- Dung cho d~p vira d6n Ian hay vilng c6 s~n da.
b. B(jph(m thoatmro-c kiiu ap mai
1\1
s
-
V MNHLmax
2m
DuOng baD hoa
L&p da x8p
L&p soi l,?c ~ L&p cat l,?c
Hinh 4.4. B{>ph(ln thoat nucYcki8u ap mlii
- C6 d(lng mQt lap phu b~ng da d6 hay da x6p vii c6 b6 tri t~ng IQc nguQ'c d~ch6ng x6i ng~m cho than va n~n d~p. ch6ng x6i ng~m cho than va n~n d~p.
- Cao triOO diOO(Dam) phiii cao hon di~m ra cao OO&tcua duang biio hoa t6i thi~ula: la:
V6'i d~p e&p III (theo TCXDVN 285:2002) traxu6ng la 1,5 m. V 6'i d~p cAp I va II (theo TCXDVN 285 :2002) la 2,0 m
- Chi~u day lap da amai ill (25 +30)cm, achan d~p;:0: 1,Om.
- Ph~n a chan d~p: Cao dQ day aph~n chan d~p phai th&p hon m(it n~n it nh&t1,Om va phu rQng ra h6t chan d~p it ooit ill (2 + 3)m (HiOO4.4). 1,Om va phu rQng ra h6t chan d~p it ooit ill (2 + 3)m (HiOO4.4).
- T~p trung dong th&mathan va n~n d~p d~ diin v~ h(lluu.- Ch6ng x6i ng~m cho than d~p va n~n d~p. - Ch6ng x6i ng~m cho than d~p va n~n d~p.
- Ch6ng s6ng cho mai h(lluu.
- Kh6ng h(l th&p duQ'c duang biio hoa trong than d~p.
- C6 it tac d\lng t6t OOu 10(li ki~u lang tf\l OOung kh6i luqng 006 nen it t6n kinhphi. phi.
- Dung cho d~p000.
Ngoili cac hiOOthUc b<)ph~ thoM nuac da triOOMy atren tuy theo di6u ki~n su d\ll1g,v~t li~u, yeu du phong th~m, quy mo cong trinh ... co th6 dung hiOOthuc b<) pMn thoM nuac ki6u h6n hQ'P.Khi m\lCnuac h<;1luu thay d6i nhi6u, dUng hinh thuc b<)ph~ ki6u h6n hQ'P:Lang tI'\IthoM nuac k~t hQ'Pki6u ap mai Iii thich hQ'P.
4.3. D~PBE TONG TRQNG LVC4.3.1. Khlii ni~m 4.3.1. Khlii ni~m
D~p betong tr9ng l\lc lillo<;1id~p co kh6i lugng betong (hoi,icda xay) Ian vii duqc gift 6n dinh nha tr9ng lugng Cllaban than.
LO<;1id~p nily thuang duqc xay tren n6n da. Cling co tmang hQ'Pd~p xay tren n6n d~t, nhung khi do day d~p phai rnar<)ngvii phi'lixu ly kha t6n kern.
D~p be tong tr9ng l\lc thuang gi,ipa cae cong trinh dang nuac khong co di6u ti~t nuac (khong t<;10thi'lnh h6 chua) tren song su6i, a cac h6 chua mil khong co di6u ki~n Iilm tran xa Iii ngoili cong triOOdang nuac hoi,icdi6u ki~n Iilm d~p d~t, d~p da kho, kinh phi d&t...hoi,ickhi d~p cao n~u Iilm d~p d~t, d~p da d<)an toiln se khong cao.
D~p be tong tr9ng l\lc thuang thuang co kiOOphi d&than d~p d~t, d~p da; vi~c thi cong doi hoi v6 ky thu~t caohan.
M<)ts6 di6m cfrn chu y khi xay d\lllg 10<;1id~p nily la: yeu du v6 n6n luang d6i cao, betong kh6i Ian kho toa nhi~t nen cfm b6 tri kh6i d6 va cac khe thi cong hQ'PIy d6 tranh cho be tong khoi bi nUtne do irng su~t nhi~t.
V6 v~t li~u lam d~p tmac day su d\lng da xay hoi,icbe tong thuang. Giin day, cong ngh~ be tong diim liin da duqc pMt tri6n va ph6 bi~n r<)ngrai. Di,icdi6m chinh Clla d~p be tong diim lim Iii su d\lng it xi mang, do do h<;1nch~ duqc kha nang toa nhi~t Cllakh6i d6. Ngoili ra, trong thi cong su d\lng cong ngM rai - san - diim timg lap nhu khi d&pd~p d~t nen tang nhanh duqc t6c d<)thi cong va giam kh6i lugng c6p pha. 0Vi~t Nam, cac d~p Dinh Binh (tinh Binh Dinh) va Play Krong (tinh Kon Tum) Iii nhiing cong trinh diiu tien su d\lllg cong ngh~ nay..
