đồ án môn học thiết kế cầu bêtông

  TRƯỜNG ĐẠI HỌC GIAO THÔNG VẬN TẢI THÀNH PHỐ HỒ CHÍ MINH KHOA CÔNG TRÌNH – NGÀNH XÂY DỰNG CẦU ĐƯỜNG    ĐỒ ÁN MÔN HỌC:         I.1.1 - Tiêu chuẩn áp dụng 6 I.1.2 - Tài liệu tham khảo 6     !"##   I.3.1 - Vật liệu lan can, lề bộ hành, bản mặt cầu, dầm ngang 6 I.3.2 - Vật liệu thiết kế dầm chủ 7  $%&  ' ##  ' II.2.1 - Thiết kế thanh lan can 7 ()*+, /+01+23-4' 51678+9.:;-51678+.1<+=<+.> 6>-8>-? !.0-@-48.AB6788C>+.> 6>-8>-? D1EF+GH-+.> 6>-8>-I II.2.2 - Thiết kế cột lan can 9 ()*+, /+01+23-4I 51678+2G-485+6>-8>-+9.:;-51678I !.0-@-48.AB6788C>85+6>-8>-I D1EF+GH-85+6>-8>-J !##K$L  J II.3.1 - Sơ đồ tính và tải trọng 10 II.3.2 - Tính toán nội lực 11 II.3.3 - Thiết kế cốt thép 11 II.3.4 - Kiểm tra nứt 11 D##$MNOPQ$   II.4.1 - Sơ đồ tính và tải trọng 12 II.4.2 - Khả năng chịu lực 13 DR-4+.S8=1EF+2>! D.0-@-48.ABFRFT-8C>+UV-4+2W-F5+)(-XA8.1YBZ[1)\1X]1+2^8-4>-4_8`! D!.0-@-48.ABFRFT-8C>+UV-4+2W-F5+)(-XA8.1YBZ[1)\1X]1+2^8)S-4_a`! DD, +GH-=.0-@-48.AB6788C>bcXd>D De1EF+GH-D  ! &  D &$f  D III.2.1 - Sơ đồ tính 14 III.2.2 - Xác định tải trọng 15 III.2.3 - Tính toán nội lực 15 !&$gh   III.3.1 - Sơ đồ tính 16 III.3.2 - Xác định tải trọng 16 III.3.3 - T? h@p và tính toán nội lực 16 D##i$Qg  ' III.4.1 - Thiết kế cốt thép chịu mômen âm 17 III.4.2 - Thiết kế cốt thép chịu mômen dương 18 ej%k  I III.5.1 - Kiểm tra nứt với mômen âm 19 III.5.2 - Kiểm tra nứt với mômen dương 19 "#$% ##  J &Ll   IV.2.1 - Sơ đồ tính 21 IV.2.2 - Xác định nội lực do tĩnh tải 21    IV.2.3 - Xác định nội lực do hoạt tải 22 !PUV-40 .Um-4H;678ZnF-4>-4+.TG;.U(-4Z388nB !9.:;oT.>1+2^8X[+016[- !!9.:;oTb>+2^8X[+016[- !pLl  ! D##i  D IV.4.1 - Thiết kế cốt thép chịu mômen âm 24 IV.4.2 - Thiết kế cốt thép chịu mômen dương 24 ejk  e IV.5.1 - Kiểm tra nứt với mômen âm 25 IV.5.2 - Kiểm tra nứt với mômen dương 26 ##P  ' IV.6.1 - Mômen và lực cắt thiết kế 27 IV.6.2 - Cánh tay đòn dv giữa t?ng h@p lực nén và t?ng h@p lực kéo khi uốn 27 IV.6.3 - Ứng suất cắt trung bình 27 IV.6.4 - Giả sử góc nứt và tính biến dạng dọc trục tại trọng tâm cốt thép chịu kéo 27 