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<b>D I I N DAN KHOA HOC</b>

<b> CdNGNGHi </b>

<b>KINH NGHIEM Nlf^C NGOAI TRONG PHdNG TRANH SU CO </b>

<b>CONG TRINH Ol LAN CAN H 6 DAO SAU TRONG 0 0 THI </b>

<b>PGS.TS. NGUYtN BA KE </b>

<b>Hoi Cd hpc d i t vd Dja ky thuat c6ng trinh Vi#t Nam </b>

T6m t6t: Gi6i thieu kinh nghiem cua nu6c ngoai, dya tren ket qua quan trSc hon 530 cong trinh ho dao sou trong
dat mem y§u, de xuat tri canh bdo va trj gidi hgn ve chuyen vj ngang cua tudng vd chuyen vj ddng cua dot lan can ho
ddo, dung chung de kiem sodt vd phong ngua nhung hi/ hgi cd the xdy ro doi vdi cong trinh 6 gan ho ddo.

Tir kho6:Bien dgng ngang; bien dqng g6c; trj gi6i hgn; trj ofinh bdo.

<b>1. To'ng quan </b>

Trong nhQng nam gin ddy khi ptidt trien vd hien
dai hod do thj d nudc ngodi vd nhit Id d nudc ta,
khong ft cong trlnh Idn can hd ddo da bj su cd ndng
nl, gay nhilu tdn thdt v l kinh t l vd xd hpi, vf du nhU:
<i><b>- d Ha Long, Quang Ninh, ngdi nhd 3 ting dd </b></i>
nghieng vdo Trung tdm Thf nghiem Kiem djnh Xdy
dung (Cdng ty Co phin Xdy dung Bach Dlng),1 ngudi
chit, do ddo mdng nhd ben canh;

- Vidn Khoa hpc xa hpi vung Nam Bp bj sdp vd nin
nhd xe Sd Ngoai vu TP. Hd Chf Minh bi sut cd lien quan
din viec thi cong tdng hdm cao dc Pacific liln k l ;

- Sap, nOt 10 can nhd d dudng Hdm Nghi, TRHCM
md Cao dc Saigon M&C da bi dinh chi thi cdng mpt

thdi gian;

-T6a nhd cao 13 tdng, tren mdng cpc, d thdnh phd
Thupng Hdi do sap do hd mdng ben canh bj trupt vl
ngap nudc mua; vd..

Co chi cua hien tupng thudng gap ndy dupc trinh
bay tren hinh 1.

sf^\^

<i><b>Hinh 1. Anh hUdng ho dio den cdng trinh </b></i>
<i>1. Nguyen nhan gay chuyen vi </i>

<i>2. Bat bi dao hoic dich chuyen. </i>
<i>3. Phan bd chuyen vi the tfch. </i>
<i>4. Chuyen vi mit dit </i>

<i>5. 6. Chuyen vj ket cau vi si/huhdng (nClt,nghieng). </i>

<i>7. Chuyen vi dat quanh hd dio phia khdng cd cong trinh hien hdu. </i>
TQ tren hinh 1 ndy ta thiy:

Khi lly di mpt lupng dit ndo dd se Idm thay ddi
trang thai Qng suit - biln dang cua khdi dit quanh hd

ddo.

Olt se djch chuyen v l phfa hd ddo, dp Idn ciJa
chuyen vi phu thuoc vdo chit lupng cua he kit cdu

chdng giQ, loai dit, khodng cdeh cGng nhu vj trf vd tdi
trpng cua cdng trlnh Idn can;

<i>Tong hpp cdc loai chuyen vj ndy se Idm mat ddt b </i>
Idn cdn hd ddo lun xudng;

N I U trong vijng dnh hudng ndy cd cdng trinh thi
cdng trlnh se bj biln dang.

Nguyen nhdn gdy ra ehuyin vj vQa neu thudng phu
thude vdo nhilu y l u td, nhu Id:

+ Tdc dpng cua su thay ddi Qng suit trong nin;
+ Kfch thude cua hd ddo;

+ Su tilp can (gin /xa vd song song hay vu6ng
gdc) cua cdng trinh vdi hd ddo;

+ Cdc ddc tfnh cua dit;

+ LJfng suit nim ngang ban ddu trong ddt;
+ Tmh trang nudc ngim vd ddng thdi ciJa chiing;
+ Dd cQng cua tudng vdy vd hd chdng glQ (thanh
chdng hoac neo);

+ Trlnh dd thi cdng;

+ Cdc nguyen nhdn chua bilt khdc.

