Tuygn tap bao cao Hgi nghj KHCN "30 nam DSu khi Viet Nam Cff hdi mdi, thach thde mdi" 251 Sir DUNG PHirONG P H A P P H A N T I C H MOI N G A U NHIEN DE HOACH DINH KE HOACH K H A O S A T CHI TIET KET C[.]
Tuygn tap bao cao Hgi nghj KHCN "30 nam DSu Viet Nam: Cff hdi mdi, thach thde mdi" 251 Sir DUNG PHirONG P H A P P H A N T I C H MOI N G A U NHIEN DE HOACH DINH KE HOACH K H A O S A T CHI TIET KET C A u CHIU L i r e G I A N KHOAN BIEN CO DINH CUA XNLD VIETSOVPETRO Hoang Le Ngge VTnh, Vu Xuan Lai Bui Van Ngan, Tu Le Trung XNLD Vietsovpetro TOM TAT Di phuc vu cho cdng tdc khai thde ddu a md Bgch Hd vd md Rdng, XNLD Vietsovpetro da xdy dung dugc trin 30 cdng trinh biin ldn nhd, tap trung chii yeu vdo giai dogn 1985 - 1995 vd keo ddi den ndm 2000 Do thudng xuyin phdi chiu su tdc dpng khdc nghiet ciia mdi trucmg biin, ddc biet Id su tdc dpng ngau nhien liin tuc mang tinh chdt chu ky ciia sdng biin nin qud trinh tich lUy tdn thuang mdi ciing xdy liin tuc sudt dai sdng ciia cdng trinh, ldm dnh hucmg ldm din tudi thg ciia chimg Vi vay vdn di ddt cho XNLD Vietsovpetro Id phdi dinh ky thuang xuyin thuc hien cdng tdc khdo sdt vd ddnh gid lgi tinh trgng chiu luc cua kit cdu cdc cdng trinh biin, ddy Id mpt cdng viec cd khdi lugng rdt ldn, khd khan, phirc tgp vd rdt tdn kem Di gidm thiiu chi phi khdo sdt ciing nhu ndng cao mirc dp chinh xdc, tin cay cua cdng tdc khdo sdt, cdn cd mdt phuong phdp tinh todn, phdn tich khoa hgc Viec sir dung phuong phdp phdn tich mdi ngdu nhiin di hogch dinh ki hogch khdo sdt chi tiet cho kit cdu chiu luc gidn khoan biin cd dinh cua XNLD Vietsovpetro nhdm ddp img nhu cdu thuc ti trin Id vdn di chii yiu md bdo cdo ndy di cap din TONG QUAN VE PHLTONG P H A P Ket cau eae cdng trinh gian khoan bien dugc su dung phd bien la he khung khdng gian dugc che tao tu cac dng thep lien ket vdi bang cac mdi han, dd qua trinh chiu lyc, cac nut eua ket eau la noi cd trang thai ung suat phuc tap va tap trung nhat Vdi sy tae ddng ngau nhien, thay ddi lien tyc cua tai trgng sdng sudt ddi sdng cua cong trinh da tao sy tdn thuong tich luy mdi d cac nut, cac tdn thuong tich luy dat den mdt ngudng nao dd se lam xuat hien eae vet nut, cac vet ntJt dd neu khdng duge phat hien va kip thai xu ly thi cac lien kit dd se bi pha buy nhanh chdng Vi vay, suot ddi sdng cua cdng trinh can phai cd sy phan tich, danh gia de lap ke hoach cho viee khao sat va sua ehua, dam bao cho edng trinh hoat ddng an toan Su dyng phuong phap phan tich mdi ngau nhien de hoach dinh ke hoach khao sat ehi tiet cho ket cau chiu lyc gian khoan bien dugc the hien qua so dd sau: 252 Sd dung phtfong phap phan tich mdi ngau nhign dg hoach djnh ke hoach khao sat chi tiet Hinh PHLTONG P H A P PHAN TICH MOI N G A U NHIEN Twffng tac ngau nhien cua tai sdng Qua trinh ngau nhien dac trtmg eho su phan phdi nang lugng sdng theo cac tin sd lien tuc tai mdt vung biin nao dd la ham mat phd sdng • Ddi vai trgng thdi biin ngdn hgn, cdc dgng phd sdng thudng dugc sir dung di phdn tich kit cdu cdc cdng trinh biin la phd Pierson-Moskowitz vd Jonswap Phd sdng Pierson-Moskowitz: HtT ( T,co \ exp %7f 2n (T,co n \ 2n (1) dd: T^ la trung binh chu ky cit khdng, Hs la