314 Danh gia trang thai lam viec ciia kgt c^u, dudng dng va binh ap luc cua D A N H G I A TRANG T H A I L A M VIEC CUA KET CAU, DlJOWG ONG vA BINH A P Lire CUA CAC CONG TRINH BIEN B A N G PHUOTVG P H[.]
314 Danh gia trang thai lam viec ciia kgt c^u, dudng dng va binh ap luc cua D A N H G I A TRANG T H A I L A M VIEC CUA KET CAU, DlJOWG ONG vA BINH A P Lire CUA CAC CONG TRINH BIEN B A N G PHUOTVG P H A P DO TRI/C TIEP iTNG S U A T TRONG CAC P H A N TLT CUA CHUNG Nguyin Van Tinh, Shkolnyu G.N.,Afonhin V.E XNLD Vietsovpetro TOM T A T Hien nay, di tiin hdnh cdng tdc sira chira ldn cdc kit cdu chiu lire, cdc dudng dng cdng nghi vd binh dp luc ciia cdc cdng trinh biin thupe XNLD Vietsovpetro qudn ly, cdn thiet phdi tiin hdnh cdng viec khdo sdt theo cdc quy trinh sogn thdo Tren cd sd cdc sd lieu khdo sdt, tiin hdnh phdn tich ddnh gid trgng thdi ldm viec cua chung Tuy nhien, qud trinh xir ly cdc so lieu khdo sdt di ddnh gid trgng thdi ldm viec eiia kit cdu vd dirdng dng da gap rdt nhieu khd khdn, tdn nhiiu thai gian vd kit qud cd dp chinh xdc khdng cao Do do, tiin hdnh cdng tdc sua chira ldn, da gap rdt nhiiu khd khdn viee lira chgn cdc gidi phdp gia cirdng di ddm bdo an todn cho cdng trinh Di ndng cao tinh hiiu qud ciia cdng tdc sira chira ldn cdn thiit phdi nghien cuu ung dung phirang phdp ddnh gid nhanh vd chinh xdc trgng thdi ldm viec cua kit cdu, dudng dng vd binh dp lire Bdi bdo phdn tich su cdn thiet vd khd ndng ung dung cdc phirang phdp vd thiit bi hien dgi irng sudt di ddnh gid trgng thdi ldm viec ciia kit cdu dudng dng vd binh dp lire qud trinh cdi hodn vd sira chira lan cdc cdng trinh biin DAT V A N D E Trong nhung nam gan day, de chuan bi cho cdng tac sua chua ldn va cai hoan cac cdng trinh bien (CTB) tai md Bach Hd thudc XNLD Vietsovpetro quan ly, cac don vj cua XNLD Vietsovpetro va mdt sd nha thau cua Viet Nam da tien hanh khao sat tinh trang ky thuat de lay sd lieu phan tich va danh gia tinh trang lam viec cua cac ket cau, dudng dng va binh ap lye Cac phuong phap khao sat va danh gia hien chu yeu la dya vao cac quy trinh khao sat va cac phuang phap danh gia XNLD Vietsovpetro soan thao Tuy nhien, qua trinh thyc hien cdng viec nhan thay cac phuong phap khao sat va danh gia hien cdn cd nhieu nhugc diem ma chu yeu la chinh xac cua cac sd lieu khao sat khdng cao thdi gian khao sat keo dai dan den sy ldi thdi cua cac sd lieu, viec phan tich tinh toan phuc tap va khd dam bao dugc ket qua chinh xac cac cdng trinh bien cd cau tao phuc tap va che tai trgng mang tinh dae thu Hien nay, yeu cau ve sua chua ldn cac cdng trinh bien rat ldn, dd cung vdi viec hoan thien cac phuong phap khao sat va danh gia hien cd, can phai nghien cuu ung dyng cac phuong phap khao sat va danh gia nhanh tinh trang lam viec cua ket eau, dudng dng va binh ap lye Myc tieu nghien cuu la phan tich sy can thiet va kha nang ung dyng cac phuong phap chan doan nhanh trang thai ung suat cac phan tu de danh gia trang thai lam viec eua ket eau, dudng dng va binh ap lyc 315 Tuyen tap bao cao Hgi nghj K H C N "30 nam Dau Viet Nam: Cff hgi mdi, thach thde mdi" CAC V