r KHOA HOC M^'UHTPTIPM
NGHIEN CUtJ HE T H O N G DONG MO TlT DONG DOI V 6 l CUA VAN BAN LAT TRUC DAY
Giang Thu, Nguygn Tign Hai, T6 Vinh Cuong, Nguygn Viet Hung, Nguyin Thanh Khoi Phdng thi nghiem trgng diem Ouoc gia ve ddng luc hgc Sdng Biin Tom tat: Cira van true day (cua van claple) eo nhiiu uu diim trong viec diiu tiit muc nu&c nhimg khd trdnh khoi va ddp. ning dpng khi van hdnh; khdng cd khd ndng ldm viec tu dpng.
Trong bdi bdo ndy, bdng thuc nghiim vd linh todn da dua ra he thdng hd tra ddng ma tu ddng dua tren nguyen ly edn bdng lire. Hi thdng ddng ma tu dpng duae dua vdo da chuyin cua van tnic ddy thdnh cua van tu dpng thuy lue (ciea van bdn lat true day) ldm viec dn dinh trong cdc diiu kiin khdc nhau, ddp img cdc yeu cdu nhu diiu tiit muc nu&c, thdo Id vd ngdn man. Kel qud nghiin cuu cho thdy. he thdng ddng m& tu ddng van hdnh linh hogt, em di, cdu tgo don gidn, di ldp ddt vd duy tu bdo duang; thugn tien cho viec ndng cdp, cdi tgo do dugc che tgo sdn. Dgng ciea van bdn lat tie dpng ndy dang duae dp dung vdo cdng trinh dap ddng Phai Vong, tinh Bdc Kan, Viet Nam.
Til' khoa: Ciea van tie lat, ca edu ddng ma, he Id xo.
Summary: Claple valve gates have many advantages in regulating water level but it is difficult to avoid impact and vibration when operating; not able to work automatically. In this paper, an automatic on-off support system has been proposed basing on the principle of force balance and indoor experiment. The installed automatic on-off system has been changed the claple valve gale to a hydraulic automatic valve gale (the flipped claple valve gate) which works stably under different conditions andmeels requirements of water level regulation, flood discharge and saline prevention. The research results showed that the automatic on-off system operates flexibly and smoothly with its simple stmcture. It is easy to install and maintain; convenient for upgrading and renovating because it is built-in. The automatic flipped valve gates are applied to the work of Phai Vong dam, Bae Kan province, Vietnam.
Keywords: automatically flipped valve gates, on-off stmcture, spring system.
1. DAT VAN D £ NGHIEN CUtJ dpng ciia con ngudi hoac may moc thidt bi, do 1.1. Dat van d6 ^° S'^™ '^^' P^^ ^^^^ ^^ ^^^ ^^^^^
Cita van tu lat duoc irng dung phd bign trong ^ u y vay, cac eua van tu ddng lat: i) Ibuong bd cac cdng trinh thuy loi thuy dien dac biet vdi tri true quay kboang 1/3 ebieu eao eua, dong cae cdng trinh dang nude vdi cot nude khdng chay duae cbay qua ca tren va dudi cira lam cao hoac trong cac cdng trinh tran sir ed. Uu cho cac tbanb pban lire ciang nhu linh loan gap didm ndi bat eua loai hmh cii'a van nay la cd nbigu khd khan; ii) qua trinh lam viec thudng thg khdng chg muc nuoc d mdt dp cao nhat say ra rung ddng manh; iii) khdng cd kha nang dinh, khi muc nude tang cua van tu ddng md | ^ j ^ yiec lu ddng; iv) Chua duoc ap dung pbd dg ha thap mue nude nbung khdng c^n tac ^-^^^ y j ^^y ^^n thidt phai nghien cuu cita van tu lat ed he thdng hd tra ddng md lu dpng va Ngaynhanbai: 18/12/2019 j^g^ c4u phii hpp dd kbic pbuc nhirng nhuoc Ngay thdng qua phan bien: 20/01/2020 _ ;
Ngay duyet dang: 12/02/2020 ^'^"^ "^^•
TAP CHl KHOA HOC VA CONG N G H £ T H U Y L O I SO 58 - 2020 ^ i
KHOA HOC
:^^MM!^M
Trong bai viet nay chung tdi de xuSt giai pbap cdng ngbe be tbdng ddng md tu ddng cbo cua van ban lat dg digu tiel, thay the cac dap dang cd dinb, pbai tam v v. Cdng ngbe nay rat linb boat trong viec tu ddng dang dau nude va tbao lii dot ngpt ma kbdng can su dieu khien cua con ngudi, mat kbac giai phap nay cung don gian, dd dang tbi edng, lap dat va ed the giu' nguygn liet dien long dan khi thao lii.
