D I E N D A N KHOA HOC & C O N G NGHE
^ A C H L f N G D U N G P H U O N G P H A P P H A N T U "
H O U H A N B E T I N H T O A N C O N G T R I N H B E N T R E N N E N C O C T H E O S d D O K H U N G P H A N G
V C f l T R U C O C T R O N G D A T
* TS. PHAN D U N G I . G i d i t h i e u c h u n g
1.1 Giong nhit trong [ 7 ] , doi ttfdng duoc nghien ctfu 6* day la cong trinh ben (CTB) tren nen coc hd, bao gom hai loai:
n6n coc v d i cac coc thang diing ( H . l a ) va nen coc v d i goi coc cheo ( H . l c ) . Be7 chuyen sd dd ket cau thu'c ve sd do tinh toan ta van phai sii dung khai niem chieu
dai chiu nen L N khi coc chiu life doc true;
con khi coc chiu ltfc ngang thay vi diing khai niem chieu dai chiu udn LTJ, ta xet stf ttfdng tac ciia he coc - da't thtfc thdng qua viec phan tich toan bd ket can. Theo each l a m nhtf the', chiing t d i g o i day la sd dd khung phang v d i tru coc trong dat ( H . l b va
Id).
a/ So do ket cau thirc Dam tignng
H
bf So do k l m n g phang v o l tru coc t r o n g dat.
Prim ngang H " ~
i -i J
T & T*T*T T s* \-^< T * T vt T s* ' " >» T 5*- "i
t—1 Tni coc trons dat
t—1
X S X 1 779^- TAT- 77fe c So <to ket cau time
Dam ngnrio
d,r So do Jdumg phang v d i t r u coc t r o n g dat P;im ugaug
\ Hinh 1: So do ket cau CTB va so do khung phang vdi tru coc trong dat.
So thang 3+4 • Nam 2011
D I E N D A N KHOA HOC & CONG NGHE 1.2Cho den nay, each tinh CTB tren nen
coc theo sd do khung phang vdi tru coc trong dat khong cd nhieu.
Dtfa tren ldi giai epe chiu life ngang cua TCXD 205 - 1998 va tfng dung phirdng phap chuyen vi, GS.TS. Le Dtfc Thang [3] da de xuat "phirdng phap tinh loan mdng coc dai mem cd ke den chuyen vi thu'c ciia coc trong dat"'(1970).
Thay the dat quanh coc bang mot he thong lien ket loai mot nam ngang, Antonov bien khung phang cd tru coc trong dat ve mot khung "phut lap" hdn roi ap dung phifdng phap phan phoi md men de tim chuyen vi - noi ltfc ket cau. Phitdng phap nhu" the cua Antonov da dtfdc diing trong "Htfdng dan thiet ke cong trinh ben cang.bien" [4].
Chung tdi cung da de nghi each giai bai loan neu tren rat cd hieu qua va de tinh nhcJ thuat loan ciia phifdng phap Ma tran chuyen tiep [9]. Theo do, khung phang cd tru coc trong da't du'pc quy ve mot dam lien tuc nhieu nhip tren cac goi dan hdi roi thu'c hien tich lien tiep cac ma tran chuyen nut (goi epe) vdi ma Iran chuyen nhip de thu du'pc mot he phifdng trinh dai sd luyen tinh luon chi chtfa
ba thong an so' (khong phu thupc vao so'ltfpng goi coc). Giai he nay cho phep la xac dinh dtfpc chuyen vi - npi life cua CTB trang thai khong hoac cd xet ud'n dpc.
1.3 Vdi mong mudn nang cao hieu nang tinh toan va lam phong phu each giai, d bai viet nay se tong ket lai viec u"ng dung phifdng phap Phan ttf hffu han (PTHH) de tinh toan CTB tren nen epe theo sd do khung phang vdi tru coc trong dat xuat phat tif viec xet hieu tfng ciia life dpc true khi ket cau chiu ud'n [5], [6]va[8].'
Ly thuyet cd ban cung nhu" each trinh bay viec thiet lap Ma tran dp ctfng (MTDC) ciia phan ttf hoan toan gid'ng nhu" cac muc I I va I I I trong [7].
I I . M a t r a n d p e t i n g c u a p h a n tu*
coc t r o n g d a t :
Dtfa tren tdng ket ly thuyet chung de thiet lap M T D C 6 muc 3.1, d day trinh bay cac cong thu'c chung ciia Nhemtrinov
[1] theo trinh ttf da l a m d 3.2 va 3.3 [7].
2.1 MTDC ciia phan ttf dam chiu ud'n ngang tren nen dan hoi
Sd do phan ttf du'pc trinh bay 5 hinh 2.
- y
f <i2(R2) H f ^ 4 ^
• i N k - \ -. J
. " ' ' . - i _ j — f Bieu do
x ''• y(x) phan bo he so nen L L Hinh 2: Phin tir doin chiu uon ngang tren nen dan hoi vdi he s6 nen khong doi k.
24 s° thang 3+4 • Nam 2011
D I E N D A N KHOA HOC & CONG NGHE 1 .Phtfdng trinh vi phan va nghiem cua no:
d)
d4y k , i + ~ y ( x ) = 0 d x4 EI Dat: b4 = — y( x )
EI Viet lai ( I ) :
dx
Nghiem tdng quat ciia (3):
y ( x ) = A191( x ) + A292( x )
(2)
(3)
+ A303( x ) + A494( x ) Trong do:
( ^ ( x ) = c h a x c o s a x cj)2 ( x ) - c h a x s i n a x 93( x ) = shaxsin a x 94( x ) = s h a x c o s a x Vdi: a :
4~2
(4)
(5)
(6)
2. Ma tran [B] va [ B ] - l : 1
0
^ i ( L ) [B]
0 a )2( L )
0 0
>3(L)
0 a
>4( L ) a [ 64( L ) - *2( L ) ] a t ^ C ^ + ^ C L ) ] a [ p4( L ) + 62( L ) ] ot[9i ( L ) - 03 (L)]
sin" A-slrA -(siiAcosA+chAshA
0 0
chAsinA+sliAcosA shAsinA 0
—sh A
2 7 1 1 a a
chA-cof A - (cliAshAsniAcosA) -2sliAsinA -(chAsinA-sliAcosA)
a a sinAcosA+chAshA - sin2 A -(chAsinA+sliAcosA) slrAsinA
Trong do: a a
a} = s i n2 A - s h2A A = a L
3. Ma tran cac ham Hertmite dang (20) trong [5]:
H, (x) = — {2a](|>! (x) + (sh2A + sin2A)[(j)4 (x) -62 (x)] + (ch2A - cos2A)f>3 (x)}
2a,
PL, (x) = — {(1 - ch2 A)0, (x) + (sh2A - sin 2A)63 (x) + (1 - cos 2 A)(b4 (x)j 2aa,
H3 (x) = — {(chAsm A + shAcos A)[cf)0 (x) -<|>4 (x)] - 2shAsin A03 (x)}
a.