Nhu vdy cd rit nhilu nguydn nhdn dnh hudng tdi

ehuyin vj cua kit d u vd vung dit xung quanh h i ddo
cd vd khdng cd cdng trlnh Idn cdn. Do tfnh bOc xuc
cua vdn d l vQa neu len hien cd nhilu nghien cQu ting
kit kinh nghiem trong thilt k l vd thi cdng cdng trlnh
hd ddo trong dilu kien dd thj cd mdt dp xdy dung cao.

Trong bdi bdo ndy se trlnh bdy nhQng kinh nghidm
thuc t l cua nudc ngodi dua trdn sd lieu quan trie tCr
hon 530 hd ddo trong ddt mim y l u vd phdn Qng cua
cdng trlnh Idn can hd ddo cung edch ddnh gid vd
phdng trdnh thong qua thilt k l yd thi cdng.

<b>2. Blln dang cua tudng chin yd dat gdn ho ddo </b>

<i><b>2.1. Nhin dang chuyen vl, blin dang </b></i>

Christian Moormann (2004) da tdng kit trdn 530
su cd hd ddo trong ddt y l u trdn t h i gidi vd dua ra
nhQng khuyin edo rdt quan trpng d l han c b l vd
phdng ngQa sued. O l tilp cdn vdn d l vQa ndu xin tdm
t i t nhOng kit qud quan trpng tQ cdng trinh nghidn cQu
ndy.

Trudc tien Idm quen vdi mdt sd djnh nghTa vd cung
chfnh Id cdc tidu chf chfnh dung d l kilm sodt vd ddnh

<b>NGUdi XAY DUNG S 6 THANG 3 - 2011 </b>

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KINH NGHIEM NtftfC NGOAI TRONG

P H 6 N G

TRANH Stf C6...

gid hu hai khi cd su cd. Trdn hinh 2 trlnh bdy cdc dinh

nghTa v l tieu chf ehuyin vj cua tudng chdn vd dit
quanh hd ddo vdi cdc thdng sd cd lidn quan se dupc
dung trong bdo edo ndy

pbiWng diJDg guza cac thanh choqg ^ i k '
N

\

.max
<i>xusas.. </i>

<i>:. / </i>

Uh(2)

<i>Hinh 2. Cac dinh nghia lien quan hd dao </i>
<i>H: chieu sau hd dio [m]; </i>

<i>t: chiiu sau tudng chin [m]; </i>

<i>hf. khoing cich glOa cie thanh chdng/neo [m]; </i>
<i>(/^fr ehuyin vi ngang ldn nhat cua tUdng [m]; </i>
<i>uT'^chuyin vi ddng Idn nhit cOa mit dit [mj; </i>
<i>N: sd tang/hing thanh chdng/neo </i>

Mdt sd ket ludn ddng chu y cua Christian
Moormann (2004) Id ehuyin vi cua tudng vd dit
quanh tudng tuy thude vdo tfnh chit cua ddt vd loai
kit clu tudng chin. Trdn hinh 3 trlnh bdy quan he giQa
u""". vdi u"""h vd dd lun cua ddt canh hd ddo cdn tren

hinh 4:2 (u™,) = f(H).

<b>35 </b>
<b>30 </b>
<b>25 </b>
<b>20 </b>
<b>15 </b>
<b>10 </b>
<b>S </b>
<b>0 </b>

*/
<i>in </i>

^Pff*^ • • SCI uua cihig tdi ciihi, <i>•- C4i*4cu6itdi </i>

<b>10 IS 20 2S 30 3S </b>

<b>uj"tan) </b>

vc

<i>Hinh 3. Ty sd uTjir; {a) vi liin mit dit canh hd dio (b) vdi mot </i>
<i>sd loai dit nin </i>

TQ dd ta thdy:

Odi vdi hd mdng sdu trong ddt mim, dd lun Idn
nhit cua mat ddt canh hd ddo phu thupc vdo chilu
sdu hd ddo vd ndm trong pham vl u'""yH=0,1-10,1%,

trung binh u'""yH = 1,1%.

