Sự cố một số công trình thuỷ lợi ở Việt Nam và biện pháp khắc phục

Sự cố mốt số công trình thuỷ lợi tại Việt Nam và biện pháp khắc phục. Quyển sách giới thiệu các công trình thuỷ lợi như hồ chứa, đập dâng, cống... xảy ra sự cố, tìm hiểu nguyên nhân, đánh giá thiệt hại và đưa ra biện pháp khắc phục, rút kinh nghiệm trong thiết kế, thi công, quản lý vận hành, duy tu, bảo dưỡng, bảo trì...

GS TS PHAN SY KY

THUY talI!lI a V~ET . A

~I

LOI GIOI THI~U

Trang hem50 ham qua, cang tee thuylqi aa thu auqc nhCtng thenn tuu to ton trang c6ng cuoc (lieu hoe; khai thee tsi nguyen nuoc, phvc vu san xuf/t

quan ironq VaG st/nghi~pphet trien kinh te, xa h¢i cua cJa't nuoc fJ¢i ngO can b¢ khoa h9C ky tnuet voi tinh than t?n tuy va sang teo tLl quy hoech, I?p dt/ an aen thiet ke: thi cang trang nhung hoen cenb kho khan, nhCtng thang nem khang chien gian kh6cJscJf/t nuoc ngay nayco nhung cang trlnh mang tam voc

the ky nhu Hoa Binh, nh[(ng cang trfnh thuy tol thuy cJi~n len nhU Thee Be, fJ?P

fJay, Gam Son, oso Tiang, Tri An, Ke G6, Phu Ninh, Ayunh?, Thech Nham, song Quao, nhung cong trlnh ng9t hoe ban cJao Ce Mau, Nam Mang Thit, cang trfnh kiem soei ID TO gick Long Xuyen va fJong Thep Muoi, ,.

Tuy nhien trang qua trlnh xay dt/ng va truong tnent; khong trenh khai co

nhung vf/p vep, sai 18m do thie'u kinh nghi~m ve nghe nghi$p, do to chuc va

quan 1:/ cha't luqng thieu ch~t che ae xa?y ra mot so st/ cocong trlnh gay nen

cua Nganh nhu Vi~n truong Vi~n Khao sat thie't ke' Thuy lc;Ji, Thu truong B¢

Thuy Ie;;i (nay la B¢ Nang nghi~pva Phat trien nang than).

Gong trlnh thuy Ic;i - thuy ai~n c6 nhfJng yeu cau rifmg va ky thu?t, trang qua trlnh xay dt/ng thuong gi;ip nhieu tinh huong phuc t?p. Vi~ccJanh gia nhCtng st/cochac chan se c6nhCtng cJieu con can trao cJ6i va thao lu?n.

GhLingta tran tr9ng cang hfen cua tac gia va cuan sach "St/ co m¢t so cang trfnh thuy lc;Ji aVi~t Nam vacac bi~n phap ph6ng tranh" qua tht/c la m¢t tai li~u tham khao quy bau cho cac can b¢ khoa h9c ky thu?t, can b¢ quan Iy, can b¢ giang d?y, sinh vien va lTnh vt/c xay dt/ng thuy lc;Ji - thuycJi~n.

3

Loi gioi thieu

?

- aVIf;:T NAM

Chuang 2 Nhtmg bophan quantrong trongcongtrlnh tlnrylei, sir eo thuong g~p

Phan 2

su CO MQT s6 CONG TRINH THUY LQI

? '" ".

a VIf;:T NAMChuang 3 D~pDay

Chuang 4 Dap tran Dau Tieng

Chuang 5 DapSuoiHanh

Chuang 6.D~pSu6iTral:l-~

Chuang 7 DaptranNam Thach Han

Chuang 8 Cong trlnhPhiiNinh

Chuang 9 Dap SOng Mire

Chuang 10 Dap VueTron

Chuang 11 H6 Yen lap

Chuang 12 DapCa Giay

Phan 3

CACBIEN PHAP PHONG TRANH VA XV LY SV CO

.'0 NHONG CONG TRfNH THUY LQI Chuong 13 Cac nguyen tac.va bien phap ehung, ,"

Chuang 14 Cac bien phapky thuat d~phongtranh sir co dap da~'

Chuang 15 Cac bien phap ky thuatdephongtranh su eo dap tran xci lU

Chuang I6.C<ie bienphapkythuatdephongtranh BlJeocongd~ai dap

Chuong 17 Cac nguyent~e-vabien phapxu ly'slJ'eo

VE BAT BAPa MQT SO BI:\P T1:\1 VIl;T NAM

Tid lieu tham khao

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121151175193204213222

241255298

Narn 1945 ca nuoc ta chi co 13 h¢ th6ng cong trlnh thuy lei, tong nang luc nroi

VaG khoang 30 V,,1n ha, tieu ung 8 van ha: va mot so h~ th6ng kenh true ?:J Narn bo dti

khai hoang va gieo trong I1:1Qt vu Narn duoc rnuatong san hrong luang thuc qui thoc

d"lt duoc 6,2 den 6,4 trieu tan.

4 Tir nam 1955 duoi su lanh dao cua Dang va Chinh phu, voi 51! no hrc cua cac naanh cac dia phuong dac biete ' . e ' El su. doria gop'-"e to Ian ve consc SUC cua nhan dan

trong ca ruroc, den nam 1995 nganh Thuylei ruroc ta c1a xay dung va dua V~lO

phuc vu san xU<it tren 5000 cong trlnh thuylei: trong do co tren 500 cong trinh Ion,

tren 2500 cong trinh vira; dira dien tfch nroi ca nam len 5,6 trieu ha gieo trong Ida,

56 Vi;111 ha rau mau; tieu iing eho 86,5 van ha; tieu xo phen cho 1,6 trieu ha, cai tao

70 vanfiadat man ven bien thanh dat san xuat nang nghiep, Thuy 19'i da thtrc 51! 1a

bien phap ky thuat hang dau trong nang nghiep, gop phan quan trong trong chien

Iuqc dam bao an ninh luang thuc quoc gia, dua nucc ta (]1 thieu hrong thuc tra thanh nuoc xuat khau gao dting thtr 2 tren the gioi. J

Tir thap ky 60 cua thien nien ky 20 nay, d9i ngu can b,? khoa hoc ky thuat cua nganh Thuy I9i cung dil tnrong thanh, dil tv luc dam nhiernduoc toan bo cac khau tu

dao tao, nghien ciiukhoa h9C, (lieu tra khao sat, quy hoach, thier ke. xaydung, che' tao

va quan ly van hanh cac cong trtnh thuy loi anurrc tao

'-4:Tuy nhien so vci cac nuoc tien tien, r6 rang 18 trinh d9 can bQ cong nhan cua chung to chua· cao, can thieu kinh nghiern, cong trtnhthuy I9i can lac hau, cung voi viec thleU tinh than trach nhiem eua mot s6 can bova c6n~ nhcin nen da xciv fa slf c6 (~ mc.?t s6 cong trlnh thuy 19i: gay nen 't6n thal k.~6ng nhl; v0 t'ai san cua "Nha

Th0l l~l h"mh phuc Ian lao d6i voi toi 121 duqe may man tham gia eong tac thuy

l~Ji t1'9n dai mmh trong thai ky lieh su hao hung nhat eua cong tae phat tri€n Thuy 19'i a nu6c ta, dong thai cCing duqc chU'ng kien nhfrng slf c6 ade cong trlnh thuy 19'i trang thai ky nay Nay c6 thai gian t0p hc;Jp l(;1i m9t each c6 h¢ thong de trein tr9ng giai thi¢u vai dQc gia, vai hi v9ng neu len nhfrng kinh ngh i~m chua phai lathua d0 tranh dUge sv co xay ra .

( H1u h0"r a cae cong trmh deu c6 51.! e6 ian ho~c nho Trong do co ca nguyen

nhan ve khao sat, thiet ke, thi cong va quan Iyky thu~t adc cajJ )

Do khuon kh6 hl;1n che eua 5ach, dong thai ci~ cung cap thong tin hiIu fch eho dong dao dQe gia quan tam, a day chi gioi thi~u nhfrng SI! coIan acae 10<;1i eong trmh thuy 19'i, trong do co nguyen nhan ve khao sat, thiet ke (thuy van, d!a chat cong trmh, co khi, lhuy cong) va ve thi cong; cung e6 cong trmh sl! c6 x~y ra do ca

khao sat, thiet lee va thi eong gay ra.

Sach gam co 3 phan :

- Phan 1: Tong quan ve sv co cac cong trlnh thuy l<;1i aVi¢t Nam;

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- Phan 2: Sl;rco mot so cong trinh thuy 19i aViet Nam;

- Phan 3: Cac bien phap phong tranh vaxuIy SI! coanhirng cong trtnh thuy lei,

Phan 1 cung cap cho ci¢c gia nhtrng thong tin tong quat v~tinh hlnh 51! co acac

cong trlnh thuy lei amroc ta d~ c6 nhtrngdanh gia dung d~m tong quat ve tlnh trang

chat luong cua cac cong trtnh thuy loi noi chung, tu d6 tren cuong V! hCiu trach cua

mirih c6 5Uy nghi vabien phap thich hopd~nang cao cnglt lirong cho khong chi d6i voi

cac cong trlnh daxay dung rna quan trQng han la doi vci nhttng cong trmh thuy 19i

Phan 2t~p trung giai thieunhfrng SI! co da x~y ra a mot s6cong trlnh thu)'19i a

mroc ta, cophan tfch cac nguyen nhan va neu ra nhfing bien phap xu Iy cung voi

nhfing thiet hai do sl! co gay ra Trong phan naytac gia da c6 gang rhu thap cac tai

lieu c6 lien quan, d~ cung cap cho d¢c gia nhfrngthong tin can thiet va chan thuc,

nharn neura nhung VI du cu th~ va song dong ve sI! co, qua d6 moi nguoi nr rnlnhrut

ra nhtrng bai hoc b6 Ich cho ban than va don V!

Phan 3 trlnh bay nhtrng nguyen tac, bien phap phong tranh va xu 1)'SI!co, do tac

gia due ket va rutra tir nhtrng su co da x8y ra acac congtrtnh thuy loi cua rnroc ta va

tir kinh nghiem cua ban than Phan nay mangtfnh chat goi rna va trao d6i cac yan

de thirc51!quantrong vacan thietci~phong tranh cac sir cocling nhu cac bien phap xu

1y thfch hop cac 51.! co, d~ cac doc gia tham khao

' ' -TacgTa xin chan thInh cam ancac donol ; : : nghiep cia c6 nhirnul ; : : khfch Ie vaSU'<-giiip

d6' rat qUI bau trong qua irmh bien soan cuon sach nay

Ch~c chan trong sach can nhtrng thieu sot, mac dau tac gia da hei suc co gang

thu th~p tai li~u, nghien CUll va phEin tlch vai tinh than trach nhi¢m, tam huyet va thl!C

sl! khach quan vai mong muon d6ng g6p m¢t phan cong sue nho becua ml,nh vao

vi~c nang cao chat 1uqng cong trlnh thuy 19ianirac ta, ci~ tranh duqc sl! co xGy ra VI

the rat mong cac b<;1n dQc g6p y kien d~ b6 sung, hOEm chlnh:

Phan 1,:, , '.', ' : _ N- A '

1.1.f)AC f)IEiVl ClfA cxc CONG TRINH THUY LaI

Cac cong trlnh thuy loi co nhung dac diem quan trong sau day:

1 Cai tao thien nhien, khai thac cac mat lei va khac phuc de mat eo hai c1~

phuc vu cho nhu cau cua connguoi

2 Phai thuong xuyen deli mat true tiep voi sir tan pha cua thien nhien, trong do

co 51!pha hoai thuong xuyen va su pha hoai bat thuong.