IV.6.5 - Xác định lại góc nứt từ biểu đồ 28 IV.6.6 - Xác định khả năng chịu cắt của bê tông 28 IV.6.7 - Xác định bước đai tính toán 28 IV.6.8 - Xác định bước đai theo cấu tạo 28 IV.6.9 - Kiểm tra lại khả năng chịu kéo của cốt dọc 29 IV.6.10 - Cốt đai thiết kế 29 "&'($) Mq$gh  I V.1.1 - Hệ số phân bố ngang đối với mômen cho dầm giữa 29 V.1.2 - Hệ số phân bố ngang cho lực cắt cho dầm giữa 30 q$g$  !J V.2.1 - Hệ số phân bố tải trọng xe cho dầm biên 30 V.2.2 - Hệ số phân bố tải trọng làn và tải trọng người cho dầm biên 31 V.2.3 - Tính hệ số phân bố ngang theo phương pháp dầm trên gối đàn hồi 31 !r)UV-40 .Um-4;.0-6784\1)[-.*1+s1XA+2,ZnFb1W-! !, .tu\;.v-b\-4>-4! "#*++ &LlwQx  !! VI.1.1 - Các mặt cắt tính nội lực 33 VI.1.2 - Xác định tĩnh tải – Tính nội lực do tĩnh tải 33 fH8)A +y +01!! , -51678ZG+y +01!D VI.1.3 - Hoạt tải thiết kế 35 VI.1.4 - Tính toán nội lực do hoạt tải tại mặt cắt I-I 35 D()*o<;+01!e DRFT-! D!788z+! VI.1.5 - Tính toán nội lực do hoạt tải tại mặt cắt II-II 37 e(Z*o<;+01!' eRFT-!' e!788z+!' VI.1.6 - Tính toán nội lực do hoạt tải tại mặt cắt III-III 38 (Z*o<;+01!? RFT-!? !788z+!? VI.1.7 - Tính toán nội lực do hoạt tải tại mặt cắt IV-IV 39 '()*o<;+01!I 'RFT-!I '!788z+!I VI.1.8 - Tính toán nội lực do hoạt tải tại mặt cắt V-V 40 ?()*o<;+01DJ ?RFT-DJ ?!788z+DJ    pLlwQx  D VI.2.1 - TTGH CƯỜNG ĐỘ 41 9.:;FRFT-mPD 9.:;6788z+mPD VI.2.2 - TTGH SỬ DỤNG 43 9.:;FRFT-mD! 9.:;6788z+mDD !PQ%{|}~#  De VI.3.1 - Chọn sơ bộ tiết diện và cốt thép DƯL 45 VI.3.2 - Đặc trưng hình học tiết diện V-V 45 !P•8+2U-4.€ .38+1<+Z1t-41>1)Gs-D !P•8+2U-4.€ .38+1<+Z1t-41>1)Gs-D' VI.3.3 - Đặc trưng hình học tiết diện IV-IV 48 VI.3.4 - Đặc trưng hình học tiết diện II-II và III-III 49 VI.3.5 - Đặc trưng hình học tiết diện +I-I (phải) 51 VI.3.6 - T?ng h@p đặc trưng hình học tại các mặt cắt 53 Di#Pw•g  e! VI.4.1 - Bố trí thép sơ bộ 53 VI.4.2 - Kiểm tra khả năng chịu lực 54 VI.4.3 - Kiểm toán nứt 55 VI.4.4 - Thiết kế thép đai 56 DDRFT-X[6788z++.1<+=<e DDH +>‚)ƒ-ZX41„>+9-4.:;678-…-X[+9-4.:;678=…G=.1B\-e DD!k-4uB†+8z++2B-4b€ e DDD10u‡4c8-S+X[+, b1<-Zs-4Z38+2^8+s1+23-4+vF8\++.