I KHOATIOC ^ E I 3 3 I E I I ^ B
NGHIEN CL L ANH HUONG K £ T CAU CHONG DO TAM DEN UNG SUAT \ 6 H.AM KHI THI CONG QUA VUNG DAT YEU
Dao Van Himg T,-,ring Dai hoc Thiy lgi Tom tut: Duiftig hdn, thuy cdng Id tnal trong nhirng hang muc quan Pong cua he thing cdng uinh thuy lm. thin then Kh, ddo hd,n gi,p phdl cdc dii da yiu thi bdi budc phdi ci kil cdu chdng dd lam de hc'un khdng bi sdp vd cdng \,ec ddo ham duoc an ,odn. ddm bdo cdc diin bin ky thudl Laa, ke, cdu cluing dir lam nd,- ihiring la khung chiu luc. chira dam nhieni chtre ndng gidm dp nhdm vd cdch ntric di' bao ve khdt dd xung quanh hdm. Do do, ngiiien ciru dnh hiring kit cdu chdng da tatn kh, ddo hiim qua vimg dal ven den irng sud, ciia vo hdm Id cdn Ihiit di ddm bdo at, lodn Irong qua trinh tin cdng ci„,g nhu vdn hdnh. tiet hiim ch, phi xdy dung cong trinh.
Tirkhda: dirdng him thtiy cdng, kit cdu chong dd, vd him, gia co, vitng dal yeu, Ung suat.
Summarj'; llyilnntlte tunnel is one oflhe most important elemenls ofirrigalional or liydropomr ,,-oi-ks slrnelwes inns, he nislalled lo ens„,-e the technical conditions This kind of struclure uMmlly sy.uems When the excmutuin encoumering soft soil or ,,-euk rack zones, temporary supporting co„s,sls nf load bearing frames „-,lho,a funclion of reducing Ihe roughness and
„„prov,ng ,,-uici-proofness lo protect Ihe tunnel .mrroimding rocks mass. This study seeks to understand effects of temporary supporting siriicliires on strcues m tunnel linning in order lo propose soluhons ensuring safely iliirlng construction and operation processes as well as reducng construction cost
Keyieorils: Ilydriiulic luunel: liydropcver works; temporary supporting structures; stress: soft .soil zone
. D.^T VAN DE Vigc xay dgng dutag hdm thuy cflng rJt phiic 0 Vigt Nam, ttong thoi gian qua, xay dung thuy ^ P ' khong phdi dutag hjm nao ciing dugc xdy Igi - thuy dien da phat trign manh mg va mang ^'^B tren ngn da tot, ma chiing con phai di qua lai nhthig Ihanh qua to lta trong su nghigp cflng "^^S vimg co dja chjt xju, vung co dfli diit nghigp hod, hien dai hod djt nuoc. Su phdt ttign Bay.- Sja chdt cflng trinh co y nghia quan tnjng ciia thiiy lgi, thiiy dign da thiic djy xay dung 1'V^^ dinh dgn vi|c chgn tuygn, vj tri dat cong dutag ham, dac bigt la dutag hdm thiiy cflng t™* ™ kgt cdu cua no. Ngoai ra, dja chat cong tren tuygn ndng lugng cdc cflng ttinh thuy dign. •""* <^™ 'Wi^' "li"* 1™ bien phap thi cflng, den Dutag ham thuy cflng thutag dugc xay dung "•? * i cflng, gia thanh cong ttinh. Ngu Ihi cong ngam ttong long djt, xung quanh id dJt da, ngn *''™g hJm qua vilng dia chdt tflt va dflng nhjt Chung CO dac digm chung la chju tac dung ciia dp thi co thg hoan chinh cong tac dao ttuoc va xay luc dal da, nuoc ngdm tir phia ngodi va dp luc ''vng lap Iflt hodn chmh sau. Con khi ddo ham cua nuoc tir pWa ttong. ' gfp phdi cac dai da yeu thi bat bugc phai co ket
^ ^ can chong d5 tam de hJm khong bj sap va cflng Ngay nhan bai: 15/9/2016 vigc ddo hJm dugc an loan.
Ngay thong qua phan bign: 17/10/2016 Do dfl, cdn phai nghign cihi dnh hutag ciia ket Ngay duyet dang. 26/10/2016 edu chflng dfl tam thtri dgn ngi lgc, tag sujt vfl
a2 "PCHlKHOAHOCVAC0r<GN6HETHuyLais035.2016
ham de cfl cac bign phap thich hgp khi thi eong, gia cfl, bfl di cflt thep cua vfl him ttgn vimg ddt ygu nham dam bao an toan vg ky thudt va kinh tg.