D~p tran co th6 b6 tri cua van hoi,iccua phai d6 di6u ti~t. Nhiing uu di6m chinh clla d~p be tong tr9ng l\lc la:
- Co th~ k~t hQ'Ptran nuac qua than d~p, do do khi b6 tri cong trinh diiu m6i, khong ciin phai di,itduang tran xa Iiiangoai than d~p.
- C6 th~ b6 tri diin dong thi cong qua d~p dang xay do. Vi~c thi cong d~p it chiu aOOhuang cUa thai ti~t han so vrn.d~p dilt.
4.3.2. Phan 10l1-i
Theo k~t ciiu, d~p be tong tr9ng h,rcc6 cac 10l;lisau (HiOO4.5):
a. b. e. d. e.
Hlnh 4.5. Cae d~ng m~t d.t d~pbetong tr9ng h,re
a. f)~p d~e b. f)~p tr9ng h,rekhe r6ng e. f)~p co khoet 161611 (ysat nSnd. f)~p co neo vilo nSn e. f)~p ki€u ngiin h\>p d. f)~p co neo vilo nSn e. f)~p ki€u ngiin h\>p
1. D(lp tn;mg !tee age hay tJrj.ptrrng !tee truyJn thlmg (Hinh 4.5a)
Miittciit ca ban thuOng la hiOOtam giac hay da giac. LOl;limlY c6 k~t ciiu dan gian OOungsu d\mg OOi~uv~t li~u be tong, k~t du be tong kh6i Ian kh6 toa OOi~t.f)~
khiic ph\lc OOugcdi~m mlY, c6 th~ xet d~n cac 10l;lid~p tr9ngh,rc cai ti~n sau day.
2. D(lp trrng !tee khe r6ng (Hinh 4.5b)
Cac d~p thu(Jc 10l;linay dugc chia thaOOOOi~udan nguyen, giua cac dan nguyen c6 khe rna T(Jngd~ giam kh6i lugng be tong, mng kha nang toa OOi~t.
3. D(lp eo khoet 1616n asat nJn (Hinh 4.5e).
Ngoai tac d\lllg ti~t ki~m v~t li~u va dS toa OOi~t,16Ian a sat n~n d.n co th~ k~t hgp lam Moo lang khoan ph\lt vua vao n~n, Moo lang thoat nuac thilm hay b6 tri gian may cua trl;lmthuy di~n (d6i vai cac d~p Ian).
4. D(lp eo neo VaG nJn (Hinh 4.5d).
Cac thep lIng suilt truac diitt6 sat miittthugng luu d~p dugc neo chiittvao n~n da t6t nen tang cuOng dugc 6n diOOvalol;li tm dugc kha nang sinh lIng suilt keo 6 miitt nay. Nh6 v~y b~ r(Jng day d~p c6 th~ lam nho han so vai d~p truy~n th6ng.
5. D(lp kiiu ngan h(Jp (Hinh 4.5e).
Vrn.10l;lid~p nay, cac vach cua ngan h(Jp la cac tilm be tong liip ghep hoiitcd6 tl;li ch6, trong h(Jp dugc d6 d~y dilt, da d~ tang tr9ng lugng cho d~p, dam bao di~u ki~n 6n dinh ch6ngtrugt.
r(l-n)b (l-n)b
1 biZ fb biZ :t
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4.3.3. Mi,it cit cua d~pbe tong trQng Il}'c
1. Mi;it c6t c(!ban
M(it c&t co bim ella d~p co hinh d(lng tam giae, ap h;rethllY tInh aphla thuqng luu tae dl,ll1gvao d~p cling la d(lllg tam giae.
Khi thi~t k~ m(it c&tco ban thuemg xuftt phat ill ba di~u ki~n: - Di~u ki~n 6n dinh: Bao dam h~ s6 an
toan 6n dinh truqt tren m(it c&t nguy hi~m nhftt khong nh6 han tri s6 eha phep.
- Di~u ki~n (mg suftt: Khong d~ xuftt hi~n (mg suftt kea amep thuqng luu. Ung suftt nen W,
amep h(l luu khong duqe vuqt qua tri s6 ehaphep. phep.
- Di~u ki~n kinh t~: Bao dam kh6i luqng eong trinh la nh6 nhftt.
Duai day ta xet m<)tdO(ln d~p co ehi~u dai dan vi (lm) ti~t di~n ngang la hinh tam giae ABC, ehi~u eaa d~p h, ehi~u r<)ng day d~p b,
hinh ehi~u ella mai thugng luu Ia n.b, ella mai Hinh 4.6. SO"dbtinh loan m~l C~l
h(lluu la (I-n)b. Trong do n< I. cO" ban
6day ta xem mve nuae thugng luu ngang dinh d~p, h(lluu kh6ng co nuae.
Cae Ive tae d\illg len da(ln d~p g6m: - Tr9ng lugng ban than ella d~p G.