"'' r 0,80
0,93 0,98 0,94 0,88
0,95 0,96
Cic gii tri xic dinh Loai di
Tram tich cat ket
Than
2 3 l o ^ i 6i t r i m tich
Than, set, bpt,
c i t ket Bi vol, dt ket
Q c
1 6 - 3 6 2 36-271 4 - 1 3 5
22 - 368
11-259 R i
1 0 - 6 4 27-49 15-70
2 3 - 5 9
24-73
KHCNM S6 6/2012" CNKT HAM LO
Thong tin khoa hpc c6ng ngh$ m6
bin, tinh theo (7).
-/g?,MPa,,7,
3 - Tinh chi s6 v l su thay d i i dO bin.
/.„
(8)Trong do
ncofr - So luyng dilm hole m l u xae djnh dp b i n ,
fo - Dp bin tgi dilm hay m l u thCpi;
fcm - BO b i n cua m l u thu.
D l xac 6\nh dp b i n cua Qk mo bang bua Schmidt, nhiiu tac gia tiln hanh thi nghi|m va dua ra nhung cong thuc tinh dp b i n tai bang 5.
Trong d6: CTC - Dp ben nen, MPa; Et - Mo dun Young GPa, p - Trpng lup'ng neng eua da, g/em3. RL - S6 l l n d | p tr^n bua, r - H e so hoi qui
Viec su dung cac cong thuc tren rat khong thu|n Igi, nen [4]
da lap bilu d l d l xac (^nh do b i n va eae m l i lien hp khae nhu goc tiep can glua true bua, trpng lup'ng t h i tich cOa da vv ..theo bleu do hinh 7.
Tom l^i:
-Xae djnh dp ben cua da mp bang bua Schmidt giup eho can bp ky thuat mo c6 nhung quyit dinh dung dan phuc vg thilt k l , chi dgo thi cong dao, chong 16, su dung vat lieu va kit ciu ching phu hap
-Mli thilt bj thi nghipm d i u c6 nhung uu dilm va han ehi.
Viee su dung bua d i p n l y Schmidt chf hieu qua va thye sy CO tae dung khi dyp-c chuyen doi m6t each chinh xae thong qua cac m l u nen. Day la
Hinh 7. Bieu d6 tra dg ben va dg dip niy cua bua Schmidt • L vipc lam h i t sue c i n thilt eIn
duae quan tam khi SCP dgng bua Schmidt trong nglnh mo.
-Viec su dung bua Schmidt de xae dmh dp bin eua da mo chf phan anh dung s6 Ii0u do, d|e dilm khli d^ khi e6 c^e kilm nghiem va thu nghi$m cho cae khu vyc mo khie nhau./.
Tai liqu tham khio:
1. Aydin A., Basu A. The Schmidt hammer in rock material characterization. Departament of Earth Sciences, the University of Hong Kong, Pokfulam HongKong.
2005
2. Bilgin N Dincer T Copor H The performance prediction of im- pact hammer fmm Schmidt ham- mer rebound values in Istabul metro tunnel drivages- Istabul technical university mining engi- neering departament Marslak Istabul Turkey- 2002
3. Bock S. H Metody badan
wytrzymalosciowych obudowy szybow kopalnianych - Prace naukowe GIG Gomictwo i Srodowisko - Kwatamik 3/2009 4. TorabiS.R. SereshkiF Zare M Javanshir M. An empirical ap- proach in prediction of the roof rock strength in underground coal mine - the AusIMM lllwana Brach - Coal operators conference 2007 5. SilverSchmidt-N - Laborato- num konstrukcji betonow - Kate- dra konstrukcji budowlanych Pol Warszawy-Pol. 2010
6. MIotek Schmidt do Betom sena N/L , material z internetu 2012
7. Tiiu chuin (PN) Ba Lan v6 si> diing bOa Schmidt N dS xic dinh dO bin bitOng: PN-74/B' 06262 Nieniszczqce badania kon- strukcji z betonu Metoda sklerometryczna badania wytny- mahPSci betonu na Sciskanie za pomoc^mtotka Sehmidta typu N.
KHCNM S d 3/2012* CNKT H^M LO