H4(x) = — {shAsin A[ip4 (x) -(j)2 (x)] + (chAsin A - shAcos A)cj)3(x)}
aa i
4. Ma tran do cifng ciia cau kien
(7)
(8)
(9) (10)
( H )
So thang 3+4 - Nam 2011 2 5
D I E N D A N KHOA HOC & CONG NGHE
[k] = odEI
- 2 a (sh2A+
+sin2A) a(cos2A-ch2A) sin2A-sh2A
4a (chAsinA+
+shAcosA 4ashAsinA 2a2(sh2A+
+sin2A) D X
-4ashAsinA 2(shAcosA-
+chAsinA) a(ch2A-cos2A) sm2A-sh2A 2.2 M T D C cua phan tir dam t r e n nen dan hoi chiu uoh - nen:
1. PhUdng trinh vi phan va nghiem ciia no:
SO dd phan tu" dirdc trinh bay tren hinh 3.
(12)
N
q . ( R i )
q7( R2)
EI
q , ( R3)
N
yOO L
Bieu do
phan ho he so' nen
H i n h 3: Phan t i i dam chiu uon - nen tren nen dan h o i v o i he so nen k h o n g doi k.
Phirdng trinh vi phan:
d4y _ 9 d2y . 4
— V + 2 a " — f + b y = 0 d x4
Vdi:
2a2 =
d x '
N_
EI . b4= - ^ EI
(13)
(14) N g h i e m tdng quat ciia (13) cd dang (4) vdi:
(j), ( x ) = chaxcos(3x (|)2(x) = chaxsin|3x cj)3 ( x ) = shaxsin(3x 94( x ) = shaxcos(3x
(15)
Trong do:
a" 1 ( b ' - i O
P2= ^ ( b1 2+ a 0 2 r>2 2
a = p - a b =(3 + a
(16)
Theo Nhemtrinov, tir nghiem long quat tren cd the thiet lap dude MTDC cud'i ciing nhu'ng vap phai nhiing khd khan rat ldn ve mat tinh toan.
De tranh dieu dd, ta thu'c hien khai trien chuoi so' dd'i vdi nghiem chinh xac va giu* lai cac so'hang khdng qua cap bdn nhu" sau:
2 6 So thang 3+4 • Nam 2011
2j D I E N D A N KHOA HOC & CONG NGHE y(x) = A j O + a ^2 + a2x4) + A2B ( x + a3x3) + A3a B ( x2 + a4x4) + A4a ( x + a5x3) ^ Trong do:
a3= ^ ( 3 a2- B2) ; o
T ( « 2- P 2 ) ;
a. A = a , = | ( a2- P2) ;
a2 = J_(a4 -6a2B2 +B4); a5 = -^(3a2 -B2) 24
2. Ma tran [B] va [ B ] - l :
1 0 0 B
(18)
[B] =
0 0
0 a
\ + C{+C2 B ( l + C3) AB(1 + C4) A ( l + C5) - ( C i + 2 C2) B(1 + 3 C3) - A B ( 1 + 2 C4) a ( l + 3 C5) L L
(19)
6* day:
C j = a1L2; C j = a2L ; C'33 = a _ a33L " ; J C4 = a4L ; C5 = a5L r
A = a L j
B = B L l (21)
(20)
Ma tran [ B ] - l (22) rat cong kenh, xin phep khong trinh bay.
3. Ma tran cac ham Hertmite dang (20) trong [5]:
H , ( x ) = 1 1 - C4
+ (C2-3C4-C,C4) 1
[ l - C4+ ( C2- C1C4- 3 )
]
VL7
+ 2 ( l - C2+ C , C4+ 2 C4^ ' x »
H2( x ) =
H3(x) =
H3(x) =
1 - C4
1 1 - C4
1 1 - C4
x L
f x " ! 2 3 f x Y
2 IT + (1 + 3 C+ (1 + 3 C44) ) - 2 C4
J-1 J
VL7
- 2 ( 1 + 2 C4)
+ (1 + C4)
^ x V
+ 3 C
- - c4
(23)
Khi Ci = 0, he (23) trd thanh he (11) la cac ham Hertmite ciia phan tir dam chiu u6n ngang.
4. Ma tran do cvfng ciia cau kien:
So thang 3+4 • Nam 2011 2 7
1 B i e D I E N D A N K H O A H O C & C 6 N G N G H E
[ k ] = EI
1 2( l - 6 m + 78n) ^ ( l - m + 22n) ~(\-6m-27n) * ( l -m- 1 3 n ) L*
D X Trong do:
2 a" T2 m = — L
30 n b" T4
n = L 2520
L
4 ( l - 2 m + 6n) - - ( l - m - 1 3 n ) 2(l + m - 9 n ) -^f(l-6m + 78n) --(l-m + 22n)
4 ( l - 2 m + 6n)
(25)
(24)
2.3MTDC cua phan tu" dam tren nen dan hdi chiu ud'n keo:
O trtfdng hpp nay, co the dung sO do hinh 3 vdi htfdng life doc true N ngtfpc lai.
PhtfPng trinh v i phan se la:
,2 . ,i
(26) d y „ 2 dzy , ^
— V - 2 a ^ — r + b y = 0 dx d x '
Cach lam giong nhtf tracing hpp uon - nen va thu du'pc M T D C [k] dang thdng tu" (24):
^|(l + 6m + 78n) -(l + m + 22n) -(l + 6m-27n) -0 + m-13n)
L L L L tk]= EI 4(l + 2m + 6n) - - ( l + m - 1 3 n ) 2 ( l - m - 9 n )
L
— (l + 6m + 78n) (l + m + 22n)
L L (27)
D X 4(l + 2m + 6n) 2.4 Cong thu'c chung cua MTDC doi vdi ca hai trtfofng hr/p ud'n - nen hoac ud'n keo:
TO (24) va (27) ta co the viet cdng thu'c chung cua MTDC cho phan tu" dam tren nen dan hdi chiu uon - nen hoac ud'n - keo:
[k] EI L
^ - ( l + 6m + 78n) - ( l + m + 22n)
L L L
19 f\
1 (l + 6 m - 2 7 n ) - ( l + m - 1 3 n ) 4(1 + 2m + 6n)
D X
(l + m - 1 3 n ) 2 ( l ± m - 9 n )
— (l + 6m + 78n) --(l + m + 22n) 4(l + 2m + 6n)
(28)
(Dau trade so'hang chtfa m: dau phia tren ilng vdi ltfc dpc la nen, phia dtfdi - keo).