Ty sd giQa ehuyin vj dQng Idn nhdt vdi chuyen vj

z{uj™') [ml
30

Loai tudrig chan"
0 Tuimg tru +t)an c « ngang
V Tuong bang cpc tron
O Tuong van thep
<i>A Tudng trong ^ijcoc giao </i>

<i>ck </i>

He chong g&tuong chwi:
a Neo

• ThantiAar^ chong
8} Top-down

<i>O Tuong vay km hinh Iron </i>

3 C6n.K)nA3autucto

10 20
66 saM ho dao H

<i>Hinh 4. Quan he giOa do sau z Ung vdi u"'^ vi do sau hd dao H </i>
<i>trong dit s6t mem </i>

ngang Idn nhit thay ddi tQ 0.5 din 1,0, cdn ddi vdi dit
sdt mim tdi 2 ldn (hinh 3a). Dp lun Idn nhit tai mat dit
quanh hd mdng thudng gap trong khodng cdeh 0,5 H
tQ mdp mdng trong dit chat (cdt vd sdt) cdn trong dit
sdt mim thi trong khodng cdeh 2,0H (hinh 3b).

Chuyen vj ngang Idn nhit cua tudng chin u'""^
xuit hidn d dp sdu z = 0,5-1,0H (ehilm 67%) vd d ddu
tudng z =0 (ehilm 21%).

Clough vd O'Rourke (1990) cho kit qud nghidn
cQu vdi d i t cQng Id u'"VH=0,05~0,25% vd
u'"'"yH=0~0,20%; vdi ddt sdt mim chuyen vj Idn nhit
cd t h i dat tdi u'"VH=3,2%.

NhOng kit qud thu vj khdc, chi tilt hon, cd the tim
dpc trong Christian Moormann (2004).

<i>2.2. Mgt sd tieu chf diing trong dinh gia hu </i>
<i>hai/su cd cdng trinh lan can </i>

Theo suphan loai cua Skempton vd MacDonal, hu
hai cdng trinh dupc chia ra 3 loai sau: hu hai kiln true,
hu hai chQc ndng vd hu hai v l kit cdu.

<i>Huhai kien true: hu hai v l kiln true lien quan tdi hu </i>
hdng xuit hidn trong kit d u . Vlt nQt tren tudng, sdn
thupc dang hu hdng ndy. Vlt nOt vupt qud 0,5mm b l
rpng Idp trdt trdn tudng vd vupt qud 1,0mm b l rpng

khdi xdy tudng dupc xem xdt Id dp Idn gidi ban.

<i>Huhai ChQc nang: hu hai chQc ndng lien quan tdi </i>
hu hdng chQc ndng kit clu. Loai hu hdng nay bao
gdm: ket cQa sd, cQa di, nghieng tudng, sdn, udn hoac
gdy cdc dudng dng ga, nudc. Hu hdng chQc nang
khdng ydu d u sQa chQa kit clu d l trd lai cong nang
ban ddu.

<i>Hu hai kit ciu: hu hai kit c l u dnh hudng tdi dn </i>
djnh cua kit clu, thudng lidn quan tdi v l t nQt, biln
dang cua cdc d u kien CP bdn: dim, cot, khdp ndi, sQc
chju tdi cua tudng.

Tren hinh 5 trlnh bdy cdc djnh nghTa nhQng biln
dang chfnh cua cdng trinh nam trong pham vi dnh
hudng cua hd ddo vd sau dd Id cdc cdng thQc xdc dinh
Chung theo Cording et al.(2001).

Moorak Son (2003) ddn kit qud nghidn cQu cQa
Cording et'al (2001) v l edch xdc lap mpt sd thdng sd
biln dang cua cdng trlnh dung de ddnh gid su hu hai

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<b>WMHIICHieHHlMC mOAl TRONG PHdNG</b>

<b> T R A H H</b>

<b> Stf c 6 . </b>

<i><b>4 </b></i>

dua tren tri b i l n dang trung binh quan trdc dupc tQ

cong trinh idn can hd ddo. B i l n dang cua tudng dupc
xdc djnh bdi do dae theo phuong t h i n g dQng (v), theo

phuong ngang (I), chuyen vj (Ay By Cy Dy A| B| C| D|)
tai 4 gdc (A, B, C, D) n h u trinh bay tren hinh 5.