…;8.AB=…Ge DDefH8)A 6s14c8-S++ˆb1EB)*e DDfH8)A =.0-@-48.AB8z+8C>bW+R-4e' DD'fH8)A bU]8)>1+, +GH-e' DD?fH8)A bU]8)>1+.TG8†B+sGe' DDI1EF+2>6s1=.0-@-48.AB=…G8C>8\+Z38e' DDJ\+)>1+.1<+=<e? e•k•  e? VI.5.1 - Mất mát do nén đàn hồi, chùng nhão thi công 58 VI.5.2 - Mất mát ứng suất do co ngót 60 VI.5.3 - Mất mát ứng suất do từ biến 60 VI.5.4 - Mất mát ứng suất do chùng nhão trong khai thác 61 VI.5.5 - Mất mát ứng suất t?ng cộng 61 jgOPw%‰Kl   VI.6.1 - Công thức kiểm toán 61 VI.6.2 - Kiểm toán mặt cắt V-V 61 VI.6.3 - Kiểm toán mặt cắt IV-IV 62 VI.6.4 - Kiểm toán mặt cắt III-III 63 VI.6.5 - Kiểm toán mặt cắt II-II 64 VI.6.6 - Kiểm toán mặt cắt I-I 65 'jgOŠ  e VI.7.1 - Giới hạn ứng suất 65 VI.7.2 - Kiểm toán tại mặt cắt V-V 65 VI.7.3 - Các mặt cắt khác 66 ?j%{‹PL  ' VI.8.1 - MẶT CẮT V-V 67 VI.8.2 - MẶT CẮT IV-IV 68 VI.8.3 - Mặt cắt III-III 69 Ij%{pij  ' VI.9.1 - Kiểm toán cho mặt cắt V-V giữa nhịp 71 VI.9.2 - Kiểm toán cho mặt cắt IV-IV 71 J##Pg~  ' VI.10.1 - Thiết kế thép đai cho mặt cắt I-I 72 JRFT-X[6788z++.1<+=<' JH +>‚)ƒ-ZX41„>+9-4.:;678-…-X[+9-4.:;678=…G=.1B\-'! J!k-4uB†+8z++2B-4b€ '! JD10u‡4c8-S+X[+, b1<-Zs-4Z38+2^8+s1+23-4+vF8\++.…;8.AB=…G'!    JefH8)A 6s14c8-S++ˆb1EB)*'D JfH8)A =.0-@-48.AB8z+8C>bW+R-4'D J'fH8)A bU]8)>1+, +GH-'D J?fH8)A bU]8)>1+.TG8†B+sG'e JI1EF+2>6s1=.0-@-48.AB=…G8C>8\+Z38'e JJ\+)>1+.1<+=<'e VI.10.2 - Thiết kế thép đai cho mặt cắt IV-IV 75 JRFT-X[6788z++.1<+=<'e JH +>‚)ƒ-ZX41„>+9-4.:;678-…-X[+9-4.:;678=…G=.1B\-'e J!k-4uB†+8z++2B-4b€ ' JD10u‡4c8-S+X[+, b1<-Zs-4Z38+2^8+s1+23-4+vF8\++.…;8.AB=…G' JefH8)A 6s14c8-S++ˆb1EB)*'' JfH8)A =.0-@-48.AB8z+8C>bW+R-4'' J'fH8)A bU]8)>1+, +GH-'' J?fH8)A bU]8)>1+.TG8†B+sG'' JI1EF+2>6s1=.0-@-48.AB=…G8C>8\+Z38'? JJ\+)>1+.1<+=<'? ##Mg  'I    CHƯƠNG I - SỐ LIỆU THIẾT KẾ   ,-.'#"/    01234256789:6; 'JeŒ•1WB8.BŽ-+.1<+=<8nB•  $ <0=0>2?4@AB4CD  nBbW+R-48\++.…;+2W-)UV-4R+RWP€ vF H8X,Z^+.1<+=<8nBbW+R-48\++.…;Z7S-4678+.TG+1WB8.BŽ- 'Je .G>8R-4+2€ $5FR-8nB)UV-42UV-4P; !<+8†B$W+R-48\++.…;+.TG•B‚;.sFG>‘4B‚’-2B-4ƒ> $ EF. \)Yb[1Œ! .1YBZ[1 A;Œ?_F` 01+23-4+.1<+=<ŒI! ,8.