chieu cao sdng dang kl • Phd sdng Jonswap: ^^^i^) = cig'^^'^ exp exp (O K^'P (2) J dd: a, Wp y\k cac tham so phy thudc vao H^ va T^ cua trang thai bien ngin ban d vung dang xet crdae trung cho nhgn cua dinh phd, Wp la tan sd gdc cua dinh Pierson-Moskovitz tuong ung Khi y= phd Jonswap trung vdi phd Pierson-Moskovitz Ddi vdi vung md Bach Hd, cac tham so tren dugc xac dinh nhu sau: a - 0,0097; y= 1,45; Wp= 0,465; o-= 0,092 w < w^ va (T= 0,102 w >W/, • Ddi vai trgng thdi biin ddi hgn Tuyen tgp bao cao Hgi nghj KHCN "30 nam Dau Viet Nam: Cff hgi mdi, thach thde mdi" 253 Tap hgp cac trang thai biin ngin han mdt khoang thdi gian dai tao mdt trang thai biin dai ban Tu tap hgp cac sd cap gia tri (//,, Tf) ngudi ta thiet lap dugc bilu phan tan sdng, dya vao bieu dd phan tan sdng ta cd the xac dinh dugc ham phan phdi xac suat hai chieu dai ban cua Hs va 7^: P[{H, < / / , < //,),(r, < r, < T,)]= jjf, ,,{H,T}lHdT (3) H,T, dd: F„ , {H,T) - la ham mat xac suat hai chieu cua chieu cao dang ke va chu ky cit khdng Tuy nhien de don gian, trdng thuc te ta thudng quan tam den ham phan phdi cua chieu cao sdng dang ke / „ , (H) Theo kinh nghiem thuc te chieu cao sdng dang ke xay khoang thdi gian dai thudng phan phdi theo quy luat Weibull: P',.iffs)= ( j/«„ (//>///=!-exp H-H, (4) dd: a, p la cac tham sd hinh dang va kich thudc cua phan phdi dugc xac dinh tu cac sd lieu quan trac cd dugc tai vung bien dang xet Khi chieu cao sdng rieng biet d mdi trang thai bien phan phdi theo quy luat Rayleigh thi phan phdi xac suat dai ban cua chieu cao sdng rieng biet cung tuan theo luat Weibull: ^//^" FSHS)=^ exp 0/3 (5) dd: C va Z) la cac tham sd phu thudc vao cc, cdn or va y5 la cac tham sd Weibull cua chieu cao sdng dang ke H^ • Sd sdng cd chiiu cao vugt mpt chiiu cao sdng rieng biet cho truac N ndm: Neu Nl la tdng sd sdng nam va Nei la sd sdng cd chieu cao vugt mdt gia tri cho trudc H cua chieu cao sdng rieng biet thi tan suat cua sy kien dd se la N^i/N, va xac suat cua su kien dd dugc bieu dien theo cdng thuc: e,(^)=l-^/.(^)=exp H cfi (6) Tir dd suy ra: A^„=exp ^ H^ cff N, (7) Tir bieu thuc (7), da biet cac tham sd fi C, D va N; ta thiet lap dugc bieu the hien mdi quan he giua chieu cao sdng H va /gTVg/ Tu bieu dd ta cd the xac dinh dugc sd sdng cd chieu cao nam khoang (//,, //,+/) va dd xac dinh dugc sd chu trinh thay ddi ung suit kit ciu dl phuc vu cho tinh toan mdi • Tdi trgng sdng tdc dpng len cdng trinh dugc xdc dinh theo phuang trinh Morison Luc thuy ddng phan bd tren mdt don vi chilu dai tac dung len mdt phan tu manh {D < 0,2A, vdi D la dudng kinh cua phin tu, A la chilu dai bude sdng) dugc xac dinh theo cdng thuc: 254 Su' dung phuong phap phan tich moi ngau nhien dg hoach dinh kg hoach khao sat chi tiet, (8) q{z,t)= pC„Aii^ + -~pC,,Du„ do: ^ - dien tich mat cit ngang cua phan tu ket cau w„ - vecto gia tdc phap tuyen cua phan tu nude vudng gdc vdi true cua phan tu CM - he sd khdi lugng nude kem CD - he sd can ii„ - vecto van toe phap tuyin cua tu nude, vudng gdc vdi tryc cua phan tu ket cau p - la ty khdi cua nude bien Trong cdng thue (1-8) phin lyc can la mgt sd hang phi tuyen Do tinh toan ddng lyc ta cin phai tuyin tinh hda