N h u v d y de cd sd lieu dung trong ddnh g i d tinh
trang ky thudt ciia cdng trinh Idn can, hd ddo phdi tien
hanh khao sat nhQng cong trinh l y trudc khi xdy dung
cOng n h u thuc hien quan t r i e no can than theo chuong
trinh xdc djnh trong sudt q u d trinh thi cdng hd ddo.

TQ sd lieu do dae, dung cdc tieu chf sau ddy de

NHIPfl) NHIPg) NHIP®

30.90. 39.12 16.51

TD^

14.48 6.35 14.48 - 3 . 5 8

<b>UQ,</b>

<b> • • • • </b>

<i>5.92 A ^</i> TB<i> ^^ I ^^ </i>

38.77 16.54 6.12 - 3 . 4 0
<i><b>\-</b></i><b> 5 f ^ , - . ^ - •; •. ^ </b>

<i>Hinh 5. Biin dang cua cong trinh lan can hd dio </i>
ddnh gia:

Do ddc trung binh (slope) S Id s u thay ddi dp ddc

tai day nha tren c h i l u ddi L:

<i>S=^^-^' </i> <b>(1) </b>

0 6 nghieng (tilt) T Id gdc xoay cua tudng dupc tfnh
theo cong thQc:

<i>2H </i>

<i>T = </i>

<i>(C,-B,) </i>

<i>H </i>

(2)

B i l n dang g6c (angular distorsion) p Id b i l n dang
cdt duoc tfnh theo cong thUc:

P = S - T (3)
B i l n dang ngang tai dinh (lateral strain at top)

Eia,(T) Id s u thay ddi chuyen vj ngang tai dinh cong
trinh tren toan c h i l u ddi L:

<i>SiAT) = </i>

<i>D,-C, </i>

(4)
B i l n dang ngang tai ddy (lateral strain at base)
eia,(F) Id SUthay ddi chuyen vi ngang tai ddy mdng tren
todn c h i l u ddi L:

<i><b>s.iF).^^ </b></i>

₍₅₎

Burland (1995) sQ dung ty sd b i l n dang (A/L) de
thay cho b i l n dang goc (P) nhdm ddnh gid s u h u hai

cua cong trinh, trong do A Id chenh lun tai 2 d i l m edch
nhau L. Chu y r i n g b i l n dang goc p se dupc dung de
ddnh gid s u h u hai cua cong trinh hien hOu g i n hd ddo:

P = A/L - (6)

<b>NGUdi</b>

<b> XAY DUNG S 6 THANG</b>

<b> 3-2011 </b>

_ SiJf dung cdc cdng thQc trdn ta tfnh todn cdc thdng
sd biln dang cho cdng trinh thuc t l neu trdn hinh 5,
ta dupc:

Cung c6 the du bdo ehuyin vj cua cdng trinh Idn
Tai nhip 1:

<i>Dp die trung binh ^ J ^ Z L z l ^ = 3,64x10"'; </i>

6100

OA KA - 14,73-4,83

0 6 nghiSng T =

= 1,62x10"

6100

Biln dang gdc p = (3,64-l,62)xl0"^ = 2,02x10"^
<i>Biln dang ngang B^tl) = —^ '-—=2,65x10"' </i>

6100

B i l n dang ngang e,^(F) =

8,92-4,83

6100

= 0,67x10"'.

cdn b i n g phdn tfch k i t c d u khi d e m ket edu nhd hiSn

hQu qui ddi thdnh d i m c d d d cQng tuong duong tr§n
n i n d d n hdi, tQ d d tfnh d d lun/vdng v d b i l n dang g6c
theo cdng thQc (6) v d i mdt s d thay ddi nhd theo
R.J.Finno et al.(2005) hoac theo ludn vdn dd s6 tr§n
CP s d tdng k i t v d k i l m chQng hdng 100 cdng trinh h6
ddo c u a N.S.Nikiphorova (2006).

<i>2.3. Phan Ung cua cdng trinh lin cin hd dio md </i>

Hd ddo md thudng Id nguyen nhdn chfnh Idm hu
hai cdng trinh liln k l do chuyen vj nin dit, ddc biet 1^
<i>d khu vuc dd thj. Cdc chuyen vj nin dit do hd ddo md </i>
cd cd hai thdnh phin ngang vd dQng dnh hudng din
cdc phan Qng cua edng trinh. Cdc phdn Qng ndy dircic
nhilu nhd nghien cQu quan tdm do gia tang yeu clu
bdo ve cdng trinh tai khu vuc dd thi.