+.U]8F•+8z+-4>-4Œ_F` Je“!e“'I“!e“Je_F` $W+R-4ZnF8.CŒ ” eJ c f MPa= $W+R-4+UV-46>-8>-•6Yb5.[ •ZnF-4>-4•b0-F•+8nBŒ ” !J c f MPa= Gs1.€ +1<+Z1t-ZnF8., ŒZnFB;;T28@-4+2U]8 € $\+2,8.B-48R-4+2€ + "G +  "H?=0>2=@63@6=IJK4<64JC6AL?3M29MA6;@6; $W+R-4Œ     ” !J c f MPa= X[ e ” e JJD!– – JJD!–eJJ – !J IDDJ _ ` c c c E f MPa γ = = = \++.…;8c !e y f MPa= X[ JJJJJE MPa =  .…;+.> •85+6>-8>-6[+.…;D8c8UV-4)58.AB=…G— ‚ ˜DJ> +$ "H?=0>2?40N?BN9MA34O $W+R-4Œ ” eJ c f MPa= X[ e ” e JJD!– – JJD!–eJJ – eJ !?JJ' _ ` c c c E f MPa γ = = = \++.…;+.UV-4u‡Z^-4+.…;8c !e y f MPa= X[ JJJJJE MPa=  \++.…;Z7S-46786Gs1)UV-4=, +>G'FF'u:1•8c)58.™-4 šG+.†;• S-4uB†+=…G)S+6[ ?!? pu f MPa= X[FR)B-)[-.*1 I'JJJ p E MPa= ›Z1t-+,8. F5++>G6[JJFF   CHƯƠNG II - THIẾT KẾ LAN CAN, LỀ BỘ HÀNH   P& € .1+1<+6>-8>-/6Yb5.[  $  $  40N?BN?4@64=@63@6  !"# PE)(-410-•u()9+, 8.GFœ1 A;+.> 6>-8>-6[u()*ZnF410-)(- .A;+, +GH-6[=.G0-48H8.41„>.>185+6>-8>-61Y-=Y˜IJJFF $   € !()*+, X[+01+23-4+H8Z^-46W-+.> 6>-8>- 01+23-4+H8Z^-46W-+.> 6>-8>- U.€ •b>G4*FŒ •23-46U:-4b0-+.v-6>-8>-+2W-FF8.1YBZ[1Œ   e _'J  ` '?e–J –!D D DC − − = ž˜JJeŸFF •Gs++01+.1<+=<Œ 01;.v-b\+2W-8.1YBZ[1+.> 6>-8>- ˜ J!' ŸFFX[+01+¡;+2B-4˜?IJ+.TGP1YB!? %&'()*+&'(,',, •RFT-ZG+01+23-4b0-+.v-4v‚2>+s1F•+8z+8., 41„> A;Œ   JJe–IJJ !eJJ _ ` ? ? DC x qL M Nmm= = = •RFT-ZG.Gs++014v‚2>+s1F•+8z+8., 41„> A;Œ   a a a J!'–IJJ ?eJJJ _ ` ? ? x y M M Nmm= = = =    ?IJ–IJJ DDeJJJ _ ` D D x y M M Nmm= = = = •9.:;+01+23-4m+2s-4+.H141]1.s-8UV-4)5Œ RFT-+s1F•+8z+8., 41„> A;+2G-4+2s-4+.H141]1.s-8UV-4)56[Œ a  a  – ¢  _ “ `£ ¢ _ “ `£ DC P P DC x L x x L y y M M M M M M η γ γ γ = + + 2G-4)cŒ tu\)1YB8.d +01+23-4 – –  D I R η η η η = = +.TG8H8P1YB!›!!›!D X[!e tu\+01+23-4X]1.Gs++016[ 'e L γ = ›.tu\+01+23-48.G+y +01 e L γ = +.TG P1YB!D•$0-4!DX[!D ž   ¢e–!eJJ 'e–_?eJJJ“DDeJJJ`£ ¢'e–_?eJJJ“DDeJJJ`£M = + + ž˜e??e_FF` -"./'(0,,',, •RFT-•BH-+, 8C>+1<+Z1t-Œ  D D D D D D D  JJe _ ` JJe–'J _ ` D?! _ ` 'J d I D mm D = − = − =  1   •S8=.H-4B\-Z> )A 8C>+1<+Z1t-Œ D?! – –DJ Je– Je–'J n y I M f D = = ž-˜!e??_FF` -23,',, R-4+.S8=1EF+GH-+2s-4+.H141]1.s-8UV-4)5Œ  n M M φ ≥ tu\uS8=.H-4  φ = )\1X]1B\-+.TGP1YBeD ž–!e??