phin Ap dyng phuong phap binh phuang tdi thilu ddi vdi qua trinh chuin trung binh bang khdng ta ed the viet phuang trinh Morison nhu sau: q{z,t)= pC^Au,, + -pCa (9) dd cr„ la lech chuan cua phan phdi van tde iTng suat ngau nhien Trong qua trinh phan tich mdi cua cac gian khoan bien cd dinh bang thep, chu yeu ta quan tam din ung suat d eae mdi han va dd can quan tam den qua trinh thay ddi ung suat eye bd ldn nhat tae dyng eua tai trgng gay d eae lien ket Do tac ddng eua mdi trudng bien la mdt qua trinh ngau nhien nen phan ung cua ket cau cung la mdt qua trinh ngau nhien Cac sd lieu dau vao cho phan tich la tap hgp cae trang thai bien ngan ban theo cac hudng sdng nhat dinh Mdi trang thai bien dugc dac trtmg bdi hudng sdng, chieu cao sdng dang ke Hj, chu ky trung binh cat khdng F bay phd nang lugng sdng S,j^(co) cua trang thai bien dd Qua phan tieh ddng lyc ket cau ket qua nhan dugc la ham mat phd ung suat Sss((o), nhu vay qua trinh ung suat cd lien quan vdi qua trinh sdng thdng qua bam truyen tuyen tinh (cac sd hang phi tuyen cdng thuc Morison da dugc tuyen tinh hda) Qua trinh tuong tac cua sdng bien dugc gia thiet la mdt qua trinh Gauss trung binh bang khdng, nen ung suat ket eau cung la mdt qua trinh Gauss trung binh bang khdng Ss!i";t ^i'nham-^ Vf, Qud trinh img sudi ddi liep I L A * '"ft Qud Irifili img sudi ddi rdng Hinh Cac dac trung quan trgng cua mat phd phan ung dugc su dyng phan tich moi: Mdmen bgc k ciia phd Tuygn tap bao cao Hgi nghj KHCN "30 nam Pau Viet Nam: Cff hgi mdi, thach thuc mdi" M, = jo)''S^X'^)d(o voi k= 0,1,2 251 (10) Phuong sai cua qud trinh img sudt, S„ = CO (11) Tham sd bi rpng ddi tdn s^ = 1-r' i , "'- M,M, (12) He sd diiu hda M, :V7^ ^MJ^, (13) Trudng hgp phd ddi hep Can eu vao tham sd s de xac dinh be rdng cua ham mat phd, thdng thudng e< 0,4 tbi qua trinh dugc coi la dai hep Ddi vdi qua trinh cd cae dac trung sau: Ham mat cua ung suat bien Sa (gia tri cue dai) la mdt bien ngau nhien phan phdi theo luat Rayleigh, xac dinh theo cdng thuc: ^(S) = a.4exp (14) dd tham sd o^ bang phuong sai cua qua trinh ung suat a^ = MQ Sd gia ung suat danh nghia trudng hgp giai tan hep ed gia tri gan dung: Sr — Smax " Smin — S a (i5) Phan phdi Rayleigh cua sd gia ung suat vdi lech chuan bang 2Sa se la: /Js)= 4c7: -exp ^ 15^^ (16) Chu ky cua qua trinh ung suat la chu ky cit khdng vdi ddc duong Nd ciing la mdt bien ngau nhien cd gia tri trung binh gan dung: T.=2n^ Sd chu trinh ung suat iing vdi trang thai bien dang xet dugc xac dinh bang: T « = • T (17) (18) Trong dd: T^ la khoang thdi gian cua trang thai bien ngan ban dang xet Tru&ng hgp phd ddi rdng De don gian cho qua trinh phan tich kit ciu cac MSP ngudi ta thudng gia thiet qua trinh ung suat la dai hep Tuy nhien, mdt sd trudng hgp qua trinh sdng khong phai la 256 Sddung phu-QTig phap phan tieh mdi ngau nhien dl hoach djnh ke hoach khao sat chi tiet qua trinh Gauss, bien ung suat khdng phan phdi theo luat Reyleigh va sd gia ung suat khdng cdn thda man bilu thuc (15) Trong qua trinh phan tich dgng luc hgc ket cau, ddi cd thi nhan dugc qua trinh ung suat vdi ham mat phd cd bai dinh quan trgng: mdt dinh ung vdi tin sd dinh cua phd mat sdng, cdn