1.2. De xuat cua van ban lat t u dong 1.2.1. Hinh thiic kit cau
Be khae phue nhirng nhupc diem cua cira van hien cd va de van chuyen lap dat, cbiing tdi da tien hanh nghien euu va dg xuat mot loai hinh cira van ban lal tu ddng mdi vdi dac diem su dung be tbdng Id xo true khuyu de tao md men do trpng luang ban than (md men chdng lal), true quay dupe bd tri d dudi day cira lat. Md hinh mpt cum eira van ban lat tu dpng dupe cho d Hinh 1 va 2.
HQpkyiliLai .-^ \K>ifii ba tang
Hinh 1; Md hinh cua van bdn lat tu dpng
Hinh 2; Cdu tgo cira van bdn lal tu dpng
Cau tao mpt cum cira van ban lat iif ddng g cac bp phan: (1) Ban mat; (2) SmVii chdng: (3) True quay; (4) True khuyu; (5) Thanh truyen;
(6) Ld xo; (7) Hop ky thuat 1.2.2. Nguyen ly ldm viec
Cira van ban lat lu ddng lam viec tbeo nguyen ly tbay ddi ap luc nude thupng luu va dp eung tuong duong eiia he Id xo F=f(K]0; '^^i mo men do ap lire tbiiy ddng, trpng lupng ban than cua lat va ma sat d gdi quay ldn bon dp cung ciia he Id xo, eira van se dupe md den trang thai can bang vdi luc nen (keo) ciia be Id xo.
Khi ap lire khdng thay ddi, luc nen (keo) he Id xo khdng ddi thi goc md cira ciing khdng tbay ddi. Khi md men do ap lire thiiy ddng van edn ldn ban lire nen (keo) cua be Id xo thi cira van se dupe md hoan toan (d trang thai nam ngang); khi lue nen (keo) cua he 16 xo Icm ban md men ap luc thuy ddng, trpng luong cira lat va luc ma sat, eira van se tu dpng ddng lai (d trang thai dii'ng).
2. C O s d K H O A H O C VA PHlTONG P H A P NGHIEN ClTU
2.1. Ctf SO' khoa hoc
Cac nghien cim ve cira van lu lat xuat bien tren loan the gidi, bat ngudn lii' Ha Lan, sau dd den Hoa Ky, Trung Qudc va cac qudc gia khac. Tai Trung Qude tir nhirng nam 60 eua the ky 20 da nghign euu cira van tu lat cd binh thirc kieu gdi don cd dinb, bd pban gdi d o dupe lap dat dudi vi tri 1/3 chidu cao cira (Hinb 3-a,b). Khi muc n u a c thupng luu vuot qua dinb cua vdi mdt dp eao nbat djnh, eira van md tbeo budng dd ra pbia sau dgn vi tri nam ngang. Khi muc nude thupng luu ha den day cira, eua van ty ddng quay vg vi tri ddng dg tiep tuc cbuc nang cban nude. Qua nhidu nam cira van nay tirng budc dupe cai tign nhu them co can can de khac pbuc rung ddng khi ddng md [1].
72 TAP CH[ KHOA HOC VA CONG NGHE THUY LOi SO 58 - 2020
Hinh 3; Ciea van tu lat kliu gdi dan Cho dgn nay cira van tu lat tbudng sir dung binh thirc banh cd lan khe din budng hoac banh lan cd thanh noi (Hinh 4-a,b) [2],[3].
Tuy nhign trong thue te kbi cira van d trang thai md hoan toan, dg quay lai vj tri ddng se gap nhigu khd khan, tbudng sii' dung thgm he tbdng xi lanh thiiy luc de day cira van vg vj tri ddng ddng thai giup dn djnh trong qua trinh lara vigc.
(a)
Hinh 4; Ciea van tu lat kiiu bdnh ldn. thanh ndi Tbeo Styles, S. W [4], lpi ieb ciia viee sir dung flap gate bao gdm: Van hanh dn dinb d cac dieu kien dong ehay khac nhau, dp cao muc nude dupe duy tri, cd the dupe thidt kg va ldp dat trong vdng mdt tuan va tang kha nang cung cap nude linh linh boat.
Theo Javier Cavazos [5], eho thky rang lpi ieh ldn nhai ITRC flap gale la khdng ddi hdi sue manh cua con ngudi de van hanb. Day la mdt lpi the rat ldn de kigm soat cac pban eua kgnh khdng cd dien (Cavazos, 2014).
Theo Doug Welch [6], TTRC flap gate cd lpi cho viec duy tri mue nude Ibuong ngudn, giir cho tham thuc vat trgn kgnh dat, vi cira van duy Iri muc nude khdng ddi va giir cbo loai chudi khdng dao hang Irong cac kenh dat.
