{"id":459,"date":"2019-06-22T08:29:15","date_gmt":"2019-06-22T08:29:15","guid":{"rendered":"https:\/\/thuvienxaydung.com.vn\/?p=459"},"modified":"2019-07-13T08:21:28","modified_gmt":"2019-07-13T08:21:28","slug":"thiet-ke-san-composite-theo-ly-thuyet-toi-uu","status":"publish","type":"post","link":"https:\/\/tailieuxaydung.net\/?p=459","title":{"rendered":"Thi\u1ebft k\u1ebf s\u00e0n composite theo l\u00fd thuy\u1ebft t\u1ed1i \u01b0u"},"content":{"rendered":"

  S\u00e0n li\u00ean h\u1ee3p ( s\u00e0n composite) l\u00e0 m\u1ed9t d\u1ea1ng k\u1ebft c\u1ea5u h\u1ed7n h\u1ee3p gi\u1eefa b\u00eat\u00f4ng v\u00e0 s\u00e0n th\u00e9p, trong \u0111\u00f3 s\u00e0n th\u00e9p c\u00f3 c\u1ea5u t\u1ea1o d\u1ea1ng t\u1ea5m g\u1ea5p n\u1ebfp, n\u00ean \u0111\u00e3 gi\u1ea3m b\u1edbt chi\u1ec1u d\u00e0y v\u00e0 tr\u1ecdng l\u01b0\u1ee3ng s\u00e0n \u0111\u1ebfn m\u1ee9c t\u1ed1i \u0111a. \u01afu \u0111i\u1ec3m c\u1ee7a lo\u1ea1i s\u00e0n n\u00e0y l\u00e0 kh\u00f4ng c\u1ea7n s\u1eed d\u1ee5ng v\u00e1n khu\u00f4n. L\u1edbp b\u00eat\u00f4ng \u0111\u00fac t\u1ea1i ch\u1ed7 tr\u00ean m\u1eb7t s\u00e0n th\u00e9p t\u01b0\u01a1ng \u0111\u1ed1i m\u1ecfng. K\u1ebft c\u1ea5u s\u00e0n nh\u01b0 v\u1eady s\u1ebd t\u01b0\u01a1ng \u0111\u1ed1i nh\u1eb9 v\u00e0 c\u0169ng c\u00f3 \u1ea3nh h\u01b0\u1edfng t\u00edch c\u1ef1c \u0111\u1ebfn s\u1ef1 l\u00e0m vi\u1ec7c c\u1ee7a khung s\u01b0\u1eddn v\u00e0 n\u1ec1n m\u00f3ng c\u00f4ng tr\u00ecnh. Ngo\u00e0i ra, c\u1ea5u ki\u1ec7n c\u1ee7a s\u00e0n li\u00ean h\u1ee3p d\u1ec5 gia c\u00f4ng, v\u1eadn chuy\u1ec3n, l\u1eafp r\u00e1p \u0111\u01a1n gi\u1ea3n, t\u1ed1c \u0111\u1ed9 thi c\u00f4ng nhanh; ph\u00f2ng ho\u1ea3 t\u1ed1t, c\u00f3 kh\u1ea3 n\u0103ng ch\u1ecbu l\u1eeda \u0111\u1ebfn 2 gi\u1edd kh\u00f4ng c\u1ea7n l\u1edbp b\u1ea3o v\u1ec7 \u0111\u1eb7c bi\u1ec7t v\u00e0 4 gi\u1edd n\u1ebfu c\u00f3 b\u1ecdc th\u00eam l\u1edbp ph\u00f2ng ch\u00e1y.<\/p>\n

        \u0110\u1ec3 c\u00f3 \u1ea3nh h\u01b0\u1edfng t\u00edch c\u1ef1c \u0111\u1ebfn s\u1ef1 l\u00e0m vi\u1ec7c c\u1ee7a n\u1ec1n m\u00f3ng, c\u0169ng nh\u01b0 gi\u1ea3m dao \u0111\u1ed9ng c\u1ee7a c\u00f4ng tr\u00ecnh, em \u0111\u00e3 l\u1ef1a ch\u1ecdn gi\u1ea3i ph\u00e1p thi\u1ebft k\u1ebf t\u1ed1i \u01b0u l\u00e0 kh\u1ed1i l\u01b0\u1ee3ng c\u1ee7a s\u00e0n nh\u1ecf nh\u1ea5t b\u1eb1ng ph\u01b0\u01a1ng ph\u00e1p quy ho\u1ea1ch to\u00e1n h\u1ecdc.<\/p>\n