dinh ung vdi tin sd dao ddng rieng thu nhit cua kit ciu tuc la ung vdi dinh cua ham truyen Khi nhin vao bieu dd md ta qua trinh ung suit, ta thiy ed mdt sd cue dai va cyc tieu dia phuong nam d ca hai mien (-), (+) Trong trudng hgp dd nlu ap dyng cdng thuc (18) de tinh sd chu trinh ung suat se khdng cdn phu hgp nua, dd phan tich mdi va tin cay can phai xet den anh hudng cua be rdng dai, tuc la anh hudng cua chung tdi sd gia ung suat va sd chu trinh ung suat D I khic phuc, ngudi ta su dung he sd hieu chinh p(m,a), dd cd ke den tham sd m cua mdi quan he S-N va su phan phdi mat phd mien tan sd co Dua vao phuong phap dem ddng mua ddi vdi cac the hien cua qua trinh ung suat nhan dugc bang md phdng, Monte Carlo, Wirsching va Ligh da dua kien nghi chinh p(m,o)), qua trinh ung suat la qua trinh Gauss dai rdng cd he sd dieu hda r va tham sd be rdng e da biet: p{fn,(o) = A{m) + \[ - ^(m)](l - V l - r ' j Vdi: ' (19) w ) = 0.926- 0.033W ; 5(w) = 1.587-2.323m Trong dd:OTla tham sd dudng cong mdi S-N Tuy nhien, viec xac dinh he sd hieu chinh tren chi dua vao su md phdng mgt so it kieu phd nen thuc te neu thieu thdng tin ta cd the xac dinh chung dua tren gia thilt ung suat la qua trinh Gauss dai rdng tdng quat, hoae qua trinh Gauss dn tring He so tap trung irng suat Lien ket cua ket cau cdng trinh bien la cac lien ket dng ndi vdi bing mdi ban Trong qua trinh chiu lyc su phan bd timg suit va biin dang d phin giao tuyen mdi ban la rat phuc tap Nhung dilm cd ung suit ldn nhit ggi la cac dilm ndng, cac dilm ndng dd cd the xay tai chan mdi ban ve phia ong chu hoae phia ong nhanh D I dac tnmg cho cac diem ndng ung suit dd ngudi ta dua cac khai niem la he sd tap trung timg suit SCF va he sd tap trung bien dang SNCF: SCF = ^22^ (20) dd: S„ax la ung suit cue bd ldn nhit va S„ la ung suit danh nghia d dng nhanh SNCF^^^^ (21) dd: f„^ la biin dang cue bd ldn nhit va £„ la biin dang danh nghia d ong nhanh Quan he giua SCF va SNCF: 1+ ^ SCF = SNCF ^ dd: v la he sd Poisson cua vat lieu; £2 la biin dang vudng gdc vdi f„^ Trong trang thai ting suit phang, ung suit cue bd ldn nhat se la: (22) ruygn tap bao cao Hgi nghj KHCN "30 nam Dau Viet Nam: Cff hdi mdi, thach thde mdi" 251^ 1+ i ^ 1.8 Brace SCF a = YP^ ; P = yCj; y = y^; Axial Load SCFa, r = ' ^ ; G la goc nghieng giiia dng nhanh va ong chu Ung suat cue bd ldn nhat tai cac lien ket Do giao tuyen giua dng ehu va dng nhanh la mdt dudng cong ghenh hinh yen ngya nen viec xac dinh chinh xac tai hai phia eua giao tuyen la rat phuc tap Nen tinh toan thudng su dung cac bieu thuc sau day de tinh iing suat tai diem dge theo giao tuyen: S) = ajSCFaxSax + biSCFipbSjpb 52 = a2SCFaxSax " b2SCFjpbSipb 53 ~ ^sSCFa^Sax + CsSCFopbSopb 54 — a4SCraxSax " C4SCropbSopb 55 = a4SCFaxSax + bsSCFjpbSjpb + CsSCFopbSopb §6 ~ SgSCFaxSax - bgSCFjpbSjpb - CgSCFopbSopb S7 ~ aySCFaxSax " bySCFjpbSjpb + CySCFophSopb beminq momtdl Sg = agSCFaxSax + bgSCFjpbSjpb - CgSCFopbSopb Trong dd: ai, bj, Cj la cac he sd xet den vi tri eua cac diem ung suat; Sax, Sjpb, Sopb la eae phan ung suat danh nghia; SCFax, SCFjpb, SCFopb la cac he sd tap trung ung suat He th6ng dirdng cong mdi Phuong trinh dudng eong mdi thi hien