2. NOl DUNG NGHIEN CUtJ:
2.1. Mgt so phirorng phap gia c6, chong do khi iio ham gap phai dia chat yeut'U^I Cdc phuang phap gia co, chflng do tam thoi khi gap dia chjt ygu ttong qua trinh thi cflng nham nhanh chflng khflng chg bign dang, dua khfli da vg trjng thai fln dinh ngay sau khi dao.
Cac bien phap chflng do tam co thg chia thanh cdc dang sau:
II. 1 Gia ci dgng Ireo: Sir dung cdc neo thep hutag kinh kgt hgp bg tflng phun vdy, tao ma sdt giOa cdc lop da voi nhau, han chj bign dang cho vung da xung quanh mdt cJt ham, Iam cho cac lop da lign kgt lai voi nhau. Be tflng phun vay ldm kgt cJu chflng dfl him nhu mgt lop da mong nhung cfl tac dgng tang cutag sire chflng dfl.
2.1 2 Gig ci dgng ching: Sir dung cdc vi thep ehit I tag thanh mgt khflng gian ghep hodc cac loai thep hinh chuygn dung khac dugc giing lili voi nhau dg chflng giii nhdm ddm bdo on djnh cho guong ddo.
2.1.3 Neo VU0 Iruic: Su dung cac loai neo dugc bfl tti dgc theo ehu vi dao, hgp voi phuong tuygn ham mflt gfle a, hinh thdnh mgt vdnh neo chdt truac vimg djt da ygu.
2 1.4 Gidn ing Ihep. Lgi dung gid la cdc vflm thep. dgc theo chu vi dong cac flng thep (chigu dai tir 10m-15m) vg phia guong dao tao thanh gian che, chflng viing djt da phia truoic guong dao.
2.2. Mflt sfl phuang phap linh toan kgt cju gia CO dutag bjm'"'"'^'
Mge dich cua tlnh toan kgt cdu gia cfl Id xdc djnh ngi luc va phan bo ling sudt, tir do lign hanh kigm tra digu kign bgn va bfl tri cflt thep.
2.2.1 Phtrangphdp ca hoc kil cdu
KHUA HUC ^ ^ . i ; i c l . V . 1 ! l : ^ Khi xac dinh so dfl tinh todn dua vao trinh ttr thi cflng theo chu vi mat cat dutag h jm, so dfl tinh toan se Id mgt kgt cju khep kin. (Hinh 1) Tinh toan phdn vflm ttgn chii y bign vi goe chan vflm do cac ngoai luc gay ra (Pp) va bign vj gfle fl chan vflm do mfl men don vi gay ra (Pi) va xet den anh hutag cua vom day.
IIIMNIII.
Hinh 1. Sadd linh lodn vim kin 2.2.1 Phuang phdp ca hoc vdl rdn biin dgng Phuang phap nay dua tten Ioi giai ciia ly thuygt dan hfli deo va tir bign voi nira khflng gian hay nira mat phjng co lo khoet hlnh ttfln hoac hinh cfl bign phiic tap hon.
Dutag ham co ap mat cat tron, thutag sir dung so dfl hinh xuygn gjn kgt voi lo khogt hinh ttfln ddt trong mfli trutag dan hfli vfl han, hoac la loi gidi cua Iy thuygt dan hfli cho hinli tru thdnh day chju tac dung ciia dp Igc bgn trong va ben ngoai.
hdm' III
Phucmg phdp phdn tii hOu ban:
Mien tinh toan dugc rcri rae hoa, chia luoi cdc phan til ngn va kgt cJu. Khi tinh toan co xet dgn su tuong tdc cua kgt cJu va nen, cung nhu tai trgng tac dung true tigp lgn kJl cju Ihflng qua cdc tham so truygn trong ngn djt xung quanh. Tat ca cac tdi ttpng va luc tac dung lgn kgt cau gia co dutag h Jm cfl thg phan ra didnh cac tai ttgng thutag xuyen va tam thoi, phan
TAP CHl KHOA HOC VA CONG NGHE THUY LOl 5(5 35 • 2016
I KHOA HOC ^ E ! I 3 ! B A ^ B thanh nliieu tfl hgp tai trong.
Phuang phap phan tu bien:
Phuang phap phan tu bien dimg cac phuang trinh tich phan bien da dugc ung dung rgng rai
trong nhimg nam gan day trong viec tinh tofc cong trinh tren may tmh. Ban chSt cua phuong phap nam flf khai niem bai toan bien dfli voi cac phuang trinh vi phan din dfln phucmg trinh tich phan theo bien cua mien hay mgt phSn cua no.
