Xác định vị trí chuyển ngang của tường vây trong hố đào sâu

Xac djnh chuyen vj ngang cua
tu'ang
vay
trong ho dao sau
Ngay nhan bai: 4/12/2013
Ngay
sCra
bai: 12/12/2013
Ngay chap nhan dang: 25/12/2013
Tran Xuan Tho,
Doan Van Toan
T6M TAT:
Noi dung cua bai bao la phan tich
chuyfa
vi ngang cua
tvldng
vay
trong ho dao sau
sti
dung philong phap phan ttl hiiu han va dam
tren nen dan hoi. Ket qua phan tich chuyen vi ngang cua tiidng
diigc
kiem
chiJng
vdi so lieu quan trac hien trildng de danh gia
6n dinh cua ho dao. Ket qua chuyen vi ngang ciia tiidng phan
tich bang phan
tii
hfiu han gan sat vdi sd lieu quan trac hien
trildng vdi dp sai so khoang
8%.

Tuy nhien, chuyen vi nhan
dtlgc
tfl philong phap
dSm
tren nen dan hpi cho ket qua ldn hdn ban
so vdi phan thil hflu han khoang til 1,88 - 2,47 lan.
ABSTRACT
This paper is aimed at analysing the horizontal displacement of
diaphragm
vfall
in a deep excavation, using the Finite Element
method (FEM) and beam on elastic foundation method (BEF).
The analysed results are compared to the measurements to
evaluate the stability of deep excavation. The results of horizontal
displacement of the diaphragm wall from FEM are equivalent
to the monitoring data with the difference of 8%. However, the
horizontal displacement results from BEF analysis are higher from
1.88 to 2.47 times than that of FEM results.
Keywords: Deep excavation, diaphgram wall, displacement, Finite
Element method (FEM), beam on elastic foundation method
(BEF).
PGS.TS. Iran Xuan Tho
Khoa Ky Thuat Xay Diing,
Trilclng
Dai hpc Bach khoa
TP.
HCM
268 Ly
Thiidng Kiet, Q. 10, TP. HCM
Email:

DT:
0939.369.777
KS.
DoAn
Van Toan
Khoa Ky Thuat Xay DUng, Tnidng Dai hoc Kien triic
TP.
HCM
196 Pasteur, Q.3, TR HCM
Email:
doanvantoanraihcmuarc.edu.vn
DT:
0973.392.357
I.Datvande
Dfldi didu kidn dao dat thdng thfldng, mdt Iflpng dat ben trpng hd
dio dflpc dd
bd,
tap ra ip Iflc dat khdng ein bang tic dung ldn tfldng. Ap
Iflc dat khdng can bang se lim phit
sinh
biln dang cfla tfldng va be mat
dat. Nln dat, dilu kidn mflc nudc ngim, hinh dang hd dio, qui trinh thi
edng,
phuong phap thi cdng, loai tfldng chin gifl va nhilu yeu td khae
lien quan tdi chuyen vj cua tudng. Ol dam bio dn djnh cfla hd dio, cin
xic djnh chuyen vj cfla tudng trong cie giai doan thi cong dao dat.
Hidn nay cd nhieu phuong phip dl phin tieh tudng vay trong hd
dao siu. Hai phuong phap phan tfl hflu han (FEM) va dam trdn nln dan
hdi (BEF) thfldng dflpc sfldung.
FEIVl

li mdt phflong phip tflong thieh Si
md phdng dng suit - biln dang eua dat. Khi
lUa
chpn giii phip ddn giin
hon thi BEF trd thinh mdt md
hinh
dugc sfl dung. Ol danh gii
kit
qui
phin tich dfl doin chuyin vj ngang eua tudng viy thi can thilt phii tiln
hanh quan trie chuyen vj ngang eua tudng khi tien hinh thi edng hd dio.
Tudng viy trong hd dio siu edng trinh Hud Tower, Hi Ndi dupe
nghidn cflu trpng bii bap niy.
2.
Phuong phap nghien cflu
Phflong phap phan tfl hflu han thdng qua phan
mim
Plaxis dupe
sfl dung dl phan
tich.
DUa vip dae diem dja tang va eac die trUng co ly
eua cic Idp dat, md hinh Mphr - Cpulomb (MC) dugc ap dung trong mo
phdng tinh
toan.
Phuong phap dam tren nln din hdi thdng qua chuang trinh VEX
dugc sfl dung md phdng phin tich dua tren gii tri he sd nen theo
phuong ngang eua nen dat. Xac djnh he sd nen theo phuang ngang dua
trdn phuong trinh cfla Ou
(1997).
Oe cac cdng cu phin tieh nay dupe sfl dung an tpin thi can dflgc