_FF`¤e??e_FF`žP0Fb0G8.AB678 $$ 40N?BN3K?=@63@6  !"# $¥•B>678+.¦-4)S-4+H8Z^-4X[G85+6>-8>-†‚85+6>-8>-m41„>8nB)E +, 01+23-4+H8Z^-46W-85+8.d8.db>G4*F8H8678+.TG;.U(-4-4>-48nB+s1 8H8XA+2,61W-=<++.> 6>-8>-•b>G4*FŒ •Gs++01;.v-b\ ˜J!'ŸFF+2W--‡> A;+.> 6>-8>-)UV-4+2B‚Y- XY85++.[ 678+¡;8.B-4§˜ –˜J!'–IJJ˜'DJ_` •Gs++s1+¡;+2B-4˜?IJ+2W-+.> 6>-8>-->‚)U:8Z18.B‚E-XA)•+-4>‚ XA+2,41>GX]185+ ž¡‚+9-4.:;678+H8Z^-46W-85++.TG;.U(-4-4>-48nB+s1Fœ1XA+2,41>G X]1+.> 6>-8>-6[Œ —˜“§˜'DJ“?IJž—˜!J_` ()*+, X[8H8=,8.+.U]8.€ .388C>85+ U.€ ZU]1)v‚Œ € D()*+, 85+6>-8>- %&'(#3&',,)*+&'( RFT-+s1F•+8z+$$Œ –_!DJ eJ '?J` !J–?J B B M F − = + + = ž˜?D?JJFF RFT-=1EF+GH-+s1+2s-4+.H141]1.s-8UV-4)5Œ – 'e–?D?JJ LL B B M M γ − = = ž˜!II?DJJ_FF` _tu\+01+23-4X]1.Gs++016[ 'e LL γ = ` -"./'(0,&',, ()*+, 85+6>-8>-6[ZnF8G-4oG6_=.1b¥•B>678+.¦-4)S-4Z38+2^8` 4   RFT-•BH-+, 8C>+1<+Z1t-85+6>-8>-+s1F•+8z+$$ )U:8u‡Z^-4 B+G>ZJJ'+, )U:8=<+•B06[Œ 2T>ŒIJ!?J T21FT+T2ŒIeII?DI $GB-Z1-4bGoŒfŒJJJJJDJJJJJJ ‰ŒJJJJJ!JJJJJJ T-+2G1ZŒfŒIII'J ‰ŒDI'D? GFT-+uG¨1-T2+1>ŒfŒeJDe!DeJe? ‰Œ'I!'!!IJ 2GZB8+G¨1-T2+1>Œf‰Œe'D'DJIeDID %>Z11G¨4‚2>+1G-ŒfŒD!J ‰Œe?! 21-81;>6FGFT-+u>-Zf‰Z12T8+1G-u>bGB+8T-+2G1ZŒ ŒIJeJ'''>6G-4¢JJJJJJJJJ£ ©ŒeD!J'e!DD>6G-4¢JJJJJJJJJ£ ž f ˜eD!J'FF D  S8=.H-4B\-Z> )A 8C>85+6>-8>-Œ   – – eD!J'–DJ– •'•e•!'J _  ` JJ r x y M I f N mm h = = = -23&',,  2s-4+.H141]1.s-8UV-4)5Œ    –•'•e•!'J –'e–?D?JJ !II?DJJ_  ` r LL B B M M N mm φ η γ − ≥ = ≥ =  ž.¥>ª +  +  QRS?T64U<?C0?VW6; ()*+, 6[ZnF410-)(-•8z+JJJFFZ[1+.TG;.U(-4Z388nB)E+, •+1<+ Z1t-+, 6[.€ 8.„ ¡+b–.˜JJJoJJFF•8.1YBZ[1 A;+, +GH-6[˜ eJFF € e/()*+, 6Yb5.[ X[+01+23-4 01+23-4+H8Z^-44*F+y +01b0-+.v-_`•.Gs++01-4UV1_` e e–J –JJJ–JJ e_ Ÿ `DC N mm − = = ! !–J –JJJ !_ Ÿ `PL N mm − = = 5 [...]... ( N mm ) u 15 Đồ án môn học thiết kế cầu Bêtông III.3 - TÍNH BẢN DẦM GIỮA III.3.1 - Sơ đồ tính - Sơ đồ tính bản dầm giữa là sơ đồ dầm liên tục nhưng để đơn giản trong tính toán ta sẽ với sơ đồ dầm giản đơn sau đó kết quả nội lực sẽ được nhân với hệ số điều chỉnh cho sơ đồ liên tục Nhịp tính toán là L = 1400 mm - Cắt 1 mm dài theo phương dọc cầu