moi quan he giua sd chu trinh tdi pha buy N vdi sd gia iing suat Sr dugc viet dang sau: 258 Sd dung phuong phap phan tieh mdi ngiu nhign dg hoach djnh ke hoach khao sat chi tiet \gN = \ga-m\gS^ (24) Trong dd: a va m la cac hang sd thyc nghiem Do bin mdi cua kit ciu phy thudc vao kieu lien ket, hinh dang cua phan tu, tinh chat ung suit, phuang phap ebl tao va kiem tra Ngoai chung cdn phu thudc vao chieu day cua dng, cac dudng cong S-N co ban da cho phu hgp vdi chieu day 32mm ddi vdi mdi noi dang T, cdn cac loai mdi ndi khae la 22mm Vi vay, cac mdi ndi cd chieu day khae chuin tren thi cdng thuc (24) phai ed sy dilu chinh IQN = \Qa m 't^ mlgS^ K^B J Trong dd: t la chilu day thyc cua phin tu dang xet; ts la chilu day chuan ung vdi dudng cong S-N 32mm hoae 22mm iriN/mnt) Cdc ducmg S-N cua moi noi ong Hinh Tinh toan tudi tho mdi theo quan diem tdn thtrong tich IQy Theo Miner, mdi bae ting suat cao hon gidi ban mdi deu gay mgt phan tdn thuang cho vat lieu Neu phan tu ket cau chiu tap hgp ung suat gdm k bae khae thi sd ton thuang tich luy tdng cdng cho phep la: (25) dd: n, - sd chu trinh ung suat ma phan tu phai chiu vdi ung suat S, [D] - tdn thuong mdi cho phep A', - sd chu trinh tdi pha buy lay theo dudng cong mdi S-N ung vdi S, Tudi thg mdi cua phan tu ket cau dugc tinh theo cdng thuc: L=- ^ AI nam (nam) (26) Tinh toan tuoi tho mdi theo quan diem co* hoc pha hiiy a Lugt tdc dp phdt trien vet nut cua Paris-Erdogan Mdi quan he giua tdc phat triln vlt nut da/dN va sd gia yeu td cudng ung suit AK = AcTF4na dugc ggi la dudng cong tde phat trien vet nut: Tuygn tap bao eao Hgi nghj KHCN "30 nam Pau Viet Nam: Cff hdi mdi, thdeh thde mdi" iO^d.M -ruT :'.chi; - Vung A la vung ngudng, vlt nut bit diu hinh AK,h la gia tri ngudng cua ylu td cudng ung suit Khi AK < AK,h vlt nut khdng phat triln Khi AK > AK,h vet nut phat trien cham dan - Vung B la vung tdc phat trien vet nut dn dinh 251_ trinh] /i Vijng B Vijmj C ( / - Vung C la vung pha buy Khi AK > Kjc kit ciu bi pha buy Di/dng cong td'c dd phjt Irien vei nift Phuang trinh Paris vung A: (27) = C{AK)'' Hinh dN da Phuang trinh Paris cho vung A va B: — = C(M:"' Phuong trinh Forman cho ca ba vung: - AK^) da AK' dN Ana^E (28) HAK-A^II-R) (l - R)K^ - AK (29) Trong dd: R la he sd bat ddi xung cua chu trinh ung suat R = '^"^/i^^', cTy gidi ban chay eua vat lieu; E module dan hdi cua vat lieu; C, m la cac tham sd phat trien vet niit, dugc xac dinh tu thyc nghiem Ta cd the thay rang phuang trinh Paris an toan cho vung A ma khdng an toan cho vung C Tuy nhien, hau bet tudi thg mdi deu nam vung A va B nen tinh toan tudi thg mdi thi su dyng phuong trinh Paris la an toan Neu thieu cac sd lieu ve C va m thi su dyng cdng thuc (29) la tien lgi Khi da xac dinh duoc tdc dd phat trien cua vet nut — , ta cd the xac dinh duoc sd dN chu trinh can thiet de vet nut phat trien tu chieu sau a, den a^: \da '-2 (30) J do/ a /d" Viec xac dinh sd chu trinh lam vlt nut phat triln ttr chieu sau a, tdi chieu sau pha buy a^ cung ddng nghia vdi viec xac dinh tudi thg mdi b Trudng hop irng suat cd bien dp fihdng ddi Lien quan den bai toan dang xet, ta chi xet trudng hgp vet nut da xuat hien, su dung