 <\/p>\n

        II. M\u1ed9t s\u1ed1 ph\u01b0\u01a1ng ph\u00e1p c\u01a1 b\u1ea3n trong l\u00fd thuy\u1ebft quy ho\u1ea1ch to\u00e1n h\u1ecdc<\/strong><\/p>\n

        Trong v\u00f2ng n\u1eeda th\u1ebf k\u1ef7 nay, m\u1ed9t ng\u00e0nh to\u00e1n h\u1ecdc m\u1edbi \u2013 l\u00fd thuy\u1ebft quy ho\u1ea1ch to\u00e1n h\u1ecdc  – \u0111\u00e3 h\u00ecnh th\u00e0nh v\u00e0 ph\u00e1t tri\u1ec3n m\u1ea1nh m\u1ebd do nh\u1eefng \u0111\u00f2i h\u1ecfi c\u1ea5p b\u00e1ch v\u1ec1 kinh t\u1ebf \u0111\u1ec3 th\u1ef1c hi\u1ec7n c\u00e1c ch\u1ec9 ti\u00eau t\u1ed1i \u01b0u: nhi\u1ec1u nh\u1ea5t, \u00edt nh\u1ea5t, nhanh nh\u1ea5t, r\u1ebb nh\u1ea5t, t\u1ed1t nh\u1ea5t\u2026<\/p>\n

        V\u1edbi l\u00fd thuy\u1ebft quy ho\u1ea1ch, ng\u01b0\u1eddi k\u1ef9 s\u01b0 \u0111\u01b0\u1ee3c trang b\u1ecb th\u00eam m\u1ed9t s\u1ed1 c\u00f4ng c\u1ee5 to\u00e1n h\u1ecdc r\u1ea5t c\u00f3 hi\u1ec7u l\u1ef1c \u0111\u1ec3 gi\u1ea3i c\u00e1c b\u00e0i to\u00e1n t\u1ed1i \u01b0u m\u00e0 tr\u01b0\u1edbc \u0111\u00e2y c\u00e1c ph\u01b0\u01a1ng ph\u00e1p c\u1ed5 \u0111i\u1ec3n ch\u01b0a th\u1ec3 gi\u1ea3i \u0111\u01b0\u1ee3c. Sau \u0111\u00e2y gi\u1edbi thi\u1ec7u m\u1ed9t s\u1ed1 ph\u01b0\u01a1ng ph\u00e1p c\u01a1 b\u1ea3n v\u1ec1 l\u00fd thuy\u1ebft quy ho\u1ea1ch to\u00e1n h\u1ecdc.<\/p>\n

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  1. \n\t\tPh\u01b0\u01a1ng ph\u00e1p \u0111\u1ed3 th\u1ecb.<\/li>\n
  2. \n\t\tPh\u01b0\u01a1ng ph\u00e1p \u0111\u01a1n h\u00ecnh.<\/li>\n
  3. \n\t\tPh\u01b0\u01a1ng ph\u00e1p gra\u0111i\u00ean<\/li>\n<\/ol>\n

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            III<\/strong>. Gi\u1edbi thi\u1ec7u m\u1ed9t s\u1ed1 h\u00ecnh \u1ea3nh v\u00e0 c\u1ea5u t\u1ea1o v\u1ec1 s\u00e0n li\u00ean h\u1ee3p<\/strong> :<\/p>\n

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      C\u00e1c d\u1ea1ng s\u00e0n li\u00ean h\u1ee3p:<\/p>\n

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    \n\tT\u1ea5m t\u00f4n g\u1ea5p n\u1ebfp \u0111\u00e3 \u0111\u01b0\u1ee3c li\u00ean k\u1ebft v\u00e0o d\u1ea7m<\/em><\/p>\n

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                                          K\u1ebft c\u1ea5u d\u1ea7m trong s\u00e0n li\u00ean h\u1ee3p<\/em><\/p>\n

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                                       Tr\u1ea3i c\u1ed1t th\u00e9p tr\u00f2n ch\u1ecbu m\u00f4men \u00e2m<\/em><\/p>\n