3 La ket qua tonghop vaco quan he mat thiet hilu co ve lao dong cua nil

nhieu nguci trong nhieu Iinh vue, bao gam tircong tac quy hoach, nghien cuu khoa hoc, khao sat, thiet ke, che tao, thi cong, den quan I}' khai thac, v v

4 Chua dung nit nhieu Iinh vue khoa hoc ky thuat X~lY dung khac nhau.

5 Von dau tu thuong la rat Ian .

6 Thai gian c10 ra doi mot cong trlnh thuy lei phai mat nhieu nam, va hang chuc nam ckii voi nhirng cong trinh lOr Tu6i tho cua cong trinh la hang chuc den hang tram narn tuy theo cap cong trtnh.

Nhirng u<:ie diem do co anh huang true tiep den chat IUQng cua cong trlnh thu)' lei, VI the neu d0 x<4y ra kernchat hrong abat kykhau nao,trong thai gian nao cling co th0 dan den su co Ian hoac nho Dieu do cung eo nghia la 51!eo a cal' cong trinh thuy loi eo quem h~ mat thiet voi nhirng dac diem dli neu tren.

1.2 f)~C DIEM VE SV co cxc CONG TRINH THlT)' LQI

SI! eocac cong trinh thuy loi co nhirng d~c di€m sau day:

1 Do mot hoac nhieu nguyen nhan gay ra, trong do c6 khao sat (etta hlnh, uta chat cong trtnh, dia chat thuy van, thuy van cong trinh), thiet ke (thuy cong, co khi, dien), che tao, lap dat, thi cong va quan lykhai thac Thuc te ve sir co dll x~y ra a

cac cong trlnh thuy lei anuac ta cho thay tang, trong cae nguyen nhan do cae nguyen nhan ph6 bien la: khao sat, thiet ke, thi cong va che t<;lo lapdi;'it.

i 2 Cal' h"mg my.c cong trlnh x~y ra st;! co co ca cac cong trlnh dau moi, h~

thong kenh, cong trlnh thuy cong cung nhuCefdi¢n.

7

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Sir coJon thuong x~yra doi voicac cong trlnh thuy congo

3 Sir co x~y ra khong phai chi c6 ngay sau khi hOEIn Thanh cong trlnh, rna

thuang ]a sau nhieu nam Thy nhien sl!co IOn vanghiem trong thu0ngx~y'ra khi

giflp II1 eire IOn (nhu va ,d~p v~ Vimg &tinhNghe An, varar nhieu dap nho khac) va

Trang qua trlnh thi cong (nhusu eocong HiepHoa- &' hethong thuy nang Do Luang

&tinh Nghe,An,s\!, cosat kenh dan va va dapSongMuctinhThanh Hoa, su co Ian

thu 3 d~p··Su6iTrau-':& tinh Khanh Hoa, SV co:d?p'ca Giay tinh Blnh Th~?~, v.v );

hoac & nam tfchmroc dau tien, xa II1 dau tien (sir co va d~p Suci Trau Ian thrr 1,

Ian thri 2, va dap Suoi Hanh, va dap Am Chua, deu x~y ra t<;li' tinh Khanh Hoa;

va dap Hq V5 a tinh Ha Tinh, va dap Day CU, sir.co d?p tran thuy dien Hoa Binh,

v.v )

Nhtrngsu co nghiern trong khac la do sirconho x~y ra nr tirnhung khong duoc

xu 19, d~ tiep di~n lau ngay tich ti~u thanh dai (cong Trung Luang &Thanh pho Hai

Phong, congCau Xe atinhHai Duong,cong LanI &tinh ThaiBinh, cong Lach Bang

atinh Thanh Hoa,va cong Mai Lam &tinh Bac Ninh,w ).

4 Nhtrngsu co IOn va nghiem trong thirong x~yra rat dQt ngot, trang mot

thai gian rat ngan, khong kip ling pho (va dap Suoi Trau Uin -1, Ian 2; va dap Suoi Hanh:

gaycira dap tran DauTieng; vadap HqV5; va cong Mai -LaJ!l.LS~lt~Ql}g Hi~R Hoa, "'C,l•._ _

-_··-k:enh-vao -transong Mire;'vfJO?]J'\7~Viliig~va d~p"bay CU, sat dap Vue Tron, sat

dap Yen My, x6itran NamThach Han, v.v )

5 Hau qua do sir co gay ra thirong la nghiern trong, viec xu 19 nrt ton kern, gay ra

uSn that IOn ve tinh mang, tai san cua nhan dan va tai sancuaquoc gia, c6anh huang

xau ve kinh te, va doi voi nhtrng sir co 16n va nghiem trqng con anh huang xau den

tlnh hlnh xa hQi ~

Muon phong tranh sl! co & de eong trlnh thU)l Iqi, th1 dieu quan trqng dau tien

11'1 phai nam cho duqe cae d?c di~m ella dc cong trlnh thuy Iqi va nhung d~c di~m

ella sl! co d~ c6 bi~n phap phong tnlnh tot, xu 15' dung d&n, kjp thai va thfchhqp.

.1.3 TONG QUAN TINH HINH Sl/ co VE HO CHUA NU'OC 0

VI¢T NAM

Ho chuanuac la l0<;li hlnh cong trlnh thuylqi ph6 bien nh£1t &nuac ta, trlT cac tinh

&clong bang song Ci'ru Long Thea so Ii~udieu tra nam 1992, khong k~cac ho IOn do

nganh nang luqng quan 19, so Iuqng cae ho chua nuac c6 dung tfch tlT 1 tri~u m3tr&

len va cac h6 c6 dung tfch duai 1 tri~u.m3

nhung d~p cao trenTO m Iii 445 ho, vait6ng dung tfch toan bQ lEI 5.002 tri~um3, nang Il!ctuai Iii446.600ha

Trang sl! co cac cong trlnh thu)'Iqi th1 sl! cove h6chua nuac thuang la ph6 bien

v~ dan den nhUng t6n that I&Lve tfnh ml;U1gva taisan.Nh~nthucduqc dieu d6, BQ

Thuy Iqi nam 1992-'d~tien ~Jinht6ng ki~rr;.:tra, d~nhgia'd8 ba\l:'/~ an toan cac ho

Ket qua 'ki~nl: tiaruy chUa th$tdc1Ydll riHurig cung da lieu fa m¢l bue tranh

t6ng qualve hi~htr<;1ng cac 'h6 chuaflUOC &; nu6c 'la,\radi~u q'uan trQhg 1£1 cilIa d6

thay duqc nhi~u · vi~c phai lam cling nhuduc rut ranhfrng kinhnghi~mb6 feh d~

nang cao chat Iuql1g va phong tnlrili svcotho cac ho chua riuacda, dangva'se'xay

I

,(

L3J PHAN'L0AI HOCHUA 6VIF;:T NAM

1 I'han.loai thea qui rna dung tfch.ho

Hien nay trong nganh Thuy loi, qui moho duoc phan loai nhu sau :

1.HoIan: e6 dung tfeh roan bo W> 10 trieurrr'.

2 Ho vira : _ -nt- W=5-10tri~um3

3 Ho nho : - nt - 'vV==2 -5 trieu m"

4 Ho r8t nho : - nt - W < 2 trieu rn',

S6 luong cac loaiho phan theo qui mo dung tlch duoc trlnh bayabang 1.1.

Bang 1.1 Sohl<;Jng ho chua phan leal theo qui rno dung tich

2. Phanloai theo chieu cao dap tao thanh ho chua nuoc

S6 lucng cac loai dap tao thanh ho chua phan loai thea chieu cao duoc trinh bay

Bang 1.2 Phan Ioai d$ptheo chlsu cao

SoTT Ten cac h~ng rnuc Caclo?id~p

1 Chieu cao (m) > 40 i 30-40 20-30 I 10-20 <10 Tong

2 Lo?id~p Rat cao i Cao Trung Thap Rat C9n9

1.3.2 DANH GIA CHUNG VE CHAT LVQNGcAc HO CHUA NUdc

D~ danh gia chung ve ch8t luong ho chua, ho duoc phan loai theo nhtrng tlnh trang sau day:

1 Loai lam viec binh thuong: la nhimg ho chua nuoc trong d6 cong trinh dau moi bao gorn : dap, dap tran xa lei, cong lay mroc, c6 chat luorig nhu thiet ke; cong trlnh a

trang thai tot.

2 Loai 51! co nho: la nhtrng ho chua co nhirng hang rnuc cong trinh kh6ng quan trong bi hir hong, hoac nhfrng hang rnuc quan trong bi hu hong nho, lam giam hieu

9

qua cua cong trinh, van hanh eotrue trac,khong.darn baa diroc hoanhao thea thiet

ke, nhung khong anh huang den an toan cua cong trlnh

3 Loai 51!co1611: 1a nhfrngcong trlnh cocac hang muc khong quan trong bi hu hong

nang, hoac nhtrng hang muc quantrong bi htrhong 1611, co anh huang nghiem trong

den che' d9 lam viec cua cong trtnh, co nguyco.xdyra mat an toano

Tmh hlnh chung v~chat hrongh6 chuaduoc trlnh bay trong bang1.3 va 1.4

Thea so lieu dbang1.3, co39,1 %h6 chua lamviec binh thuong, nghia1a khong

cosirco; 38,7 % cosirconho; va22,2 %cosu co 1611 Neu xetthea guy rno h6 th; h6

16'n bi sir co Ion . la 13 g(,;ho vira bi str. co 1611 la 14,3 %; h6 nho 1a26.1. % va h6 rat. nho

la 23,7 %; nghia1a ty1~51!co16nd h6nho vanitnho nhieu gap gan2Ian so voi h6 1611

va h6 vira

Bang 1.3 Phan leal Sl! co theo so111<;'$ng ho chua rurdc

So Muc d9sl!,co Theo qui mo he chua (cai 1%)

Bang 1.4.Phan loal sl! co theo qui mo ho chua

Muc d9 slJ co So fuqng theo qui mo he chua

Nhfmg IO(;1i 51! e6 phdbien 0 cac h6 chua nuoc la: Tham (0 nen, vai,than dapvamang cong trtnh): sat 10 phan gia e6 mai thuongluu: ruroc Hl tran qua dinh d~p dolu

100 han tan sw1't thiet kehoac m~\t d~p thap.hon cao trinh thiet ke; than va tieu nangtran xa let b! xoi; cira tran b] gay, b] ket: c6ng lay ruroc bi IUn, gay, xoi tam day vatran, <.19t, kh6p n6i bi hong.hoac dill; elm c6ng b].gay,b]ket

So So IlfQng cac d?p b] 51!eo theo qui rna hochua

Lon Vua Nho Rat nho Ci?ng

Ttr nhtrng56lieu tren co th0 xep trtnh ur cac loai5L! c6 theo so hrong nhu sau:

1.S~t maithirong lull: 25,84 q

2 Hong d~p tran xiiW: 25,39 9(.

3 Cong bi hong: 17,309i

4 Dap bitharn : 15,069c:

5 Dinh dapthap : 9,009C

6.Cua bihong 3,60 9G

11

Dtroi day trinh bay nhirng be> phan quan trong va sir co thuong g~p trong caccong trlnh thuy lqi amroc ta, neu cluing c6 chat Iuong kern chac chan cong trinh se bi.sy: co; ya nhfrng nguyen nhan gay ra sl!co .

