MOT SO VAN DE VE CHE DO T H O Y LLfC MANG TRAN NGANG KET HOP CONG TRINH THAO SAU
PGS.TS Huynh Ba Kfr Thuit
PGS.TS Nguyen HCru An, PGS.TS Hoing VSn Qu^
TS. Le VSn Thuan, KS. Nguyen Cdng Thanh Khoa XSy dung Cdng trinh thu}
Trudng Dai hgc XSy dt/ng
Tdm tit: Vipc ap dt/ng edng trinh thSo lu (CTTL) dang mSng trSn ngang (MTN) trong diu mdi cdng trinh thu} Igi rit thich hgp cho nhimg cdng trinh miin nui cd Idng sdng hep, dp die Idng sdng Idn, 10 tSp trung nhanh v.v... Trong trudng hgp khi cd lu Idn, MTN khdng dd kha nSng thao, cin phai xSy dt/ng them CTTL dang khSc di phoi hgp xi 10. Hipn nay, 6 Vipt Nam ehua ed nhCfng nghidn ciru ve dang CTTL dang MTN kit hgp vdi CTTL d^ng khSe, dpc bipt IS cdng trinh thSo sSu, do dd eSc kit qui nghidn cifu duge trinh bSy dudi dSy se phan anh phin nSo chi dp thu} It/c cCia loai hinh cdng trinh tbSo kit hgp nSy.
Summary: The application of side channel spillway In Headworks is very suitable for highland projects which have strait river-bed, high slope, quickly concentrated flood... In case of big flood, side channel spillway can not drain off the water. People need build more other flood spillways. Now, In Vietnam, we have not researched about side channel spillway combine with other flood spillways yet, especially (bottom outlet) culvert spillway.
Therefore, the following research results will express somewhat hydraulic regime of the combination spillway work.
LMidoAu
Hidn tai, MTN da va dang dUpc ap dung rdng rai trdn the gidi cQng nhu tai Viet Nam, thudng k i t hpp vdi dap ddng nudc loai dap vdt lidu dja phuong. Cd t h i k l ra mpt sd cdng trinh MTN da vd dang dupc xdy dung nhu Oa Mi, Oa Thien, Ngdi Phdt, Ble Binh, Nam Xe (Vidt Nam), Hoover Dam, Teton Dam... (My), Corrin Dam (Uc).
MSng trSn ngang (Thuy dipn Da Mi) MSng trSn ngang (Thuy dipn Da Thipn)
MSng trSn ngang (Thuy didn Hoover - My) MSng trSn ngang (Corin Dam - Australia) Cdng trinh thao lu dang MTN thudng ldm viec dpc lap dUdi dang ngoai than dap chinh la cae dap VLOP hoac ed t h i ke't hpp vdi cac edng trinh thao lu dang khac nhu cdng trinh xa mat, cdng trinh thao sdu v.v... Hidn nay, d ViPt Nam, MTN thudng dupc thie't ke lam viec dpc lap.
Vide ke't hpp vdi eae cdng trinh thdo khac cdn chUa dupe dp dung.
2. CONG TRINH THUY DIEN NGOI P H A T 2.1 Gidi thieu cong trinh
Cdng trinh thuy dien Ngdi Phdt (Lao Cai) dupc xudng Tu vdn thidt kd Thuy Ipi-Thuy dien (thupe CPng ty Tu vdn Oai hpc Xdy dung) thie't kd cd edng sudt 72MW bao gdm cum cdng trinh ddu mdi, dudng ham d i n nudc (Ly„ = 7109m), dudng dng dp life ( L „ = 1021,4m) vd NMTO. O l giai quyet vdn de dja hinh ddc, thdo lu vdng ndi, thao bun cat, dap thdp (30m) ndn da thid't k l cum cdng trinh dau md'i bao gdm:
- Mdng trdn ngang (B,, = 70m), dang trdn tu do.
- Cdng trinh thao sau ( n x b x h = 3 x 8 x 1 0 (m))
- MNLTK (p = 1%) = 437.03m, Q,,^ = 3273 m'/s (QMN = 369 m'/s, 0 ^ = 2876 m'/s).
- MNKT (p = 0.2%) = 439.34m, Qo.2% = 4555 m'/s (Q„N = 1304 m'/s, Q^= 3222 m'/s).
