Hd ddo md thudng Id nguyen nhdn chfnh Idm hu hai cdng trinh liln k l do chuyen vj nin dit, ddc biet 1^ d khu vuc dd thj. Cdc chuyen vj nin dit do hd ddo md cd cd hai thdnh phin ngang[r]
Trang 1D I I N DAN KHOA HOC CdNGNGHi
KINH NGHIEM Nlf^C NGOAI TRONG PHdNG TRANH SU CO CONG TRINH Ol LAN CAN H 6 DAO SAU TRONG 0 0 THI
PGS.TS NGUYtN BA KE Hoi Cd hpc d i t vd Dja ky thuat c6ng trinh Vi#t Nam
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
1 To'ng quan
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:
- d Ha Long, Quang Ninh, ngdi nhd 3 ting dd
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^\^
Hinh 1 Anh hUdng ho dio den cdng trinh
1 Nguyen nhan gay chuyen vi
2 Bat bi dao hoic dich chuyen
3 Phan bd chuyen vi the tfch
4 Chuyen vi mit dit
5 6 Chuyen vj ket cau vi si/huhdng (nClt,nghieng)
7 Chuyen vi dat quanh hd dio phia khdng cd cong trinh hien hdu
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;
Tong hpp cdc loai chuyen vj ndy se Idm mat ddt b
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
2 Blln dang cua tudng chin yd dat gdn ho ddo
2.1 Nhin dang chuyen vl, blin dang
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
NGUdi XAY DUNG S 6 THANG 3 - 2011
Trang 2KINH 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
xusas
: /
Uh(2)
Hinh 2 Cac dinh nghia lien quan hd dao
H: chieu sau hd dio [m];
t: chiiu sau tudng chin [m];
hf khoing cich glOa cie thanh chdng/neo [m];
(/^fr ehuyin vi ngang ldn nhat cua tUdng [m];
uT'^chuyin vi ddng Idn nhit cOa mit dit [mj;
N: sd tang/hing thanh chdng/neo
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)
35
30
25
20
15
10
S
0
*/
in
^Pff*^ • • SCI uua cihig tdi ciihi, •- C4i*4cu6itdi
10 IS 20 2S 30 3S
uj"tan)
vc
Hinh 3 Ty sd uTjir; {a) vi liin mit dit canh hd dio (b) vdi mot
sd loai dit nin
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
A Tudng trong ^ijcoc giao
ck
He chong g&tuong chwi:
a Neo
• ThantiAar^ chong 8} Top-down
O Tuong vay km hinh Iron
3 C6n.K)nA3autucto
10 20
66 saM ho dao H
Hinh 4 Quan he giOa do sau z Ung vdi u"'^ vi do sau hd dao H
trong dit s6t mem
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)
2.2 Mgt sd tieu chf diing trong dinh gia hu hai/su cd cdng trinh lan can
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
Huhai kien true: hu hai v l kiln true lien quan tdi hu
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
Huhai ChQc nang: hu hai chQc ndng lien quan tdi
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
Hu hai kit ciu: hu hai kit c l u dnh hudng tdi dn
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
NGUdi XAY DI/NG S 6 THANG 3 - 2011
Trang 3WMHIICHieHHlMC mOAl TRONG PHdNG T R A H H Stf c 6
4
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®
TD^
14.48 6.35 14.48 - 3 5 8
38.77 16.54 6.12 - 3 4 0
\- 5 f ^ , - ^ - •; • ^
Hinh 5 Biin dang cua cong trinh lan can hd dio
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:
0 6 nghieng (tilt) T Id gdc xoay cua tudng dupc tfnh
theo cong thQc:
2H
T = (C,-B,)
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:
SiAT) = D,-C, (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:
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)
NGUdi XAY DUNG S 6 THANG 3-2011
_ 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:
Dp die trung binh ^ J ^ Z L z l ^ = 3,64x10"';
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"^
Biln dang ngang B^tl) = —^ '-—=2,65x10"'
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)
2.3 Phan Ung cua cdng trinh lin cin hd dio md
Hd ddo md thudng Id nguyen nhdn chfnh Idm hu hai cdng trinh liln k l do chuyen vj nin dit, ddc biet 1^
d khu vuc dd thj Cdc chuyen vj nin dit do hd ddo md
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
dua tren sd lieu thuc t l da dupc quan trie vd ddnh g\&
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
- Cdc v l t nQt gdn t h i n g dQng x u i t hien g i n mdi n\\k,
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
- Cdc v l t nQt g d n t h i n g dQng tdp trung xdy ra gdn mdng cdng trinh, cdc v l t nOt kdo ddi tQ m d n g tdi d6
Trang 4KINH NGHIEM NtfdIC NGOAI TRONG PHONG TRANH SI/ CO
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)
2.4 Dinh gia mUc dp hU hai cdng trinh
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
2
1
1
f
® N
®
n b KIU NOHC H4 oto
k 1 , , 1 , \
©
ooeS™«« \
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
Vet nUt yeu cau ck bo va phu
lai
Thay the xi mSng cho gach Sijfa chUa phdi thay the tudng,
dae biet Ici d vung cila s6' vJ cu'a
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
Mile M thiet hai:
(0): Khdng nh$n biet;
(1):Rknhe;
2 3 4
8I{N 1))N0 GfiC II (XIO'")
(2): Nhe;
(3)(4):Vifatdinianh;
(5): Rit manh
p theo cong thufc (3)
Eh theo cong thufc (4)
Hinh 6 Bieu dd dinh gii hUhai cdng trinh theo bien dang gdc p vi
blin dang ngang E^
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)
Rk nang (5)
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
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
V^20•^f70
>1/70
NGl/dl XAY DUNG SO THANG 3 • 2011
Trang 5MNH NGHIEM NtftfC NBOAI TRONG P H 6 N G TRANH Stf C6
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
Tri
thiit
ki
8
12
LiJn ldn nhit d mat dit (cm)
Tri
giam sat khing chi
3
6
Tri
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
Kit ciu ching gifl bi pha hoai, nin dit mit 6n (^nh
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
1 Boscardin M; Walker M (\99&)-Ground
Movement.Building Reponse and Protective Measures
ASCE.October 18-21
2 DBJ-61-97 -Shanghai Standard Code for Design of
Excavation Engineering (in Chinese)
3 Finno Richard J et al (2005)- Evaluating Damage
Potential in Building Affected by xcavations J of Geotechnical
and Geoenronmental Engineering,131 (10)
4 Moormann C (2004)- Analysis of Wall and Ground
Movements due to Deep Excavations in Soft Soil Based on A New Worldwide Database.So\\ and Foundations,Japanese Geotechnical
Society, Vol.44,No 1 ,Feb
5 Moorak Son (2003)- The Reponse of Buildings to
Excavations-inducted Ground Movements Thesis of Ph.D
University of Illinois
6 Nguyin Bd K§ (2006)-X^y dung cdng trinh ngim do
thi theo phuong phip dio md Nhd Xudt bdn Xdy dung Ha
Noi
7 Storer J Boone {\99S)-GroundMovement Related Building
Damage J of Geotechnical Engineering, November
8 HnKnct)opoBa H.C (2006)-/7e<;fopMat<uty sdanuu
e6nu3U zny6oKUx KomnoeaHoe u nodaeMHbix ebipadomoK
e ycnoeufix mecHou aopodcKou aacmpouKu u Memodbi
saaiumbi flMCcepraMMn na concKaHne yMSHOM creneHM
flOKTopa TexHMHecKMx HayK MocKsa, HklHOCn MM H M Tepee saHOB
NGUdi XAY DONG s 6 THANG 3 • 2011