Nhin chung, mdt kit c l u gdm nhilu thdnh phdn c6
dp cQng vd dp bin khdc nhau, mdt sd khuylt tdt ciJa
kit clu nhu v l t nQt cd t h i cd trudc khi bj chuyen vj cua
nin dit do hd ddo gdy ra. Cdc kit qud nghien cQu d§u
<i>dua tren sd lieu thuc t l da dupc quan trie vd ddnh g\&. </i>

Gdc lech vd ehuyin vj ngang nhu nhOng thong s6
chfnh d l ddnh gid su hu hai. Mac du cd mdt sd cdeh
khdc nhau d l md td lun lech, nhung ly do lua chon
biln dang gdc Idm tidu chf vl: 1) Cdng trinh gdn h6
ddo thudng cd dd lun Idch Idn. 2) Biln dang gdc dl
ddng quan sdt trong thuc t l .

Cording et al (1978) dd nghien cQu phdn Qng cdng
trinh do cdc ehuyin djch n i n dit. Cdc quan sdt thuc
nghiem hu hdng cdng trinh tai Washington D.C vS
New York tuong Qng vdi mQc dp biln dang. So d6,
d^ng v l t nOt dupc quan trie tai kit c l u nhd gach canh
hd ddo, tudng chju luc vudng gdc vdi hd ddo, c6 ba
dang v l t nQt dupc quan sdt vd md td nhu sau:

- Cdc v l t nQt v d dOt gay tdp trung c h u y l u d g i n
cQa s d . Khi cdc v l t nQt chdo t i l p x u c vdi mat tudng
chfnh, cdc mdnh vun c u a Idp trdt c d t h i xdy ra.

<i>- Cdc v l t nQt gdn t h i n g dQng x u i t hien g i n mdi n\\k, </i>
kdo ddi vd xuyen qua hdng gach, cdc v l t nQt ndy xudt
hien c6 lien quan tdi s u vdng Idn cua k i t c l u . Cdc v l t
nQt tdp trung gdn tudng chfnh noi c d gdc Idch Idn nhdt.

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<b>KINH NGHIEM NtfdIC NGOAI TRONG PHONG TRANH SI/ CO. </b>

cao khodng 1,5~3,0m. Vi trf vd hudng cua chung dupc

cho Id bj dnh hudng cua chuyen vi ngang cua nen.

Ngodi vlt nQt, dd nghidng ra thi dp lun them vd

chuyen vi ngang cua cong trinh Idn cdn cung c6 the

din din nhGmg biln dang khong cho phdp (Ng. Bd

Kl, 2006).

<i>2.4. Dinh gia mUc dp hU hai cdng trinh </i>

Boscardin vd Cording (1989) da nghien cQu sulien

quan giQa hu hai cdng trinh dua trdn biln dang kdo tdi

han vdi cdc thdng sd biln dang (biln dang gdc p vd

biln dang ngang tdi han Sh). Trong nghien cQu nay hai

ong da sQ dung dim tmh dinh dat tren hai gdi don

gian va tdi trpng tap trung ddt d giQa nhjp de lien he

vdi biln dang tdi lian (p, e^). Bleu dd ddnh gid hu hai

dua tren ty s l giQa mo dun ddn hdi vd md dun trupt

E/G=2,6 vd ty sd giQa chilu ddi vdi chilu cao ngdi nhd

l_/H=1. Hinh 6 dudi ddy ehl ra biln dang tdi han

0,0005, 0,00075, 0,0015 va 0,003 cho biln dang liu

Bang 1. Phan loai mQc dp hu hai theo be rpng vet

nQt cua cdng trinh canh hd ddo

<i><b>i </b></i>

<i><b>2 </b></i>

<b>1 </b>

<b>1 </b>

<b>f </b>

<b>® N </b>

<b>® </b>

<b>n b KIU NOHC H4 oto </b>

k 1 , , 1 , \

<b>© </b>

<b>ooeS™«« \ </b>
MUc do
thiet hai
Khong
dang ke
Rat nhe

Nhe

Trung
binh

Ndng

R^t
n ^ g

IV161§ loai hu hai

Vet ran nUt

Vet nUt de dang sUa chUa trong
qua trinh trang tri

Vgt nUt de dang lap day, c6 the
ygu C2lu trang trf lai

<i>Vet nUt yeu cau ck bo va phu </i>
lai.