O Viet Nam cGng da nghign cim va ap dung loai hinh cica van lal lu ddng vao mpt sd cdng Irinb tbuc te dien hinh nhu cdng trinh tbiiy dien Ta Loi 2, Lao Cai (Hinh 5). Tir nbiing nam 70 Vien Khoa hpc Thuy Ipi Viet Nam da bat dau nghien cuu ve dap dang tu dpng va cua van tu dpng lat va da ap dung cho nhieu cdng trinh thue lg nhu: Cdng trinh dap dang Can Nba (Thanh Hda); Dap Ba Tri (Kon Tum);
Cdng trinh Lai Giang (Binh Dinh); Anh Trach, BSu Nit (Quan Nam), Cdng Bien Nhj, Pbat Diem, Ygn Khanh (Ninh Binb) v.v. Song ehua dupe pbd bign rdng rai do va dap, rung ddng v.v [7],[8] va [9].
TAP CHi KHOA HOC VA CONG NGH^ THUY LOI S6 58 - 2020 73
2MMM3M
Hinh 5; Cira van tu lat - Cdng trinh thuy dien Td Lai 2, Ldo Cai Vdi cira van tu lat bang thity lue true ngang (tam true dupe dat d 1/3 chieu cao cii'a van) so dd cira van lu ddng lat nbu Hinb 6 da duoc mdt sd tae gia di sau nghign euu:
Hinh 6; Sa do tinh todn cua van true ngang + Tran Dinh Hpi [8], da dua ra cdng thuc long quat tinb md men ap lire va trpng lupng cua van tac dung Ign eira trong digu kien ba luu cd nude.
^ M ^ ^G(Hi,—sina„)cotga„
( I )
(2) +(y-sin^aJ[Hf(3H^-H,)
6 - H ^ ( 3 H , - H J ]
Trong dd md men do ap luc nuac:
^ M „ - ( Y - s i i r a „ ) [ l - l ^ ( 3 H ^ - H J 6
-H^(3H,-H|,)]
Tir (2) tac gia ket luan rang I]Vln>0 cira md va SMn<0 cira ddng.
Tac gia cung da kien nghi cdng thirc tinb loan tbiiy luc ddng tac dung len mat tren cira van tai mpt diem bai ky cd dang:
- ^ = h, -m-.h,.< —
y b, (3)
Trong dd:
P, - ap sudt tbuy ddng tae dung len cua van tai didmM
h| - chigu cao cdt nude tai didm can tinh loan d i g m M
hi - chieu cao cot nude tmb tir dinb cua m - he sd luu lupng ddng chay qua dinb cua.
+ Trdn Duib Hda [7] da nghien ciru md men ap lire nude tac dung vao eira van theo thuy ddng luc hpc va xac dinh them thanh phan md men can Md trong cdng thiic md men tdng quat (4) do anh budng ciia van tdc dong chay va dua ra phuang trinh (5) trang thai toi ban ma tai do cira van chuygn dpng tir dang md sang ddng:
M o = M n + M . i + M g = 0 (4) Z M O - ^ Y B [
sina^ h, +Lsina„
- h J X L - L , - — ! - ) - - ^ ^
sina^ sm" a„
ln(-
•^ ) + h,(t-L,)
h, + L s i n a „ 2 (5) L sina,, .L . .., 1 ^ „^ . , + ~(— - L,)] + - CnpBL sm^ a ,
2 3 ' 2 ' v-( L,) + (G,L, - G 2 L 2 ) c o s a „ Trong do:
kl - He so CO hep bgn.
C(i - He sd can;
V - Van toe ddng chay;
p - Mat dp ciia nude.
+ Nguyen Ngoc Nam [10] da ngliicn cuu ap su4t thiiy dpng tac ddng len cura van clape kbi ddng chay dudi canh ctia van trong digu kien cdt nude thkp nhu so do Hinh 7:
74 TAP CHl KHOA HOC VA C O N G N G H E T H O Y L O I SC5 58 - 2020
KHOA HOC
- Doi vol he 16 xo chiu nen: Tnrong hop nay nhu Hinh 8b.
Hinh 7: Sa do tinh dp sudt thuy diing len cira van clape
"zgf (6)
IplffthuSt Ldnochjukio Q
ppkSitbua
| M ^
d
Vi - Van tdc trung binh eua mat cat qua digm i tren mat cira;
Hii - Khoang each thang diing tir diem i tdi muc nude ngang thuang luu;
Hz, - Khoang each thang dii'ng tir tam dien ticb phang qua digm i tdi mue nude ngang thupng luu;
Ngoai ra ed mdt sd tac gia ngbien ciru va phan tich tbanh pban luc tac dung len eira van tu lat cd true tam quay dupe bd tri 1/3 chieu cao cira de dua ra qua trinh ddng, md ciia van trdn co sd quy luat tbiiy ttnh.