MAT B A H G DAU H O I CONG I R I H H T H U I CNCN NGOI PHI.T
Hinh 1. Mpt bSng cdng trinh thSo 10 thuy dipn Ngdi PhSt
24 TAP CHf KHOA HOC CONG N G H E XAY DUNG Sd04/2009
2.2 Thi nghiem md hinh thuy lire
D l kiem tra ket qua thiet ke dupc tinh todn qua ly thuyet, nhdm nghien cdu da tidn hdnh thi nghipm mo hinh thuy life cdng trinh thao lu thuy dien Ngdi Phat. Thifc hidn thi nghiem trdn 3 md hinh tai Phdng thi nghiem Thuy life, Trudng Oai hpe Xay dung.
Vdi nang life cda tram bom, san mo hinh, he thdng cap nude, mang hdi, b l chda Idn, quy md chuypn nghiep do Lien Xd (eu) trang bj, dac biet tram bom cap nude gdm 5 bom cd tong cdng sudt 900//s eung vdi dpi ngu ehuyen gia can bp co nhieu kinh nghiem da tien hanh xdy dung va thi nghiem vdi 3 md hinh;
- Md hinh mat elt cdng trinh thao sau (MHMC); Ty le 1/30.
- Md hinh Mang bdn - Ddc nudc (MHMB); Ty Id 1/30.
- Md hinh tdng t h i cdng trinh thdo (MHTT); Ty Ip 1/50.
Tidu ehuin tuong tu dupc dp dung la tieu ehuan Froud. Oa kilm tra cac dilu kipn tupng tuddi vdiea 3 md hinh.
. N/OWIJ^ Ifjj
MHTT-Ty IS 1/50 2.3 K^t q u i thi nghidm
2.3.1 PhSn b6 Sp suit trin mpt trSn thSo sSu
MHTT-T} IP 1/50
|nt\.iW|(>ii;3rtii||
Hlnh2.D6thl ^^ = f MHMC ty IP 1/30
* x^ ' ' ' - | H * ^
\ I I I I I I
\ ^ . • r - . 1» 1
^
— ^ f>^-
- ^
- / — • - r -
| l « ^ = ia98[0=34l*niM
"" " " " I " \
* _ ( H N . = 2I05 1 I9l(0=aita3K)|-
—'
Hinh 3. Dp thi
H. - = f X H MHMC ty 1$ 1/30
Tiln hanh do dac vd kilm tra phdn bd dp suat trdn mat trdn cdng trinh thdo sdu khi MNTL # MNDBT (435m) dng vdi ca 2 md hinh: MHMC vd MHTT. Kit qua thi nghidm cho thdy trong ca 2 thi nghidm, dp suit du trdn mat trdn thao sdu deu Idn hon khdng, tdrc Id khdng xult hidn chdn khdng trdn mdt trdn. Kit qua thi hidn trdn hinh 2 vd hinh 3.
2.3.2 Kit qua thf nghipm md Mnh kha ning thio
Kit qua kha nSng thao cda 3 md hinh dung d l so sdnh ddi chdng vdi kd't qua tinh toln cda thilt k l ky thuat, dupc trinh bdy trong cac bang sau.
Md hinh thi nghipm
MHMC (Ty Id 1/30)
MHMB (Ty Id 1/30)
MHTT (Ty Id 1/50)
Thdng sd
MNTL (m) Q (m'/s)
m, Q (m'/s)
m Q (m'/s)
Thiet ki ky thuSt Lu thiet ki
(p=1%) 473.03
2876 0.9 369 0.408 3273
Lu kiim tra (p=0,2%)
439.34 3222
0.9 1305 0.47 4555
TNMH Lu thiit ki
(p=1%) 473.03 3072 0.932
373 0.416
3437
Lu kiim tra (p=0,2%)
439.34 3375 0.919 1320 0.471 4569 Nhdn xet kit qua: TNMH cho kit qua kha nang xa cda tdng cdng trinh cao hon so vdi tinh todn ly thuylt trong thilt k l .
2.3.3 Du&ng mpt nudC (DMN) trong ming ngang
Da tiln hdnh do OMN trong mdng ngang vd so sanh gida kit qua TNMH va tinh todn ly thuylt, kit qua dupe trinh bay trong dd thj hinh 4.
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cac phuang phap giai bing tinh toan ly thuyet dupc trinh bay trong cae TL [4], [5], [6],[7].