                IV. T\u00ednh to\u00e1n:<\/strong><\/p>\n

     <\/p>\n

               Ta ch\u1ecdn lo\u1ea1i b\u1ea3n th\u00e9p \u0111\u01b0\u1ee3c d\u1eadp g\u1ea5p n\u1ebfp v\u1edbi c\u00e1c th\u00f4ng s\u1ed1 c\u1ea5u t\u1ea1o nh\u01b0 sau:<\/p>\n

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                2.1. S\u1ed1 li\u1ec7u t\u00ednh to\u00e1n nh\u01b0 sau:<\/strong><\/p>\n

    + T\u1ea5m t\u00f4n d\u00f9ng lo\u1ea1i Lysaght BONDESK c\u1ee7a h\u00e3ng BlueScope Lysaght Vi\u1ec7t Nam, c\u00f3 Rs<\/sub> = 2975 Kg\/cm2<\/sup>.  E = 2,1.106<\/sup> Kg\/cm2<\/sup>.<\/p>\n

    +   S\u1eed d\u1ee5ng b\u00eat\u00f4ng m\u00e1c 350, c\u00f3 Rc<\/sub> = 155.104<\/sup>  kg\/m2<\/sup>. Eb<\/sub> = 310.103<\/sup> kG\/cm2<\/sup><\/p>\n

    +  C\u1ed1t th\u00e9p tr\u00f2n b\u1ed1 tr\u00ed \u0111\u1ec3 ch\u1ecbu m\u00f4men \u00e2m l\u00e0 th\u00e9p AI, c\u00f3 Rr<\/sub> = 230.105<\/sup> kG\/ m2<\/sup>.<\/p>\n

                D\u1ef1 \u0111\u1ecbnh b\u1ed1 tr\u00ed th\u00e9p a150, c\u00f3 di\u1ec7n t\u00edch Ar<\/sub> = 1,98 cm2<\/sup><\/p>\n

           +   b: Chi\u1ec1u r\u1ed9ng c\u1ee7a b\u1ea3n:                                       b = 1m.<\/p>\n

           +   n1<\/sub>: S\u1ed1 s\u00f3ng th\u00e9p d\u01b0\u1edbi:                                       n1<\/sub> = 4<\/p>\n

           +   n2<\/sub>: S\u1ed1 s\u00f3ng th\u00e9p tr\u00ean:                                        n2<\/sub> = 5<\/p>\n

           +   b1<\/sub>: Chi\u1ec1u r\u1ed9ng s\u00f3ng th\u00e9p b\u00ean d\u01b0\u1edbi :                  b1 <\/sub>= 105 mm = 0,105 m<\/p>\n

           +   b2<\/sub>: Chi\u1ec1u r\u1ed9ng s\u00f3ng th\u00e9p b\u00ean tr\u00ean :                   b2 <\/sub>= 67 mm = 0,067 m<\/p>\n

           +   da<\/sub> : Chi\u1ec1u cao s\u00f3ng t\u1ea5m th\u00e9p :                           da<\/sub> = 46 mm = 0,046 m<\/p>\n

           +    : G\u00f3c nghi\u00eang b\u1ee5ng t\u1ea5m th\u00e9p so v\u1edbi ph\u01b0\u01a1ng ngang:    = 600<\/sup>.<\/p>\n

           +     t : Chi\u1ec1u d\u00e0y c\u1ee7a t\u1ea5m th\u00e9p:                                t = 2 mm = 0,002 m<\/p>\n

              <\/p>\n

                 2.2. X\u00e1c \u0111\u1ecbnh t\u1ea3i tr\u1ecdng:<\/strong><\/p>\n

         a. T\u0129nh t\u1ea3i:<\/strong><\/p>\n

      \n
    1. \n\t\tG\u1ea1ch l\u00e1t:<\/p>\n

       <\/p>\n

        \n
      • \n\t\t\t\tChi\u1ec1u d\u00e0y: 1 cm = 0,01m<\/li>\n
      • \n\t\t\t\tKh\u1ed1i l\u01b0\u1ee3ng ri\u00eang : = 2000 kG\/m3<\/sup><\/li>\n
      • \n\t\t\t\tH\u1ec7 s\u1ed1 v\u01b0\u1ee3t t\u1ea3i : n = 1,1<\/li>\n
      • \n\t\t\t\tT\u1ea3i tr\u1ecdng ph\u00e2n b\u1ed1 t\u00ednh to\u00e1n tr\u00ean 1m2<\/sup> l\u00e0: 0,01*2000*1,1 = 22 kG\/m2<\/sup><\/li>\n<\/ul>\n<\/li>\n
      • \n\t\tV\u1eefa xim\u0103ng:<\/p>\n