De cung cap nhCing thong tin hlru feh va ph6 bien, diroi day chi trinh bay gioihan d6i voi nhtrng cong trlnh thuy Iqi ph6 bien amroc ta, d6 la :

1- D0r uHt (cMng chat,khong dong chat)

2.1.1 :\HlJNG Be) PH.~N QUAN TRQNG TRONG DAp DAT

I Tai lieu v~ thuy van congtrlnh,trong d6 c6 :

a Luu luong lu;

b T6ng IuonglO.:

c Cac dans lU e b:~lt loi: ,

d Gi6 baa

2 Dia chat nen dap

3 Bien phap xuI)' nen

4 Dat d~pdap.:

5 Tlep giap dap voi nen va cac vaidap,

6.Tiep giap than dap voi cac cong trlnh xay dtic

7 Cac khop n6i thi congo

2.1.2 ?\HONG su CO THUONG GAp VA NGUYEN NHAN GAY RA str co

1.Lii trim qua dinh dap

Do de nguyen nhan sau day gay ra:·

a Tinh toan thuy van sai: Mira gay ra lU· tinh nho, luu Iuong dinh lU nho; tong luong 10 nho han thl!c t€;cac dang lU thiet ke khong phai Et bat loi; lhicu luu vue: lap

dirong cong dung tfch ho W=f(Hjlechve phfa 16'0, lap duong cong kha nang xa

IG cuadap tranQ= f (H) sai lechvci thuc teo

b Cua dap tran bi ket.

C. La vuot tansuar thier ke, khong c6 tran xa lU dir phong

d. Dinhdap dap thap han cao trlnh thietke

2 S~1t mai dap thuong ltru

Docac nguyen nhan sau day gay ra:

a Tlnh sai cap baa

b Bien phap thiet ke gia comai khong uu sire chiu dung s6ng do baa gay fa.

c Thi cong16'p gia co kern chat Iirong: Kfch thuocdalar hoac tam be tong nho honthiet ke; char hrong uahoac be tong kern; Cill1ar d~tnam, khong chen chatcac honda.

d Dat mai dap thuong hru dam nen khong chat, hoac khong xen maio

3 Tham rnanh hoac sui ntroc anen d*p

Dode nguyen nhan sauday gay ra :

a Danhgia sai tlnh hlnh diachat nen, d~ s6t lop tham manh khong duoc xu 1Y.

b Bien phap thiet ke xu ly nen khong dam bao chat Iuong,

C. Chat luong xu 1y nen kern : khoan phut khong dat yeu cau; h6t khong sach lapboi tfch; thi cong chan khay, san phu kern dan den thung lor each nuoc.

d Xu l~' tiep giap nen va than dap khong tot dothiet ke khong dera bien phap xu

ly, hoac do khi thicongkhong thuc hien tot bien phap xuly

4 Tham manh hoacsui rnnrc avai d*p

Do cac nzuven nhan sau .J day'" eoay ra:

a Thiet ke khong de ra bien phap xu1y hoac bien phap xu 1y de ra khong tot

b Khong b6c het lap thao moe acac vai dap

b.Dam nen dat tren dean tiep giap acac vaidap khong tot

e Thi cong bien phap xu ly tiep giapkhong tot

5 Tharn manh hoac sui nuoc &mang c6ng trinh

Docac nguyen nhansauday gay ra :

a Thiet ke khong de ra bien phapxuly hoac bien phap khong tot

b Dap dat a mang cong trlnh khong dam bao chat luong : chat luong dat dap

khong duoc 1t;ra ch9n ky, khong d9n v~ sinh 5<;1ch se d~ vUt bo cae t<;1P cI1[{ttmae khi dap dat, damn~n khong kyo

e~ Thgchi~n bi~n phap xu1ykhong dam bao chat luqng

d Hong khap noi eua cong trmh

e. Cong bi thung

13

6 Tham rnanh hoac sui mroc trong pharn vi than dap

Do cacnguyen nhan sau day gay ra :

a Ban than da't d~p d~p co chat hrong khong tot: ham Iuong cat, bui dam sannhieu, ham luong setIt,dat bi tanra manh,

b Ket qua khao sat sai voi thuc te, cung cap sai' cac chitieu co 1:9 Iuc hoc, do k1180 sat sa sai, khoi Itrong khao sat thirc hien It, khong thi nghiem day du cac chi lieu co 1)1 II!C hoc can thiet, ttl' d6 danh gia sai chat hrong dat dap.

e Chon dung trong kho thiei ke yua thap, nen dat sau khi dam van toi xop, bo

roi,

d Khong c6 bien phap thieh hop d~ xu Iyd¢ ~m, do do d¢ £1m cua dat dap khong et&u, cho kho cho~m, lam cho dat sau khi dap co cho chat c6 cho van roi rae toi x6p.

dinh, s6 Ian dam it, nen dal sau khi dap co d¢ chat khong dong d&u, phan lop, tren mat

th) chat phia ducJi van con toi x6p khong d~t o¢ chat qui dinh, hlnh thanh tung lop

dat yeu narn ngang trong su6t cab~ matlap clam.

'_g.-Thiclki'v'2! thicfJllg-khemg-'co hi~n-phapAlrIfkh6'PJY6i ihicOng do rhein do~n­ dap cl~ dap trong que! trlnh thi congo

h Thie! bi tieu nuoc biuk

7 NUt ngang dap

Do cacnguyennhan sau day gayra:

a Lun nencl(ll bien do chat luong nen kern:

b Liin khong deu d¢t bien trong than dap do chenh lech dot bien ve dia hlnh nen dap khong diroc xu 1:9 '

C Dat dap dap co tfnh ltin tr0t Ian hoac tan ra manh nhung khi khao sat khong phat hien ra, hoacco phat hi~n ra nhung thiet ke' ket cau dap khonghop 1)1

8 NUt doc dap

Do cac nguyen nhan sau day gay fa:

a Nuoc h6 chira dang cao d¢t ngot gay ra tai trong tren mai dap thuong hru tang dot bien.

'b Niroc h6 rut xu6ng d¢t ng¢t gay ra giam tai d¢t ngQt tren mai -thuqng lUll.

c Nen d0pb~ lun tren chi~udEli dQctim d?p : '

d Dat dap d?p kh6i thuqng lUll c6 iinh lun uot hd~C tan ra m~nh-nhung khao sat khong pha! hi~n ra ho~~ co phat hi~n fa n.hung thietkeketcau ~~pkh(mg hQ'PIY.

9 NUtne sau m~t ho~cmai d*p

Do dat dap d?p thuQc Io~i truangnattl do mi;1nh.

10 Truot sau mai dap thuong luu

Do cac nguyen nhan sau day gay ra :

a Bao 100 s6ng to keo dai, dau tien pha hong lap gia co, tiep do pha khoi d.ata

b Nuoc h6 nit dot ngot ngoai du kien thiet ke.

c Sire ben cua dat dap dap khong dam bao cac yeu cau cua thiet ke.

d Thier ke' chon t6 hop tai trong khong phu hop voi thuc teo

e.Thierkechon sai SCJ do tfnh toan 6n dirih,

g Chat luong thi cong dat dap dap khong dam bao yeu cau thiet ke.

h.Dia ehalnen dap xau khong duoc xU:ly,

11 Truot sau rnai d*p ha luu

Do cac nguyen nhan sau day gay ra:

a Dia chat nen xau hon du kien cua thietkedo khao sat danh oia khons duns vciC' c c

b Sue ben cua dat dap dap kern hon du kien cua thiet ke do danh gia sai cac chi tieu ve chatIirong dat dap dap

c Nen dap bi thoai hoa sau khi X[lY dung d~p nhirng khi khao sat va thiet ke aa

d Thierkechon sai t6 hop taitrong.

e Thier k€ chon sai SCJ do hoac phuong phap tinh toano

g Chat luong thi cong dat dap dapkhong dam baa.

iAh Thiel bi tieu nuoc bi tac lam dang cao duong baa hoa.

i Tieu thoat nuoc rnua tren mat -mai ha hru khong tot, khi mua keo dai toan than

2.2 D~P TRAN XA LiT

2.2.1. NHUNO BQ PHAN QUAN TRQNG CUA DAp TRAN xA LU

NhCrng b¢ phan quan trong trong dap tran xa 1111a :

1 Tai lieu ve thuy van cong trinh, trong do c6:

a Dinh Hi;

b.Tong luong 111;

C. Cac danz. "- 111bat lei: ,

d Gi6 bao,

2 Dia chat nen dap

3 Bien phap xirly nen.

4 Bien phap tieu nang.

5 Bien phapnoi tiepvoi long dan ha hru dap

6 Cua d~p tran,

7 Thier bi d6ngrna.

15

2.2.2 NHUNG Sl/CO THUONG GAP vA CAe-NGUYEN NHAN GAY RA str

co 6 DAr TRAN xA LU

1 Lii vtrot qua dinh dap trim

Do cac nzuven nhan~ sau day oay· ra:_ e

a Tfnh-toan thuy van sai : Mira gay ra h1 t£11)1 nho, luu rluong dinh h1 nho; tong

Iuong h1 nho han thirc te; cacdang h1thiet ke khong phai la bat loi; thieu hru V1!e; lap

duong eong dung tfch ho W =f (H) lech ve phia 1611, lap duong eong kha nang xa li1

cua dap tran Q=f (H) sai lech vci thirc te,

b Oradap iran bik~t.

e LG Vl1Q1 tan suat thiet ke, khongcotran xah1 dir phong

2. Tham qua nen

Do cacnguyen nhan sau day gay ra :

a Danh giasai dia chat nen.

b Khong co bien phap xu I)' nerihoac conhtrng bien phap xu 19khong thich hop.

c.Thi c(mg bien phap xuIfl'len kh611guaillbaochat TUQ'ng

Do cacnguyen nhan sau day gay ra :

a Chat luong be tong hoac da xaydap iran khong darn bao do:

+ Mac belong hoac mac vfrathap khong dat yeu cau chong tharn

+ Chat hrong cong tac xay due khong dam bao (do chat IU9'ng cot lieu, chat IU9'ng

xi mang, chat hrong darn, xay, baa duong, vv ) '

+ Khong co bien phap tot d~ xu 19 nhiet trong khi d6, be tong gay ra mit ne do

nhiet.