2.2. PhtfOTig phap nghien euu
Phuong phap nghien eiiu bang ly thuyet, sii' dung md hinh toan (Ansys) de tinh toan va Md hinh vat ly dg kigm cbiing.
2.2.7. Ly thuyit tinh todn a) Sa dd he thdng ddng m& cua van - Ddi vdi be Id xo chiu keo: Trudng bpp nay nhu Hinh 8 a.
(b) He Id xo chiu nen
Hinh 8; Sa do hi thdng ddng m& eiia van bdn lal tu dpng
Trong bai bao nay chung tdi tinb toan cbo Irudng hpp he tbdng Id xo chiu nen (do Id xo chju nen dupe san xuat phd bien tren thi trudng).
b) Sa do cdu tgo vd cdc thdng sd ca bdn - Sadd cdu tgo:
Tir tinh toan va kiem tra, khi he Id xo chiu keo la dam bao ky thuat nhu sa do hinh 8.a.
Ddi vdi so do tinh loan ebo trudng hpp he Id xo chiu nen, eau tao he thdng ddng md dupe dieu chinh nhu binh 9. True ban lg 0 cd dinh, true ban lg A chuygn ddng quay quanh tara O, thanh AB ed the xoay tu do.
Ggt
(a) He Id xo chiu keo
Hinh 9: Sa dd cdu tgo hi thdng ddng ma cira van bdn lat tu ddng - Thdng sd ca bdn:
L\^ - cbieu dai Id xo (m)
TAP CHi KHOA HOC VA CONG NGHE THUY LOI SO 58 - 2020 75
KHOA HOC
KK - dp cimg ciia be Id xo (kN/m) B - be rdng cii'a van (m) Hy - cbieu eao ban ehan eira van (m) Gv - trpng lupng ban cban cii'a van (kN) Got - trpng luong gia tai (kN); cd tbg ed hoac khdng, dat tren boac dudi tiiy didu kien e - khoang each tir trpng tam ban ehan eira van den tam O (m)
Q] - gde nghieng true kbuyu so vdi phuang dimg (dp)
02 - gde nghigng cua tbanb truygn so vdi phuong ngang (dp)
L ] - chigu dai true khuyu (m) Ao - dp nen ban dau ciia Id xo (m)
L3 - kboang each tbeo phuong dirng tir vi tri Id xo B den true cd dinh O (m)
L4 - kboang each theo phuong ngang tir vi tri Id xo C dgn true cd dinb 0 (m)
H - cbieu cao edt nude trudc cira van (m) Fs - lire ma sat d tam trupt va hop ky thuat (kN)
Fio, FiA- md men can do ma sat d cac d true quay (kNm)
a - gde md cira van so vdi phuong dung (dp) - Sadd luc-
Khi bd qua ma sat d d true quay va ban dan budng vdi hop ky thuat [1][4], theo sa do Hinb 9, quan he giira dp cirng he Id xo vdi ap luc nude lac dung vao ban mat cifa van nbu sau:
+ Luc dan bdi ciia Id xo kbi chiu nen ban dau Ao (kN):
FixQ - Ku.Ao (7) + Luc dpc vao tbanh AB (kN):
FAB = (FM-F,).cos(e2) (8) + Luc tac dung vuong gde vao thanb OA (kN):
FA=FABC0s(e,+e2) (9)
+ Md men dan boi ciia Id xo ddi vdi true q'J^y O (kN.m):
M , , O = F A . L , t^*^)
+ Tdng md men can ddi vdi true Ljiiay O do dan hdi ciia Id xo (kN.m):
Moc = M)^o + F,o + FtA + (Gg, + Gv).e (^ 1) + Tdng md men gay lat ddi vai true quay O do ap luc nude (kN.m):
Mog- [(ynXHxH/2)x(B/2)]x(H/3+Hv- H) (12) Khi Moc > Mog eua van d vi tri thing dirng (gde a ^ 0); kbi Mog > MQC ciia van xoay vg pbia ba luu. De xac dinh dp nen ban dau cua Id xo Ao, iky MOc = MOg.
2.2.2. Mo hinh todn
- Gi&i thieu phdn mim ANSYS; ANSYS cd kha nang md phdng tiep xiie giiia cac vat the vdi be sd ma sat bat ky, lien kdt Id xo (hinb 10)...
Doi vdi lien ket Id xo trong kgt cau cd the su dung pban tir C0MBIN14 vdi bai tham sd dac trung la dp ciing k va he sd can Cv.
