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7/23/2019 AASHTO-TCTK-cauV-09a-Mat Cau Va He Mat Cau
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Tiu chun thit k cu 134
Phn 9 - Mt cu v h mt cu9.1. Phm vi
Phn ny bao gm cc quy nh phn tch v thit k mt cu v h! mtcu b"ng b# t$ng v kim %o&i v cc t' h(p c)a ch*ng chu t+i t,-ng t,-ng %.c/
0i mt cu b"ng b# t$ng %i2n khi tho+ mn cc i2u ki!n ,i#ng (c ph5p thitk th6o kinh nghi!m m kh$ng cn phn tch /
7#n 89ng mt cu v cc c:u ki!n ; n< c< tnh %i#n t=c/
> n?i v2 mt k@ thuAt c< th th.c hi!n (c cn c:u t&o c< tc Bng %i#n h(pgiCa mt cu v cc c:u ki!n ; n mt tip M*c c)a chi tit vXhocc:u ki!n (c ni vi nhau/
C#u ,inD Thi tit kt c:u hoc t' h(p cc chi tit kt c:u Ii hYi W. M6m M5tthit k ,i#ng /
c !ng /in hpD Zi2u ki!n m hai hoc nhi2u chi tit hoc c:u ki!n .occ:u t&o c9ng %m vi!c nhH ng[n ngUa W. 8ch chuyn t?ng i > mt tip M*cc)a ch*ng/
nh /in tcD \,ong mt cuG bao gm tnh %i#n t=c kt c:u v kh+ n[ng ng[nngUa nc thm nhAp m kh$ng cn c< th#m chi tit phi kt c:u/
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Tiu chun thit k cu 13]
Chi%u ca0 /3i c 4a0 t(0ng ,hung c)t th5p D T. %y giCa Fnh c)a ct th5ppha t,#n ti y c)a ct th5p pha 8i c)a b+n b# t$ng/
Mt cuD ^ bB phAn c< hoc kh$ng c< %p ma haoG t,.c tip chu t+i t,-ng
bnh M6 v t.a %#n cc c:u ki!n khc/
$h6 n)i mt cuD _Loc kh6 bin 8&ng / \on bB hoc tUng o&n b ngKtqung c)a mt cu i2u tit chuyn v t?ng i giCa cc phn c)a ktc:u/
7 mt cuD t c:u phn t,#n t,ong < mt cu v c:u ki!n ; n< % mBt
th thng nh:t hoc t,ong < cc hi!u ng %.c hoc bin 8&ng c)a c:u ki!n ;
c< +nh h>ng ng k n W. %m vi!c c)a mt cu/
$h'u ! thit ,D Zi vi mt cu % c. %y tU tim n tim giCa cc c:u ki!n
; %i2n k2G tnh th6o hng ch) yu/
Chi%u 8i hu hiuD Thi2u 8i nhp 89ng thit k th6o kinh nghi!m c)a
b+n b# t$ng th6o Zi2u /d/e/3/
:n h;iD V. p ng c)a kt c:u t,ong < ng Wu:t t %! thuAn vi ng bin v
kh$ng c< bin 8&ng 8 Wau khi 8; t+i/
C < t'ng cc %.c Wong Wong vi b:t kf t,=c no v
t'ng m$ m6n i vi b:t kf t,=c no t,ong kh$ng gian 2u b"ng RGR/
>?i tng ngD OBt c:u ki!n tuyn tnh gi+ nh tch ,a khYi mt cu 89ng
phn tchG t,ong < hi!u ng %.c c.c t, tnh ton cho t+i t,-ng c)a mBt
bnh M6 th6o chi2u ngang hoc chi2u 8-c % M:p MF vi cc tc 8=ng th.c t,ong
b+n/
C@c t( D \i a hoc ti thiu/
nh /in tc chu u)nD h+ n[ng t,uy2n m$ m6n v W. Moay giCa cc c:u
ki!n hoc t,ong c:u ki!n/
>m An D \#n thHng 89ng c)a 8m ngang _O`/
Bt 4nhD i!n tch tip M*c giCa bnh M6 v mt Hng/
c 8ng ,hung D \nh %i#n t=c ngang giCa mt cu v b+n b=ng c)a cc mt
cKt ,Qng hoc giCa mt cu v b+n b=ng/
B t( 4#t /iD 0 t, v hng c)a t+i t,-ng tc thHi gy n#n hi!u ng %.c c.c t,/
$hng n h;i D V. p ng c)a kt c:u t,ong < ng Wu:t kh$ng t %! t,.c
tip vi ng bin v bin 8&ng cIn 8 Wau khi 8; t+i/
Mt tip DEcD 7?i m hai chi tit vXhoc c:u ki!n tip M*c vi nhau/