để tính toán Tiết diện tính toán là hình chữ... s M 1/ 2 = 0.5* M s = 0.7 * M sDC2 + Dw + M sLL = 0.5*(9,368,816 + 123,943, 276) s M 1/ 2 = 66, 655,946 ( N mm ) 23 Đồ án môn học thiết kế cầu Bêtông IV.4 - THIẾT KẾ CỐT THÉP IV.4.1 - Thiết kế cốt thép chịu mômen âm + Mô men thiết kế thép: M goi = 160,117,379( N mm) + Tiết diện thiết kế là bxh = 700x800 (mm) + Chọn ds = 700 mm + Chiều cao vùng nén : u 2.M u 2*160,117,379 = 700 − 7002 − = 34.4 ( mm... diện như khi thiết kế cốt thép 19 Đồ án môn học thiết kế cầu Bêtông - Công thức kiểm toán: f s ≤ f sa = min(0.6* f y ; 3 Z ) Ac d c Trong đó: Z = 30000 N/mm với khí hậu ôn hòa fy = 365 MPa dc = 30 mm < 50 mm Ac = (30+30)*1000/5 = 12000 (mm2) → f sa = min(0.6*365; 3 30000 ) = min(219; 421.7) = 219 ( MPa) 12000*30 - Với bê tông cốt thép thường sơ đồ sơ đồ ứng suất kiểm tra với sơ đồ đàn hồi nứt,... sơ đồ dầm congxol có nhịp tính toán là L = 750 mm - Cắt 1000 mm dài theo phương dọc cầu để tính toán Tiết diện tính toán là hình chữ nhật có kích thước là b x h = 1000 x 200 (mm) 14 Đồ án môn học thiết kế cầu Bêtông Hình 8 - Sơ đồ tính bản congxol và tải trọng III.2.2 - Xác định tải trọng - Tĩnh tải bản mặt cầu phân bố đều: DC = 2.5*10−5 *1000* 200 = 5( N / mm) - Tĩnh tải tập trung tổng cộng... LIỆU THIẾT KẾ + Chiều cao dầm ngang (bao gồm phần bản mặt cầu) : h = 800 mm + Bề rộng dầm ngang b = 700 mm f c' = 30MPa + Bê tông: 1.5 Ec = 0.043* γ c * f c' = 0.043* 25001.5 * 30 = 29440 ( MPa) + Cốt thép AIII có f y = 365MPa và E = 200000MPa + Nhịp tính toán dầm ngang lấy bằng khoảng cách hai dầm chủ L = 2225 mm 20 Đồ án môn học thiết kế cầu Bêtông IV.2 - TÍNH TOÁN NỘI LỰC IV.2.1 - Sơ đồ tính Hình... thép thiết kế: As = 0.85* f c' * a * b 0.85*30*6.6*1000 = = 461( mm2 ) fy 365 - Lượng cốt thép tối thiểu: As ,min = 0.03* b * h * f c' 30 = 0.03*1000*100* = 247 mm2 fy 365 ( ) → chọn lượng cốt thép bố trí: 2 As = 461 mm2 → chọn φ12a 200 ( As = 565mm ) bố trí cho 1 m dài bản mặt cầu theo phương dọc cầu 18 Đồ án môn học thiết kế cầu Bêtông Hình 11 - Bố trí thép chịu mô men dương trong bản mặt cầu. .. thiết