Thay the xi mSng cho gach
Sijfa chUa phdi thay the tudng,
<i>dae biet Ici d vung cila s6' vJ cu'a </i>
di

SiJfa chffa Idn keo theo phSi xay
lai dSm mit kha nang chju luc.
Ciia sd bj h6ng hodn toan.

Be rgng vet nUt
xjp xi (mm)

<0,1

<1
<5

5 - 1 5 hoac
nhieu vet nirt
>3mm

15-25 va phu
thuOc vao so
lUdng vgt nUt
>25 va phu
thude vao s6
lUdng v6t nUt

<i>Mile M thiet hai: </i>

<i>(0): Khdng nh$n biet; </i>
<i>(1):Rknhe; </i>

<i><b>2 3 4 </b></i>

<b>8I{N 1))N0 GfiC II (XIO'") </b>

<i>(2): Nhe; </i>
<i>(3)(4):Vifatdinianh; </i>
<i>(5): Rit manh. </i>

p theo cong thufc (3)
Eh theo cong thufc (4)

<i>Hinh 6. Bieu dd dinh gii hUhai cdng trinh theo bien dang gdc p vi </i>

<i>blin dang ngang E^ </i>

hai tQ khdng ddng k l tdi rit nghiem trpng. Gid trj gidi

ban ndy se cd mpt sd gid trj thay ddi vl kit clu co ty

sd E/G vd UH thay ddi Idn.

Phuong phdp cua Boscardin vQa neu hien dung khd

rpng rdi de ddnh gid mOc dp thiet hai cua cong trinh ldn

can hd ddo, tQdd se xdc djnh giai phap xQ ly thfeh hpp

cho hd ddo hoac cong trinh, c6 khi kit hpp vdi nhau, d l

dat dupc hieu qud kinh t l vd ky thudt mong dpi...

Trong thuc t l khi chi quan trie dupc su hinh thanh

vd phdt then vlt nQt cua cdng trinh hien hQu thi dung

kit qud nghien cQu cua Burland de ddnh gid trang thai

ky thudt ciJa cdng trinh lan can hd ddo theo b l rpng vlt

nQt vd chQc ndng sQdung theo mQc dp hu hai (bang 1).

Trong nhQng nghien cQu sau do, Storer J.Boone

(1996) da tdng hpp 3 y l u td : b l rpng v l t nQt, dp lun

hi/hai
Khflng
dang ke (0)
Ritnh?(1)

Nhe (2)

Trung binh (3)

N?ng (4)

<i>Rk nang (5) </i>

<b>B a n g 2. P h d n d p h u hai c d n g trinh theo b i l n d a n g </b>

Mo ta sir hi/ hai

Dau nUt n6 mflng

NiJt manh, de xijf II trong khi trang tri binh thUdng. Trong nha c6 the
cd lap nhQng cho nUt gay nh?. Nhiing nUt ng d bgn ngoai ciJa cdng
trinh xay bing gach c6 the nhSn thay khi nhin ki

NhUng ngt ng cfl th^ de dang tram. Yeu cau phai trang tri lai. Trong

toa nha cfl mot so cho nUt gay. Nhflng nUt ne cfl the kha Idn. Ygu
ciu trat Vila lai de chong thim. Cijfa va cijfa so' cfl the bi ket nhe
NhUng nUt ng cfl the ygu ciu dap ra va va lai. Dinh ki lam Idp vUa trat
de che giiu nhUng nUt ng. Trat lai bgn ngoai cua cong trinh xay bing
ggch va cfl le mdt s6 ch6 nho ciia cdng trinh xay bing gach phai
siKa chUa lai. Cfla va cfla s6 cfl th^ bl ket. Hg thong dUdng 6ng cfl
th^ bj dflt giy. Tinh ch6ng thim thudng bi suy yeu

Nfll Chung vigc sifa chfla gom ca pha va xay lai mot phan tudng, dae
bigt ca phin cfla va cfla s6. Khung cfla va cfla so bi udn, san tang bj
doc rit dang k l TUdng b| nghigng hoac phinh ra rit dang k l Kha
nang chiu lUc cua dim bj kgm di. Hg th6ng ve sinh bi pha vd.
ygu ciu chinh vg sfla chfla bao g6m ca cue bfl hoac xay 1^1 hoan
toan. Dim mit kha nang chiu liie; tudng nghigng xiu va ygu ciu
eh6ng dd. Cfla sd' bi giy do u6n. Tin higu bdo nguy do mat d'n dinh.