kiem chflng bing cich ddi chieu vdi ket qui quan trie hidn trfldng. Tien
hinh quan trie chuyin vj ngang eho tudng viy hd dao trong qui trinh thi
edng dao dat bang cic thilt bj Inclinometer (Hinh 2).
3. Mo ti cong trinh va mo phdng tinh toan
3.1 Mo ti eong trinh
Cdng trinh
HudTower
cd 3 ting ham, sfldung phflong phap thi cdng
Top-Down vdi 4 giai doan dio dat. Hd dap rpng 40m vi siu nhit
12,0m.
Hd dap dupc chan gid bing tudng viy ed bl day 800mm vdi dp siu
eua tudng 25m, thanh giang
H300x300x10x15
vdi khoing cich thanh
giang li 5,0m vi
kit
hgp vdi san tang ham lim giang chdng cho thi edng
dao dat. Sau khi thi edng xong tfldng viy
DW800
va epe khpan nhdi va
kingpost thi tiln hinh thi edng dao dat tang ham. Mat cat ngang hd dao
dflgc md ti trong Hinh
1.
3.2 Bgc diem dia chdt eong trinh
Ciu tao dja chit va chi tilu eo ly cfla eac Idp dit:
01.2014BniniflHl 103
S£T
PHU
D£OM£M-D£0
CUNG

y„i=19.8kN/m'
9'
=17°13'
C
=19,5kN/m'
s.
=
50kN/m'
N =
8.12
SET
CLING
r,.i
=
20.4kN;m'
f'
=17°13'
C
=42.5kN;m'
Su=iaokN;m'
N
=
30
-
40
DAOQJITUM
1-3000)
SANBI
0A0
0i(TLJlll2|-5n0)

SANB2
OAOOSTLANa(-9000)
DA0D)(TU(N4{-1ZD00)
CAT
PHA,
TRANG
THAl
CHAT
rs,i
=
20.1kN;m'
•p'
=29°19'
c'
=
4.8kN/m'
N
=
30-45
Hinh
I.Mat
cat
ngang ho
dio
Hinh
2.
Mat
bing
bo
tri

thiet
bj
quan trac
5000
!;!!• — •
50.00
i
i i i !
'•.',.'•
'.
,1
! ' !
i
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:
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;
[2]:
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j
:•.',',•. ^
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;
: : ' : •
':•;:•
k
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: \ : :
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f -•:• ; •:• ;
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[11
[2]
Hinh
3. Mo
hinh phan tich
ho
dao
trong
VEX
-
Ldp

1:
Set pha, mau xam
trang, trang thii
ddo
mem den ddo
cflng,
diy
12m,
trgng Iflgng
rilng trdn mflc nudc ngam
y^^^^^
=
^6,5kN/m^
trgng Iflgng ridng
bio hda
y^^^
=
19,8kN/m3,
c'
=
19,5
kN/m^
cp'=
17°13',
sfle ehdng
cit
khdng
thpit nfldc
S„
= 50

kN/m^
he
sd tham
k =
8.64E"'
m/ngay-dem, module bien dang tilp tuyen
E^^,
= 2800N (SPT)= 25000
kN/m^
he sd
Poisson'v
mmm^^Eame-
hi #» tit * ""» .^. «
V-
i.
it
i'.
'<•
•• >i .1 <
li"
ji t
Hinh
4.
Mo
hinh phan tich
ho dao
trong
Plaxis
etxa
oo

Chu
in
11
uug
(nun)
•
/
i,-',
//Vm
1
l\
i I
i
1
.'
/
/
'
.'1/1
'', ;
«
D
/
1
1
'
UorUlllnl
EUDdillln?
EUodilliil}
E»o<>lllln4

Hinh
5.
Ket
qu3 chuyen
vj
ngang
cOa tilJng
trong
cac
giai
doan
dao
dat
(bang
VEX)
Omffo
v|
BfiBg (u)
Hinh
6.
Ket qua
chuyen
vj ngang ciia tudng trong
cac
giai
doan
dao dat
(bang
Plaxis)
= 0,35.