Hinh 10; Phan tir COMB1N14 - Xdy dung md hinh ciea van; Do eira van lam viec doi xirng ngn chi xay dung Yi md binh cira van. Cac vi tri cd dinh thay bang cac Hen kel de giam khdi lupng md hinh tinh loan nhung van dam bao dp chmh xac. Cac vi tri tigp xuc tai eac d true dupe md phdng thdng qua phiin tir tigp xiic vdi be sd ma sat tiiy y. Cae kich thudc va vat lieu cbg tao ciia van dupe md phdng thdng qua tbam sd de cd the dg dang eho viec thay ddi. Md bmb pbSn tii biru ban be tbdng kht cku xem binb 11.
76 TAP CHi KHOA HOC VA CONG NGHE THUY LOl SO 58 - 2020
KHOA HOC
mM^
Bang 1: Bang so sanh kit qua tinh toan
Hinh 11; Md h'lnhphdn fir hiru hgn - Kiim tra dp tin edy eua md hinh; Xae dinb dp nen ban dau cua he Id xo cho mdt Irudng hop kich thuoc cita van Li ^ 0,18m; L3 = 0,145m; L4 = 0,25m; Hv = 1,0m; B = 2m; H - 0,875m; 61 = 50"; Lix - 1,0m; Gv - 2,93kN;
Gg, = 0,93kN; dp lech tam e = 0,107m; Kix - 103,95kN/m; bd qua he sd ma sat tai cac 6 true. Kel qua tinh toan chuygn vi va lire nen trong he Id xo xem hinh 12 va 13.
Hinh 13: Lue nen trong Id xo Ket qua so sanh khi tinh loan bang giai tich va bang phan mgm cho d Bang 1.
Tham so Do nen tnrdc ban dau cua he 16 xo Ac Luc dan hoi cua he 16 xo Fuo (kN)
Tinh toan Giai tich -0,1045 10,8588
ANSYS -0,1070 11,0688
Sai so 2,39 1,93 Nhdn xet: Khi linh loan dp nen ban dkn cna he Id xo vdi ciing mdt dieu kien ebo tbay ket qua tmh toan bang giai ticb va bang phan mgm ANSYS cd sir chgnh nhau vdi sai sd nhd dudi 3%. Su chgnh lech nay la do khi tinb toan bang giai tieb da bd qua nhigu ygu td va chi xet ddn tbanh phan lire theo mpt pbuong va chidu dai tbanh L2, gde ngbieng 6? la cd dinh khdng phu tbude vao dp nen ban dau Ao nen gia tri nhd ban so vdi tinb toan theo bai toan kbdng gian bang pban mgm ANSYS. Vi vay cd thg ndi mo binh linb toan lap bang phan mgm ANSYS dam bao do tin cay.
2.2.3. Md hinh vatly
Do day la bude dau ngbien cim mdi vdi he thdng ddng md cho cira van ban lat true day khi ket hpp tbiiy dpng lire va eo khi chg tao, chiing tdi da lien hanb thi nghiem mo hinh vat ly tren md hinh phang, ty le 1:1.
• Muc tiiu eua thi nghiim
+ Kigm tra nguyen ly lam viee tu ddng dang nude va thao lu cua ciia van;
+ Kidm tra didu kien lam viec (can bang) giUa tbuy dpng lire va dp cirng cua be 16 xo;
+ Danb gia dp nhay va su rung dpng khi cira van van hanh;
Thi nghiem tign banh vdi cac luu lupng, muc nude thupng luu khae nhau, muc nude ha luu tirdo.
'Xdy dung md hinh
+ Md binh ciia van ban lat tu ddng xay dung dat trong mang kinh rdng lm, cao 2m dai 16m.
P CHf KHOA HOC VA CONG NGH^ THUY LOI Sd 58 - 2020 77
KHOA HOC
+ Ciia van ban lat dupe Iam b§ng bg tong cdt thep M250 cd kba nang lap ghep tbao roi (dl dang lap dat va thay ddi chigu cao, tai trpng...).
+ Hop ky thuat eho be tbdng ddng md dupe thigt ke tinh loan bang phan mgm 3D Solidworks, Autocad va dupe tinh toan bang phin mgm ANSYS (hmh 14).
Thiet kg ban dau:
+ Kich thudc cira lat BxH^lxO,5m;
+ Dp cirng be Id xo K|;^=60KN/m.
Hinh 14; Md hinh mdng kinh thi nghiim ciea van bdn lat
3. KET QUA NGHIEN ClTU
3.1. Ket qua nghien cuu he thong dong mo*
tren mo hinh toan ANSYS
• Trudng bpp Id xo cbiu keo (Hmh 8a):
Khi cira van d vi tri thang diing Id xo khdng lam viee; khi eua van bat dau chiu ap lire nude, ban mat eira van cd xu hudng quay quanh true cd dinb O ve phia ba luu, Id xo ciing ddng tbdi ebju keo chdng lai md men do ap lire nude gay ra.