Cdng thu'c (28) cd the du'pc bieu dien dtfdi dang to'ng cac ma tran dp ciing thanh phan:
[k] = [ ku] + [ kN] + [ k ° ] (29)
Trong dd:
2 8
r^u] = M T D C thanh phan ciia phan tir dam chiu ud'n ngang;
[kN] = M T D C thanh phan ciia phan itf dam chiu ud'n ngang dpc, va
[kO] = MTDC thanh phan ciia phan tu* dam chiu uon tren nen dan hdi vdi he so nen khong dd'i.
So thang 3+4 • Nam 2011
D I E N D A N KHOA HOC & CONG N G H $ H I . D a c dieTn t f n h t o a n C T B t r e n
n e n c o c :
3.1 Cac sd do tinh toan:
Gia su" ta co mot CTB ddn gian vdi nen coc ddng xuyen qua hai Idp dat khac nhau (Hinh 4a).
a) b) Ldi L(12
• Bieu do lie so oen Idp I : Bieu do he sd nen i
Idp II
w
Hinh 4: Cac so do tinh toan khi chiu luc ngang.
a. So do ket cau C T B ,
b. So do ket cau da duoc r d i rac hoa.
Sau khi rdi rac hda, ta thu dtfdc sd do hinh 4b. Luc nay, bieu do he sd'nen bien dd'i bat ky theo chieu sau ddng coc se trd thanh dang bac va trong pham vi mot phan t i i rieng biet, gia tri he so' nen la khdng ddi.
Tu" viec so sanh cac gia tri ciia ldi giai chinh xac vdi l d i giai thu dtfdc theo each ndi tren, Babanov va Perov [2] da khuyen nghi:
chieu dai cua moi phan t i i coc phai thoa man dieu kien:
aL < 0,1-1,5 vdi
a = i kb 4EI
(30)
(31)
coc.
0 day:
k = he sd'nen,
b = chieu rong ciia tie't dien ngang ciia 3.2 Cac loai ma tran do ciing:
Trinh tu* cac budc tinh toan van diing theo
sd do khd'i hinh 3 trong [5] vdi mot so' chu y sau:
MTDC ciia cac phan t i i dtfdc sii dung cho bai toan nay gom hai loai:
- Loai khdng tiep xiic vdi da't: cac phan tir coc thuoc chieu cao tu" do va cac phan tii dam ngang.
- Loai tiep xuc vdi da't: cac phan t i i coc thuoc phan coc chon trong dat.
O vdng tinh dau tien, trang thai chuyen vi - noi lire ciia ket cau dtfdc xac dinh khi dung cac MTDC ciia phan t i i dam chiu ud'n ngang nhtf (12) hoac (36) trong [5] vdi £ = 0. Lite doc trong cac phan t i i thu dtfdc d btfdc nay dtfdc dung l a m gia t r i thtf dau tien cho cac vdng lap tiep sau k h i xet ud'n doc.
I V . C a c v i d u :
4.1Vi du 1: Coc ddn chiu ud'n ngang va ud'n ngang doc.
So thang 3+4 • Nam 2011 2 9
D I E N D A N K H O A H O C & C 6 N G N G H E :
a) N=l 500fcN
M=J0kNm
b ) N=1000kN
M=50kNm
C) d ) e)
H=50KN
1+0.0
M=50kNm
f X T * T * T * T » T D = 700mm
t = 12mm
EX =332371 OkNm2 EF = ?.4474.10 °kN
-24.0
# •' * T T >* T H=50kN
-24.0
H=50kl-I
Y * T * ti
O.ILJ
lm+L
• S.8kN/m3 k = <52 OOfcN/m 4 .22° C = 2Sk'N.'m2
H i n h 5: Sa do tinli toan coc don chiu luc ngang ciia v i du 1.
d. Bieu dd he sd nen theo TCXD 205 1998.
e. Bieu dd he so" nen dang bac.
a. Coc dOn chiu uon - nen.
b. Coc ddn chiu u6n - keo.
c. Coc ddn chiu uon ngang.
1. Bau bai: Cho mot coc 6ng thep dong thang du"ng trong mot Idp dat set ddng nhat trang thai deo - mem ( I I = 0,3) cd cac so" lieu ghi d hinh 5. Yeu cau xac dinh chuyen vi - noi lite trong coc khi chiu uon ngang (Hinh 5c) va ud'n ngang - doc (Hinh 5a va 5b).
2. L d i giai khi coc chiu ud'n ngang:
Coc dtfdc rdi rac thanh sau phan tir, nam trong sd'dd thudc phan coc ddng trong da't, cd chieu dai mdi phan tir" nhtf hinh 5d; con gia tri he so' nen tmng binh khdng ddi tren mdi phan tir: hinh 5e. Cach chia phan t i i nhtf vay dtfdc goi la chia "thd". Ap dieu kien (30) ta thu dtfdc cac sd' lieu ghi d bang 1.
Bang 1: Danh gia muc do chinh xac tir dieu kien (30):
Sd thir tiT phan t u
Chieu dai (m)
He so a
(m"1) a L Nhan xet dieu kien (30)
1 2.4 0.307 0.738 Thoa
2 2.4 0.405 0.971 Thda
J 4.8 0.481 2.310 Khdng thoa
4 7.2 0.560 2.688 Khong thda
5 7.2 0.624 4.496 Rat khdng thda
3 0 So thang 3+4 - Nam 2011
D I E N D A N KHOA HOC & CONG NGHE Cac con so' trong bang cho thay each chia
tren khong thoa dieu kien (30) & tat ca cac phan tir nen ket qua tinh se khong dii chinh xac. Tuy nhien, cac phan tir khong thoa dieu kien (30) nam d dudi sau, ndi ma chuyen vi - ndi life ciia coc chiu life ngang khdng ldn.
Them vao do, vdi muc tieu la xay difng mot giai thuat PTHH diing, nen se dirdc chap nhan de trien khai mot so' tinh loan tiep theo.
Neu chia phan coc ddng trong da't thanh 48 phan tif cd do dai L i = 0,5m thi dieu kien
(30) se cho ket qua chinh xac v i : ((XL)^ =0,104;
( o L )m a x= 0,324
Cach chia nhu" the goi la chia "min" . Ngoai ra, chuyen vi - ndi life cua coc cdn difdc tinh theo cdng thu'c giai tich ciia TCXD 205 - 1998.
Ket qua tinh toan dirdc tdng hdp trong bang 2.
Bang 2; Chuyen v i - noi hrc cua coc chiu lye ngang.