+Xu 19khongtot cac khe thi cong

4 D~p bi troi hosegay

Do cac nguyen nhan sau day gay ra:

a Nen bj pha hoai (hin, rong) do danh gia sai tlnh hinh diachat nen.

b Khong cobien phap xuI)'nen hoac conhung bien phap xu lykhong thfch hop,

e Khong du kien diroc kha nang bi thoai hoa ellanen

d Thietkechon t6 hop tai trong saivoithirc teo

e Thiel ke chon sai sadohoac phuong phap tfnhtoan.: -

g. Thi cong bien phapxu1)' nen khong dam~ao chat Iuqng.·

5 X6i tieunang

Do cac nguyen nhansau day gay ra :

,.1

,

'\

a.Danh gia sai etta chat nen.

b.Xac dinh sai rrurc nuoc ha luu dap do lap duang quan he Q= f (H) aha Iuu dap tran sai lechso voi thucteo

C. Bien phap tieu nang khong thfch hop

d Thi cong phan tieu nang khong dam bao chat luong.

e Van hanh d~ptran sai quy trinh,

6 Xoi 10' ha hru

Do cac nguyen nhan sau day gay ra :

a Khonz khao sat dia. chat cons trinh hoac danhe .£ia sai tinh hlnh dia~ chat ha du

d~ptran tren doan noi tiep ha du trong pharn vi chiu anh huong xa lQcua dap tran

b Khong co bien phap xu 1:9 hoac co nhirng bien phap xu 1:9 khong thich hop

C. Thi cong bien phap xu 1:9 khong dam bao chat luong.

7 Gay cira

Dode nguyen nhansau day gayra :

a Thiel ke khong dam bao chat lUQT1g do:

+ Ket cau bat hop1:9 hoac khong thich hop:

+ Chon sai t6hop tai trong;

+ Chon sai sa do hoac phuong phap tfnh toan,

b.Gia cons che'c" tao lap ' dat khonz . dam bao chat hronz.. e

c Khong bao duong tot trong qua trinh quan 1:9 van hanh

8.K~t cira

Docacnguyen nhan sau day gay ra :

a Thier ke khong dam baa chat hrong, do :

+ Ket cau bat hop 1:9 hoac khong thfch hop:

+ Chon sai t6 hoptai trong;

+ Chon sai sa do hoac phuong phaptfnh toano

b Gia cong, che tao, lap d~t khong dam baa chat lUQT1g

C Viec baa duongcira khong dam bao chat luong

uKhong van hanh thirtnrcc moi tran in~d~ khac phuc kip thai

9 Hong thiet b! dong rna

Do cac nguyen nhan sau day gay ra:

a.Thier ketfnh toan sai tai trong gay ra quatai,

b.Thietke'khong co bien phapbaa ve thietbi

c.Viec che tao valap d~t thiet bikhong dam baa chat lUQT1g

G·fA'! J ~;~;'f':'~~~~',:~~;·;"~~- ~-1

d Viec bao duong thiet 'bj khongdam bao chat luong.

e Van hanh sai quy trlnh

2.3.1 NHDNG BQ PHA-N QUAN TRQNG eVA CONG

Nhirng be? phan quan !r9ng cua cong la :

1 Dia chat nen congo

2 Cac khop noi

3 Dean congathap va dean dau tien sau cira

Do cac nguyen nhan sau day gayra :

a Nen xau do danh gia sai tinh hinh dia chat nen

b Thap congd~t tren nen khongthuannhai

e Bien phapxuIynen khong tot

2 Hong de khop not

Do cac nguyen nhansau day gayra :

a Nen cong hin khong deudo dia chatnenxau khong duoc xu Iy, hoac bien phapXLI' Iykhong thich hop

b Phan doan ccng va bo trf vj trf cac khop noi khong hop 19-

C. Thier ke khop noi khong hop15'

d Thi cong khrrp noi khongdambao chat luong

3 Gay cong

·.i·

: i

Do cac nguyennhan sauday gayra :

a Danhaia sai dia . chat nen cona,

b Nen cong bi thoai hoa,ding I ! ' "

c Thier k€ cong khong du kha nangchill.ll!~ (thanh cong mong, bo trf cot thep

.d Thi congbetongkhongdam bao thatliiqng

e' Be tong than conghi th;oai~pa .

':".~,

4 D~lY cong bi xoi

Do cac nguyen nhan sau day gay ra :

a Tinh toan sai che dQ thuy luc trong cong, nen cong phai lam viec vci che' dQ

thuy luc khong 6ndinh .

b. Kh~u dien on. clJ thoris khi khons du Ione c ct~ khir chan khons. c: avuns sau cua e

e Thiet ke khong e6 bien phap chong x6i do luutoe Ianva do chan khong gay ra

d Thi cong day cong khong dam baa ch<1't lucng.

5 Cong bi dot va rnuc

Do cac nguyen nhan sauday gay ra :

a Thier k6 thanh cong khong dam baa kha nang chong tharn ( chieu day thanh cong mong, mac be tong thap ).

b. Thier kekhong c6 bien phapchong tharnaphia ngoai thanh congo

c Thi cong than cong va thuc hien bien phap chong tharn khong darn bao chat luong.

6 Hong tieu nang

Do cac nguyen nhan sau day gay ra :

a Tinh toan sai che dQnoi tiep thuy luc sau congo

b Thier ke bien phap tieu nang khong tot.

c Thi cong bien phap tieu nang khong dam bao chat luong.

d V ~n hanh cong sai quy trlnh.

7 Ket va gay cira

Do cac nguyen nhan sau day gay ra :

a Thier ke' khong dam bao chat luong, do :

+ Ket cau bat hop ly hoac khong thich hop;

+ Chon sait6 hop tai trong:

+ Chon sai sado hoac phuong phap tinh roan

b Gia cong, che' tao, lapdat khong 'dam baa chat luong.

C Viec bao duong cira khong dam bao chat luong.

d Van hanh sai quy trinh.

2.4 TR~lVl BOM

2.4.1 NHUNO130 PHA.1:-J QUAN TRQNO CLJA TRAM B~M

Nhirng bo phan quan trong cua tram born la:

1 Vi trf dattram born.

2 Dia chat c6ng trinh cua m6ng tram born.

3 Ket cau phan duoi ruroc cua tram.

1(.)

Tuong nguc Ia I dam hop rong, cao 2,30 m, day a cao trinh 12,50, mat acao

trinh 14,80 m, rong 2,00 m day 0,25 m Tuong ngtrc vira lEi tam chan mroc, vira d~

chan ciraphfa tren, virala cau cong taco "

Viec dong mo' ci'ra dtroc thuc hien theo nguyen tac thuy IY'c bang each dan

mroc vaoham phao thong qua'cac cira van d~t anach cac tru pin d~ dciy phao nang

cira len va thao niroc ra khoiham phao qua cira van amat tru pin ha hru d~ ha cira

xuong, Ngoai ra con h~ thong khf nen 06 h6 tro khi canthiet,

Cot mroc thiet ke tnroc khi phan lfi Ia 9,00 m, nrong ling voi rmrc rnroc thtrong

ltru la 14,00 m va ha hru lEi 5,00 m

3.2 1\10 TA su co

Ket qua cac Ian phan lfithirnghiern va phan lfi chfnh thuc dap Day truce khi xay

dung cong Van Coc nam ] 966 nhu sau:

3.1.I PHA.N LOTHUNGHI~M LAN THU I NAM 1939

Vao mira lfi narn ]939, 2narn sau khi hcan thanh xay dung, nguai PMp(1acho

Mrrc mroc lu aH8N¢i laL9,OO 111; .MNTL~d0p EL±ll,OO-rn(thap·-hollmlh::~

·nl16'c·~t11ieCke3,00 m):lvINHL d~p Ia + 5,60 m; cot nuoc Jam vice Is 3,40 m, hang

37.8 7r, cot nurrcthiet ke.

Bat dau 5 gia sang thi cho ha dong thoi ca 7 cira dap til cao trlnh + 12,50 m

xuong dan Den] 2 gio' trua ha den cao trlnh nguong dap acao trlnh + 7,00 m Sau

do cho nang tat ca 7 ciralen cao trlnh + ]2,50 m, d~ dong cac cira dap lai Thai gian

dong ciramat] giO'

Cong trmh lam viec tot, cac CU8 duoc dong rno blnh thtrong, khong co gl true

trac Viec thir nghiem dat ket qua tot, tuy rang cot nuoc lam viec moi chi dat 37,8% c<:)t

nuoc thiet ke,

3.2.2 PHA.N LO CHfNH TRUC LAN THU 1 NAM 1940

Narn 1940 o Ha N9i dil xciyra lfl 1611 Vao hie 18 gio ngay06 thang 8 nam 1940,

rmrc mroc song Hong aHa Noi la + 11 ,00m Iv1NTL dap Day la + ] 3;04 m, MNIIL

dap la+6, 50 m

Ca 7 cira dapdircc mo dan dan trong 5 gio' lien voi d<:) mo 5 - 10 ern; luu lirong xa

qua dapQ =:400 - 500m3/s ,

Ltic 6 h 45' ngay O]thaI1g 8, dinh cira ha toi cao trinh + 10,75 m; mire mroc

thironghru la 12,90m;ii'!~Criuaeh1;1 lUll la n AOm.