Vdi dp Cling Id xo nhat djnb, tiiy thudc chieu cao cot nu'dc tac dung ma ban mat eira van cd dp md kbac nbau va kbdng d vi Iri tbang dirng (hoac mpt gde md ban dau) nhu mong mudn.
Song trgn thi trudng loai 16 xo chju keo it i.' -' P^
san xudt (khdng ed sin), day cu.i^ la r\h^'^(^
diem cua hinb tbiie nay.
• Truang hpfp 16x0 chiu nen (Hii'.'8b):
Trudng hpp ciia van lam viee vd\ he 16 xo d trang thai chiu nen; kbi cua van bat dau chju ap lire nude, ban mat cua van cd xu hudng quay quanh true cd dinh O vh phia ba luu, 16 xo eiing ddng thdi ebiu nen cbdng lai md men do ap lire nude gay ra. Dg giir cira van ludn d vi tri thang diing (hoae mpt gde md ban dau) khi cdt nuoc trudc cira van nbd hon hoac bang cot nude thigt kg, tao cho he 16 xo mdt bien dang nen ban dau (Ao) du de can bang md men do ap lue nude thigt kg gay ra. Khi muc nude trude eira van ldn hon muc nuoc thiet ke, cira van mdi dieh cbuyen. Nbupe diem cua so do nay la ma sat true 16 xo vdi tam cban (tai diem B) ldn dg bi ket, tbanb truyen AB khdng co tac dung vdi hanh trinh lam viec ciia cua van do lam gde 0| thay ddi ldn va chieu dai ban dau cua he lo xo ldn.
De khac phue nhupc diem nay, ehiing tdi da nghign ciiu, dg xuat binb tbirc kel cau nhu Hinh 15 va so dd tinh toan nhu Hinh 9 d trdn, lua chpn nay lam co eau ddng md don gian bon va giam quy md hop ky thuat. Ddng Ihdi de lang dp linh boat ciia cira van, bd bi them gia trpng d dinh hoac d day eira van dg giam dp nen ban dau eua Id xo, cd lpi khi lira chpn edt nude tae dung vao ciia van trong qua trinh ddng md.
Hgpk?thu9l
M
Hinh 15: Sa dd nguyen ly ldm viee eua cua van bdn lat lu ddng sie dung hi thing Id xo
chiu nen (phucmg dn chgn)
TAP CHI KHOA HOC VA C O N G NGHg THUY LOI SO 58 - 2020
KHOA HOC
mim
3.2. Kit qua nghien cihi bang thuc nghigm Vdi viee luc chpn so dd va cae kich tbude vg cira van ban lat nbu trgn, gia thiet muc nude thuang luu thigt ke bang dinh cira lat (ZTL=0,5m) de xem xet kha nang van hanh tu ddng ciia be thdng.
Trang thai tich nude ban dau: 6 trang thai ban dSu (khdng ed nude thupng luu), ban lat can bang voi Irang thai ban dau eua he Id xo d trang thai ddng (tbang dirng), khi cbo mue nude thupng luu tang dan ddn 3/4 chigu cao cira lat thi cita bat dau chuygn dpng md ve phia ha luu; khi mue nude thuang luu den dinb ciia (ddng van cap nude) tbi cira lat dat dp md a=20° va duy tri dn dinh vdi muc nude thugng luu Zii^0,47m. Tigp tuc md nude, cdt nudie thupng luu Z, tang len, cdt nude trdn dinb cira lat Hi tang, cira lat md vdi gde md ldn hon (xem cac Hinb 16, 17 va 18).
Hinh 16: Dd ma eua van 0^25"
Hinh 18: Dp m& cua van a=. -5Cf Tren md binh da xac dinh cac gia trj cdt nude thupng luu, tren dinh ban lat quan he vdi dp md cira va xae djnh td hpp luc tac dung gay md cira luong iing vdi dp ciing cua he Id xo va Cling xem xet trang thai ban dau lam viec ciia ban lat va dp md tdi da tbeo so do Hinb 19.
Hinh 19: Sa dd thi nghiim cira van tu lat a: dp md cira (dp)
Zi: cot nude thupng luu (m) Hi: cot nude tac dung dinh ciia (m) Li: chuygn vi ngang cira lat (m) Pi: chigu cao ciia lat (m)
Td hpp lire tae dung vao eira lat va be 16 xo tbeo dp md cua tir 0-^90° nbu Bang 2, Hmh 20:
Bang 2: Ket qua do lyc ddng mo
Hinh 17: Dp ma ciea van a=35°
a(d6) 0 5 10 15 20 25 30 35
AKix (m) 0,000 0,001 0,009 0,018 0,029 0,040 0,054 0,066
F(kn) 0,00 0,06 0,54 1,08 1,74 2,40 3,24 3,96
a(d6) 40 45 50 55 60 65 90
AKi, (m) 0,081 0,093 0,105 0,122 0,133 0,145 0,250
F(kn) 4,86 5,58 6,30 7,32 7,98 8,70 15,00
TAP CHl KHOA HOC VA CONG NGH6 THUY LOI SO 58 - 2020 79
I KHOA H O ^
Tir ket qua d Bang 2, neu mudn cira van thSng diing thi can dp nentru'dc ciia Id xo la l,74kN.