Chuyen v i - N o i lire
Phuong phap P T H H T C X D 205-1998 Chuyen v i -
N o i lire Chia ' 'tho" Chia ' m i n " T C X D 205-1998 Chuyen v i -
N o i lire
Gia tai Do sau (m) Gia t i i Do sau (m) Gia tri Do sau (m) l . y (m) 3.231.10"' 0 3.455.10"1 0 3.473 0 2. cp (rad.) -2.2762.10"2 0 -2.887.10"2 0 -2.897 0 3. Mr a a x ( k N m )
589.479 -2.4
790.695 670.429
-1.5 -2.5
816.253 670.429
-1.0 -2.5
156.689 -2.4 161.944 -2.5
4. Qm a x ( k N ) 199.459 -3.5 199.643 -3.5
152.341 -4.8 159.120 -5.0 156.275 -5.0
107.656 1.5 109.486 -1.5 5. pmax ( k N / m2) 45.776 -2.4 67.424 -2.5 68.603 -2.5
-44.601 -4.8 -51.269 -5.0 54.527 -5.0
3. L d i giai khi coc chiu ud'n ngang - doc:
Ket qua tinh toan dirdc tdng hdp trong bang 3.
Bang 3: Chuyen vi - noi lye cua epe chiu uon ngang va uon ngang - doc.
Chuyen v i - N o i luc
Trudng hop chiu uon Chuyen v i - N o i luc Uon - keo
(N=1000kN) Uon - ngang Uon - nen
(N=1500kN) 1. y (m) 2.332.10"1 3.231.10"1 8.057.10"1 2. (p (rad.) 1.973.10-2 -2.762.10"2 -6.981.10"2
3. Mm f l X( k N m ) z=0 568.519 790 1946.851
3. Mm f l X( k N m )
z=-2.4 447.869 589.479 1395.489
4. C W ( k N ) z=-2.4 112.478 156.689 407.675
4. C W ( k N )
z=-4.8 117.478 152.314 364.262
5.pm ax(1<N/m2) z=-2.4 39.290 45.776 90.134
5.pm ax(1<N/m2)
z=-4.8 -32.232 -44.601 -54.039
i ——— —
Ghi chu: z la chieu sau diem tinh te tir mat dat (m).
So thang 3+4 - Nam 2011 3 1
D I E N D A N KHOA HOC SE C 6 N G NGHE Dtfa vao so' lieu bang 3, ta ve dirdc bieu do chap chuyen vi - npi lire cua coc trong trang thai ud'n ngang va ud'n ngang - dpc tren hinh 6.
-0.005 0.000 0.005 0.010 0.015 0 020 0.025 0.030 0.035 0.040
14.4 m / l j 14.4
12 12
9.6 S 1 " 9.6
7.2
4.S / / 1
7.2 4.8
2.4 2.4
0 0
-2.4 -2.4
-4.8 ^1.8
-7.2 -7.2
-9.6 -9.6
-12 - -12
-14.4 -14.4
-16.8 -16.8
-19.2 -19.2
-21.6 kN -21.6
2500 -2000 -1500 -1000 -500 -24 0 100 200 300 400 500 Hinh 6: Bieu do chap chuyen vi - npi life khi epe chiu ud'n ngang va ud'n ngang - dpc:
Ky hieu: uon - keo,
• ud'n - nen, • ud'n ngang.
3 2 So thang 3+4 • Nam 2011
D I E N D A N KHOA HOC & CONG NGHE Tu" bang 3 va hinh 6 co the neu mot so'
nhan xet sO bo sau:
© So vdi uon ngang, uon - nen lam gia tang dang ke chuyen vi - ndi life trong coc.
Trai lai, ud'n - keo cd tac dung lam giam cac dai hrdng nay.
Nhu* vay, ket qua tinh toan phan anh diing ban chat vat ly ciia bai toan du'pc dat ra.
© Gia tri md men ud'n trong coc tai tiet dien mat dat la khac nhau. So vdi ud'n ngang, ud'n - nen gia tang life nay de'n 146%. Trai lai ud'n - keo, gia tri md men nay giam di 28%.
© Nhu" da phan tich tnfdc day, do each rdi rac ket cau "thd" nen cac ket qua nay chira dat do chinh xac can cd. Cung vi the', cac bieu do chuyen vi - noi life chira the phan anh chinh xac trang thai ciia ket cau.
© Dieu nay hoan toan cd the khac phuc dirdc neu ta chia "min" phan coc ngap trong da't nhu" da lam d bang 2 dd'i vdi coc chiu life ngang. Khi rdi rac coc thanh 49 phan tii, ket qua ciia PTHH khdng khac may vdi ldi giai giai tich.
4.1. V i du 2: CTB tren nen coc vdi cac coc thang diing.
1. Dau bai: S6' lieu xua't phat ciia CTB nay hoan toan gid'ng nhu" vi du 1 trong [7].
Dieu khac d day la trang thai chuyen vi - noi life ciia nd se difdc xac dinh theo sd do khung ngang phang cd tru coc trong da't (Hinh 7a).
2. Ket qua tinh toan:
Sii dung each rdi rac phan epe ddng trong dat nhu" d vi du ta nhan difdc sd do rdi rac hda ke't cau nhu" hinh 7b.
Thu'c hien phan tich PTHH theo cac sd do ndi tren khdng xet ud'n dpc de lay life dpc lam so' lieu thii d lan dau tien khi trien khai tinh toan cd xet ud'n dpc.
Chuyen v i mit ciia ke't cau ghi 6" bang 4.
Npi life dau epe: life dpc N , life cat Q va md men uon M cho cac bang 5, 6 va 7 tifdng irng.
Cac ndi life trong dam ngang bieu thi trong bang 8.
Do han che ciia khudn khd bai bao nen ndi life trong epe du'pc ve d hinh 8 chi dd'i vdi
epe thii nha't.
Mdt so' nhan xet sd bd:
© Sd do khung cd tru epe trong da't lam tang ldn khd'i lirpng tinh toan nhu'ng so' vdng lap thi khdng tang. Sau nam vdng lap, life dpc trong tat ca phan t i i deu hdi tu.
© Xet ud'n dpc lam tang chuyen vi, dac biet la cac chuyen v i ngang ciia CTB: trong khi cac chuyen vi diing sai khac khdng qua vai phan tram thi chuyen vi ngang tang deu de'n 36,5%.
Dieu nay can phai liru y d cac CTB ma chuyen vi ngang khdng du'pc vu*dt qua mot gia tri khd'ng che cho tnrdc.
© Npi life trong cac epe la van de can du'pc xem xet dau tien khi thiet ke' CTB. Cac con sd'cho thay life dpc va ca life cat epe thupc phan epe chiu md men ldn nha't cd thay ddi nhu'ng khdng dang ke.
Dang chu y nha't la md men ud'n, khi xet ud'n dpc thi gia tri tai dau epe tang trung binh 32% cdn tai viing md men cd gia tri ldn trong da't thi tang gan 40%.
Ke't qua tinh toan cho thay, md men ud'n tai dau epe luon cd gia tri ldn hdn md men ud'n ldn nhat tai tiet dien epe nam trong da't.