Luc 7 h 50' cung ngay, dinh cac cuah1;1 tai cao trmh +10,45 m thl khong th6 h1;1

xuongdU9'criua;m~Nb~pbenh lenxu6nggiao d<:)ng trongph1;1m vicao trmh + 10,32+

Tmhtrl;lI1g nayk¢bCi~.iJrong 26g~g, tuc Hi deli' ]0 h s~ngngay 08 thang8

Luc nay muc nuae thuqng lUll d~p h<;1 xu6ng cao trmh +12,78 m; muc nuac a ~

luu dang len a cao trmh + 11,75 m; cua s6 1bi mrae phun ra qua tam bung h1;1 lUll

,OT

o

"

Liic nay dong chay qua d~p tro nen h6nI0<;1n,' va cira s61 bi d9tng9t:' sap xu6ngngl16'ng lt0pl1 cao trinh +7,00 m, Da phai dung hoi epbom vao ham phao cfing nhu

dong tit cira van X~1 (.1 ha luu d0 dang cao rruic niroc trong ham phao nham nang

Den 5 gia sang ngay 09 thang 8, mire nl10C song I Iong 0 IIa N9i dclng cao t{l'icao trinh + 12,30 m, nghia la cao han 1,30111 so voi khi bat dauphan 111; MNTL cl~p

cling dang len cao trInh 13,55 111; tvfNI-IL d~p dang len cao trinh 12,15 111.Dokhoang d~p s6 1 bi sir c6 khong th0 phan lil tiep, VI the can phai dong cac cira d~p lai,nhims cam: dong tht nuoc canz chay don vao khoang dap s6 I da bi sap nen cac. c 1 0 e ,

cua tirs6 2 den s6 7 chi co lh~ nang len cao trtnh + 10,65 den 10,75 rn roi dung 1<;11khons th0 dong kin (lilac ~

Ngay 10 thang 8 nuoc 10 song H6ng rut xuong thl cac cira cling nr dong haxuong ttl tir,

Liic 14 giangay13thang 8, ettas6 3 bi rung <19ng rat 111<;1nh Luc 9 h 15'ngay 14

thang 8, eva s6 3 b]sap xuong cao trinh + 7,07m, cira s6 5 xuong cao trlnh + 7,45

m va dung tai do; nhirng den 13h 30' lai tu dang cao len cao trinh + 10,00 111, sau do

lai W ha xu6ng cao trinh 9,40 m rei dot nhien sap xu6ng cao trinh + 8,37 va bap

benh ttl cao trtnh 8,30 mden8,64 m

Khi mroc song Hong rut xu6ng lhap tat ca cac cua deu ur ha xu6ng cao trlnh

,+7,00 m.

Qua trlnh dien bien duoc trinh bay 0 bang 3.1

Sau lCi c.1a tien hanh kharrr nghiern hien tnrong va phat hien nhttng hu hong 0 cua

so 1 nhu sau:

1 Van bung earth cira ha luu b] bat ra

2 Hai mai nha (tarn thuong luu va tam ha liru) khong khit voi nhau

3 Canh eva ha luu bi oan

4 Ham phao b] cat lap nhieu

5 Long song ha luu bi x6i sau

Nguyen nhan su c6 khoang cua s6 1 da duoc ket luan la:

I Cira chuaducirng nen bi OM sau d6 lam ho khe nen van bung bi bat ra khoi khe

2 Cua nh<.; nen gay rahi~n tt19'I1g b0p benh

Mua kho nam 194i da tien h~mh gia c6 nhl1 sau:

1 Gia ctXcmg lhem cling khung cua b2mg each bal them 1 dam 1V~tO tat d cae cua

2 86 cat kho vao phao, moi phao 400 kg

3 Lap l';'li tam bt1llg cho cua s6 1

4 Lap phan x6i h<;1luu cua s6 1

Nhl1 v0y co th0 ket lu~n vi~c phan lCi Ian thu nhat da that bi;li miiic du c9t mr6'clam vi~e cua ll~p chim6'i d<;1t 76,70 %~ C9t nl16'c th iet ke

25

Bang 3.1. Qua trinhv~n hanh d~'tJ'£>ay khi phan Jij narn 1940

06/8 18,00 12,50 13,04 ·6,50 Bat dau h~ ca 7 clla

07/8 6A5 10,75 12,90 11,40 Hi? binh thudng, Q= 400 - 500 m 3 /s

07/8 7,50 10,45 CLta khOng hi? dU<;1c rna b~p benh Ci

V' +10,32 - 10,45

-08/8 10,00 10,45 CLta so 1 bj -phun rnrcc: dong chay

h6n" loan, sau do sap . xuong caoA'trlnh V' + 7,00 m

09/8 5,00 10,75 13,55 12,15 B6ng cac cLta tu 2 ~ 7, nhunq chi

nang dU<;1c den V'+10,75 va dung Ii?i khOng the len

-rnrccsongH6ng ruUhgp

.-

-14/8 9,15 7,45 Cira so 3 sap xu~ng V'+7,45 m

14/8 13,30 10,00 CLta 3 til nang fen V'+ 10,00 rai til

9,40 hi? xuong V'+ 9,40 va d(>t nhien sap

A'

V'+8,37 va b~p benh tlt xuong

3.2.3 PHAN LU THUN.GHlf;:M LAN THU2 NAM 1941

Sau sl! c6 khi phan H1 nam 1940, nhiing huhong da dircc khac phuc, nen nam

1941 ngiroi Phap laicho phan H1 thirnghiem lAn tha2 d~kiem nghiern cac giai phap dil

khac phuc sau sirc6

Luc 7 gia sangngay30 thang 7 nam 1941, mac mroc song H6ng aHa Noi la

+9,06 m; MNTL dap Day la 10,88m; MNHLd~p El+5,95 m

, itr7 gio sang qen 13 gia.choina tatea} cirad?p'tlr caorrlnh +12,50 ha xu6ng

cabtrlnh + 10,00 m rci-xuong oao trlnh +7,00 rri~'·Saltd6I1arigcb len d~d6ng Liic

nay MNTL la + 9,27 m con MNHL 11!l+9,06 m Caccuas6 1,2; 3 diroc nang len de

dang; con cac cira s6 4, 5, 6 va 7 thl dirocnang len khohonnhungkho nhaHacuas6A

Lan thU:nghi~m naY'd~lke{qua;tuynhien cot.mroc lam viec mai'chid(;1t.54,78%

cot ntroc thiet ke

3.2.4 PHAN LO THUNGHIJ;:M L~N THV3 NAM 1942

Do Ian phan H1 thir nghiern bin thu 2 rrurc nuoc qua thap, nen mua H1 nam 1942, nguoi Phap lai eho thir nghiem Ian thtr 3.

Luc 6 gia sang ngay22 thang 7 nam 1942, mire mroc song Hong 0 Ha Noi la

+ 9,70 m, nghia la chi cao han rmrc nuoc nam 1941 la 0,6'4 m I\1NTL dap Day la+I I,40 m: MNHL dap la +6,20 m

Khi me, cac cira 1,2,4, 5, 6, va 7 deu ha xuong cao trlnh + 7,00 m Rieng cira s6 3chi h~ duoc den cao trtnh +7,30 m.

Khi dong, de cira 1 2, 3 duoc nang len d~ clang; con de cira s64, 5, 6 va 7 th:

ph~li dung hoi ep L10 h6 tro,

Nhu vayIein thir nghiernnay da khong x~y ra true trac 100, tuy nhien cot rurcclam

vice ella d~p cung moi chi dat 57,78 % cot nuoc thiet ke.

3.2.5 PHAN LD CHfr-iH THUC LAN THlT2 NAM 1945

N2l1n 1945 da co 1tran Io Ian x~y ra tren song Hong. Nzav 08 thang 8 nam

1945 rrurc nuoc song Hong 0 In Noi 121 + 11,30 m, Ie fa phai phan 10 vao Q~P Day,

nhung nguoi Nhat khong chap nhan, VI so troi cau MaiLinh 0 ha luu d~r Day.

Den ngay 17 thang 8 mire nuoc l1 Ha r\¢i dang len 0 cao trinh + 11,86 m,

co nguy co va de thi nguoi Nhat mdi chap nhan ra lenh phanH1 vaosongDay.Luc me'] ctrad~p Ivf:\ITL"d~p 121 + 13.50rn chi thap han iYINTK la 0,50 m Luc

7h ngay 17thang 8, tat eel 7 cira ha toi cao trmh +11,60 m, hru luong Q= 1.300m.l/s Den 20 gia ngay 18 thang 8, nuoc Io song Hong van tier tuc dang len cao, nen

du dinh ha thap cua xuong d0 tang them luu luong phan [G Tuy nhien chi co th0 ha

toi cao trinh + 10,50 m roi cac ciratu dongngirngtai de khong th~ ha tiep duoc mra Luc nay luu luong H1 chay qua dap la Q = 2.200 m3/s Cira so 1 bat dau co hien

tuonggiong nhirn211n 1940.

'De'n 4 gia sang ngay 19 thang 8 cira so 1 bi s~p dot ngot xuong cao trinh

+7,00m; dong thai cac cira khac con lai thI dang 0cao trmh + 10,50 m ur dong nang cao len cao trinh +11,30 ;-+11,40 m.

Dii co gana ha cac'-" b . ciraxuonz nhunz khon!! th€ ha du:a.c Lue naye '- rvINTL da.p Ia 14,20 m, l'vINI-IL et~p Ia 12,40 m.

Nu:ae eta ehay don vao cua so 1 gay ra 51!co rat nghiem trQng doi vai d~p : Gay

ra xai 10 h':1 luu d~p tren chi~u dai 500 m; toan b¢ san sau ella khoang cua so 1 bi cuon troi va xai sau den cao trlnh - 10,40 m, vai chieu sau tai 15,40 m nhu: hlnh 3.4; mo

l1~P phia Son Tay bi nghieng, nen khoang dap s6 1 bi hin nang ne; tam van bung,

cua cira s6 1 bi bung ra; cac phao thep bi xe reich Tcan bo khoang dap s6 1 xem

nhu phai loai boo

Narn 1945 - 1946 dli tien hanh khac phuc mot phsn sir c6 nhtr treo va khoa cting

khoang ctra s6 1 khong cho heat dong, xay bao hoanh trier khoang d~p s6 1; lap h6

x6i ha luu

Nhir vay viec phan Iii Jan nay voi cot mroc lam viec dar 95 % cotmroc thiet ke,

oahoan tO~lI1 that bai; dap bi sir co rat nghiern trong,

j

Quatrlnh van hanh dap Daynarn 1945diroc trinh bayabang3.2

Bang 3.2 Qua trinh v~n hanh d~pBay khi phan 10 narn 1945

CLta so 1 bat dau co hien tl1<;:lng

nhu narn 1940

+ 7,00 m.

len Da co ha cac cLta nhlfng

11,40

kh6ng dlf9c.

3.2.6 PHAN LV CHINH THUC LANTHU3 NAM 1947

Nam 1947 tren song Hong lai c6 Iii Iannen dEi phai phan Iii VaG songDay

Lnc 7 gio.sang ngay 30 thang 7 nam 1947 muc rnroc song Hong o Ha Noi la

+ 12,20m MN1Ldap Day Ia+14,06m xap xi MNTK; MNHLd~pIa+ 6,70m

Dap chi cho lam viec 5 cira : Cac ciras63, 4,5,6 va 7 Boi VI khoang ctra s6 l·dEi

bi hongvahoanh trier: ciras6 2 khongdam cholamvi~GVI chiu <1nh huang strc6 x6i

hahrucira s6 1 chuaxu Iy xong

.Iu]gia ngay 30 thang 7bat dall cho hC;1 cira' dap Khi hC;1' ciras63 kh6ng th~ha

dugc; con cac cira s64, 5; 6va 7.chih<;ixu6ng dugcraicao trlnh+11,37 m :r6i tv ngirng

t~iday

I")

, ~ I

HJnh 3.4 M~tbang d~pBay bj SlJ co khiphan IGnarn1945

Den 14 gic ngay 01 thang 8, cira s6 6 G9t nhien bi sap xu6ng caotrinh +7,00m:

nen IvINTL hC;1 xu6ng cao trtnh 13,16 m, J\1NHL dang len cao trinh +9,05 rn Domay

nen khf bi hong nen khong th~dung hoi ep d~ho trc,

Den 7 giG sang ngay 03 thang 8 chua xong may nen khi, nen dil nang ducccua s6 6 len ngang cac cua khac Qua trtnh van hanh cira dap duoc trinh bay

abang 3.3

29

\7+ 7,00 m.