A N D E LIEN QUAN D E N P H U O N G P H A P D A N H G I A TRANG T H A I LAM VIEC CUA KET CAU THEP VA D U N G O N G Hien nay, de danh gia trang thai lam viec cua ket cau thep va dudng dng cac cdng trinh bien (CTB) cua XNLD Vietsovpetro quan ly, can phai tien hanh khao sat xac dinh cac khuyet tat va chieu day cua cac phan tu (Hinh 1) Tren co sd cac sd lieu khao sat tien banh phan tich va danh gia tinh trang lam viec cua ket cau va dudng dng (Hinh 2) Tuy nhien, phuong phap danh gia cd nhung nhugc diem sau: a: s- ••UJ > 1^ (>/ •< s m ' o ,< m o — ( I z o a < o I •< X ^ z —••< • < • < (^t ONQOHl ±viAi oNva xvs ovHX z nan ivi AT HNIH3> 316 D a n h gia trang thai lam viec ciia kgt c a u , d u d n g d n g va binh a p luc c u a >2 '5ii JS e ^« J3 e u •*# >% O ri e X < • OS H • < wya Nvoa j NVOI HNU iva nam j o a i u wya v i i o / i i o X z NVHd j y o oa Jiio NOW NV o a ivi NOO HNia DKnvi i.va a < < X o z 'in •< Q i\ya w o a v i j \ y o i H N I L lya vjiiijoaiii i\ya v n j i u NVHd Oyj 1130 NOW NV 0 IVI \ J HNIS ONHai WO 00 u ~ E 1130 NOW NV HNVa NOW NV Nvs i w i 3y3 i v i vno ONHHj NOW NV 0 n y j i3>i J ivi NOJ Ava a Nvs i w i low v n j HNia DNIDII wa 6a Tuygn tap bao cao Hgi nghj KHCN "30 nam Dau Viet Nam: Co hgi mdi, thach thde mdi" 317 • Khdi lugng cdng viec va thdi gian khao sat qua ldn (~ 100.000 diem do day ddi vdi gian khoan khai thac cd dinh (MSP); thdi gian ~ nam); • Cac sd lieu tien banh phan tich danh gia bi ldi thdi so vdi tinh trang thyc te; • Viec xu ly sd lieu va phan tich danh gia rat phuc tap va ket qua danh gia cd tinh chit tuong ddi; • Khd khan can danh gia nhanh cac ket cau va dudng dng xay sy cd SU" C A N THIET CUA VIEC XAC DINH TRANG T H A I ITNG S U A T TRONG CAC PHAN Tir Trang thai ung suat cac phan tu la yeu td thiet ke dau tien de danh gia trang thai lam viec va an toan su dyng cua cdng trinh Trang thai ung suat phan tu thudng tdn tai d hai dang: ung suat du (xuat hien qua trinh ban, bien dang dan hdi che tao va thi cdng) va ung suat tac dyng cua cac loai tai trgng Cac nguyen nhan chinh gay sy hu hdng cac ket cau thep, dudng dng, v.v la tdn tai cac khuyet tat va cac vung tap trung ung suat, tai dien manh me cac qua trinh bat lgi cho cdng trinh (pha hoai tinh toan ven cua cdng trinh, nut, an mdn gi, bien dang deo) Cac phuong phap kiem tra khdng pha buy truyen thdng (phuong phap sieu am, phuong phap bdt tu, phuong phap tia gama, v.v ) khdng cho phep thyc hien viec chan doan trang thai ung suat ma chi tap trung vao viec tim kiem cac khuyet tat dang phat trien, cho nen nhieu khdng xac dinh dugc tin cay cua cdng trinh chan doan De phat hien kip thdi cac vung cua ket cau cd xu hudng se bi hu hdng, can thiet phai biet dugc trang thai ung suat thyc te cac phan td cua chung Sir C A N THIET SlT DUNG THIET BI DO UlVG S U A T T R I / C TIEP Hien d XNLD Vietsovpetro, de phan tich trang thai ung suat cac phan tu ket cau va dudng dng cua eae CTB, qua trinh thiet ke thudng su dyng cac phan mem khae nhu SAP2000, SESAM, CEASAM, ANSYS, v.v Tuy nhien, viec xac dinh trang thai ung suat cac phan tu ket eau td hgp thugng tang (THTT) cua cac cdng trinh bien dang boat ddng bang phuang phap tinh toan kiem tra rat phuc tap va gap rat nhieu khd khan cac nguyen nhan sau: • Phuc tap viec md hinh hda ket cau (td hgp thugng tang cd 21 block-modun lien ket vdi va cd sd phan tu rat ldn); • Phuc tap viec md hinh hda trang thai thyc te cua ket cau (thay ddi day an mdn, tdn tai cac vet nut, bien dang deo, v.v ); • Su thay ddi cae tai trgng ben ngoai va eae dieu kien bien qua trinh khai thac; • Sy anh hudng cua chat lugng che tao va thi cdng cdng trinh Do dd, viec nghien cuu img dung cae phuong phap va thiet bi hien dai cd kha nang true tiep ung suat cac phan tu la rat cin thiet Cdng viec dac biet cd y nghTa ddi vdi cdng tac sua ehiia ldn cac cdng trinh bien, cin thilt phai danh gia nhanh trang thai lam viec cua cac phan tu de cd cac giai phap gia cudng thich hgp Danh gia trang thai lam viec ciia ket cSu, duong dng va binh ap lire cua 318 Phuong phap ung suat tryc tiep (Hinh 3) cd kha nang dap ung cac yeu cau sau viec danh gia trang thai ky thuat cua ket cau va dudng dng: • Kha nang danh gia nhanh trang thai lam viec cua ket cau va dudng dng; • Giam thdi gian khao sat va xu ly sd lieu; • Giam khdi lugng cdng viee khao sat va xu ly sd lieu; • Tang chinh xac cua ket qua danh gia Thiet bi ung suat Phuang an sua chiia Jl KHAO SAT + DANH GlA w tr Sif A CHUA Co sd du lieu Ji Hinh 3: Quy trinh danh gia nhanh bang phirong phap trng suat tryc tiep CAC PHUONG PHAP DO irNG SUAT Nhung nam gan day tren the gidi da xuat hien rat nhieu cac thiet bi ting suat cae phan tu cua ket cau va dudng dng Cac cdng nghe ung suat mdi nhat cd kha nang xac dinh duge trang thai ung suat cac phan tu ket cau tren co sd nhieu thdng sd mdt luc va su dyng cac phan mem chuyen dung de xu ly Cac phuang phap dugc su dyng phd bien hien bao gdm: • Phuong phap xung phan hdi (Echo-pulse method); • Phuong phap tdc sdng sieu am (Ultrosonie velocimeter method); • Phuong phap tu trudng di budng (Magnetic anisotropy method); L PhiroTig phap xung phan hoi (Hinh 4) Xung phan hdi Xung tham dd \ /\ A / ^ I / V V ^ x-'^v^sx-'^v^^ B6 biSh d^i 'ir Ph^n mim chuyen dung £ Trang thai urng xu^t Hinh Tuygn tap bao cao Hgi nghj KHCN "30 nam D^u Viet Nam: Co hdi mdi, thach thde moi" il9 fl lfu diem - Xac djnh dugc cac vung tap trung ung suat va gia tri tuyet ddi cua ung suat - Cd the su dung vdi cac kim loai khae b Nil uac diem - Do chinh xac phy thudc vao ddng nhat cua vat lieu - Chiu anh budng cua rung - Can phai chat tai bd sung Phu-QTig phap tdc song sieu am Sy phy thudc giua thdi gian truyen sdng sieu am va ung suat ddng tryc kim loai dugc bieu thi bang cdng thuc: Aa = E.