NQI N/NGHIEN CtfU

iesLbcf Ditm

DAN KHOA HOC VA C6NG NGH£

N/NGHIEN CtfU BIEN DONG CUA QUAN HE HINH THAI LONG SONG HONG DOAN QUA HA NQI

Bo mon XD Cdng - EXJdng thuy

' GS.TS. Li/dng PhJdng Hgu TS. Nguyin Thanh Hodn TrUdng E>Qi tiQC Xdy di/ng Do nhflng bid'n ddi vl dilu kidn khi

ban va dilu tid't cdc hd chfla thfldng ngudn, qua trinh IflU lfldng trong ldng ddn sdng Hdng tfl sau nga ba Ld-Hong da cd nhflng thay ddi Idn vl trj sd' vd phan bd' theo thdi gian, dan dd'n thay ddi lflu Ifldng tao ldng. Khi hm lfldng tao long thay dd'i till cdc yeu td' hinh thdi cua ldng dan sd dflpc tai tao lai de phu hdp vdi dilu kidn mdi, trong dd quan trpng nha't la cac yd'u td' trdn mat cat ngang Id chilu rdng mat nfldc B va chilu sau tmng binh mat cat h dfldi hm lfldng tao ldng.

Phan tich didn bid'n qua 6 thdi ky 1976, 1991,1996, 2000, 2003, 2007 trdn 6 mat

cit ngang dai didn dfldi day cua ldng dan sdng Hong doan qua Ha Ndi:

Khu vflc Chdm - clu Thdng Long flng vdi mat elt sd' 1 (Hinh 1);

Khu vflc gifla bdi Phu Gia flng vdi mat cat sd' 3 (Hinh 2);

Kliu vflc dudi bai Phfl Gia - Nhat Tan flng vdi nid'i cat sd' 4 (Hinh 3);

Kliu vflc thfldng lflu cfla Dudng flng vdi mat cat sd' 5 (Hinh 4);

Khu vflc bdi gifla Tfl Lidn flng vdi mat elt 7 (Hinh 5);

Khu vflc dudi bai Tmng Ha flng vdi mat elt 8 (Hinh 6).

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DI£N DAN KHOA HOC VA C6NG NGH£

16 • 14

12 • 1 0 •

1 8 •

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i

O 4 2 • 0 -2 -1

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IT I

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i

i 1

197C_f/C 2-2 2O03_MC 2-2

it ^1 V J t l l - . •

; 1 1 \ J ! ^ i 1 ^*Q/\f>^

i i

MC 2-2

1 : i

A — Y ¹

i \

^ S S M 3 / *

§^ 1 ylrif

^ : : : :

3 2 DO 400 600 800 100C 120C

K h o a n g e a c h (ni)

1400 IWJL IbUU ^UUl

////j/i 2. Diin biin tren mat cdt ngang giira bai Phu Gia

Khoang cach(m)

Hinh 3. Diin biin tren mat cdt ngang dudi bai Phu Gia-Nhdt Tdn

^^^Q MM

9

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^{DAN KHOA}

^{Hpc vA}

C 6 N G NGH£

Hinh 4. Dien bien tren mat cdt ngang thuang luu cira Dudng

% o

5

C IW 40J KUO 8UU lUUJ 12UU 14U0 1bU0 1BUL 2UJU 2200 240U i^'bOU i:BLiU aUUO 32UJ Kliudiig cad) (rn)

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DAN KHOA HOC VA C6NG NGH£

197D_VC 8-8 i 1991_WC 8-8 1996 WCB-8 2000_WC 8-8 2B03_IVC 8-8 2007 f/C 8 8

00 JO(I 700 800 ?00 1000 1100 1200 150C 1400 150O UOO 1700 1800 1900 2000 2100

Khoang each (rr)

Hinh 6. Diin biin tren mat cdt ngang dudi bdi Trung Hd

Nhan tha'y rang, vdi nhflng bid'n ddng nhfl da phan tich, quan he hinh thdi ldng din sdng Hong dfldi hm lfldng tao ldng da cd nhflng thay ddi theo hfldng giam nhd din tri sd' yjBlh

Vdi cdc so lieu tmng binh tinh todn theo so lieu thflc do tfl doan sdng Hdng qua Ha Ndi vl B, h va cdc ddc tnrng bun cat:

d9o = 0,3nim : Dfldng kinh hat bun cdt tiiih toan;

W = 3,96cm/s : Dp thd thuy lflc;

S = 0,615kg/m' : Lfldng tai cdt tmng biiih;

Ta xdc dinh dfldc gid tri cua he sd trong cdng thflc tong qudt vl quan he hinh thdi ciia Lfldng Phfldng Hau [1] la:

K n = 2,60; K h = 1,52 Nhfl vay quan he hinh thai long sdng dn dinh cua doan sdng Hdng qua Hd Ndi dflpc xdc lap lai theo quy luat sau:

j ^ 0 . 2 4 ^ 0 . 2 4

B — 2 , 6 n I .n 5T Q / ^0.57

/; = 1,52

„ 0.4 10.32 _ 0 . 0 5 j O . 2 4 r7^0.43 0 O . 4 3 ^ f

(1) (2) Vdi quy luat quan he hinh thai mdi, so vdi sd lieu cua Lfldng Phfldng Hau [2], mat cit ngang ldng ddn sdng Hong doan qua Ha Ndi trfldc vd sau khi cd dilu tid't 2 ho dfldc thd hidn trdn bang 1

letted

^DitN D A N KHOA HOC VA C 6 N G N G H £

Bang 1. Mat eat ngang long dan on dinh doan sdng Hong qua Ha Ndi

Doan sdng

Lidn Mac - Cfla Dud'ng Cfla Dud'ng - Van Phuc

Trang thai Tfl nhien Ho(m)

8,86 8,25

Bo(m) 843 748

Sau khi dieu tie't Ho chfla Ho(m)

9,04 8,38

Bo(m) 835 688

Cd the tha'y rang, sau khi cd dilu tid't ho ty Id rdng/ sau nhd hdn, long sdng hep va thfldng ngudn, long din cd ban d ha du cd sau hdn, nhfl sd' lieu trong bang 2 the hidn.

Bdng 2. Su thay ddi ve quan he hinh thdi tren mat cdt ngang -jB/h

Doan song

Lien Mac Cfla Dud'ng Cfla Dud'ng - Van Phuc

Trang thai Tfl nhien

3,35 3,32

Sail khi dieu tie't Ho chfla thirpng nguon

2,84 3,13

TAI LIEU THAM KHAO

1. Lfldng Phfldng Hau, Phung Quang Phuc (1999), "Cdc quan he hinh thdi song dUa tren tuang tdc ddng chdy bdn cdt - long dan", Tuyd'n tap kd't qua khoa hpc cdng nghd 1994-1999, Tip 1, Vidn KHTL, tr.25-27

2. Lfldng Phfldng Hau vd cdng sfl (2003), Ca sd khoa hoc cho cdc phuang dn dn dinh vd ton tao ldng ddn song Hong doan qua Thu do Hd Noi, Dl tdi cap Bd B202-34-32;

3. Lfldng Phfldng Hau va cdng sfl (2010). Bdo cdo tdng ket de tdi KC08.14/06-10. Bd KH-CN.

4. Ld Dflc Ngan. Nghien cdu dnh hudng cua ho chvCa thuang nguon de'n bie'n dong thuy dong lUc trong ldng ddn ha du DBBB, Luan an tid'n sT, 1/2011.