11,37 2 Cac clla 4,5 ,7 ;an tu dUng b.

Y' + 11,37 m 03/8 7,00

I 11,37 13,14 1 Dung hdi ep nang dl1¢c ctra s6

61en Y'+11,37 m

I·-~ '

11,37 2 Cac cLta 4,5,7 van kf?t b

Y'+11,37m

Do cira s6 6 bi sap xuong trong 42 gia nen mroc chay don VaG d6 gay fa hir hong

nghiern trong ha luu: Toan bo san sau hinuoc cuon troi hetva bi x6i den cao trlnh

-6,92 m voi chien sau ]] ,92 m, nhtr trlnh hayahlnh 3.5

Ngoai ra mroc con moi rong nen cac khoang dap s6 5,6 va 7.

Trong rnua kh6 cac n~m ] 949 - ]950 da tien hanh viec khac phuc S!! c6, bao g6m:

- Laph6 xoi akhoang d0ps6 ] va 6.

- Khoi phuc Iai cac doan san sau di1 bi mroc cu6n troi,

- Khoan phutcat VaD nencac khoang d~p da bi rong :'56 1, 2, 5, 6, va7;

Hinh 3.5. M~t b~mg d~p Bay bjsuco khiphan 10 riarn 1947

3.3. PHAN.TICH NGUYEN NHA.N su CO

T6ng hop I(;1i truce khi xay dung cong Van Coc, dap Day dli ducc phan Hithuc

nghiem 3 binva phan Iiichinh thiic 3 Ian Nhirng Ianphan Wthuc nghiern do mire nuocra'tthapso voi thiet ke, nen tuy co true trac nhirng ela khongx~y ra su~o Ian.

Nhtrng bin phan Iii chinh thtrc voi rmrc mroc cao hon, thl ca 3 Iandeu that bai, khong th~ chu dong kiem soat duoc qua trinh dongrna cira, ettatu dong lenxuong rat

31

that thuong, dacbiet la bi i~p dot rigor, nen khong nhilng da gay ra nhirng su co

rat nghiern trong cho cong trlnh rna nguy hi~m hon la acho neu nhu khong phan lU

duoc theo yeu cau thrkhi g~p lU nit 16n, Thu do HaN9i va cac tinh ha IUD song Hong

-OradapDay la 1 IO<;1i cira ratd~c biei, it duoc xay dung tren the gioi. T<;1i Phap

co xaydung Ioai ket cau wong tu, voi be rongB ='34,00 m, cao H = 1,97 rn; tai Ao

cling coxay dung m<)~, dap voi be rong B=23, 00 rn, caoH =1,57 rn Nhung dap nay

duoc xaydung tren kenh.

Nhirvay dap Day la cong trlnh 16n nhat the giai ve _ket caucira mai nha, cling

la dap phan lCi duy nhat co ket cau d~c bietnhuvayd~t tren song thien nhien. VI the

ngtroi thiet ke khong co duoc nhtrng kinh nghiern &nhfrngc(~mg trinh wangtl;!' lJe!1,t1:V~

te dii xfiiy rangoai nlnrng du tfnh rat lyrhuyet cua tac gia d6 an

Xem XCI1C;1i, cac cira cua d~p Day dJ ap dung nguyen tk can bang ap luc lhuy

tinh d~ dong rna cira, Ve 1y thuyet, do la nguyen t~c dung dan Nhung trong thuc te sl!

can bane d6 chiu tac dono cua rat nhieuc . . c yeu to rna, truce het 1a trans thai thuv dong. e * ,

"-chii khong phaithuy tinh don thuan; 1a Iucrna sat giCi'a cira va try, giCi'a cac 23R true

ooi han Ie cira: Iatlnhhinh kin nuoc cua 1068 tam van buns va haria loat cua van () cac

ycu vao t111h hinh thircte cu tl16 cua cong trlnh, tham chi la cua tung cira rieng biet

Han nira can d~c bier IUD 5' 1 van de rat quan trong khi thiet ke nhirng cong

trlnh ur dong dong rna bang thuyluc; do la "diem chet". Diem chet Ia vltrf t<;1i do co

rnornen t6ng c9ng bang kh6ng nen ci'.ra O' vi trf can bang tuy0t d6i, cil'a khCmg th~

len ho?c xuong 1mb hmh nay cling eta xiiy ra t<;1i eila d~p Day, cling nhu etta xa ceil

eua d~p Do Luong tren h0 rhong thuy nong Bk Ngh0 An Vi~c xac dinh vJ trf "di~rn

chel" la rat quan tr9ng et~ tim bi~n phap khi'.r Han nua do phuong trlnh can bang chju

rae d(mg cila nhieu yeu to chu yuan Cl;l th~ eila tung cong rrlnh nen khong th~ xac dinh

chfnh xae bang tinh toan, rna phai thong qua thil nghi¢m Doi v6i d~p Day vi~e thtl'

nghi~m n~y khong th~ thl;l'c hi~n dU'9'c VI khongth~ thl!_~ nghi¢m v6i uhiel;,l rnll'cnu'o'c

-1\1<)t van de quan tr9ng khac la c16i v6i nhling eila ill d<)ng dong rna bang thuy

lu'c la. "d~ d6ng thl k.ho n1avam~lIO'c1ai " ,

-' - -' ,

Neu muon d~ca <.iong vade eamalhl nhat thier phai co bi¢n phc'ip h6 trQ' dang tin

c~y va du sue d~ trq ll;I'C cho ap lifc nu6e

Tu nhfrngnh~nrhuc do Va can c,uvao nhCi'ng hi~J.1 tl1.9'ng rhl;l'c te.da x8y ra tTOng

nhfrng Ian phan mc6 th~ rut ra nhfrng nguyen nhan co b~;l sail dByt<;10 eho d~p Day

khong hO<;1t o<)ng c1u9'c thea thiet k(:~ " ' " \'; -.' ;~r ~., ' , i ,

1 Dong chay vaod~p xien v6i trl;Ie d0p, do do ap Il;tc len 7 cila 1a khong gi6ng

nhau;'di1ad~p vao tr~1I1g thai'lam vi~crheo.bai tpan khong'gian'khacv&i bai- t08n

phahg't'flmg thietke Tuy':tro~gihietkeda dung kh&pni'e~o~ khu d<)l¢ch ap ll;I'ctlk

<.i(mg lenci'.r~,'nhl1I1g cua vankhong thang bang va hi v~ri,'dan den hjha cac khe eua

.~

(~

~. Ma sat giua canh cira va tru pin la khac nhau dai voi moi cira cilng nhu khac

nhau gifra cac cira; vi thetrong Lcira co dau cao dau thap;cac cira lenxuong khong th~ d~u nhau: ticp do tao ra dong chay roiloan trong hamphao ngcai su kiem soar

3. Khi dong hoac rna da hlnh thanh nii khong khf trong ham phao, pha hong sir can bang, tao cho cira bap benh va len xucng that thuong khong th~ kiem soat duoc.

4 Khi dong hoac rna da hlnh thanh nii chan khong trong ham phao la hien nrong

rat nguy hiern VI da gay ra tinh trang S?P cira d¢t ngot va gay ra su ca

5. Ham phao khong kin do cac vat chan nuoc khong khft, do cac tam van bungcira khong kin nuoc, do cira bi van khi d6ng va rna lam hacac khe Vl khong kin mroc

nen gay ra kh6 khan eho viec dieu khien rrurc nuoc trong ham phao, dan den tlnh

trans khons kiem soar. c e diroc rrurc niroc. d6no deu tronz ham phaoe a cac cira oay ra cira, e *'

C2.D Cl'r::l thap tam rai loan dong chay qua elm dan den viec khong kiern soat duoc quatrlnh dong rnaciradap

6. Khi chenh lech mire mroc nho khong th~ dong cira duoc VI thieu bien phap h6tro c6 hieu qua

7 Viec vanhanh dong rna cua dap la thong qua viec dong rna cac cira van nachd0 dieu hanh rrurc nuoc trong ham phao Cach van hanh d6 khong th~chinh xac va d~u l1i~n cho tirngcua vacac cira. Khi da lech nhau thl rat kh6dieu chinh vakh6 kiem soat

3.4. QuA TRINH KHAC PHVC

Scm nhirng Ian su co, da tien hanh khac phuc chu yeu la nhirng hu hong dosir co gay ra nhirda trlnh bay tren

Tuy nhien duoi thai Phap thuoc viec nghien cuu nguyen nhan dil khong diroc tienhanh 1 each wan dien va day du, nen viec khac phuc chua nham dung VaG nhirngnguyen nhan cO' b~li1; VI the du da sua chua sau rn6i Ian ph<.\n III v~ bi sv ea thl Ianphan lil sau vanbithat b(;li vad~p l(;li b! sl! eo

Sau khi giai ph6ng mien Bac, Chfnh phu ta rat qUem tam den vi¢c phan lCl quac10p Day, nen c1a chi dSlO B¢ Thuy tqi, cGng nhu UBKHKTNN nghienClm bi~n phap suachua c1~p Day

Tuy nhien do hie bay gia trlnh d¢ KHKT va eong ngh~ che ti;lo cO' khi cua chung

ta co nhi~u hi;ln che nen chua tlm duqc bi~n phapMdti tl;1o et~p Day

Do do narn 1963, B¢ Thuy lqi da de nghi Chinh phu X~ty dvng eong Van C6c a

cua VaG song Day d~thay the m¢t phan

3.4.1. DAF DAY THOI KY SAU KHI xAY DVNG CONG VAN cae

Nhi¢rn YI;l thiet k€cong Van Coc da c1uqc Thil tuang Chfnh phu phe chu~n t:;tiVan ban so 1879 -NLngay 09 thang 7 narn 1963

Cling vai h6 Tam Nang va h6 Thanh Thuy c6 nhi~m Vl;l doi vai tr~n lil tren songH6ng vai tan suat 0,33 %dl;1ng lil nam 1945 giam lil t'ili San Tay duqc 1300 m3 Is, ttl

Cong c6 nhi~m YI;l thao h1 song H6ng VaG songDay vai luu luqng Q= 2.000 rn3/s, cl~ giam thap muc nuac h1 cho Ha N¢i va cac tinh

ha duo

33

Cong diroc xay dung sat betsong Hong, cling voiviec dap desong B6ng dean

Van Coc - Hat Mon dai 10km tao thanh tuyen phan H1 vong ngoai cua dapDay, Cong

co 62 cira, voi b~ rong roanb~ cong la B= 390m

Thietke ky thuat duoc B¢ tnrong B¢ Thuy lqi phe duyet tai van ban 'so 1046 - ,

TLI Q~TCngay21 18/1965.