phuong trinh Paris ta cd: da ^ dd: da ir UvY ^ },c(Aa^Ff J }c{AKr da d^ Cn^^ },c(Aa^Ff (31) AK - sd gia cua yeu td cudng iing suat: AK = AaFyfm A CT - sd gia ung suit Ao- = a^^ - o-,,„ a - ung suat danh nghia d phin tu, vudng gdc vdi hudng lan truyen nut F - ham sd phy thudc cac ylu td hinh hgc Theo tieu chuan cua DNV thi cdng thuc (31) thi hien sd chu trinh tdi pha huy dugc viet thanh: Sd dung phu-ong phap phan tieh mdi ngiu nhien di hoach djnh ke hoach khao sat chi tiet 260 ' Trong dd: a,=-^, da CT'"'''''ACT"' }JFJ^ (32) CT''-'Aa" a^ =^-,T la chieu day cua dng 'J da (33) a, \F4naJ Vdi gia thilt kit ciu bi pha buy vlt nut an sau bet chieu day («/= 1), thi sd chu trinh dl vlt nut phat trien tu chieu sau a, tdi chieu sau aj la: N{a^ -> «2) = da Cr'^^-'Acr"' a, \F4na) da (34) a, \F4na] D I thuan tien cho tinh toan, cac tich phan / dugc xay dung cac toan dd cho cac dang moi ban chung nam khdng cung nhu chung ngap nude bien c Trudng hpp irng suat co bien dp thay ddi ngdu nhien Khi ling suat dugc biet dudi dang the hien, bang phuong phap dem chu trinh ta se nhan duge mdt tap hgp ung suat (ACT, - nJ vdi i = H- I, Ila sd bae ung suat Khi ung suat dugc biet dudi dang ham mat xac suat /(Acr), bang phep tinh xac suat va thdng ke, ta cung bien ddi mdt tap hgp ung suat (ACT, - « , ) nhu tren hinh bieu dien Hinh Trong dd: ACT, la trung diem cua bae ung suat thu i, nj la sd chu trinh cua bae i, ni = nn/tAcr,) f(A5) A5 A5max f^50=S A5i Oi "" A5 Hinh Tu each lam tren, ta se xac dinh dugc so gia ung suit tuong duong Aa " theo cdng thuc: i I \ Z«-Ac7; Ao- = (35) eq Bai toan trd ve trudng hgp ung suit cd bien khdng doi vdi Ao- dugc thay bing Ao-^, d Tieu chudn phd hiiy Tren co sd ly thuyet vl tin cay, co hgc pha huy dua tieu chuin danh pha buy qua trinh phat trien cua vlt nut la: Tuyin tSp bao eao Hgi nghj KHCN "30 nam Dau Vigt Nam: Cff hgi mdi, thach thde mdi" ac-a^ (43) Trong trudng hgp kit qua khao sat tim thiy vlt nut, thi khoang an toan gidi ban dugc xac dinh nhu sau: M= A f y - ^ ^ - CYs: (44) Mj = vdi dilu kien: A(Tj)=Aj Mj < vdi dieu kien: A(Tj)>Aj Trong trudng hgp ma vlt nut khdng dugc tim thiy lan khao sat thu r tai vi tri dang xem xet thi xac suat hu hdng tich luy la: P ; - P ( M < | M , >0nM2 > n n M , >0) (45) Cdng thuc tren cung cd the dugc tinh bang viec giai bai toan tin cay eho hai he song song d tu sd va mau sd: _ P{M O n M , > O n n M ^ > ) '•'" P(M, > n M > O n n A / , >0) Trong trudng hgp neu biet trudc vet nut la khdng tim thay r lan khao sat dau tien tai mdt vi tri, vet nut dugc tim thay d lan khao sat thu r+I va kich thudc vet nut dd tiep Uic giii nguyen cho den lan khao sat thu s-1, thi dd viec cap nhat xac suat hu hdng la: P" = P ( M < | M , >OnM^ > O n n M J n A / „ , = O n n M , = (47) MOT SO KET QUA PHAN TICH CHO CAC CONG TRINH CUA XNLD VIETSOVPETRO Quy trinh tinh toan phan tich - Buac 1: Tinh toan tac ddng cua mdi trudng tac ddng len ket cau dya tren md ta ngiu nhien - Buac 2: Tinh toan cudng chiu luc tuong ung cua ket cau cdng dya tren phuang phap md ta ngau nhien - Buac 3: Xac dinh cac tieu chuin pha buy, su dyng kit cua bude va xay dyng ham gidi ban tuong ung Tuyin tap bao cao Hdi nghj