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Tiu chun thit k cu13
c !ng /in hp 4n t(0ngD V. tc Bng qua %&i giCa mt cu v %p ph) kt
c:u/
F?n Gng hHngD E+n c< nhCng c tnh kt c:u ng nh:t thit yu t,#n
hai hng chnh/
C)t th5p Gng hHngD Lai %p ct th5p ng nh:tG vu$ng g
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Tiu chun thit k cu 13d
$h0 Och)t chu cNtDLc Wn > %2 c:u ki!n *c Wn (c %:p b"ng vCaG
hoc mBt h! cc m:u i tip %i v hc %m > cc mt khc +m b+o tnh
%i#n t=c v2 cKt giCa cc c:u ki!n/
QRc ch50 D
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Tiu chun thit k cu13
TW (WngD ho+ng t,ng kh$ng %i#n t=c > b#n t,ong mt cu %m gi+m t.t,-ng/
Mt cu ,h05t (WngD Ot cu b# t$ng t,ong < 8i!n tch kho5t ,Qng kh$ng
kh$ng %n h?n 4RS t'ng 8i!n tch/
Fnh D6D OBt hoc mBt $i %p > mBt u c)a t,=c M6
?i t(Xng 4nh D6D OBt nra t+i t,-ng t,=c thit k th6o quy nh/
THp mt chu mi m"nD ^p c< th m:t i c)a kt c:u mt cu hoc %p ph) b+o v! kt c:u mt cu chng mi mInG mui Hng v tc Bng c)a m$it,Hng/ ^p ph) c< th bao hm c+ phIng nc/
:+ng ch?L 8Y0 D ZHng ch+y 8so t,ong biu quan h! ng Wu:t D bin 8&ng
Ph 8i c< th %Kp WHn c)a b+n t,.c hng _mm`
_//3/d/4`6 c. %y t,ng giCa cc WHn kn > b+n mt cu th5p t,.c hng _mm`_//3/d/4`/
h chi2u 8i c)a phn nghi#ng c)a b+n b=ng WHn _mm` _//3/d/e`
V chi2u 8i hCu hi!u c)a nhp _mm` _/d/3/e`/
t chi2u 8y c)a b+n hoc t:m _mm` _//3/d/1 /
t8G6 ch2u cao hCu hi!u c)a b+n mtG bao gm hi!u ng %m t[ngB cng c)a %p mt
_mm` _//3/d/e`/
t, chi2u 8y c)a b+n b=ng WHn _mm` _//3/d/e`/
9.\. Cc Lu cu thit , chung
/4/1/ \c Bng > mt tip M*c
Ot cu kh$ng ph+i %o&i Wn %i h>G ph+i (c %m %i#n h(p vi cc c:u ki!n ;ch*ngG t,U khi c< nhCng %w 8o buBc ph+i %m khc i/ Ot cu kh$ng %i#n h(p ph+i(c %i#n kt vi c:u ki!n ; phIng W. tch thjng ng/
Tc m:u n6o chu cKt hoc cc %i#n kt khc giCa mt kh$ng ph+i %o&i Wn %i h> vcc c:u ki!n ; ch*ng ph+i (c thit k th6o hi!u ng %.c tnh ton t,#n c? W> tc
Bng %i#n h(p y ) 89 cho tc Bng %i#n h(p < c< (c M5t n hay kh$ng t,ong
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Tiu chun thit k cu 13
khi nh kch thc cc c:u ki!n ch) yu/ Tc chi tit t,uy2n %.c cKt qua mttip M*c vi c:u ki!n ; b"ng th5p cn thYa mn cc quy nh thch h(p > Zi2u //
Ph+i c:u t&o hCu hi!u ng %.c giCa mt cu v cc chi tit ph= hoc c:u
ki!n khc/
/4/e/ \hot nc mt cu
\,U mt cu b"ng %i th5p kh$ng ph) knG mt cu ph+i %m 8c ngang v 8c8-c th6o quy nh > Zi2u e/// Li!u ng kt c:u c)a cc %Q thot nc ph+i (cM5t n t,ong thit k mt cu/
/4/3/ Tc chi tit ph= b"ng b# t$ng
\,U khi Th) u t c< quy nh khc iG cc b< vFaG tIng phIng hBG %an canG %an
can $ t$ v tHng phn cch ph+i (c %m %i#n t=c v2 mt kt c:u/ 6m M5t W.tham gia v2 mt kt c:u c)a ch*ng vi mt cu cn (c gii h&n ph9 h(p vi cc
quy nh > Zi2u /]/1/
/4/4/ E! ; m5p