1"
£• '^°
f
"^°
a 50
^
Hinh 20; Quan he giiea do ma vd luc ddng m&
Trong qua trinh thi nghiem chiing ldi dieu chinh muc nude tang giam dot ngpt (tiie la luc tac dung vao ban lat tbay ddi dot ngpt), ban lat ciing lam viec theo trang thai ddng md lien tuc, kbdng gay ra rung dpng, rat em.
- Lap quan he thue nghiem giiia luu lupng vdi cot nude tbupng lu'u Z„ cdt nude dinb cira H,, cbuyen vi ngang cira Li va dp ba thip ciia P, kbi dd q=f(Z,H,L,P) nhu Bang 3, Hmh 21.
Bang 3: Ket qua thi nghigm theo cac d6 md" cua
a{d6) 0 20 25 30 35 40 50
q (mVs) 0,000 0,002 0.019 0,041 0,102 0,157 0,327
Zi(m) 0,500 0,470 0,498 0,517 0,540 0,555 0,587
Hl(m) 0,000 0,001 0,004 0,065 0,108 0,142 0,215
Li(m) 0 0,171 0,211 0,25 0,287 0,321 0,383
Pi(m) 0,500 0,469 0,453 0433 0,410 0,383 0,321 Nhu vay, qua trinh lam viec cua cua van ban lal tu dpng tbay rang: Khi luu lupng (q) tang thi cdt nude lac dung Ign ban lat (H) tang, song muc nude thugng luu (Z) gan nhu duy tri d trang thai cot nude thiet kg ban dku (dn dinh), su chenh lech dao ddng edt nude trung binh la nhd khoang 4,58% vdi gia tri nay trgn thuc 16 la cbap nhan dupe.
'^cT'
L .__
^^^ :
0.00 0.05 0.10 0.15 0.20 0.25 0.30 0.35
•-•-q~H - - - q - L i - * - q ~ P i -i—q~Zt q(m7s)
Hinh 21 • Quan he q=f(Z,H,L,P) 3.3. Ap dung vao cong trinh dap dSng Phai Vpng, tinh Bac Kan, Viet Nam
Hien trang cdng trinh: Dap Phai Vpng xa Pbuong Vign, huyen Chp Ddn dupe dau xay dung va ban giao dua vao sii dung nam 1992.
Dap cao 1,0m, kdt cau dap la bg tdng cdt thep dang thanh mdng. Mue tieu la dang nude vao kenh tudi va thao In. Hien tai thupng luu dap bi bdi lap den eao truih mat dap, cira xa bi bit kin (khdng van hanb ddng md dupe); than dap bi bong Irdc, xam thue gay ihkm thkn ldn, lai vi tri tiep giap giiia than dap va san tidu nang bi xdi sau; san tieu nang da hoc xay bi bong trde mat va va, xdi Id sau ha Imi tieu nang.
Dap ed nguy co mat an toan cao va khdng dam bao bieu qua khai thac (Hmh 22).
Hinh 22; Hien trgng cdng trinh dap Phai Vong Vi vay, can phai sira chira, kh4c pbuc dd dam bao su boat dpng dn dinb, an toan cho cdng trinh.
TAP CHi KHOA HOC VA CONG NGHE THUY LOl Sd 58 - 2020
KHOA HOC - Sira chira nang cap dap Phai Vpng:
+ Gia ed, bpe lai loan bp than dap, bang BTCT M200, da 1x2, t=15cm, nang cao trinh dinh dap 15 cm so vdi dinh dap cii.
+ Giii nguygn bg tieu nang cii, pha dd tudng ngudng bg, gia cd be tigu nang bang mdt ldp BTCT M200, da 1x2 day 20cm trgn ndn da xay mat bg.