2 (ml
«S6 0
Oi/^ng mdt nifOc trong ming ngang, Q = 700m^/s
Hinh 4a. DMN trong mSng ngang (Q = 700m /s)
DVATIO mft nir6c trong ming ngang. Q • lOOOmVs 436 0 .
436 0
434 0 fc-
432 0 1
430 0
428,0
426,0
424 0
-4—^
_ l^^
—^,_
\
, , . . T N U B
• p ; .
. -•-^_
Pnjo-'g o"»r 3 1
OuOngdty m'ng
7/ AL.
.»...'
»•—. 1 ^ " ^ " 1
- ^ 1 cm..,, 1
• ^ •
•—Oi/Ong dly ming
• etch giti 3
—A—C»chDi4>2
— • — K i l gu* TNMH
.
Hinh 4b. DMN trong mSng ngang (Q = 1000m^/s) Nhpn xit:
- OMN trong mang ngang theo TNMH luPn thap hon so vdi k i t qua tinh toan ly thuyet (ed nhilu each giai bing ly thuyet khae nhau). Oieu nay cho tha'y, neu thie't kd theo tinh toan thi edng trinh ed dp an toan Idn hon.
Trong mang ngang khdng xay ra ehe dp ehay ngap dng vdi cac cap luu lupng thi nghidm (cd'p Idn nhd't Id 1380 m'/s).
- Cd su chdnh Idch Idn ve mdc dp ngdp d 2 md hinh (MHMB va MHTT) ed ty Id md hinh khdc nhau (1/30 va 1/50), kdt qua eho thdy a„ (1/30) > a„ (1/50).
2.3.4 Dudng mSt nud>c trong ddc nircic
Tidn hdnh do dac va kilm tra vd so sanh OMN trong dde nUdc ndi tidp sau mdng ben giua TNMH vd tinh toan bing ly thuylt. Kdt qua dupc trinh bay trdn hinh 5.
3K -.\-^f*^T.:i39y ,1M*.«T-.|oa^.
H/n/i 5. Dtfdng mSt nudc trong die nirdc
Nhan xet: OMN trong dd'c nudc theo TNMH xdp xi bing k i t q u i tinh todn ly thuyet, sif chPnh Idch Id khdng dang k l .
3. KET LUAN CHUNG
- Ke't q u i TNMH cho thdy thief k l edng frinh phd hpp, hoi thien an todn.
TNMH da lam ro hon mdf sd van de ma trong thifc t l thilt ke cdng trinh chUa giai quylt mpt each triet de dupc nhu kha nang thao cda ePng trinh thdo sPu cung nhu mang ngang, anh hudng lan nhau khi hai cdng trinh lam viee ddng thdi... nen can cd cdc nghien edu tidp theo.
- OMN cda TNMH frong mang ngang thdp hon OMN ly thuyet, k i t qua nay phd hpp vdi cac nghien cdu trudc day, do dd, khi thilt k l , finh toan theo ly thuyet la thien ve an todn. Mac du vay. cd nhiJmg nghien cdu bd sung mdi lam sang td hon su chenh lech nay.
- CP su anh hudng eda ty le mo hinh tdi ehe dp ngap eua mdng ngang frong MHMB vd MHTT, can nghien cdu them ve van de nay.
Tai lieu tham khao
1. Hd so thiet k l ky thuat giai doan 1, 2 cdng trinh thdy dien Ngoi Phdt tinh Lao Cai. 6ao cao thi nghipm md hinh thuy IUc cdng trinh thCiy dipn Ngdi PhSt tinh LSo Cai.
2. P.G.Kixelep (1960) - Cam nang tinh toSn thCiyli/e (Ban dich).
3. Ven Te Chow (1959), Open Channel Hydraulics, McGraw - Hill Companies, United States of America.
4. Fuat Senturi<, Ph.D (1989), Hydraulic of Dams and Reservoirs, Wafer Resources Publications, United States of America.
5. X M . Xlixki (1986). Tinh toSn thu} lire cSc cdng trinh thu} cdng xi nude (Ban tieng Nga), Nxb Nang lupng nguyen td Matxcova.
6. MeGravi/-Hill Companies (1996), Handbook of Hydraulics (Seventh Edition).
7. Trdn Ode Thudng (2005), Thi nghidm md hinh Thdy li/c cdng trinh, Nxb Xay dung. Ha Npi.
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