\,U khi b+n mt cu (c thit k chu t+i t,-ng bnh M6 > v t, m5pG cc
m5p b+n c< b! ;/ m ; m5p kh$ng y ) cn ph9 h(p vi cc quy nh >
Zi2u /d/1/4/
/4/]/ 0n khu$n %&i cho bB phAn hxng
0n khu$n %&iG ngoi %o&i 89ng > mt cu b"ng th5p (c %:p knG kh$ng (c
89ng t,ong phn hxng c)a mt cu b# t$ng/
9.]. Cc t(ng thi giHi hn
/]/1/ \'ng qut
0i!c c9ng tham gia chu %.c vi mt cu c)a cc chi tit b# t$ng c< th (c M5t
n cho t,&ng thi gii h&n Wr 8=ng v mYi nhng kh$ng (c M5t cho t,&ng thi giih&n cHng B v c bi!t/
\,U phn mt cu hxngG n?i no tho+ mn (c cc i2u ki!n ghi > Zi2u /d/e
thN c< th M6m nh mt cu b# t$ng thYa mn cc y#u cu c)a cc t,&ng thi gii
h&n Wr 8=ngG mYiG c bi!t v cHng BG v kh$ng cn ph+i thYa mn cc quy
nh khc c)a Zi2u /]/
/]/e/ \,&ng thi gii h&n Wr 8=ng
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Tiu chun thit k cu14R
> t,&ng th i gii h&n Wr 8=ng mt cu v h! mt cu ph+i (c phn tch nh %
mBt kt c:u hon ton n hi v ph+i .oc thit k v c:u t&o thYa mn
cc quy nh > cc phn ] v /
Tc hi!u ng c)a bin 8&ng mt cu q*a mc cn (c M5t > cc mt cu kh$ng
%m b"ng b# t$ng v mt cu th5p c< %:p b"ng b# t$ng/
/]/3/ \,&ng thi gii h&n mYi v t gy
OYi kh$ng cn ph+i kh+o Wt i vi
Ot cu b# t$ng v mt cu 8&ng m&ng 8m %:p y t,ong cc kt c:u c Zi2u
/]/3/
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Tiu chun thit k cu 141
Ot cu b# t$ng kh$ng ph+i % mt cu nhi2u 8m ph+i (c kh+o Wt v2 t,&ng
thi gii h&n mYi ghi > Zi2u ]/]/3/
/]/4/ \,&ng thi gii h&n cHng B> t,&ng thi gii h&n cHng B mt cu v h! mt cu c< th (c phn tch nh
kt c:u n hi hoc kh$ng n hi v cn (c thit k v c:u t&o thYa
mn cc quy nh > Phn ] v /
/]/]/ \,&ng thi gii h&n c bi!t
Ot cu ph+i (c thit k th6o hi!u ng %.c t,uy2n tU Ma v t' h(p t+i t,-ng
89ng cho %an canG cc bi!n php phn tch v t,&ng thi gii h&n ghi > Phn 13/
\h nghi!m nghi!m thuG ph9 h(p vi Phn 13G c< th (c 89ng thYa mn ccy#u cu ny/
9.^. p7 Zi2u 4//e/1G hoc
ph?ng php chnh Mc > Zi2u 4//3/eG hoc thit k b+n b# t$ng th6o kinh
nghi!m > Zi2u /d cho cc t,&ng thi gii h&n khc nhau cho ph5p t,ong Zi2u /]/
//e/ \+i t,-ng
\+i t,-ngG v t, t+i t,-ngG 8i!n tch tip M*c c)a %p M6 v cc t' h(p t+i t,-ng
cn ph9 h(p vi cc quy nh c)a Phn 3/
9._. F?n mt cu 4 tng
/d/1/ \'ng qut
9._.1.1. Chi%u 8L t)i thiSu v /Hp 4?0 v
\,U khi (c Th) u t ch:p nhAnG chi2u 8y b+n mt cu b# t$ngG kh$ng bao
gm b:t kf 8. phIng no v2 mi mInG M Zi2u ]/1e/3/
9._.1.2. c !ng /in hp
O:u n6o chu cKt ph+i thit k ph9 h(p vi cc quy nh > Phn ] cho 8m b#
t$ng v Phn cho 8m kim %o&i/
9._.1.Z. Mt cu ch50
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Tiu chun thit k cu14e
7u g
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Tiu chun thit k cu 143
9._.1.\. F ` m5p
\,U khi c< quy nh khcG > Hng t o&n tc m5p c)a b+n mt cu ph+i (ct[ng cHng hoc ; b"ng 8m hoc c:u ki!n 8&ng tuyn/ m hoc c:u ki!n