         <\/p>\n

          \n
        • \n\t\t\t\tChi\u1ec1u d\u00e0y: 2 cm = 0,02 m<\/li>\n
        • \n\t\t\t\tKh\u1ed1i l\u01b0\u1ee3ng ri\u00eang : = 1800 kG\/m3<\/sup><\/li>\n
        • \n\t\t\t\tH\u1ec7 s\u1ed1 v\u01b0\u1ee3t t\u1ea3i : n = 1,3<\/li>\n
        • \n\t\t\t\tT\u1ea3i tr\u1ecdng ph\u00e2n b\u1ed1 t\u00ednh to\u00e1n tr\u00ean 1m2<\/sup> l\u00e0: 0,02*1800*1,3 = 46,8 kG\/m2<\/sup><\/li>\n<\/ul>\n<\/li>\n
        • \n
            \n
          • \n\t\t\t\tChi\u1ec1u d\u00e0y ph\u1ea7n b\u00eat\u00f4ng: h – da<\/sub>\/2 = h \u2013 0,023(m)<\/li>\n
          • \n\t\t\t\tKh\u1ed1i l\u01b0\u1ee3ng ri\u00eang : = 2500 kG\/m3<\/sup><\/li>\n
          • \n\t\t\t\tH\u1ec7 s\u1ed1 v\u01b0\u1ee3t t\u1ea3i : n = 1,1<\/li>\n
          • \n\t\t\t\tT\u1ea3i tr\u1ecdng ph\u00e2n b\u1ed1 t\u00ednh to\u00e1n tr\u00ean 1m2<\/sup> l\u00e0:<\/li>\n<\/ul>\n<\/li>\n<\/ol>\n

            \n\t    (h \u2013 0,023)*2500*1,1 = (h \u2013 0,023)*2750  kG\/m2<\/sup><\/p>\n

              \n
            1. \n\t\tT\u1ea5m th\u00e9p g\u1ea5p n\u1ebfp:<\/p>\n

               <\/p>\n

                \n
              • \n\t\t\t\tChi\u1ec1u d\u00e0y: t = 2 mm = 0,002 m<\/li>\n
              • \n\t\t\t\tKh\u1ed1i l\u01b0\u1ee3ng ri\u00eang : = 7850 kG\/m3<\/sup><\/li>\n
              • \n\t\t\t\tH\u1ec7 s\u1ed1 v\u01b0\u1ee3t t\u1ea3i : n = 1,1<\/li>\n
              • \n\t\t\t\tT\u1ea3i tr\u1ecdng t\u1eadp trung tr\u00ean 1m2<\/sup> l\u00e0:<\/li>\n<\/ul>\n<\/li>\n<\/ol>\n

                      [n1<\/sub>.b1<\/sub>+ n2<\/sub>.b2<\/sub> +(n1<\/sub> + n2<\/sub>).da<\/sub>\/sin]*1* 0,002*7850 =<\/p>\n

                      = [4.0,105 + 5.0,067 + (4 + 5).0,046\/sin600<\/sup>]*1*0,002*7850 = 19,3588 kG.<\/p>\n

                               –   T\u1ea3i tr\u1ecdng ph\u00e2n b\u1ed1 t\u00ednh to\u00e1n tr\u00ean 1m2<\/sup> l\u00e0:  kG\/m2<\/sup>.<\/p>\n

                  \n
                1. \n\t\tTr\u1ea7n treo (k\u1ec3 c\u1ea3 c\u00e1c \u0111\u01b0\u1eddng \u1ed1ng k\u1ef9 thu\u1eadt):<\/p>\n

                   <\/p>\n

                    \n
                  • \n\t\t\t\tT\u1ea3i tr\u1ecdng ph\u00e2n b\u1ed1 ti\u00eau chu\u1ea9n tr\u00ean 1m2<\/sup> l\u00e0: 5 kG\/m2<\/sup>.<\/li>\n
                  • \n\t\t\t\tH\u1ec7 s\u1ed1 v\u01b0\u1ee3t t\u1ea3i l\u00e0 : n = 1,3<\/li>\n
                  • \n\t\t\t\tT\u1ea3i tr\u1ecdng ph\u00e2n b\u1ed1 t\u00ednh to\u00e1n tr\u00ean 1m2<\/sup> l\u00e0: 5*1,3 = 6,5 kG\/m2<\/sup><\/li>\n<\/ul>\n<\/li>\n
                  • \n\t\tT\u1ed5ng c\u1ed9ng t\u1ea3i tr\u1ecdng t\u0129nh t\u1ea3i:<\/li>\n<\/ol>\n