-
Ldp 2: Set mau nau
vang, trang thii cflng,
day
18m,
y^^
=
20,1
kN/m=,
c' = 42,3
kN/m^
cp'
=
21
»26',
sdc chong
eat
khdng thoit nudc
S^
=
180
kN/m^
k =
8.64E-^
m/ngay-dim,
E
,
=
2800N
(SPT)

=
89600
kN/m^
v = 0,35.
-
Ldp 3: Ldp eat pha, mau nau
ving,
trang
thii chit,
bl day rat Idn,
y^^^
=
20kN/m^
e' = 0
mim\
cp'
=
29°19;
k =
0,864m/ngiy-dem,
E,^,
-
2500N
(SPT)
=
80000
kN/m^
v = 0,3.
3.3
Bic

diem tudng vdy BW800
Tudng
viy cd
chilu
siu tfl mat dat
tii
nhidn
L=25m,
tudng
day
800mm.
Bd
tdng dirng
mac
M350(B25)
ed
modul
dan hdi
E,
=
3,0x10'kN/
m^
dp
cdng ehdng
nen EA =
2,4x10'
kN/m,
dp
cflng ehdng
udn El =

1,28x10'
kN/mVm,
He sd
Poisson
v = 0,2.
3.4
Bic
diem
sin
tret
vi hdm
B1,
B2
San tret,
ham 1
(Bl)
va sin ham 2
(82)
cd
eao
dp lin
lucrt
la
±0,0;
-3,5m va -7,0m san day
200mm,
be
tdng
mic
M350 (B25)

co
modul
din
hdl
la
E„
=
3,0xl0'kN,
dp
cflng
dpc
true
EA =
6,0x106
kN.
3.5Biediemthanheh6ngH300x300x10x15
He thanh chdng thep hinh
H300x300x10x1521
tai cao dp
-2,0m,
sfl
dung
thep
ed mac
SS400
hay
(CT34)
cd
modul
din

hdi
E =
2.1xl0'kN/m^
dp
cflng
dpc
true
EA =
4,914x10'
kN, budc chdng
L^
= 5,0m.
3.6 Quan trie
Men
truing
Quan trie chuyin
vj
ngang
eua
tfldng
viy
theo tflng giai doan
dio dat va thi
cdng ting
ham.
Trflde
khi do be
tdng tfldng,
cie
thiet

bj
Inclinometer dflgc
dit
trong eac
dng
thep de
do
chuyen
vj
ngang cfla tudng theo
chu vi
tfldng
vay nhfl Hinh
2.
Dfla trdn nguyen
tie con lie
trgng lugng
ludn ludn
duy tri
tinh chat thang dflng
eua diy
dgi,
thdng
qua
viec
do lay gdc kep
gifla dfldng
true
d
trong

miy
vdi dudng thing dflng cfla
day
dgi
eon lac de
tinh
ra
chuyen
vj
ngang cfla
doi
tflgng phii
do.
6
diu
tren
con lie ed
djnh
mpt
la ddng nhip,
la
ddng
nhi'p
dau
tren
ed
djnh,
dau dfldi dfla
vio diy lac, khi may do
nghieng

bj nghiing,
day lac
dfldi
tic
ddng cfla trgng lfle
con
lie
duy tri
thing dflng
nen ep vao li
ddng
lam
chp la
ddng
bj
eong,
nhd vao
philn bien
dang didn
trd din
trdn
li
ddng dfla
ra tin
hieu
didn,
may thu
trdn
mat dat
se

thu
nhin
tin
hieu
didn
trd vi
tinh
ra trj udn
cong cfla
la
ddng, tfle
la
cd the
bilt dflgc
gdc
nghieng
6
cua miy do
nghiing,
tfl do
tinh dflge chuyen
vj cua doi
tflgng phii
do.
3.7
Mo
phdng tinh todn
Qui trinh
thi
cdng

hd dio siu
dflge
mo
phdng
bao gdm cic
giai doan sau:
Giai doan
1
:Thi cdng tudng vay day 800mm,
sau
25m.
Giai doan
2: Oio dat lan 1
xudng
cao dd
-3,0m.
Giai doan
3: Lap
giang chdng
H300x300x10x15
tai eao dp
-2,0m.
Giai doan
4: Oao dat lan 2
xudng
cao do
-5,0m.
Giai doan 5: Thi cdng
sin him
Bl