ny ph+i (c %m %i#n h(p hoc h(p nh:t vi mt cu/ m m5p c< th thit knh mBt 8m c< chi2u ,Bng %:y b"ng chi2u ,Bng hCu hi!u c)a mt cu th6o Zi2u4//e/1/4/
> n?i hng chnh c)a mt cu % hng ngang vXhoc mt cu % %i#n h(p vi baD,iD6 b# t$ng %i#n t=c v kt c:u thN kh$ng cn %m th#m 8m m5p/
9._.1.]. hit , 4?n hng
Phn b+n hxng c)a mt cu ph+i (c thit k chu t+it,-ng va Ap vo %an can v ph9 h(p vi cc quy nh > Zi2u
3//1/3/Li!u ng cKt Muy#n th)ng > chn pha ngoi c)a cBt %an can hoc baD,iD6 8o t+it,-ng va Ap c)a M6 ph+i (c kh+o Wt/
/d/e/ \hit k th6o kinh nghi!m
9._.2.1. Vng but
Tc quy nh c)a Zi2u /d/e chF %i#n quan n ph?ng php thit k th6o kinhnghi!m i vi b+n mt cu b# t$ng t t,#n cc c:u ki!n 8-c v kh$ng (c p
8=ng cho b:t kf i2u no khc t,ong phn nyG t,U khi c< quy nh ,i#ng/Tc thanh ct th5p 8-c jng hng c< th tham gia chu m$ m6n un > cc gigiCa c)a cc kt c:u %i#n t=c/
9._.2.2. ng 8ng
\hit k mt cu b# t$ng ct th5p th6o kinh nghi!m c< th (c 89ng nu thYamn cc i2u ki!n ghi > Zi2u /d/e/4/
Tc quy nh c)a i2u ny kh$ng (c 89ng cho phn hxng/ Phn hxng cn (cthit k vi
\+i t,-ng bnh M6 cho mt cu c< %an can v baD,iD6 kh$ng %i#n t=c b"ng ph?ngphp 8+i t?ng ?ngG
\+i t,-ng 8&ng tuyn t?ng ?ng cho mt cu c< baD,iD6 %i#n t=c ghi > Zi2u3//1/3/4G v
^.c va 89ng c? c:u ph ho&i ghi > Zi2u z13/e/
9._.2.Z. Chi%u 8i hu hiu
Z 89ng ph?ng php thit k th6o kinh nghi!mG chi2u 8i hCu hi!u c)a b+n (c%:y nh Wau
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Tiu chun thit k cu144
0i b+n *c %i2n khi vi vch hoc 8m c. %y tU mt n mtG
0i b+n t.a t,#n 8m th5p hoc 8m b# t$ng c. %y giCa Fnh nch cBng
th#m phn nch c< ngha % c. %y tU Fnh nch b#n kia n b+n b=ng b#n
ny b:t k g chQ nch t&i cc b+ncnh 8m v nhCng chQ t[ng 8y c=c bB khc/
\ %! giCa chi2u 8i hCu hi!u v chi2u 8y thit k kh$ng (c v(t qu 1/R
v kh$ng (c t h?n GR/
Thi2u 8y phn %ic)a b+n kh$ng (c t h?n 1RRcm
>m 1
Thi u 8i c< hi u
^:y t,W % n h?n t,ong hai t,W>m 2
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Tiu chun thit k cu 14]
Thi2u 8i hCu hi!u th6o quy nh t,ong Zi2u /d/e/3 kh$ng (c v(t qu
41RRmm
Thi2u 8y b+n ti thiu kh$ng (c t h?n 1d]mm ngo&i t,U %p mt chu
t'n th:t 8o mi mIn nu c
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Tiu chun thit k cu14
THng B quy nh e ngy c)a b#t$ng b+n mt cu kh$ng (c nhY h?n
e/R OPa
Ot cu (c %m %i#n h(p vi cc c:u ki!n c)a kt c:u ;/
Z p 8=ng i2u kho+n nyG ph+i %m t nh:t hai n6o chng cKt vi c. %y tim
n tim % RRmm t,ong v9ng m$m6n m c)a kt c:u phn t,#n %i#n t=c
b"ng th5p/ Tc quy nh c)a Zi2u /1R/3 c{ng ph+i (c tho+ mn/ Zi vi cc
8m b#t$ngG cc ct ai k5o 8i vo t,ong mt cu ph+i coi nh tho+ mn y#u
cu ny/
9._.2.]. Cc Lu cu v% c)t th5p
Ph+i t 4 %p ct th5p jng hng t,ong b+n thit k th6o kinh nghi!m/ Tt
th5p ph+i t cng gn cc mt ngoi cng tt nh cc Ii hYi v2 %p b+o v!