© Ndi life trong dam ngang ed dac diem sau: life dpc va life cat cd bie'n ddi nhu'ng khdng nhieu, rieng mo men ud'n cd nhu'ng dac diem dang chu y la:
- M d men tai tiet dien trai nut giffa bi ddi dau va tang ldn. Dd'i vdi epe, viec ddi dau md men npi life khdng cd y nghia gi nhu'ng dd'i vdi dam thi day la mdt van de cd tam quan trpng dac biet.
- Mffc dp bien ddi va gia tang md men ud'n dien ra tap tmng d nhip dam thii nhat, ben hai.
Nhan xet nay la rat cd ich cho ngnfli thiet ke.
© So sanh ket qua tinh toan theo sd dd khung tifdng difdng (KTD) va sd do khung cd tru epe trong da't (KTC) ve chuyen vi ciia ke't cau (Bang 9) cung nhff ndi life dau epe (Bang 10) cho thay giai thuat PTHH da kien nghi la diing dan, bieu dat chinh xac ban chat vat ly ciia bai toan.
So'thang 3+4 - Nam 2011 3 3
D I E N B A N KHOA HOC & C 6 N G N G H f i
a/ n=2000kN hi
Pl=1600kN H=150kN
O : Oo O : —<
I! ' II
Pl=1600kN
q=200kN/(«
... = 8.8kN/m3
;-=22°
C = 2okN7m2
B = 0.3 . ' Coc ong thep D700, t=12mm Ra=3150kN/m2 E=2.1c8 kN/m2
ql6
7 q
0
© -
q)7 . © q61
20
q62 q29 10 i l L ^ j q^3?2o <S*&\ ©
A © q57^^>® ©
ql2^"?W q3flO
V * 4 oST^?19
qVt> q jn > 4"<L>
57—I? 3 <S-1M«
qll
y q8
q4
l3
© q54
,56
©
q49
©
q35
© q39.
qS3
q50 q40
©
q3S
© 14 q41
© q4S»T> q45iT>
1 q46-?16 q4T« 1 5 ql T 1 q46
|q2 |q4 q44
Hinh 7: Cac scf do tinh toan cua v i du 2.
a. CTB tren nen coc vdi cac coc thang diing theo sO do khung ngang phang vdi tru coc trong dat.
b. Sd do rdi rac hda ket cau.
3 4 So thang 3+4 - Nam 2011
D I E N D A N KHOA HOC & C O N G NGHE Mot sd' nhan xet sd bo:
© Sd do khung cd tru coc trong dat lam tang ldn khd'i ltfdng tinh toan nhu'ng sd' vong lap thi khdng tang. Sau nam vdng lap, kfc doc trong tat ca phan tir deu hdi tu.
© Xet ud'n doc lam tang chuyen vi, dac biet la cac chuyen vi ngang ciia CTB: trong khi cac chuyen vi diing sai khac khdng qua vai phan tram thi chuyen vi ngang tang deu de'n 36,5%.
Dieu nay can phai ltfu y d cac CTB ma chuyen vi ngang khdng dirdc vtfpt qua mot gia tri khdng che cho trtfdc.
© Ndi life trong cac coc la van de can difdc xem xet dau tien khi thiet ke CTB. Cac con sd'cho thay life doc va ca life cat coc thudc phan coc chiu md men ldn nha't cd thay ddi nhu'ng khdng dang ke.
Dang chu y nha't la md men ud'n, khi xet ud'n doc thi gia tri tai dau coc tang trung binh 32% con tai viing md men cd gia tri ldn trong da't thi tang gan 40%.
Ke't qua tinh toan cho thay, md men ud'n tai dau coc luon cd gia tri ldn hdn md men ud'n ldn nhat tai tiet dien coc nam trong da't.
© Noi life trong dam ngang cd dac diem sau: ltfc doc va life cat cd bie'n ddi nhu'ng khdng nhieu, rieng md men ud'n cd nhu'ng dac diem dang chu y la:
- M d men tai tiet dien trai mit giffa bi ddi dau va tang ldn. Dd'i vdi coc, viec ddi dau md men ndi life khdng cd y nghia gi nhu'ng dd'i vdi dam thi day la mot van de cd tam quan trong dac biet.
- Miic do bie'n ddi va gia tang md men ud'n dien ra tap trung d nhip dam thu* nha't, ben trai. Nhan xet nay la rat cd ich cho ngtfdi thiet ke.
© So sanh ke't qua tinh toan theo sd dd khung tifdng dirdng (KTD) va sd dd khung cd tru coc trong da't (KTC) ve chuyen vi cua ke't can (Bang 9) cung nhu* npi life dau epe (Bang 10) cho thay giai thuat PTHH da kien nghi la dung dan, bieu dat chinh xac ban chat vat ly cua bai man. Mdt so' nhan xet sd bd:
© Sd do khung cd tru epe trong da't lam tang ldn khd'i hrdng tinh toan nhu'ng so' vdng lap thi khdng tang. Sau nam vdng lap, life dpc trong tat ca phan tir deu hpi tu.
© Xet ud'n dpc lam tang chuyen vi, dac biet la cac chuyen vi ngang cua CTB: trong khi cac chuyen vi dtfng sai khac khdng qua vai phan tram thi chuyen vi ngang tang deu de'n 36,5%.
Dieu nay can phai lifu y d cac CTB ma chuyen vi ngang khdng du'pc vtfdt qua mdt gia tri khdng che' cho trtfdc.
® Npi life trong cac epe la van de can du'pc xem xet dau tien khi thiet ke' CTB. Cac con sd'cho thay life dpc va ca life cat epe thudc phan epe chiu md men ldn nha't cd thay ddi nhtfng khdng dang ke.
Dang chu y nha't la md men ud'n, khi xet ud'n dpc thi gia tri tai dau epe tang trung binh 32% cdn tai vung md men cd gia tri ldn trong dat thi tang gan 40%.
Ket qua tinh toan cho thay, md men ud'n tai dau epe luon cd gia tri ldn hdn md men ud'n ldn nha't tai tiet dien epe nam trong da't.
© Npi life trong dam ngang cd dac diem sau: life dpc va life cat cd bien ddi nhu'ng khdng nhieu, rieng md men ud'n cd nhu'ng dac diem dang chii y la:
- M d men tai tiet dien trai nut giffa bi ddi dau va tang ldn. Dd'i vdi epe, viec ddi dau md men npi life khdng cd y nghia gi nhu'ng dd'i vdi dam thi day la mot van de cd tam quan trpng dac biet.
- Mffc dp bie'n ddi va gia tang md men ud'n dien ra tap taing d nhip dam thff nha't, ben trai. Nhan xet nay la rat cd ich cho ngirdi thiet ke.