(t - tg - At)/ L.tg dd: Aa: Sy thay ddi ung suat E: Modul dan hdi L: Hang sd dan hdi sdng sieu am phu thudc vao mac vat lieu va dang tai trgng At: Sy thay ddi thdi gian truyen sdng to: Thdi gian truyen sdng tham khao phy thudc vao tinh chat cua cai cam bien va dugc xac djnh ddi vdi vat lieu khdng cd tai; a lfu diem - Cd the su dung vdi cac kim loai khae - Xac dinh dugc cac vung tap trung ung suat va gia tri tuyet ddi cua ung suat b Nhugc diem - Chi cd the su dung vdi vat lieu ddng nhat - Can xu ly ky be mat cua phan tu PhiroTig phap tir trudng dj hudng (Hinh 5) Phuong phap dua tren tinh chat tu trudng di hudng cua cac loai thep ed tu tinh Khi thay ddi trang thai ung suat vat lieu thi tinh tu trudng di hudng cua vat lieu se thay ddi Dua tren nguyen ly tac dyng ngudi ta da che tao cac bg cam bien tu, ket hgp vdi bd chuyen ddi va cac phan mem chuyen dung de xac dinh sy thay ddi ung suat vat lieu Cam bien tu Bg chuyen doi Phan mem chuyen dung May ve bieu ung suat I Co sd du lieu Hinh 320 oanh gia trang thai lam vifc cua ket cau, dudng ong va binh ap lyc ciia ? «r Hinh 6: Bieu dng suat tam phang bi uon a lfu diem - Xac djnh dugc cac vung tap trung ung suat - Xay dyng dugc cac bieu dd ung suat (Hinh 6) - Khdng can xu ly be mat b Nhugc diem - Chi cd the su dung vdi cac loai thep cd tu tinh KET LUAN • Hien nay, viec nghien cuu ung dyng cac cdng nghe tien tien de danh gia nhanh va chinh xac trang thai lam viec cua ket cau, dudng dng va binh ap lyc la mdt yeu cau cap bach va cd y nghia kinh te ddi vdi cdng tac sua chua ldn va hoat ddng khai thac cac cdng trinh bien thudc XNLD Vietsovpetro quan ly Phuong phap true tiep ung suat cac phan tu la mdt nhung phuong phap dang dugc XNLD Vietsovpetro nghien cuu ap dyng • Phan tich cac phuong phap xac djnh ung suit hien dang dugc su dung tren thi gidi thay rang ddi vdi cac ket cau, dudng dng va binh ap luc cua cac CTB cd thi ung dyng phuong phap tu trudng dj hudng hoae phuong phap xung phan hoi Tuy nhien, de ung dyng cac phuong phap ndi tren can thilt phai tim kilm cac thilt bi dugc che tao cd chinh xac cao va thich hgp vdi dieu kien lam viec cua cac cdng trinh bien Tuygn tap bao cao Hdi nghj KHCN "30 nam Pau Viet Nam: Cff hdi moi, thach thde mdi" 321 TAI LIEU THAM KHAO W.D Dover, P.P Brennan, B de Leeuw, 2001 ACSM Stressprobe: A new noncontacting stress measurement technic for the offshore industry Proceedings of OMAE'Ol 20"^ International Conference on Offshore Mechanics and Arctic Engineering June 3-8, 2001, Rio de Janeiro, Brazil Ultrasonic stress measurement with the LCR technique Proceedings International Petroleum Industry Inspection III, Topical Conference, American Society for Nondestructive Testing, June 1993 Schneider E., 1997 Structural and residual stress analysis by non-destructive methods Edited by V Hauk, Elsevier, Amsterdam, 1997, Chap 4, p 522 - 563 Egorov M.L, Baranov D.C, Kiim tra trgng thdi img sudt - biin dgng cdc kit cdu chiu lire chinh cdc cdng trinh lan a Moscow, {bdn tiing Nga) Rumiansev S.V., Dobromyslov V.A., 1976 Kiim tra mdi hdn bdng phirang phdp khdng phd hiiy Moscow {ban tiing Nga) Bashkov M.G., Kuzeev I.R Ddnh gid tudi thg cua thiit bi ca bdng phuang phdp diin tir UDK 658.53/.59:621.187.2 {ban tiing Nga) Bashkov M.G., Kuzeev I.R., 2001 Chan doan bang phuong phap dien tu cac thiet bi cua nha may lge dau Ufa (ban tieng Nga) ... cac ket cau va dudng dng xay sy cd SU" C A N THIET CUA VIEC XAC DINH TRANG T H A I ITNG S U A T TRONG CAC PHAN Tir Trang thai ung suat cac phan tu la yeu td thiet ke dau tien de danh gia trang