cho ph5p/ Tt th5p ph+i (c t t,ong mQi mt c)a b+n vi %p ngoi c9ng t
th6o ph?ng c)a chi2u 8i hCu hi!u/ V %(ng ct th5p ti thiu b"ng RG]dR
mmeXmm th5p cho mQi %p y v RG3R mmeXmm th5p cho mQi %p Fnh/ T. %y
ct th5p kh$ng (c v(t qu 4]R mm/ Tt th5p c:p 4RR hoc h?n/ \on bB ct
th5p % cc thanh thjngG t,U cc m cc chQ c< y#u cu/ ThF (c 89ng mi ni
chAp u/
7u g c+ hai hng cn (c t[ng g:p
$i > v9ng cui b+n mt cu/ OQi v9ng cui b+n ph+i M5t n mBt c. %y 8-c 8i
b"ng chi2u 8i hCu hi!u c)a b+n (c n#u > Zi2u /d/e/3
9._.2.^. Mt cu vHi vn ,hun S /i
Zi vi mt cu %m b"ng vn khu$n th5p g(n W hng chnh chu m$ m6n 8?ng 8i y
cho ct th5p hng chnh Wong Wong vi %n M6 S]RVX1d]R
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Tiu chun thit k cu 14d
cho ct th5p chnh vu$ng g y
V chi2u 8i nhp hCu hi!u %:y b"ng chi2u 8i hCu hi!u > Zi2u /d/e/3_mm`
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Tiu chun thit k cu14
/d/4 / 0n khu$n %&i
9._.\.1. Vng but
0n khu$n %&i ph+i (c thit k n hi 8i t+i t,-ng thi c$ng/ \+i t,-ng thi
c$ng kh$ng (c %:y nhY h?n t,-ng %(ng c)a khu$n v b+n b# t$ng cBng vi e/4
1RD3OPa/
ng Wu:t un 8o t+i t,-ng thi c$ng kh$ng c< h! W kh$ng v(t qu
d]S cHng B ch+y c)a th5pG hoc
]S cHng B chu n5n > e ngy tu'i c)a b# t$ng chu n5nG hoc cHng B
chu k5o c)a pan6n vn khu$n 8. ng %.c/
Ein 8&ng n hi gy ,a b>i t. t,-ng vn khu$nG b#t$ng t v ct th5pkh$ng (c v(t qu
Zi vi chi2u 8i nhp vn khu$n tU 3RRR mm t,> MungG b"ng chi2u 8i
nhp vn khu$n chia cho 1R nhng kh$ng v(t qu mmG hoc
Zi vi chi2u 8i nhp vn khu$n %n h?n 3RRRmm b"ng chi2u 8i nhp vn
khu$n cho e4R nhng kh$ng v(t qu eRmm
9._.\.2. Bn ,hun th5p
Pan6n ph+i (c quy nh %i#n kt vi nhau v2 c? h-c > u chung v cBt cht
vi gi ;/ h$ng (c ph5p hn vn khu$n th5p vo c:u ki!n ; t,U khi (c n#u
t,ong h W? h(p ng/
0n khu$n th5p kh$ng (c M5t %m vi!c %i#n h(p vi b+n b# t$ng
9._.\.Z. Bn ,hun 4 tng
9.7.4.3.1. Chiu dy
Thi2u 8y vn khu$n %&i b"ng b# t$ng kh$ng (c v(t qu ]]S chi2u 8y c)ab+n Wau khi hon thnh v c{ng kh$ng (c nhY h?n R mm/
9.7.4.3.2 . Ct thp
Pan6n vn khu$n b"ng b# t$ng c< th t&o 8. ng Wu:t th6o ph?ng c)a nhp thit
k/
7u khi b+n *c t,c % b+n 8. ng %.c thN cc b< cp c< th (c coi % ct th5p
chnh c)a b+n mt cu/ 0i!c t,uy2n v k5o 8i cc b< cp cn (c kh+o Wt
t,ong i2u ki!n thi c$ng v khai thc/
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Tiu chun thit k cu 14