© So sanh ke't qua tinh toan theo sd dd khung tifdng difdng (KTD) va sd dd khung cd tru epe trong da't (KTC) ve chuyen v i ciia ket cau (Bang 9) cung nhtf ndi life dau epe (Bang 10) cho thay giai thuat PTHH da kien nghi la dung dan, bieu dat chinh xac ban chat vat ly ciia bai toan. Mdt so' nhan xet sd bd:
© Sd do khung cd tru epe trong da't lam
So thang 3+4 - Nam 2011 3 5
D I E N D A N KHOA HOC & C O N G N G H E tang ldn khoi ltfdng tinh toan nhu'ng so' vong
lap thi khong tang. Sau nam vong lap, life doc trong tat ca phan tu* deu hoi tu.
© Xet uon doc lam tang chuyen vi, dac biet la cac chuyen vi ngang ciia CTB: trong khi cac chuyen vi diing sai khac khong qua vai phan tram thi chuyen vi ngang tang deu den 36,5%.
Dieu nay can phai hfu y d cac CTB ma chuyen vi ngang khong du'pc vu"pt qua mot gia tri khong che cho trtfdc.
© Npi life trong cac epe la van de can du'pc xem xet dau tien khi thiet ke CTB. Cac con so' cho thay life dpc va ca life cat epe thupc phan epe chiu mo men ldn nha't cd thay dd'i nhu'ng khdng dang ke.
Dang chii y nha't la mo men ud'n, khi xet ud'n dpc thi gia tri tai dau epe tang trung binh 32% con tai vung md men cd gia tri ldn trong da't thi tang gan 40%.
Ket qua tinh toan cho thay, md men ud'n tai dau epe luon cd gia tri ldn hdn md men ud'n ldn nha't tai tiet dien epe nam trong da't.
© Npi life trong dam ngang cd dac diem sau: life dpc va life cat cd bien ddi nhu'ng khdng nhieu, rieng md men ud'n cd nhiing dac diem dang chu y la:
- Md men tai tiet dien trai nut giffa bi ddi dau va tang ldn. Dd'i vdi epe, viec ddi dau md men ndi life khdng cd y nghia gi nhu'ng dd'i vdi dam thi day la mot van de cd tam quan trpng dac biet.
- Mffc dp bie'n ddi va gia tang md men ud'n dien ra tap trung ct nhip dam thff nhat, ben trai. Nhan xet nay la rat cd ich cho ngtfdi thiet ke.
© So sanh ke't qua tinh toan theo sd do khung ttfdng dtfdng (KTD) va sd do khung cd tru epe trong dat (KTC) ve chuyen vi ciia ket cau (Bang 9) cung nhtf npi ltfc dau epe (Bang 10) cho thay giai thuat PTHH da kien nghi la diing dan, bieu dat chinh xac ban chat vat ly ciia bai toan. Mdt sd' nhan xet sd bd:
© Sd do khung co tru epe trong da't lam tang ldn khd'i ltfdng tinh toan nhtfng sd' vdng
lap thi khdng tang. Sau nam vdng lap, ltfc dpc trong tat ca phan tu* deu hpi tu.
© Xet ud'n dpc lam tang chuyen v i , dac biet la cac chuyen v i ngang ciia CTB: trong khi cac chuyen v i dtfng sai khac khdng qua vai phan tram thi chuyen v i ngang tang deu de'n 36,5%.
Dieu nay can phai ltfu y d cac CTB ma chuyen v i ngang khong dtfdc vtfdt qua mdt gia tri khdng che' cho trtfdc.
© N p i ltfc trong cac epe la van de can dtfdc xem xet dau tien khi thiet ke CTB. Cac con sd'cho thay ltfc dpc va ca life cat epe thupc phan epe chiu md men ldn nha't cd thay ddi nhtfng khdng dang ke.
Dang chii y nha't la mo men ud'n, khi xet ud'n dpc thi gia tri tai dau epe tang trung binh 32% cdn tai vung md men cd gia tri ldn trong da't thi tang gan 40%.
Ke't qua tinh toan cho thay, md men ud'n tai dau epe luon cd gia tri ldn hdn md men ud'n ldn nha't tai tiet dien epe nam trong da't.
© Npi ltfc trong dam ngang cd dac diem sau: ltfc dpc va ltfc cat cd bien ddi nhtfng khdng nhieu, rieng md men ud'n cd nhffng dac diem dang chii y la:
- M d men tai tiet dien trai mit giffa bi ddi dau va tang ldn. Dd'i vdi epe, viec dd'i dau md men npi life khdng cd y nghia gi nhtfng dd'i vdi dam thi day la mdt van de cd tam quan trpng dac biet.
- Mtfc dp bie'n ddi va gia tang md men ud'n dien ra tap trung d nhip dam thu* nha't, ben trai. Nhan xet nay la rat cd ich cho ngtfdi thiet ke'.
© So sanh ke't qua tinh toan theo sd do khung ttfdng dtfdng (KTD) va sd do khung cd tru epe trong da't (KTC) ve chuyen vi ciia ke't cau (Bang 9) cung nhtf ndi life dau epe (Bang
10) cho thay giai thuat PTHH da kien nghi la dung dan, bieu dat chinh xac ban chat vat ly ciia bai toan.
3 6 So thang 3+4 - Nam 2011
D I E N D A N KHOA HOC & CONG NGHE Bane 4: Chuyen vj cac nut ciia CTB.
V ong lap Chuyen vj nut 7 Chuyen vi nut 8 Chuyen vj nut 9 V ong lap
Ay* (p** Ax*** Ay* <p** Ax*** Ay* (p** Ax***
VL 1 -1.2429.10"2 -35.09.10"* ^7.7105.10" -1.3646.10' -1.3329.10"1 7.77094.10- -1.3646.10- -2.2578.KV5 7.77089.10- VL 5 -1.2220.1D"- -4.1502.10"* 1.0526.10'' -1.3650.10- -8.0216.10 s 0.10525 -l.3960.Kr -1.7458.10"* 0.10524 Sai I Tuvet doi 2.0744.10- -5.9930.10-' 2.8153.Kr -1.7923.10* -5.30.10-' 2.8153.10° -3.I832.10J -l.52.Ur 2.8153.10- khac I Tuong doi (%) 1.7 16.9 36.5 0.013 39.8 36.5 2.3 673.2 36.5
*: chuyen vj thang diing (m): **: chuyen vj xoay (rad.); ***: chuyen vj ngang (m).
Banu 5: Luc dpc trong coc (kN).
Vong Lap
Coc thu nhat Coc thu hai Coc thii ba Vong
Lap 7- 1
1-7 8 - 16
16-8 9- 15 15-9 VL1 -2496.1846 -2740.5926 -2763.2228 VL1 2496.1846 2740.5926 2763.2228 VL5 -2454.5228 -2804.5246 -2740.9526 VL5 2454.5228 2804.5246 2740.9526
Tuyet
doi 41.6617 -63.9320 22.2703 Sai Tuyet
doi -41.6617 63.9320 -22.2703 khac Tuong
doi (%) Tuong -1.669 2.333 -0.806 doi (%) -1.669 2.333 -0.806 Bang 6: L u c cat trong cgc ( k N ) .