Cong cia diroc xay dung xongtrong nam 1966

Ltic naydapDay chie6 nhiemVlJ :

I Thao Hitirho VanCoc veha luu ci~p sau khi cia phan lil qua cong Van Coc vci

Q =2.000n}ls.

2 Khi nuoc Hl tren song Hong rut xuong thl dong euad~pDay lai ci~ thao

mroc nrho Van Coc chay nguoc ra song Hong d~ tieu thoat s6m vung ngap CJ ho Van

C6c do phan 111 gayra

Setd6 vi trf congVan Coc duoc trinhbayCJhlnh 3.6

VI /I

V

Song H6ng

Htnn s,«. SodovjTri,e5~p£>ay vacong Van Coc

I· Cong VanCoc; 11.8~p Day;1II~8e"Van Coc;

• • • • 'j " ' "i: ,:" ; ' "" ,,-~' ':, ':' > _ " ' , " ' , ' , " - ' : - : • ' ' , ' - _ - _ , , ' • • , - ~ ,J",

.-" :" : ,'IV D~LaTh~ch;Y''";~e'PhUcThq;VI·De ta Day.

~" : ' , " , ' : : :' -' , •., L:, -:: ,:'·':,r:; .rs.s>, i: :,,',:! ~; i ,J\"'-,J : ' , ' , ' <r , 'I

Sau khi.,~~ygl,l11g c,9ng,y~n C6c.c1eiiA':1Y,9~pharilW2liillqua d~pDay:

,j. Pha~Hllan thtr.l niWl 1969.' ',," '; , , , ' ,

2 PhEIl1 Hllan thu2 narn 1971

v,

Ii.,'

3.4.2 PHAN LO LAN THU 1 NAM 1969 SAU KHI XAY DUNG CONG

Nllaye 18thanae 8 nam 1969 nucc It1 sonse Hens tai~. Ha Noi .dansb cao l1en cao

trtnh + 13,23 m Luc nay co lenh cua Chinh philrna cong Van Coc d0 phan 111 vao song Day Cong Van Coc dl1qcma vao hie 14gia 30'ngay 18thang 8 Den 3 giO' ngay

J \) [hang 8 tht nuoc ve den thuong 1l1U dapDay Liicbay gia MNTL l1~p la +9,03 rn,

Nu'1HLd~p l~l 9,00m Tat d 6 cira dap dang nam 0 cao trlnh +7,00 m Do dO chenhmire nircc thuong ha hru dap la 3 ern nen chi co 3 cua s6 5, 6 va 7 nang duoc ttl cao

trlnh + 7,00 mien +7,25 m, con3 cira so 2,3 va4 khong nang lenduoc.

Den khi MNTL dang len cao trinh 9,76 rn thl tat d cac ciradtroc nang cao len

cao trinh +7,50 m Qua trinh nangha cirad~~pde: phan10duoc trinh bayabang 3.4

Bang 3.4 Qua trlnh mire nude tai dap Day khi phan JG narn 1969

Theo 'doi tinh hinh lam viec cua dap c6 nhirng nhan xet sau day:

1 Khi MNTL dat dencao trlnh +12,95 m va MNHL (;+11,34 m, dap vanheat

dong duoc,

2 Khi dO chenh mire rnroc duoi 1m thl viec dieu0 khien cira rat kh6 khan, dong

thai cirahj bapbenh khong th~ codinh dinh cira

35

3',4.3, PHAN LDLAN THV2 NAM' J971 SAU KHI xAv DVNGeONG

VAN coe

N:1Il1 IlJ71 trcn S(lllg I long d~ XHy ra tran IQ ljch Slr rat ]C1I1, ncn phai phan 10

V~IU S(Hlg Dely.

Luc I h30', ngay 20 thang 8 narn 1971, bat lHiU mir c6ng Van C6c el~ phan IQ

Den oh cung ngay-thl nu(rc ChH)' v~ t(ri dapD a y " Qua trinh rmrc rurockhi phun Ia nam 197J tait10rDay elm.re trlnhbay('rbang 3.5 "

Bang 3.5 Qua trinh mire ruroc dd~p Day khi phan IG narn 1971

1r.oo

12,00 1.00 19,00 8,00 24,00 24,00 23,00

MNTL m 7,41 7,50 8,26 9,76 10,20 10,49 10,72 11,11 13,04 13,21 13,21 13,04 12,27 9,91

MNHL m 7,41 7,46 7,56 7,72 8,82 10,08 10,63 11,03 12,98 13,13 13,13 12,98 12,23 9,81

£>Inh clra m 7,30 7,40 8,30 9,00 9,00

~,.9Q

9,00 7,00 7,00 7,00 7,00 7,00 7,00 7,00 ,

8 6 8 8 6

4 10

Liic elau cac cira duoc nangcao dantheo MNTL den cao trlnh + 9,00 rn, nhung

den 1] gia ngay 20tharig 8 thl khong th~ nangcao len dugc nirarnatat ca ciradeu sap

xuong va nam bepaeaotrlnh +7,00m Liruhrong X8 quadaproi dadat dtrocQmax =

Cling giong nhtrIan phan Iii nam 1969, voi d¢ chenh rmrc nuoc duai 1,00m th

khong th~nang cirad~plen cao rna nguoc 191 chung nr sapxuongday

, Nhtr v0Y trongca 21an.,rhanlCi s~u khi xay dung :.cong Vanesc tuykhorig x~y

ra sl!coituy nhien khong the dieu khien viec dong mqcira chu dong theo yeucau-thiet

k€, l1enCUa len xuong rat bat thtrong ngoai tam kiem soat;:dong thai khi dacho cira

s~p xuong ratkh6 khantrong viec nang~aociradti d o n g

3.5. CAIT~OD!P DAY,

3.5.1 YEU CAU PHAN LO SONG HONGvAo SONG DAy

',: Thirc t€ i'u n'am'i97Icho thay dingmac dulll song Hong rat Ian;mrcc Iii cao

xapxi dinh de, tuydilphan Ia song Hong vaos6ngDayv&i Q=2000m3/s qua cong

Vein Coc, thl m_lic ruroc tren song Day van con n;lt thap, cothcphan them lei song

I IClnl 'e V~IO sons Day' nhirns cons Van Coc dil xay dung qua nhoe ' e e '

VI the Hoi d()ng Chinh phil dil co Ngh] quyet so 14 CP ngay 16 thang 1 narn

1974 v6 vice tan. . duns. e kha nanu sons Day d0e e phan lei Trong Nzhi quyet nay Chinh

phu(til giao cho B¢ Thuy lei " Khao sat thiet kc cong trinh phan lCi dau moi songDay, bao dam dong me chu dong voi luu luong khoang 4.000'mIls den 5.000 mIls;

truoc mat (1974 - 1976) co th~ phan lei VaG song Day duoc tren duoi 4.000 ml/s,

cac narn isau d6 co th~ phanlCi nhieu han tuy thea mire do cai tao Ions sons va, . e ekha nang phanlCi cua de Day"

3.5.2 cAe PHUONG AN CONG TRINH DAU MOl DE PHAN LO

SONG HONG VAoSONG DAy

Thirc hien Nghi quyet cua Hoi dong Chfnh phil, B¢ Thuy lei dil giao nhiern vlfcho Vicn KSTKTL nghien ciiu va thiet ke cong trinh phan lCi song Hong VaG songDay

Cac phuong an dilduoc nghien ciru la:

1 Morong cong Van Cocatuyen ngoai va pha bo dap Day cfi

2 SLr clung ca cong Van Coc va dap Day cu bang each dap de doc <10 phan donggiQa 2 cong trinh thanh 2 cong trinh doc lap.

3 Xay dung <1~IPDay moi, bo dt cong Van Coc va dap Day cu

4 Xaydung them1cong khacatuyen ngoai cung voi congVanCocd0phan lei

5 Cai tao dap Day cil d~ phan luvoiQ =5000 mil s; SLr dung cong Van"Coenhir

1 cong c1~ dan lCi hlnh thanh khu mroc dern bao ve de Van Coc cho nuoc tran quanhung khong bi va do phanlCi.

3.5.3 PHUONG AN CAl TAo DAp DA"'{

Phuong an so 5 cHi tao dap Day ell da dLIQ'e Thu LUang Chinh phil phe chusn tai

quyet dinh so 300TIg ngay 07 thang 02 narn 1974, voi nang hrc thiet kenhu sau:

- "Dan lCi tir song Hong va thoat lCi qua dap Day voi luu luong 5.000 ml/s. Dap

Day sau khi cai tao phai bao darn d6ng rna an toan tuyet doi Sau khi cai t~o toan b¢cong trmh phan lCi song Hong vao song Day, vai rna hmh lCinhu d~ng lCi narn 1971,

cat etuQ'e luu luqng 5.000ml/s v6'i t6ng luqnglCi cat la 1,2ty den 1,4 ty rnl (khong SLr

Ul;lI1g cong trmh Luang Phu) Tw6'c mat narn 1975 - 1976 nang It!c thiet ke la

4.000rnll s Vi¢c rna r¢ng d~p Day se duQ'c xet sau khi dil nghien euu va ki~rn nghi~rn

tht!e te d0p Day cai t~o. Thai gian xay ut!llg: Khai cong thang 12 narn 1974; hoanthanh thang 6nam 1975"

Nhu di:1 trmh bayatren, nguyen nhan d0p Day khong hO~ltd¢ng duQ'c chil yeu

Et doCLra ct~p d6ng rna bang suc nu6'c khi thiet ke di:1 c6 nhieu sai s6t Co'ban Conconeo trmh thuy' cong dil duac thiet ke va thi can . ea v6'i chat luan. eo cao, c6 kha nang

t~n dlfng

37

VI the phirong huang cai tao dap Day EI tan dung trier o~ cong trlnh thu)' congcon ra't tot vat~p,trung nghien CUu cai tao co ban cira dap theo huong dung thiet bico' khfd~ dong mc cira 1 each chu dongthay VI dung thuy ]I;1'cnhirtnroc kia.

Dil nghien ciiu nhieu phtrong an cira nhu: cira cung, cira clapet Nhung co 2 van

de Ion khongkhac phuc duoc la : hrc keo rat ]6'11 va ket cau cong trloh be tong cua dapDay cfl khong thfch hop voi cac loai cira nay Cuoi cungl 1(Ysu Le Van HqpI dil

de xuai cira quat la loai cira co kha naris dap irna duoc 2 van de trcn.0" b •

Noi dung co' ban va chu yeucai tao dap Day bao gam:

1 Cai t<;10 cira mai nha thanh cira van hinh quat,

2 Dung may nang co siic nang 150 T M dong ma cira thay cho strc mroc

3 Nang cao wangngirc len 1,20m.

Trona hoan canh hie ba)' oia nen cons nghiep mroc ta chi c6c e c ~ . th~ thiet lee va che'

[<;10 maynang co tai trong 25 T,nen viecthiet ke vache'tao may nang c6 tai trong 150T

I' . ' A I'd'" , d_ "

_ ._ _ -am\)t-';'I~C'am' aysangtaova ung-cHm."