E< cp 8. ng %.c v thanh ct th5p > t,ong pan6n *c t,c kh$ng cn ph+i k5o
8i %#n phn b# t$ng ' t&i chQ pha t,#n 8m
7u (c 89ngG ct th5p phn b > pha 8i c< th t thjng %#n Fnh pan6n/
Oi ni c)a ct th5p ch) > pha t,#n c)a b+n mt cu kh$ng (c t t,#n cc
mi ni pan6n/
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Tiu chun thit k cu1]R
^p b# t$ng b+o v! > pha 8i cc b< cp kh$ng n#n nhY h?n eR mm/
9.7.4.3.3. Khng ch t bin v co ngt
\u'i c)a b# t$ng pan6n t&i %*c ' b# t$ng t&i chQ cn tnh Wao cho ch#nh %!chgiCa c+ co ng
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Tiu chun thit k cu 1]1
9._.^.2. M)i n)i mt cu
Tc mi ni mt cu c)a cu phn o&n *c Wn c< th % ni kh$G 8n k6o >mt tip M*c hoc ' b# t$ng t&i chQ _ni t`/
THng B c)a mi ni b# t$ng ' t&i chQ kh$ng (c th:p h?n cHng B c)a b#t$ng *c Wn/ E2 ,Bng c)a mi ni b# t$ng ph+i cho ph5p t,in khai ct th5p >mi ni hoc chQ ni c)a cc ng b-c nu c
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Tiu chun thit k cu1]e
7u mt cu (c %:p y hoc %:p mBt phn (c coi % %i#n h(p vi cc c:u ki!n
; n< t,ong thit k cc c:u ki!n ny thN chi2u ,Bng hCu hi!u c)a b+n t,ong
mt cKt %i#n h(p cn %:y th6o Zi2u 4//e/1/e
9.e.2.2. *n mng 8m hJ
Vn m&ng 8m h> ph+i (c %i#n kt vi c:u ki!n ; b"ng hn hoc Mit c? h-c >
mQi chi tit chnh/ > n?i 89ng hn %i#n kt c< th 89ng cch hn mBt pha vi
mi hn 8i d] mm hoc hn c+ hai pha vi mi hn 8i 4R mm/
\,U khi c< cc c[n c khcG hn t,ong Wn m&ng 8m h> cn (c coi % chi tit ^o&i
|v cn p 8=ng cc quy nh c)a Zi2u //
7/23/2019 AASHTO-TCTK-cauV-09a-Mat Cau Va He Mat Cau
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Tiu chun thit k cu 1]3
ZuG cui v m5p Wn m&ng 8m h> c< th cho M6 ch&y qua ph+i (c ; b>i cc
thanh h(p %ong hoc b"ng cch khc hCu hi!u qu+/
9.e.2.Z. Mt cu 8ng mng 8m c /#p L h0c /#p m!t phn9.#.2.3.1. $%ng &u't
^o&i mt cu ny bao gm m&ng 8m th5p hoc h! kt c:u th5p khc (c %:p
y hoc %:p mBt phn b"ng b# t$ng/ Tn p 8=ng Zi2u //e/1 cho mt cu
8&ng m&ng 8m (c %:p y hoc %:p mBt phn/
> chQ c< th cn %m %p ph) kt c:u 8y 4RGRmm/
O&ng 8m (c %:p y hoc %:p mBt phn ph+i (c ni vi c:u ki!n ; b"ng
hn hoc inh n6o t,uy2n %.c cKt giCa hai mt/
9.#.2.3.2. C'c y(u c)u thit *
\,-ng %(ng b# t$ng %:p (c gi+ nh % hon ton 8o phn th5p c)a mt cu
chu/ \+i t,-ng t,uy2n qua v tnh t+i ch:t th#m c< th gi+ nh 8o cc thanh
c)a m&ng 8m c9ng %m vi!c vi b# t$ng %:p chu/ ^p ph) b# t$ng c< th coi %