Stt nut Z ( m ) V L 1 V L 5 Sai khac
Stt nut Z ( m ) V L 1 V L 5
Tuyet <16i Tuong doi (%) Coc thu nhat
7 14.80 -48.9103 -50.38224 -1.4719 0.030094
6 0.00 -48.9103 -50.38224 -1.4719 0.030094
5 -2.40 53.1488 81.61507 28.4663 0.535597
4 -4.80 66.5954 92.39865 25.8033 0.387463
3 -9.60 -3.2402 -6.986944 -3.7467 1.156315
2 -17.80 0.1565 0.305451 0.1490 0.952362
1 -24.00 0.0000 8.88E-16 0.0000 0
Coc thir hai
8 14.80 -50.2184 -49.85459 0.3638 -0.724
21 0.00 -50.2184 -49.85459 0.3638 -0.724
20 -2.40 53.7015 83.92631 30.2248 56.283
19 -4.80 67.6615 94.14694 26.4854 39.144
18 -9.60 -3.2739 -7.193369 -3.9195 119.718
17 -17.80 0.1590 0.311586 0.1526 95.962
16 -24.00 0.0000 -6.66E-16 0.0000 0.000
Coc thu ba
9 14.80 -50.8713 -49.76317 1.1081 -2.178
10 0.00 -50.8713 -49.76317 1.1081 -2.178
11 -2.40 53.9774 83.39866 29.4212 54.507
12 -4.80 68.1937 93.64916 25.4554 37.328
13 -9.60 -3.2907 -7.145148 -3.8544 117.130
14 -17.80 0.1603 0.309831 0.1496 93.310
15 -24.00 0.0000 4.44E-16 0.0000 0.000
So thang 3+4 • Nam 2011 3 7
D I E N D A N K H O f l H O C & C 6 N G N G H £ :
Bang 7: M o men uon trong coc (kNm).
Stt nut Z ( m ) V L 1 V L 5 Sai khac
Stt nut Z ( m ) V L 1 V L 5
Tuyet doi Tuong doi (%) Coc thir nhat
7 14.80 431.9646 572.9439 140.9793 32.637
6 0.00 -291.9082 -408.234 -116.3259 39.850
5 -2.40 -254.3259 -346.6411 -92.3151 36.298
4 -4.80 -85.9607 -111.688 -25.7273 29.929
3 -9.60 9.8412 13.20478 3.3636 34.179
2 -17.80 -0.1603 0.861964 1.0222 -637.857
1 -24.00 0.0000 1.33E-15 0.0000 0.000
Coc thu hai
8 14.80 447.6889 591.1586 143.4697 32.047
21 0.00 -295.5431 -415.3583 -119.8152 40.541
20 -2.40 -258.3315 -352.7629 -94.4314 36.554
19 -4.80 -87.5475 -113.3043 -25.7568 29.420
18 -9.60 10.0000 13.47567 3.4757 34.757
17 -17.80 -0.1633 0.880984 1.0443 -639.405
16 -24.00 0.0000 -1.33E-15 0.0000 0.000
Coc thu ba
9 14.80 455.5379 585.7487 130.2108 28.584
10 0.00 -297.3574 -413.4627 -116.1053 39.046
11 -2.40 -260.3308 -350.9912 -90.6604 34.825
12 -4.80 -88.3396 -112.7569 -24.4173 27.640
13 -9.60 10.0792 13.40046 3.3212 32.951
14 -17.80 -0.1649 0.875961 1.0408 -631.350
15 -24.00 0.0000 8.88E-16 0.0000 0.000
Bang 8: N o i luc trong dam ngang.
Vong Lap
Dam thu nhat Dam thu hai
Vong Lap
M (kN.m) Q (kN) N (kN) M (kN.m) Q (kN) N (kN) Vong
Lap 7 - 8
8 - 7
7 - 8 8 - 7
7 - 8 8 - 7
8 - 9 9 - 8
8 - 9 9 - 8
8 - 9 9 - 8 V L 1 -31.9646
12.8874
496.1846 503.8154
101.0897 -101.0897
-460.5763 -855.5379
236.7772 763.2228
50.8713 -50.8713
VL5 -172.9439
-54.2999
454.5228 545.4772
99.6178 -99.6178
-531.4487 -991.1586
195.4754 804.5246
49.8546 -49.8546 Sai
khac
Tuyet doi
-140.9793 -67.1873
-41.6617 41.6617
-1.4719 1.4719
-70.8725 -135.6207
-41.3018 41.3018
-1.0167 1.0167 Sai
khac Tuong doi (%)
441.049 -521.341
-8.396 8.269
-1.456 -1.456
15.388 15.852
-17.443 5.411
-1.999 -1.999
3 8 So thang 3+4 • Nam 2011
D I E N D A N KHOA HOC & CONG NGH&
-sno -50
•4.4 12.0 9.6 7.2 4.8 2.4 0.0 -2.4 -4.8 -7.2 -9.6 -12.0 -14.4 --68 --B.2 -216 -24.C
-48.9TJ3 J -503822
kN
-48.9D3 -50.3822
816J57 53.14a6*X *~" N
665954 J ^S
" 923986 -32402 «2 -6.9869
/ J 1 I 1
\\ \\
0.-665 , 0.3055 I
m 0.0000 0.0000 Hinh 8: Bieu dd noi life trong coc thu" nha't.
a. Mo men uon; b. Life cat.
Dtfcmg net lien: khong xet u6n - doc, Dtfdng net dirt: co xet uon - doc.
Bang 9: So sanh chuyen vj nut Vong lap Chuven vi nut 2
Chuyen vi nut 7 Chuven vi nut 3
Chuyen vi nut 8 Chuven vi nut 4 Chuyen vi nut 9 Vong lap
Ay <P Ax Ay <P Ax Ay <P Ax
VL l KTB
KTC -I.2420.l0'2 -3.6540 10 4 8.8130.10' -1.3670.10 2 -1.4040.10" 8.8120.102 -1.3820 10 2 -3.2330.10' 8 8110.10 2 VL l KTB
KTC -l 2429.10'2 -3.5509.10" 7.7105.10'2 -1.3640.10 2 -1.3329.10" 7.77094.10'2 -1.3646.10'2 -2.2578.10'' 7.77089.10'2 VL 5 KTD
KTC -i.2l70.I0'2 -4.3810.10" 1.2560.10'' -1.3680.10'2 -1.9050.10" 1.2560.10' -1.4070.10'2 1.0220.10" 1.2560.10'' VL 5 KTD
KTC -I.2220.l02 -4.1S02.10-1 J.0526.10' -1.0526.10'! -8.0216,10'' 0.10525 -13960.10'' -1.7458.10" 0.10524 Bang 10: So sanh noi hrc dau epe
Vong 15p Cpc thii nhat Cpc thu hai Cpc thu ba
Vong 15p M 0 N M o N M Q N
VL 1 KTD
KTC 455.251
431.965 -48.922
-48.910 2489.357
2496.185 470.587
447.689 -50.211
-50.218 2740.528
2740.593 477.955
455.538 -50.797
-50 871 2770.116 2763.223 VL 5 KTD
KTC 626.251
572.944 -50.825
-50.382 2438.876
2454 523 637.767
591.159 -49.679
-49.855 2740893
2804.525 642.134
585.749 -49.496
-49.763 2820.140 2740.953 Ghi chii: Ay = chuyen vi thang dung (m); Ax = chuyen vi nim ngang (m); (p = chuyen vi xoay (rad.).