Cling cGn neu len sir dong gop nit qui gia cua Vien NCKHTL trong vice da tim

ra bien phap khir chan khonz trona ham cira bana each khoet cac 16 tren mat tam

buns sau cua cira nho vav da aiam diroc luc keo 1 cira ur 450 T xuons con 150"- . ' e . . "- T.Ket cau cira mai nha truce khi cai t<;1O va cira van hlnh quat sau khi cai tao duoctrlnh bay ahinh '3.7 va hinh 3.8

Thier ke ley thuat cira van hinh quat cong' trlnh phan lU song Day oil duoc B<)tnrong Be) Thuy lqi phe duyet taiQuyet dinh so 7 - TL / QD ngay 14thang 1 nam 1975.Thiet ke ky thuat may dong mo cho cira van hlnh quat cong trlnh phan lU s6ngDay dil duoc Be) tnrong Be) Thuy loi phe duyet tai Quyet dinh so 26 - TL / QD ngay 14thang 01 na111 1975

Tuy nhien khi ap dung cira quat thl bat buoc phai nang cao nrong ngtrc len1,20m; mot mat do yeu cau thiet lee, nhirng m~t khac cung do yeuC£lu I11Qc nU'acthuqng luU d~p cao hon tmac 1,Oo.~. Dam wangngl;1'c cli l'a ] da~ 'h~p ~hu nh~t

r6ng, cao 2,50 m, r<)ng2,00~, day 0,75m Khoang so 7 lil dam don, dili 40,75 m;con l<;1i cac khoang kh~c EI2 dam lie~ t\l~2 nhip, 'vai chieu dai m8i d'al~ Iii 81,50m

n~ng 460 T. Van de, d~t ra lil do tien d<) thi cong chi ouqc h<;1n ehe trang 6 thangmuakho nalni975,~enn€unI1Upha"b6 d~r;'; tuangnglJc eil dllam 7'd~in mai thl

ch~c chan 1il kh6ng bao darntie~ciQ: Vi the chico 1 phuong an duX nhat Iii Slrdl;1ngdam wang nglJc cil va nang cao len 1,20 m

Htnh 3.7. M~t cat d9C khoang dap voi cira mal nha truce khi cal tao

Tu'dng ngy'c sau

Hinh 3.9 Sodo kich dam tlfong ngl!c

I - 80n qanh; II - Cac diem kich; III - Lien ket don qanh voi dam tLfdng ngl,tc.

Thea thiet ke khi kfch dam tai 3 diem d~ d;?UH bao eho dam khorig bi gay tht

chenh lech cao do cua 3 di~m kfch phai nho hen 10111111 So' d6 kfch cHlIl.1cluQ"c'trlnh

Trang hoan canh chien tranh anuoc ta hie b£ly gio viec kfch thanh cong cac dam

v6i yeu call ky thuat cao va thai gian eo hep nhir vay thuc sir la 1 k)' tfch trong xay

dung.

Cong trinh .eta duoc hoan thanh vao thang 5 n2lJ11 1975

3.5.4 PHAN LU THV NGHIJ;:M C01'\G TRINH PHAN LU DAp DAY SAU

KHICAITAO

D~ kiem tra tinh hinh lam viec cua dap Day sau khi cai tao, B¢Thuy 19'i cia de

, nghj va da dUc.1CThu LUong Chfnh phu chuan y tai Quyet dinh ] 63 - TTg ngay ] 5 thang

4 n2l111 1976:" cho phep B9 Thuy loi ha th£lp dean de Van Coc tirK, - KG xuong

cao trinh urong irng voirnirc nuoc song Hong t(;1i Ha N'()i ] 3,00 m va van hanh thtl' dap

Day khi I11UCniroc song Hong tai Ha Noi 10,50 m."

Nal11 1976 khons coe 'lu mtrc nuccsonz-Hone iai Ha Noi c qua ihap nen khonsc-th&'

phan ]Qthir

, Mua lil nam ] 977 thea du baa eua Tong cue Khf nrong Thuy van c6 ]Q lon,

nen Thu LUang Chfnh phil da co Thong' baa so 2736 VP - 10 ngay ]6 thang 7 nam

] 977 cho phep Ban Chi huy CBLTWtien hanh thir nghiem dap Day

Qua trinh thir nghiern di:idiroc tien hanh nhu sau:

1 Cong Van cs«

Qua trlnhvan hanh cong diroc trinh bay abang 3.6

Bail'fi3.6. Ouatrlnh v~n hanh cong VanCoc khi ph§h to

:,

Vao luc 23 gia ngay 31 thang 7 narn 1977 thl nuoc chay ve11e'~ ci~p·Day

Vao hie 12h 15' ngay01I8, IvINTL=10,99 rn: ivL"IHL=7,96 m, ciraatv the dang.Qua trinh van hanh cira dap Day diroc trlnh bayabang 3.7

Bang3.7 Qua trlnh v~n hanh d~pday khi phan IG thlrnarn 1977

Cung c.in nhan manh rang, N!NTL thiet ke 121 1S,OO m va ivINTL kiern tra El

1S,50 m, con M:-iTL khi thu' nghiern 121 10,99 m con n1t thap so veri thiet ke Theo tinhtoan trong thiet ke thl luc keo cira10'11 nhat xJy ra khi keo kho va khi IvINTL thap Sau

V21 khi nzhiem thu cuns cia cho dons mo' dons thaic c c: c ca 6 cira dap; cac thong 50 ky thuat. ' - ' d;} Lll) LtUq-C deu d~1I11 bao yeu cau thiet ke

VI the cung vC)'i ket qua phan 111 thir nghiern ' I[\n nay, co th0 ket luan rang viec

cai tao dapn.iy da thanh cong ca ve rna; tien u¢ cung nhtr ve mat ky' thuat: d~p Day cokha nang dong mocira hOa11 toanchu dong va an roan theo yeu diu cua Chfnh phu.Den nay t1nh hlnh da thay d6i Truoc her phai nhac lai rang, d~p Day chi co kha

nang phan IQ veri liru luong Q =4.000 m'lsvoi tong luong W= 900 trieu m'; Q= 5.000rrr'z s voi W =1.2 - 1,4 ty m', nhir Quyet dinh cua Thuwang Chinh phu, neu nhu ngoaivi¢c di [<,w Cl)ng trlnh dclu moi d0p Day nhu ua lhl;fc hi~n thanh cong, con ph~i thy:chi0n 1 cc)ng vi~e cy:c ky qUelil trqng ve m0t ky thu0l, nhul1g ISii r;jt kh6 khan va phCt'c t~p v~ m~lt xa h¢i do El vi¢cc;.:;i t~o long lLln ca thuqng luu va h~ luu Lt~p, von 121 1 khu

dan cU' rat Lh'lng dLie va tru phd, nh21 cua vuOn tuqc ngay cang phat tri~n day d0e;

41

cung voi vice giai phong long song, vat can, chuong ngai v~t tren song Day cho t6'i

t~n cira bien Rat dang tiec la tir nam 1975 t6'i nay, khong nhtrng khong giai phong

them manguoc lai tinh hinh vat can tren long d&n thuong va ha luu va tren long song

Day da, dang va sephat trienv6'i tee d9 rat nhanh chongkhong th6 ki6msoat duoc,

Tinhhinh thu 2 la, con soQ =5.000m 3/svaW =1,2 - 1At)' m' Ii'! irng voi tnrong

hop khi chua X8Ydung ho Hoa Binh Nay ho, Hoi'! Binh daxay dung voidung rich phong

lti la 5ty m', thl thayVI d~pDaykhi thietk€cat -c:i dlnh nhon, nay phai car adinh be

thl hieu qua khong th~ can Q= 5.000 m3/s nhu ca Ngoai ra d6i voi dinh lil be khong

lh~ du bao dung nen chac chan la caltr~l dinhthi hieu qua Ii'! am

Tong hop ca 2 tlnh hrnh do lai, hien nay da d0t cong trlnh phan lil dap Day'

Vall nhung tinh the n1t bat loi sau day:

1 Neu phan lil thl ca Qva W deu phai giam eli rat Ion, va phai van hanh that

nhanh nhay neu khong. cho du Q va W nho hon thiet ke rat nhieu lac dung cal Iil

tren sons1:::Bono khona danse ~ C k~; nhU'I1£ do Ions dan hC1 luu dap Day co qua nhieu vat can'-' e . .

se lam denh cao mat nuoc va giam d9 doc mat mroc dan den nuoc tran qua dinh de

ta Day Trong inrong hop nay de ta Day chac chan bj va valil se danh don vu hoi

V~IOBaN\)i

-:2-;-Neu··phan1i1tr~1 tho'idi0111,lbLIJll~Lkhong ung.cuu QU'eW chQJ-Ul.N.t)i.\,s<.:§c

tinh ha du, mat khac lam ng0r oan cho vung phan lU Twang hop nay dung la: "ticn

mat va t$t mang "

Vl.theviec srI' dung cong trinhphan Iil d0p Day hien nay phai 00t trong boi canh

moi va tinh the moi : sau khi xay dung ho Boa Binh va tinh trang long d&n thuong

ha luu dap Day cling nhir long song Day; dong thai phai d0t no trong chien luoc

t6ng th0 v~ phong va ch6ng1i1 cho dong bangBac b(> noi chung Chi co cach lam do

m6'i co th6 tIm ra bi~n phap kha di d~ phat huy hi9U qua cua cCmg lrmh phan Iil d~p

Day Can neu chi tac d9ng cl;lC b9 vao 1 vai khau khong quan tn.?ng nhu Ihay may li0

v$n hanh cho thu$n 19i han, va hi vQng v&n dungd~p Day d~ ph&n lG sCmg Hong v6'i'

Q =5.000 m'l s va \\1=1,2 - 1A ty m3 nhu thiel ke ca, th1 do chi lay muon cbu

quan chac chan se £a)' ra hau que\ vo cuno nohiem tron' ' - ' e b . eo va co tb0ga)/ra tai hoa..

'\

Chltdng 4

4.1.1 TONG QUAT

Cong trlnh thuy 1Q'i Dau Tieng duoc xay dung tren song Sai Gon, thuoc tinh TayNinh

1.H~ thong cong trinh dau mol

H~ thong cong trinh dau rnoi gam e6 :

- 1 d0pchinh bang dat,cao 30,00m, dai 1.100,00 m;

- 1dap phu bang da't, chieu cao trung blnh 6 - 8m, dai 29.054m;

- 1 dap tran xa lCi c6 6 khoang tran kich thuoc rnoi khoang:

B x H = lOx 6 m; c6 6 cira cung bangthep d0 dong mo;

- 2 cong lay nuoc:

+C6ng 562

Cac thong 56kythuat chuyeu:

Cac thong s6 kythuat chu yeu cua cong trtnh duoc trlnh bay abang 4.1

Bang4.1 'Cacthong so kythuat chu yeu

SoTT Ten cac thong so £)dn v] Khoi 1lt<;1ng