tai
cao
do
-3,5m.
Giai doan
6:
Thio chdng
H300x300x10x15
va
thi
cdng
sin
tret
day
200mm.
Giai doan
7: Oao dat lan 3
xudng
cao do
-9,0m.
Giai dpan
8:
Thi cdng
sin ham B2 tai cap dd
-7,0m.
Giai dpan
9: Gap dat lin 4
xuong
eao do
-12,0m,

rdi thi
edng eae
dii
mdng
be.
Hinh
3 Md
hinh phan tich
hd dio
bang
chuong trinh VEX
va md
hinh phin tieh
ho dao
trong Plaxis dflgc
md ta
trong Hinh
4.
4.
Ket qui
phin tich
trmh VEX)
Kit
qui
phin tich chuyin
vj
ngang
eua
104IBWn'KnB»
01.2014

tudng qua eac giai doan dao dat bang phuong
phip dam tren nen dan hdi dugc md ti trong
Hinh 5.
6
giai doan dao dat lin 1, tfldng cd
xu hfldng djch chuyen vao bdn trong hd dao,
chuyin vj ngang Idn nhit d dinh tfldng
u_^^^
=
20,76mm.
Giai
doan dao dat lan 2, chuyen vj
efla dinh tfldng giim vi di khi lap thanh chdng,
ehuyin
vj ngang Idn nhit cfla tfldng la
u^^^
=
24,3mm d vj tri dp siu 6,0m sp vdi mat dat tU
nhien.
Giai dpan dao dit lan 4, tudng chuyen
vj vao bdn trong hd dap nhieu nhit va cd xu
hfldng bj udn bung, ehuyin vj ngang eua
dinh
tfldng la 19,8mm, chuyen vj
Idn
nhit la
u^^^=
41,17mm d vj tri dp siu 10m sp vdi mat dat tfl
nhien.
4.2 Kit qui phdn tieh bing FEM (chuang

trinh Plaxis)
Ket qui phin tieh chuyen vj ngang eua
tudng qua cae giai dpan dip dat bang phfldng
phip phan tfl hflu han dflgc md ti trong Hinh 6.
dgiai
doan dao dat lan 1, chuyen vj ngang Idn
nhat d dinh tfldng
u^^^
=
11,04mm.
Giai doan
dao dit lin 2, chuyin vj cfla dinh tfldng giim
vl di khi lap thanh ehdng, chuyen vj ngang Idn
nhat efla tudng li
u^^^
=
13,54
mm d vj tri dp siu
6 m so vdi mat dit tfl nhidn. Giai dpan dio dit
lin 4, chuyin vj ngang cua dinh tudng li
12,34
mm,
chuyen vj Idn nhit li
u^^^
=
18,5
mm d vj tri
dp
siu 10 m
so

vdi
mat dat tu
nhien.
4.3 Ket qui quan
trie
Kit
qui quan trac ehuyin vj ngang efla
tudng tai vj tri dng
1-2
dupe md ti trong Hinh 7.
Ckay^BViBgiag(m)
001
0015 OUI
OOIS
CfaofCB
vj
ngoiig (m)
Hinh 7. Ket qua quan trac chuyen vj ngang ciia tirdng trong
cac giai doan dao
dat
4.4
Bdnh gid ket qua
phdn tich
vdi ket
qud
quan
trie
hien truing
Hinh 8 tdng hgp
kit

qui chuyin vj ngang
cua tfldng trong cic giai doan thi cdng dao
dat theo Plaxis, VEX vi
kit
qui quan trie hien
tudng.
Trj sd
biln
dang tinh toin eua tfldng vay
tinh toan bang Plaxis gin sat vdi sd lieu quan
trie thflc te vdi dp sal khic khoing 8% vl dp
Idn.
Tuy nhien, cung dua tren
kit
qui sp sanh
nay, chp thay chuyin vj nhin
Siigc
tfl VEX eho
kit
qui Idn hon ban so vdi Plaxis khoing tfl 1,88
+
2,47 lan.
Trong sudt qua trinh dao dat, tudng viy sd
phit sinh hai xu hfldng ehuyin vj, tdng hai xu
hfldng nay se tao ra djch chuyen ngang Idn nhat
cho
ti'-^
J Bd
la xu huong djch chuyen ngang
H