B^ r6ng khe null

0,1mm

1mm

5mm

5 - 15mm hoac mot
s6 khe nUt > 3mm

15 - 25mm, phu
thuoc vao so lUdng
ciia khe nflt

ThUdng > 25 mm,
phu thuge vao s6
lugng cua khe nfll

Lun lech A

< 3cm
(1,2 in)
3-4em
(1,2-1,5in)

4 - 5 c m
(1,5-2.0 in)

5-8cm
(2,0 - 3,0 in)

8-13cm
(30 - 5,0 in)

> 13cm
(> 5in)

Bien dang goc

P = ' A / L

< 1/300

1/300 -1/240

1/240 -1/175

1/175-1/120

<i>V^20•^f70 </i>

>1/70

</div>
<span class='text_page_counter'>(5)</span><div class='page_container' data-page=5>

<b>MNH NGHIEM NtftfC NBOAI TRONG</b>

<b> P H 6 N G</b>

<b> TRANH Stf C6.. </b>

lech (chenh lun/lun khong ddu) vd b i l n dang gdc
P(=A/L) de phan chia mQc dp hu hai cdng trinh Idn can
h i dao nhu trinh bay d bang 2.

Nhu vay dua tren k i t qua khao sat vd quan t r i e hd
dao va cong trinh ldn can hd ddo ta x i p loai cdc hu
hai theo hinh 6 hoac theo bang 1 ( n l u chi do dupe v l t
nOt) hay theo bang 2 ( n l u co ddy du cdc thong sd), tQ
do se dua ra cac bien phap (thilt k l vd thi cong) n h i m
quan ly rui ro trong xay dung cong trinh n g i m dd thj.^
3. Kiem soat riii ro/sir c d c o n g trinh lan can h d
dao

De he k i t c l u chdng giQ hd dao cung ntiu eong
trinh lan can no khong xay ra su ed phdi khdng c h i
chuyen vj cua cong trinh hd dao thong qua tfnh toan
va quan trie. Nhiing due k i t neu d cudi muc 2.1, tQ
hinh 3 va hinh 4 v l chuyen vj ngang u'^''^ cua tudng

chin va chuyen vj dQng u'"^ cua mat d i t lan can hd
dao dupc diing cho muc dfeh vQa neu khi tu vdn thilt
k l d l xudt trj gidi han.

Chu y r i n g d cac nudc phdt trien (Illinois,
Washington D.C, My; Frantturk, OQc; Matscpva, Saint
Peterburg, Nga, Thupng Hdi, Trung Q u d c . ) ngudi ta
d i u djnh ra cdc trj sd canh bao vd trj khdng e h l (qua
tieu chuan thilt k l , thi cong hoac qudn ly) de kiem
sodt rui ro khi thi cong hd ddo trong do thj.

Thudng dua theo d p cCia cong trinh hd ddo de xdc
djnh tri khdng chd lun mat ddt vd chuyen djch ngang
cua than tudng. Khi khong cd qui dinh rieng thi diing
cdc tieu chf trong bang 3 de khdng c h i thilt k l vd
gidm sdt hd dao d gdn cdc cong trinh cd t i m quan
trpng d p 1 va d p 2 (theo DBJ-61-97).

Theo bang 3 ta t i l n hanh kiem sodt su an todn
(khong xay ra su cd) cua hd ddo nhu sau:

Bang 3. Trj khdng e h l thilt k l va gidm sdt b i l n
dang hd mdng cong trinh (theo DBJ-61 -97)
Cip

cdng
trlnh
h6
dao

COng
trinh

cipl
Cdng
trinh
cip 2

Chuyen djch
eiJa dinh tudng
(cm)

Tri
giam
sat
khing
chi
3

6

Tri
thiit

ki

5

10

Chuydn djch Idn
nhit ciia than
tudng (cm)
Tri
giam
sat
khing
chi
5

8

<b>Tri </b>

thiit
ki

8

12

LiJn ldn nhit d
mat dit (cm)

<b>Tri </b>

giam
sat
khing
chi

3

6

<b>Tri </b>

thiit
ki

5

10

(1) Trong thilt k l , tuy theo t i m quan trpng ciia
cdng trinh, tu vdn thilt k l chi djnh trj chuyen vj, gpi Id
trj thilt k l , cua h i ddo vd cua mat d i t ldn cdn hd ddo,
xem chung la trj gidi han, trong quan trie luc thi cong
xem day la ngudng nguy hiem;