Don vi do: M (kNm); Q (kN); N (kN).
KTD = khung tuong ducmg;
KTC = khung voi tru cpc trong dat.
So thang 3+4 - Nam 2011 3 9
V. K e t l u a n :
5.1. Tiep theo [ 7 ] , b a i viet nay gicti thieu mot giai thuat nCra ciia phirdng phap P T H H de tinh toan chuyen v i - n o i lite ciia CTB tren nen coc theo sd do phiic tap hdn:
killing ngang phang v d i tra coc trong dat.
Tien de cd ban ciia giai thuat nay chu yeu diia vao ldi giai ciia bai toan coc ddn trong nen phan Idp chiu ud'n phiic tap bang phifdng phap PTHH da neu trong [5] va tdng ke't trong [6].
5.2. Tinh toan theo each kien nghi cung dua den mot nhan dinh tho'ng nha't rang anh hifdng ud'n doc trong CTB tren nen cac coc thang diing la rat dang ke, can difdc xet de'n ngay tu" dau.
Hien nay rat nhieu CTB tren nen coc dang difdc thiet ke de tiep nhan tau cd trong tai tu"
nhieu chuc de'n hang tram ngan DWT: chieu cao tif do ciia coc buoc phai tir 20m trd len. Dd la chira ke de'n dieu kien dia chat cdng trinh d rat nhieu diem cang cd Idp da't yeu - day nam tren mat, buoc phai sii dung coc cd chieu dai ldn: 50 ^ 60m.
Hdn nixa each thiet ke hien nay, vi du nhu*
trong [4], trang thai chuyen vi - ndi life ciia ke't cau difdc tinh tu" dieu kien ud'n ngang; so' lieu thu difdc, sau do difdc dung de kiem tra dn dinh ud'n doc ciia cau kien coc.
TAI LIEU THAM KHAO [1]. JU. I . Nhemtrinov:
Tinh toan ket cau khong gian (Phtfdng phap phan tu"
hffu han)
Nha xuat ban "Budivelnhik", Kiev, 1980 (tieng Nga).
[2]. V. V. Babanov, V. P. Perov :
"Chon lach. thtfdc toi' tfu ciia phan tu" khi tinh toan dam tren nen dan hoi bang phUdng phap Phan tu" htfu han".
Cd hoc dat, Nen va Mong, No. 1 (116), Leningrad, 1976. tr. 21-25 (tieng Nga).
[3]. Le Dire Thang:
Tinh toan mong coc.
Nha xuat ban Giao thong Van tai, Ha Noi, 1998.
[4]. Bo Hang Hai (Lien X6 cu):
Htfdng dan thiet ke Cong trinh ben cang bien PD 31.
31. 27 - 81. Matxcdva, v/o "Morteklunphormreklama", 1984 (tieng Nga).
[5], Phan Dung:
"Tinh coc mem chiu uon ngang - doc trong nen nhieu Idp bang phtfdng phap phan ttf htfu han".
Khao sat Thiet ke, No. 2, 1986, Vi£n Thiet ke Giao thong Van tai, Bo Giao thong Van tai, Ha Noi, tr. 33 -
D I E N D A N K H O A H O C & C 6 N G N G H E
Rd rang rang, trong tinh hinh thu'c te' ndi
tren, thiet ke' tinh toan CTB tren nen coc cd xet ud'n ngang - doc tif dau se la giai phap hdp ly hdn.
Muc tieu chinh yeu cua de xuat nay la
xay mot giai thuat ling dung phUdng phap PTHH xac dinh hdp ly trang thai chuyen vi - ndi ltfc trong CTB tren nen coc, nen khdi dau cac bai toan "bang tay" la can thiet. Va cung the viec chia phan t i i coc trong da't chtfa thoa man dieu kien (30), dan de'n ket qua tinh chtfa chinh xac. Tuy nhien, cac sd' lieu so sanh d bang 9 va bang 10 cho thay cung cd the dat dtfdc muc tieu cd ban da dat ra.
Dtfa vao giai thuat nay, mdt phan mem may tinh giup ttf ddng hda tinh toan thiet ke CTB tren nen coc se la btfdc tiep sau.
5.3.Cung nhtf trong [7], giai thuat PTHH dtfdc kien nghi de tinh CTB tren nen coc d day trong dieu kien coc va da't lam viec trong giai doan dan hdi tuye'n tinh.
Tren cd sd ciia each giai nay, neu tfng dung cac de xua't trong [6] de md phong dap tfng dan hdi phi tuye'n ciia coc va da't khi chiu ltfc doc true va chiu life ngang ta cd the xac dinh dtfdc btfc tranh chuyen vi - ndi life trong ke't cau lam viec trong mien dan hdi phi tuyen.
41. [6], Phan Dung:
"Mot so' phtfdng phap tinh toan coc va mong coc".
Bao cao tai Bo mon Cang - Dtfdng thuy, Trtfdng Dai hoc Giao thong Dtfdng thuy Matxcdva 1991, (tie'ng Nga).
[7]. Phan Dung:
"Cach tfng dung phtfdng phap phan ttf htfu han de tinh toan Cong trinh ben tren nen cpc theo sd do khung phang ttfdng dtfdng".
Tap chi Bien va Bd No. /2010, Hoi Cang - Dtfdng thuy - Them luc dia Viet Nam, VAPO, tr.
[8]. Phan Dung:
'Tinh toan cong trinh ben tren nen coc theo sd do khung phang vdi tru coc trong da't bang phtfdng phap phan ttf htfu han".
Tap chi Khoa hoc Cong nghe Giao thong Van tai, No.
2/2008, Trtfdng Dai hoc Giao thong Van tai f p . Ho Ciu Minh, tr. 88-102.
[9]. Phan Dung:
'Tinh toan cong trinh ben tren nen coc theo sd do khung phang bang phtfdng phap Ma tran chuyen tiep".
Tap chi Bien va Bd No. 4/2010, Hoi Cang - Dtfdng thiiy - Them luc dia Viet Nam, VAPO, tr 45-58.
4 0 So thang 3+4 - Nam 2011