—
\ H
Hinh
8a.
Bao dot
tan
1 den
-3,0m
Chuyen
v|
aging
(m)
Hinh
8b.
Dao dot Ion 2 6en
-5,
Om
Cbin*cD
v|
ngiDg (m)
Hmh
ic
Bao dot lan 3 den -9,0m Hinli Sd Boo dot Idn 4 dm -U,Om
Hinh
8.
Chuyen vj ngang ciia tucing bang quan trac va tinh toan bang
Plaxis, VEX
vio trong hd dao cfla toin tudng (xu hfldng
1)
va xu hflong uonphanbung cfla tfldng (xu

hfldng 2). Trong giai doan dio dit ban diu, xu
hfldng 1 li chu dao, tuy nhiin trong cic giai
doan sau (khi da bd tri hd ehdng va khi thi edng
eic san tret, sin ham
1,
sin ham 2) thi xu hudng
2 dugc
thi
hidn rit rd va chilm Uu
thi.
Vj tri tfldng dat gia trj cue dai (tai vj tri tfldng
bj uon bung nhilu nhat) cd xu hfldng djch
ehuyin theo chilu siu dio dat tfl vj tri khoing
8m d (giai doan dao dit lin 3) ting len vj tri
10m
so vdi dinh tfldng (trong giai doan dao dat
lin 4). Ben canh do ehuyin vj ngang eua tudng
cung ting dan theo cie
giai
doan dao dat.
Theo tieu chuan thiet ke ASTM, chuyin vj
ngang cua tudng eho phep khoing [ux] =1,5
inches =
3,81
em,
do dd ehuyin vj ngang cfla
cflc dai thflc te eua tfldng viy la umax =l,8em,
ndn tfldng vay hd dao van dim bio dilu kien
dn
djnh.

5. Ket luin
Kit
qui chuyin vj ngang eua tudng tinh
toin bing Plaxis gin sit vdi sd lieu quan
trie
hien trfldng vdi do sai sd khoing
8%.Tuy
nhiin,
chuyen vj nhan dflgc tfl chflong trinh VEX cho
kit
qui Idn hon han so vdi chuong trinh Plaxis
khoing
tfl
1,88-2,47
lin.
Du rang phflong trinh efla Ou cho ra ket qui
khdng phu hgp vdi ket qui quan trie trong du
in,
tuy nhidn cic thdng sd cfla Idp dit set li cic
ydu td inh hudng tdi phuong
trinh.
He sd nen
theo phuang ngang cd khuynh hfldng tang
theo he so Poisson, modul din hdi cfla dit vi
sfl ting ldn cfldng do dat nln. Trong sfl tuong
phin,
he sd nen theo phuong ngang giim
xudng vdi sfl ting len be rdng hd dao vi ting
len chilu dil cim siu cua tfldng.
Ol dflpc hgp ly trpng

viec
thflc hidn tinh
tpin ip lfle ngang doe theo chieu siu vung dat
bi phi hoai keo gdm ci biln dang cfla tfldng va
phu hpp vdi hd dio thflc, sfl hilu ehinh ip Iflc
ngang phia sau lung tudng bang hai lin chilu
siu mi vung dat bj phi hoai keo la dupe xac
djnh rd trong phflong phap dam tren nen din
hdl.
TAI LlCU THAM
KHAO
[1]
Ou, Chang-Vu (2006), Deep Excavation theory and
practice.
First
edition,
Taylor
and
Francis/Balkema,
Netherlands.
[2]
Malcolm Puller (1996), Deep Excavation a practical
manual,
first
edition,
Thomas
Telford,
New
York.
[3]

Monitoring of Diaphragm
Vtfall
Displacement and
Assodated Ground Movement, Braced Excavation Adjacent to
Historical Building at The Bank of Chao Phraya River. Bangkok,
Thailand,
2000.
[4]
Vesic, A.B. (1961), Beams on Elastic Subgrade and
the Winklers's Hypothesis, Proceedings, Fifth Intemational
Conference on Soil Mechanics and Foundation
Engineering,
Paris.
01.20149Dnil[|SX
105