(2) De an todn, c6n c6 trj khdng c h i , xem chung Id
ngudng canh bdo; n l u sd lieu quan trie trong thi cdng
dat ngudng ndy thi cdn tang g i p doi t i n s u i t quan

trdc de phdt hien xu hudng phdt trien cdc chuyen djch
CLia hd ddo cung nhu cdc b i l n dang cua cdng trinh ldn
can (theo hinh 6, bdng 1/bdng 2);

(3) N l u chuyen dich vd b i l n dang ndi tren qud mOc
vd CO khd ndng g i n vdi tri gidi ban thi nhd t h i u lap tuc
dimg mpi boat dpng xdy l i p vd thdng bdo ngay cho

ctiu d i u tu, trien khai bien phdp phdng ngira. Chi khi
sd lieu dat dn djnh mdi t i l p tuc thi cdng hd ddo.

Bang 4. C i p an todn hd ddo (theo DBJ-61-97)
cip an toan

Cipl

cip II

Hau qua pha hoai

<i>Kit ciu ching gifl bi pha hoai, nin dit mit 6n (^nh </i>
hoac biin dang qua Idn lam cho cdng trinh xung
quanh hi ddo hoac vigc thi cOng kit ciu ngim bi
inh hudng nghifim trqng.

Kit ciu ch6ng gifl bj pha hoai, nin dit mit 6n dinh
hoac biin d«ing qua Idn lam cho cdng trlnh xung
quanh h6 dao hoic vigc thi cOng kit ciu ngim bi
inh hudng vfla phai.

d p cdng trinh neu trong bdng 3 Id theo su phdn
d p cua DBJ-61 -97 vd cho d bang 4.

Khi xdc djnh tieu chuan khdng e h l b i l n dang phii
tfnh d i n hieu Qng thdi gian cua b i l n dang vd khdng
c b l tdc dp b i l n ddi cua trj sd gidm sdt, cdng trinh edp
1 ndn khdng e h l d trong 2 mm ngdy, d p 2 trong 3mm
ngdy Khi tdc dp lun dot ngpt tang len hoac lien tuc d

tdc dp nhanh thi phdi kjp thdi phdn tfch nguydn nhdn,
cd bien phdp ddi phd.Q

Tai lieu tham khao

<i>1. Boscardin M; Walker M (\99&)-Ground </i>

<i>Movement.Building Reponse and Protective Measures. </i>

ASCE.October 18-21.

<i>2. DBJ-61-97 -Shanghai Standard Code for Design of </i>

<i>Excavation Engineering (in Chinese). </i>

<i>3. Finno Richard J. et al (2005)- Evaluating Damage </i>

<i>Potential in Building Affected by xcavations. J. of Geotechnical </i>

and Geoenronmental Engineering,131 (10).

<i>4. Moormann C (2004)- Analysis of Wall and Ground </i>

<i>Movements due to Deep Excavations in Soft Soil Based on A New </i>
<i>Worldwide Database.So\\ and Foundations,Japanese Geotechnical </i>

Society, Vol.44,No 1 ,Feb.

<i>5. Moorak Son (2003)- The Reponse of Buildings to </i>

<i>Excavations-inducted Ground Movements. Thesis of Ph.D. </i>

University of Illinois.

<i>6. Nguyin Bd K§ (2006)-X^y dung cdng trinh ngim do </i>

<i>thi theo phuong phip dio md Nhd Xudt bdn Xdy dung. Ha </i>

Noi.

<i>7. Storer J. Boone {\99S)-GroundMovement Related Building </i>

<i>Damage .J. of Geotechnical Engineering, November. </i>

<i>8. HnKnct)opoBa H.C. (2006)-/7e<;fopMat<uty sdanuu </i>

<i>e6nu3U zny6oKUx KomnoeaHoe u nodaeMHbix ebipadomoK </i>

<i>e ycnoeufix mecHou aopodcKou aacmpouKu u Memodbi </i>

<i>saaiumbi. flMCcepraMMn na concKaHne yMSHOM creneHM </i>

flOKTopa TexHMHecKMx HayK . MocKsa, HklHOCn MM. H . M .
Tepee saHOB.

</div>

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