6, i i i i i i i H i l i i i i i i i i n ,
* 1 2 JT g y a J
H,nh 2. Sa do linh dp luc Idc dung vdo vo hdm 2.3 Ap dung tinh toan ket cau gia co cho
dutag ham qua viing co dja chat yeut-*^
De cfl dugc bien phap chflng dor, gia cfl hgp Iy, higu qua cdn ket hgp nhieu phuang phdp tinh toan khac nhau, ciing kinh nghiem eua nha thdu thi cflng, Khi dao hdm qua vimg dia chjt ygu can dp dgng dflng bg cae bign phap xii ly dg ddm bdo thi eflng dugc an toan va ddm bdo tign do, ttong do bign phdp chflng dfl hdm sau khi ddo bang khung thep chg tao sSn. Kich thuoc tigt dign khung thep (hlnh chil I) phu thupc vao nhieu ygu 16^ khae nhau: bg rang khoang dao, chat Iugng ddi da, khodng each ddt khung...
Trong pham vi bai bag. tdc gid dp dung phugng phdp Phan til hihi han sii dung phjn mgm SAP2000 dg nghign cim mpt cflng tttah cu thg.
2.3,1 Giii thi^u cong frinh
Tinh todn cho dutag hJm cflng trinh thuy dign van Chan - Ygn Bai, cfl cflng sujt lap may 57 MW, dutag ham din nuoc eo ap dai hon 3546,64m, ket cau vfl hJm bang bg tflng cflt thep M25. be rgng ddo hJm B<,=H.=5 8m dutag kinh ttong hJm D„= 5.0 m, chigu'day
vo bgc bg tong 0,4 m. Dia chjt khu vgc dudng hdm Id da phign thach anh, phign xerixit, cd nilt ng trung binh dfln manh, khe nirt bdm it flxit sat, canxit. Diit gay bac V-6 (40-45<40- 45), CO chigu rflng khoang IOO-500mm, chil lap nhet Id set, san milonit. Diit gay da tao ra dnh hutag rgng tir 0,3-1,0m, trong dfli inh hutag cua dirt gay dd bj phong hoa mit ne vd vgn vo nhau rdt manh thanh dam cgc lan sgt, da Cling chJc trung binh^^l
2.3.2 Tlnh kil cdu ching da lam Nhjp vflm:
i =Bo + 2 ' ' o ' o n ( 4 S ' ' - I ) = 12,77 m chigu cao vflm h = 11,609m, ap luc trgn dinh:
p=Pydh=I6,972 T/m^ khodng each cac vi thdp Lc=0,7m, luc tac dung lgn khung chflng la Ptt=l l,88T/m^ vae„=l l,88T/ml Kgt qua tinh toan ngi trong thanh su dyng phjn mem Sap2000 (Hinh 3), xdc djnh dugc dugc gia trj mflmen va Iuc dgc Ita nhjt tai vj tri dinh hdm vo'i M=9,663 T.m va N=42,598 T.
Chgn vi thep 130 cfl A„=58,4 cm', W,=574,667 cm'.
TAP CHI KHOA HOC VA CONG NGHE THUY LOI Sl3 35 - 2016
KHOAHUC ^ - l - l i ' H i ' H i l - B
i,*ii .
a) - b) Hinh 3. Bieu di nil luc - a) Nil luc mdmen, b) Noi luc luc dgc
2.3.2 Tinh todn kel cdu vo ham So dfl luc tdc dung lgn dutag ham tmh todn:
Hinh 4. So do luc Idc dung len vd ham
- Cae tnrgng hgp tinh toan:
-^ Trutag hopl: ttgng qud trmh thi cflng, sau khi xong vo hdm (Tfl hgp tdi trpng thi cflng) gflm cac luc. trpng luong than vp, dp luc djt dd thang dfag, dp luc djt dd theo phuang ngang, dp luc phun vua I jp day,
+ Trutag hgp 2: trong qua trmh van hdnh (Tfl hgp tai trgng co ban) gom cdc luc: trpng lugng thdn vo, dp luc djt dd thdng dfag, ap luc dat da theo phuang ngang, ap luc nuoc ngam, ap luc thuy tinh irng vol MNDBT, dp luc mach dpng.
- Mo hinh tinh toan:
Hinh 3 Mdlnnh md, cdt ngang hdm khi khdng Hinh 6 Md hinh mii, cdl ngang hdm khi co xet,len sutham gta chiu luc cua ^ , chdng xet su,ham gia chiu luc Lsuin ching
TAP CHI KHOA HOC VA CONG NGHE THUV LOI Sl3 35 - 2016 85
I KHOA H"0C ^ E S S Z B i I M
2 3.3 Kit qud tinh todn trong hai tnrcmg hgp tinh toan khi co suon
; , . ; . ; , . - - :, o c choug va khi khflng c6 suon chong:
Mflt sfl bieu do phan vung ung suat Su, S22 a 6 s-
Hinh 7. Bieu do phdn bd img sudt Sn kht khdng cd suon chdng - THI trong gud
trinh thi cong
Q
Hinh 9. Biiu do phdn bd ung sudt Sjj khi khong cd suan chong - TH2 trong
qud trinh van hdnh
Hmh H Bieu do phdn bd img sudt S2!