KHCN "30 nam DJu Viet Nam: Cff hdi mdi, thach thuc mdi'' 2di - Buac 4: Xac djnh tin cay cua ket cau dya tren ly thuyet tin cay de hoach dinh ke hoach khao sat Mot sd ket qua da dirge phan tich Bing phuong phap phan tich nay, cac tac gia da ap dung de phan tich cho mdt sd cdng trinh cua XNLD Vietsovpetro thdng qua chuong trinh SESAM Bang md ta mdt sd kit qua dien hinh Bang Ket qua ptidn ticti gian ong dung Chi so Chi so dp tin Thai gian Niit dp tin cay tinh khao sit csy dich toin Phuang phap khio sit LlTFl-I Ket qud phdn ticti gidn S^^ phit trien cua Nut vet nirt Chi s6 Chi so dp tin Thai gian dp tin cay tinh khao sit cay dich toan MCn-6 Phuang phip khao sit Sir phit trien cua vet nirt 1,63 1,631 2005,13 PODL-MPl-UW Theo chieu sau J63 1,63 1,638 2002,55 PODL-MPl-UW Theo chieu sau 31a 1,63 1,630 2011,39 PODL-MPI-UW Theo chieu sau J63 1,63 1,630 2007,65 PODL-MPl-UW Theo chieu sau 64a 1,63 1,632 2004,85 PODL-MPl-UW Theo chieu sau J60 1,63 1,634 2002,56 PODL-MPl-UW Theo chieu sau 64a 1,63 1,632 2010,58 PODL-MPl-UW Theo chieu sau J60 1,63 1,630 2007,73 PODL-MPl-UW Theo chieu sau 73a 1,63 1,631 2004,98 PODL-MPl-UW Theo chiiu sau J592 1,63 1,621 2002,64 PODL-MPI-UW Theo chieu sau 73a 1,63 1,631 2010,94 PODL-MPl-UW Theo chieu sau J592 1,63 1,630 2007,95 PODL-MPI-UW Theo chieu sau 73b 1,63 1,632 2004,74 PODL-MPl-UW Theo chieu sau J595 1,63 1,633 2002,71 PODL-MPI-UW Theo chieu sau 73b 1.63 1,633 2010,23 PODL-MPl-UW Theo chieu sau J595 1,63 1,630 2008,14 PODL-MPI-UW Theo chieu sau J73c 1,63 1,633 2004,56 PODL-MPl-UW Theo chieu sau J603 1,63 1,638 2002,78 PODL-MPI-UW Theo chieu siu I73c 1,63 1,635 2009,71 PODL-MPl-UW Theo chieu sau J603 1,63 1,630 2008,56 PODL-MPI-UW Theo chieu sau 174a 1,63 1,631 2005,05 PODL-MPl-UW Theo chieu sau J605 1,63 1,638 2002,79 PODL-MPI-UW Theo chieu sau J74a 1,63 1,631 2011,17 PODL-MPl-UW Theo chieu sau J605 1,63 1,630 2008,58 PODL-MPI-UW Theo chieu sau 175a 1,63 1,634 2004,46 PODL-MPl-UW Theo chieu sau J124 1,63 1,638 2002,79 PODL-MPI-UW Theo chieu sau J75a 1,63 1,637 2009,41 PODL-MPl-UW Theo chiiu sau J124 1,63 1,630 2008,6 PODL-MPI-UW Theo chieu sau 75b 1,63 1,631 2005,09 PODL-MPI-UW Theo chieu sau J594 1,63 1,630 2002,77 PODL-MPI-UW Theo chieu sau 175b 1,63 1,63 2011,29 PODL-MPl-UW Theo chieu sau J594 1,63 1,630 2008,36 PODL-MPI-UW Theo chieu sau 31a KET LUAN Hau het cac gian khoan cua XNLD Vietsovpetro dugc thiet ke theo tieu chuan BCH-51-3-85 (tieu chuan tam thdi ve xay dyng), ket cau phuc tap, sd lugng nut va sd lugng phan tu ldn, cac dng chu mdng Qua thyc te phan tich lai ket cau cac MSP cho thay hau bet tudi thg mdi cua cac nut la rat thap Do dd, viec hoach dinh chuong trinh cung nhu lap ke hoach khao sat chi tiet gap nhieu khd khan, khdi lugng khao sat rat ldn, rat tdn kem va cd the gay nguy hiem cho ngudi qua trinh thuc hien cdng viee khao sat Vi vay, su dyng phuang phap phan tich cd nhiing uu diem sau: - Cho phep hoach dinh dugc vi tri cac nut cd thi bi tdn thuong tich Ifiy mdi ldn gay hu hdng xuat hien cac vet nut - Cho phep hoach dinh dugc chu trinh va phuong phap khao sat chi tilt cho cac nut ciing nhu lap dugc ke hoach sua chiia chung - Tilt kiem dugc mdt khoan chi phi