+ Lap dat he thdng cira van ban lat tu ddng thay the phai cban nude tai ciia xa (rdng 2m, cao lm). He thdng ciia van ban lat tu ddng sau kbi tinh loan, lua chpn gdm cae thdng sd Ihiet ke nbu sau (xem bang 4):
Bang 2: Cac thong sd tinh toan ap dung cho cong trinh flap Phai Vong
TT 1 2 3 4 5 6 7 8 9
10
11 12 13 14 15 16
H £ THONG COAVAN Chieu cao cira van Chieu cao cot nuoc Be rang cira van Chieu diii true khiry Khoang each Khoang each Do Cling he 16 xo Chieu diii 16 xo Goc nghieng tmckhuy Trong luong thep ban mat Trong luung be tong gia tat D6 lech tam ban mat Ma sat 6 true 0 Via sat 6 true A M.satlijrn truot va hop Do nen ban d^u
KY HIEU
Hv H B Ll L3 L4 Klx Lk OI
Gv
Ggt e FtO FtA Fs A.
DON VI m m m m m m kN/m
m do
kN
kN m kNra kNm kN m
THONG SO 1,00 0,875 2,00 0,18 0,145 0,25 103,95
1,00
50
2,20
0 0,107
0 0 0 0,127
>l
20
a
M
m
, i _ ,^.i«m«in « t
4 - f
S:l
'• u i"
(111
i 1
Tir kgt qua tinb loan, lira chpn ap dung cho cdng trmh thuc tg dap Phai Vpng nhu Hinh 23.
Hinh 23; Cua van bdn Idt tu ddngdp dung vdo dap Phai Vong, tinh Bdc Kan
4. K £ T L U A N
He thdng ddng md cho cira van ban lat true day la mpt ket eau mdi lan dau tidn dupe de xuat khi kgt hop giiia thuy dpng luc va ca kbi ehe tao (ap lire thiiy ddng va dan hdi cua he Id xo) dg van hanb. Ve nguyen tac ket eau nay cd the tao ra edt nude cd chieu cao kbac nhau liiy thudc vao dp cirng ciia he Id xo.
Qua tbi nghiem md hinh cd thg khang dinh ve nguyen Iy lam viec cua loai ciia van ban lat nay la hoan toan diing dan, lam viee hoan loan tu ddng, chu ddng, linh boat trong viee dang nude va tbao lii nhanh, co tinh kha thi eao va cd kba nang ap dung vao thuc te.
Cifa van ban lal dang nay ed nhQ:ng uu diem sau:
1) Do d true dupe dat dudi day ban lat nen viec tinb loan don gian bon so vdi cae eira van lal trudc day;
2) Lam viec hoan loan tu ddng, chii ddng, linh boat khdng can su digu khien ciia con ngudi;
3) Ddng md nhe nhanh, khdng gay rung dpng, ludn duy tri, dn dinh muc nude thupng luu;
4) Khi tbao lu cd the nam sat day, khdng anb hucmg nhigu den mat cat tu nhign ngn kbdng gay bign hinh long dan va giai phap tieu nang sau cdng Irinh se don gian;
TAP CHlKHOA HOC VA C O N G NGHE THUY LOI SO 58 - 2020
I KHOA HOC
5) Co ket can dem gian, dirge gia cong chi tao 6) Da dugc ap dung vao cong trii'-h 'hv"" ' ^ san nen thuan tien cho thi cong lap dat; gia b i t d i u triln khai thi cong trong thang 10 thanh re. nam 2019.
TAI LIEU THAM KHAO
[1] jmm, M., 7f<:f]Sitmtef'firMmMsm&i^fs- *s:7x#, ¥ » 0 3 M , 2012.
[2] HOU SHI HUA, S.C.S., Path of instantaneous center of hydro-automatic flap gate and its influences on gate's stability. Hydro-Science and Engineering, 2007.
[3] \^-^mk., mtfmtai^yKtissiimsmnmmmib. zkfij7k«4Kag, 2008.
[4] STYLES, S.W., Flap Gate, ITRC Report No. R. 07-001. Irrigation Training and Research Center, 2001: p. 1-3.
[5] CAVAZOS, J„ Flap Gate Survey - AID. Personal Cominunication, 2014.
[6] WELCH, D., Flap Gate Survey. Personal Communication, 2014.
[7] HOA, T.D., Nghien ciru che do thuy life vd dn dinh cua cua van tu dong thuy lire tnjc ngang. 2002, Vien Khoa hgc Thuy lgi.
[8] HOI, T.D,, Cua van tu dong thdo nuac vd tich nuac cho dap ddng. Tuyen tap ket qua KH&CN, Vien Khoa hgc thiiy lgi Qu6c gia, trang 89-95, 1989-1994.
[9] Viin Khoa hoc Thiiy lot (1999-2000). Tuyln tap kit qua nghien ciiu KH&CN, trang 377-384.
[10] NAM, N.N., Che do thuy lire cua ddng chdy qua cdng trinh thdo nuae sir dung cii'a van clape lien hodn. 2008, Vien Khoa hgc Thuy lgi.
TAP CHl KHOA HOC VA CONG NGHE THUY LQI SO 58 - 2020