khi khong cd sudn chong - TH 2 trong qud van hdnh
Hinh 8. Bieu do phdn bd ung sudt S,, khi cd sudn chong - THJ trong gud trinh
thi cdng
Hinh JO. Bieu do phdn bd irng sudt Sn khi cd sudn chong - TH2 trong gud trinh
Hinh 12. Bieu do phdn bo ung sudt S22 khi CO sudn chdng - TH2 trong
qud trinh van hdnh
TAP CHI KHOA HOC VA C O N G NGHg THUY LOI S(5 3:
Bang I. Ket qua tinh toan irng suat vo ham tai m9t so vi tri Mo
hinh
1
1
-6 suon chong
Tiuong hpp
THI
TH2
THI
TH2 Ung suat
s„
Sil S.I
s=
Sil Sl!
Sii So
Max
aim')
623.93 386.33 533,88 396,71 541,17 280,05 286,18 118,37
Vl tri 5 7 5 7 5 2 5 2
Min Ulm') -794,26 -963,29 -321,64 470,36 -219.11 -975.78 -124.05 -482.49
Vl tri 6 4 6 4 4 3 4 3
Til kgt qua tinh todn nfli luc, fag sudt, lign hanh tinh todn bfl tri cflt thep vo hJm: voi trutag hop khflng co suta chflng thi lugng thep ygu cJu chju keo As=10,22 cm^ chgn thep vflng 016, thep dgc hdm (dam bao cJu tao)
* I 4 ; dfli voi trutag hgp cfl suta chflng lugng thep ygu cau chiu keo la A,= 8.63 cm^ chgn thep vong 014, thep dgc hdm <I>12.
TAI L i f u THAIM KHAO
I KHOAHQC ^ W . U I J j r e l ! ! ^ 3. KET LUAN
(1) Khi xay dung dutag hJm qua viing djt ygu viec nghign cim linh todn kgt cdu chflng do tam thai CO y nghia rJt to Ion, nfl khong nhung dam bdo an toan trong thi cflng ma con co tdc dyng dam bdo dugc fln dmh, khd nang chiu luc ciia vfl hjm trong qua trinh van hanh, giiip cho nha thigt kg cfl thg lua chpn duoc phuong dn eflng hinh hgp Iy, mang Iai hieu qud cao nhjt cho nha dju tu.
(2) Ttr kgt qua tinh toan ciia hai mo hinh cfl chflng do tam va khong co chflng dfl tam thjy khac bien su phdn bfl fag sujt, trong mfl hinh tinh cfl xet dgn khd nang chiu luc ciia kgt edu chflng do tam (hlnh 7, 8, 9, 10) fag sujt Sn gidm, chil yeu la fag suJt nen, dg til do bfl tri cflt thep, vdt lieu hgp ly.
Khi tinh todn cfl xet dgn kha ndng chiu luc eiia kgt cau chflng do tam, thi cflt thep trong vo se tiet kiem dupe khodng 15% khfli lugng thep chju luc.
Con sfl nay la ddng kg khi doan hjm cfl khung chflng do keo ddi. Do do, kign nghi trong tmh toan kgt cau vo hJm ngn xet den su tham gia chiu Iuc ciia suon chflng, voi digu kign phai ddm bdo su lign kgt tflt cua khfli bg tflng lop Iflt dfl sau voi suta chflng da dat Uong then gian thi cflng.
[1]
[2]
[3]
[4]
[5]
Nguygn Chign, (2013), Thiit ki duing hdm Ihuy cdng NXB Xay Dung, Ha Ngi.
Vo Trpng Htag, Phtag Manh Ddc, (2005), Co hgc dd ung dung trong xdy dung cdng trinh ngdm Vd khdi Ihdc mi NXB Khoa hoc viKy thuat, Hk-Noi. * -^ • « S ,r,nn Ccng Jing, mik, (2007), "Phan tich so sanh cac phuang an bfl tri hdm nha may thiiy dien v'uf Z t t ^ ""^^ f ^"' ''"' "" ^'"^ ""'"'• "" '^'"^ ^"'" "^^'"^ Trung Quflc, 6 -i(l),tr. 105-109. (Trung v5n)
A A. Elsayed, (2011), Study of Rock-Lining Imeraetion for Circular Tumiels Using Finite Element Analysis, "Jordan Journal of Civil Engineering", Volume 5, No. I, pp 50-63 Cflng ty cfl phdn tu vdn xdy dung Dien 1 (PEECl), Hi sa Ihiil ki ky thudt 'eong Irinh Ihuy
dien Van Chan-Yin Bdi, 2010. ii,,,„,,,nuy
TAP CHl KHOA HOC VA CONG NGHE T H O V LOI SO 3