mBt bB phAn c)a mt cu %i#n h(p v2 kt c:u
9.#.2.3.3. $+,ng th'i gi-i h,n /i v 01t gy
^i#n kt b#n t,ong giCa cc bB phAn c)a m&ng 8m th5p > mt cu 8&ng m&ng
8m (c %:p y kh$ng cn ph+i M5t n mYi/
0i m&ng 8m (c %:p mBt phn thN %i#n kt b#n t,ong giCa cc bB phAn c)a m&ng
8m th5p > phn b# t$ng %:p kh$ng cn ph+i M5t n mYi/ Tc %i#n kt hn b#n
t,ong giCa cc bB phAn c)a m&ng 8m th5p m kh$ng (c %:p b# t$ng ph+i (c
coi % cc chi tit ^o&i |t,U khi c< chng minh khc/
9.e.2.\. Mt cu 8ng mng 8m ,hng /#p /in hp vHi 4?n 4 tngc)t th5p
9.#.2.4.1. $%ng &u't
Z tho+ mn cc y#u cu c)a Zi2u //e/1G Wn 8&ng m&ng 8m %i#n h(p kh$ng %:p
c< th bao gm mBt m&ng 8m th5p kh$ng %:p hoc h! kt c:u th5p (c %m
%i#n h(p vi b+n b# t$ng ct th5p t t,#n mt c)a mt cu th5p kh$ng (c %:p/
\c Bng %i#n h(p giCa b+n b# t$ng v m&ng 8m mt cu ph+i b+o +m b"ng
cc m:u n6o hoc b"ng bi!n php hCu hi!u khc c< th chu (c %.c cKt ngang
v ng > mt tip M*c c)a cc c:u ki!n/
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Tiu chun thit k cu1]4
\c Bng %i#n h(p giCa mt cu 8&ng m&ng 8m v c:u ki!n ; cn (c +m
b+o b"ng cc m:u n6o chu cKt c? h-c/
Ph+i p 8=ng cc quy nh c)a Zi2u //e/ \,U khi c< quy nh khc/
Tc mi ni kh$ng %i#n t=c v nguBi > %o&i mt cu ny cn h&n ch > mc ti
thiu/
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Tiu chun thit k cu 1]]
9.#.2.4.2. $hit *
\hit k b+n b# t$ng ph+i ph9 h(p vi cc quy nh > Phn ]G ngoi ,a c< th 89ng
mBt %p ct th5p cho mQi hng chnh/
Ot tip M*c giCa b+n b# t$ng v h! th5p ph+i tho+ mn cc quy nh c)a Zi2u
/1R/d/4
9.#.2.4.3.$+,ng th'i gi-i h,n /i
Ph+i p 8=ng cc quy nh v2 mYi c)a Zi2u //e/e/ E+n b# t$ng ct th5p %i#n h(p
ph+i (c a vo tnh ton bi#n B ng Wu:t/
//3/ Ot cu b+n th5p t,.c hng
9.e.Z.1. Vng but
Ot cu th5p t,.c hng ph+i bao gm b+n mt cu (c %m cng v t[ng cHng
b>i cc WHn 8-c v 8mDWn ngang/ E+n mt cu ph+i %m vi!c nh % b+n cnh
chung c)a cc WHn 8m Wn v cc c:u ki!n 8-c chnh c)a cu/
\,ong khi kh$i ph=cG nu mt cu t,.c hng (c ; b>i cc 8m Wn hi!n c< thN
%i#n kt giCa mt cu v 8m Wn cn thit k cho tc Bng %i#n h(p hon tonG
89 cho hi!u ng c)a tc Bng %i#n h(p (c bY qua t,ong thit k 8mDWn/ > n?i
c< thG cn %m cc %i#n kt ph9 h(p t&o tc Bng %i#n h(p giCa mt cu v ccc:u ki!n 8-c ch)/
9.e.Z.2. Ph Zi2u
3//1/e/]
9.e.Z.Z. THp mt ha0 m"n
^p mt hao mIn cn (c coi % mBt bB phAn c:u thnh c)a h! mt cu t,.c hD
ng v ph+i (c %i#n kt vi Fnh c)a b+n mt cu/
T< th M5t ti W.