rit ldn cho cdng tac khao sat 264 Sd dung phuong phap phan tich mdi ngiu nhien di hoach djnh ki hoach khao sat ehi tigt Vi vay, phuang phap phan tich cd y nghia khoa hgc va kinh te rat ldn, XNLD Vietsovpetro can cd ke hoach de khai thac nd tdt hon cho viec phan tich cac MSP, BK TAI LIEU THAM K H A O API, 1993 Recommended practice for planning, design and construction affixed offshore structures API RP2A-WSD 20 American Welding Society, 1990 Structural welding code AWS Dl, p - 90 Bitner-Gregersen E.M., Mathisen J., 1988 Uncertainties in statistical models for wind, waves and current DNV research report No 88-2007 Borgman L.E., 1967 Spectral analysis of ocean wave forces on piling Joumal of Waterways and Harbour Ivision, ASCE, Vol 93, p 129 - 156 Bostrem T., Overvik T., 1986 Hydrodynamic force coefficients in random wave conditions Proceedings MAE Tokyo Brouwers J.J.H., Verbeek P.H.J., 1993 Expected fatigue damage and expected extreme response for Morison-type wave loading Profast Theory SESAM REFERENCES-2 Ol-APR-2002 Program version 2.2 Applied Ocean Research, Vol 5, p 129- 133 Det Norske Veritas, 1982 Rules for the design, construction and inspection affixed offshore structures DnV Det Norske Veritas, 1984 Fatigue strength analysis for mobile offshore units Classification Note No 30.2, DnV Det Norske Veritas, 1984 Fatigue strength analysis for mobile offshore units Classification Note No 30.2, DnV 10 Buitrago J., Zettlemeyer N., Kahlicb J., 1984 Combined hot-spot stress procedures for tubular joints Offshore Technology Conference Proceedings OTC 4775, May 1984 11 Pham Khae Hung, 1995 Establishment of methodology on fatigue of offshore fixed steel jacket structures Report, Hanoi 12 Phan Van Khdi, 1994 Tinh todn tudi thg mdi cua kit cdu ngodi biin qud trinh img sudt ddi hep Tap chi KH&CN 13 Phan Van Khdi, Nguyin Cao Menh, Ngd Huong Nhu, 1995 Tinh todn tuoi thg mdi gidn khoan bdng phuang phdp chdng dao dpng rieng Bao cao dl tai KH, Vien Co hgc 14 Phan Van Khdi, 1997 Tudi thg mdi cua kit cdu thep ngodi biin NXB Khoa hoc va Ky thuat Ha Ndi 15 XoaHF Jl3 HroK BHHI>, MaxymeBHH C.B., By Cyan Jlafl, 1999 - 2001 Cosdauue u euedpenue MemoduKu, odocnoeanue onmuMCuibuux cpoKoe u odtcMoe odcjiedoeanu u pcMonmoe MCH u EK OTHCT O HayHHO-HccjieziOBaTejibCKOH padoxe, HHHH 1999, 2000,2001 16 Xoanr JIa HroK BHHB, KpaBuoB C.H., By Cyan Jlai!, 2003 - 2004 Peanajius Hccyufux KOHcmpyKiiud MopcKux coopyotcenuii u paspadomKa npedjiooiceHuu no npoenm nnanoe ux oGcnedoeanuii u pcMonmoe OTHCT O HayHHO-HCCJieflOBaTejibCKoii padoxe, HHHH 2003, 2004 ... PODL-MPI-UW Theo chieu sau 175b 1,63 1,63 2011,29 PODL-MPl-UW Theo chieu sau J594 1,63 1,630 2008,36 PODL-MPI-UW Theo chieu sau 31a KET LUAN Hau het cac gian khoan cua XNLD Vietsovpetro dugc... tich cho mdt sd cdng trinh cua XNLD Vietsovpetro thdng qua chuong trinh SESAM Bang md ta mdt sd kit qua dien hinh Bang Ket qua ptidn ticti gian ong dung Chi so Chi so dp tin Thai gian Niit dp... 2002,55 PODL-MPl-UW Theo chieu sau 31a 1,63 1,630 2011,39 PODL-MPI-UW Theo chieu sau J63 1,63 1,630 2007,65 PODL-MPl-UW Theo chieu sau 64a 1,63 1,632 2004,85 PODL-MPl-UW Theo chieu sau J60 1,63 1,634