kế cốt thép - Công thức kiểm toán: f s ≤ f sa = min(0.6* f y ; 3 Z ) Ac d c Trong đó: Z = 30000 N/mm với khí hậu ôn hòa fy = 365 MPa dc = 30 mm < 50 mm Ac = (100+100)*700/5 = 28000 (mm2) - diện tích trung bình bọc quanh một thanh thép chịu kéo 25 Đồ án môn học thiết kế cầu Bêtông → f sa = min(0.6*365; 3 30000 ) = min(219;318) = 318 ( MPa) 28000*30 - Với bê tông cốt thép thường sơ đồ sơ đồ. .. 0.494 ME ME + Hệ số phân bố ngang cho tải trọng người (PL): 32 Đồ án môn học thiết kế cầu Bêtông ( mg ) SE PL = 1.2* 1350* ( 0.673 + 0.547 ) 2 * 1 = 0.732 1350 CHƯƠNG VI - THIẾT KẾ DẦM CHỦ VI.1 - TÍNH TOÁN NỘI LỰC TẠI CÁC MẶT CẮT VI.1.1 - Các mặt cắt tính nội lực + Nhịp tính toán của dầm Ltt = 26800 mm Hình 17 - Vị trí các mặt cắt tính toán + Mặt cắt I-I tại đầu khấc của dầm, cách tim gối dầm 450 mm... Kiểm toán - Công thức kiểm toán: Rw ≥ Ft → 319191( N ) ≥ 240000 ( N ) → Thỏa ! (A.13.7.3.3) CHƯƠNG III - THIẾT KẾ BẢN MẶT CẦU III.1 - SỐ LIỆU TÍNH TOÁN - Bê tông bản mặt cầu: C30 có fc’ = 30 MPa và Ec = 29440 MPa - Cốt thép AIII có Fy = 365 MPa - Chiều dày bản mặt cầu ts = 200 mm III.2 - TÍNH BẢN CONGXOL III.2.1 - Sơ đồ tính - Sơ đồ tính bản congxol là sơ đồ dầm congxol có nhịp tính toán là L... trọng lượng bản mặt cầu VI.1.2.2.3- Nội lực do trọng lượng lan can, lề bộ hành 34 Đồ án môn học thiết kế cầu Bêtông VI.1.2.2.4- Nội lực do trọng lượng lớp phủ VI.1.3 - Hoạt tải thiết kế + Tổ hợp hoạt tải 1: Xe 3 trục + tải trọng làn + tải trọng bộ hành (PL) + Tổ hợp hoạt tải 2: Xe 2 trục + tải trọng làn + tải trọng bộ hành (PL) Trong đó tải bộ hành được gom theo phương dọc cầu là: PL = 2* 3*10−3 .   TRƯỜNG ĐẠI HỌC GIAO THÔNG VẬN TẢI THÀNH PHỐ HỒ CHÍ MINH KHOA CÔNG TRÌNH – NGÀNH XÂY DỰNG CẦU ĐƯỜNG    ĐỒ ÁN MÔN HỌC:         I.1.1. thức kiểm toán 61 VI.6.2 - Kiểm toán mặt cắt V-V 61 VI.6.3 - Kiểm toán mặt cắt IV-IV 62 VI.6.4 - Kiểm toán mặt cắt III-III 63 VI.6.5 - Kiểm toán mặt cắt II-II 64 VI.6.6 - Kiểm toán mặt cắt I-I. 16 D##i$Qg  ' III.4.1 - Thiết kế cốt thép chịu mômen âm 17 III.4.2 - Thiết kế cốt thép chịu mômen dương 18 ej%k  I III.5.1