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Tiu chun thit k cu1]
Li!u ng %.c t,ong %p mt v > mt tip M*c vi b+n mt cu ph+i (c kh+o Wt
c< M5t n cc c tnh k@ thuAt c)a %p mt > nhi!t B khai thc c.c t, cho
t,c/
\c Bng %i#n h(p 8i h&n giCa b+n mt cu v %p mt haomIn ph+i (c %w gi+i b"ng th nghi!m tnh t+i v t+i t,-ng chukf/
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Tiu chun thit k cu 1]d
Z thit k %p mt hao mIn v W. 8nh kt c)a n< vi b+n mt cuG %p mthao mIn (c gi+ nh % %i#n h(p vi b+n mt cu b:t k % b+n mt cu c< (cthit k t,#n c? W> < kh$ng/
9.e.Z.\. Ph y/
> t,&ng thi gii h&n Wr 8=ngG mt cu cn tho+ mn cc y#u cu quy nh > Zi2ue/]/e/
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Tiu chun thit k cu1]
hi M5t t,&ng thi gii h&n cHng B i vi t' h(p cc hi!u ng %.c c=c bB v t'ngth ph+i p 8=ng cc quy nh c)a Zi2u /14/3/
Tc hi!u ng m:t 'n nh 8o n5n c)a mt cu t,.c hng cn (c kh+o Wt >
t,&ng thi gii h&n cHng B/ 7u m:t 'n nh kh$ng khng ch thN Wc khngc)a b+n mt cu t,.c hng ph+i 8.a vo vi!c &t n gii h&n ch+y > m-i imc)a mt cKt/
0i t,&ng thi gii h&n mYiG cc quy nh c)a Zi2u //1/eG E+ng //1/e/3De ph+i p
8=ng cho mYi 8o t+i t,-ng/ Tc quy nh c)a Zi2u //1/3/3 vi cc y#u cu chi
tit c)a Zi2u //3/d p 8=ng cho cc c:u ki!n chu mYi 8o MoKn/
9.e.Z._. fu cu c#u t0
9.#.3.7.1. Chiu dy ti thi@u cA! bBn
Thi2u 8y t c)a b+n kh$ng (c nhY h?n 14GR mm hoc 4S c)a c. %y %n h?n
giCa cc b+n b=ng WHn/
9.#.3.7.2. n *;n
Thi2u 8y c)a WHn kn kh$ng (c nhY h?n GRmm/
ch thc mt cKt c)a mt cu th5p t,.c hng tho+ mn
~ht
at
36v/8
3
,
4RR _//3/d/eD1`
> y
t, chi2u 8y c)a b+n b=ng WHn _mm`l
t8/6 chi2u 8y hCu hi!u c)a b+n mt cu c< M5t n hi!u ng cng c)a
%p mt nh quy nh t,ong Zi2u //3/3 _mm`l
a c. %y %n h?n giCa cc b+n b=ng WHn _mm`l
h chi2u 8i c)a phn nghi#ng c)a b+n b=ng WHn _mm`
Phn b#n t,ong c)a WHn kn ph+i (c bt kn
E"ng cc mi hn %i#n t=c > mt tip M*c giCa WHn v b+n mt cuG
> cc mi ni WHn b[ng hnG v
> cc vch ngang > u cc WHn/
Tho ph5p cc mi hn c< B th:u RS giCa b+n b=ng c)a WHn kn vi b+n mt
cu/
9.#.3.7.3. i hn *hDng cho php E(n t c)u t+Fc h-ng
7/23/2019 AASHTO-TCTK-cauV-09a-Mat Cau Va He Mat Cau
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Tiu chun thit k cu 1]
h$ng cho ph5p hn cc thit b ph=G cc gi ; thit bG cc m
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Tiu chun thit k cu1R
9.#.3.7.4. Chi tit t c)u v 8n
Tc mi ni mt cu v WHn ph+i (c hn hoc Mit cht c? h-c b"ng bu %$ng cDHng B cao th6o chi tit cho > b+ng //1/e/e v LNnh 1/ VHn cu ch&y %i#n t=c
qua cc %Q cKt t,#n b+n b=ng 8mDWn nh t,#n LNnh 1/ Oi hn i u cKtm5p mBt b#n t,#n thanh !m (c %&i/
Oi hn %i#n t=c c< thanh !m 8i/
7nh 9.e.Z._.\-1- Cc Lu cu c#u t0 )i vHi mtcu t(@c hHng
Oi hn gi u cKt m5p mBt b#n\,#n thanh !m ( c %& iOi hn g b=ng
hi ch* c hX3 ti thi ub"ng d] mm Oi c c m5p hn kh$ng( c bao quanh
b V Hn giao nhau v i 8m Wn
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