                    \n\t  gb<\/sub> = 22 + 46,8 + (h \u2013 0,023)*2750 + 21,295 + 6,5 = 33,35 + h*2750   (kG\/m2<\/sup>).<\/p>\n

                    \n\t <\/p>\n

                         b. Ho\u1ea1t t\u1ea3i:<\/strong><\/p>\n

                    – <\/strong>Ho\u1ea1t t\u1ea3i ti\u00eau chu\u1ea9n tr\u00ean s\u00e0n t\u1ea7ng v\u0103n ph\u00f2ng:<\/p>\n

                                                                   ptc<\/sup> = 300  (kG\/m2<\/sup>).<\/p>\n

                    –<\/strong> Ho\u1ea1t t\u1ea3i t\u00ednh to\u00e1n:                pb<\/sub> = 1,2*300 = 360 (kG\/m2<\/sup>).<\/p>\n

                     <\/p>\n

                               c. T\u1ea3i tr\u1ecdng to\u00e0n ph\u1ea7n:<\/strong>     qb<\/sub> = 33,35 + h*2750 + 360<\/p>\n

                                                                           = 393,35 + h*2750      (kG\/m2<\/sup>).                 (1)<\/p>\n

                     <\/p>\n

                              2.3 . X\u00e2y d\u1ef1ng h\u00e0m m\u1ee5c ti\u00eau v\u00e0 c\u00e1c \u0111i\u1ec1u ki\u1ec7n r\u00e0ng bu\u1ed9c:<\/strong><\/p>\n

                                  a. H\u00e0m m\u1ee5c ti\u00eau<\/strong>:   kh\u1ed1i l\u01b0\u1ee3ng c\u1ee7a 1m2<\/sup> s\u00e0n nh\u1ecf nh\u1ea5t<\/p>\n

                     <\/p>\n

                                      P = gb<\/sub>*1m2<\/sup> = 393,35 + h*2750   (kG).<\/p>\n

                                      P \u00de Pmin <\/sub>                                                                                          (2)<\/p>\n

                                             b. C\u00e1c \u0111i\u1ec1u ki\u1ec7n r\u00e0ng bu\u1ed9c:<\/strong><\/p>\n

                    b.1<\/strong>–  \u0110i\u1ec1u ki\u1ec7n v\u1ec1 kh\u1ea3 n\u0103ng ch\u1ecbu l\u1ef1c t\u1ea1i ti\u1ebft di\u1ec7n gi\u1eefa nh\u1ecbp : Mmax<\/sub> < [Mgi\u1eefa<\/sub>].   (3)<\/p>\n

                    b.2<\/strong>–  \u0110i\u1ec1u ki\u1ec7n v\u1ec1 kh\u1ea3 n\u0103ng ch\u1ecbu l\u1ef1c t\u1ea1i ti\u1ebft di\u1ec7n g\u1ed1i          : Mmin<\/sub> <  [Mg\u1ed1i<\/sub>].    (4)<\/p>\n

                    b.3<\/strong>–  \u0110i\u1ec1u ki\u1ec7n v\u1ec1 \u0111\u1ed9 v\u00f5ng c\u1ee7a  t\u1ea5m t\u00f4n trong qu\u00e1 tr\u00ecnh thi c\u00f4ng:<\/p>\n

                             Gi\u1ea3 thi\u1ebft trong qu\u00e1 tr\u00ecnh thi c\u00f4ng, s\u1eed d\u1ee5ng h\u1ec7 c\u00e2y ch\u1ed1ng v\u1edbi kho\u1ea3ng c\u00e1ch l\u1edbn nh\u1ea5t l\u00e0 2m. V\u1edbi kho\u1ea3ng c\u00e1ch c\u00e1c \u0111\u00e3 ch\u1ecdn, gi\u1ea3 s\u1eed t\u1ea5m t\u00f4n d\u1eadp ngu\u1ed9i \u0111\u1ee7 ch\u1ecbu tr\u1ecdng l\u01b0\u1ee3ng b\u1ea3n th\u00e2n, tr\u1ecdng l\u01b0\u1ee3ng b\u00ea t\u00f4ng \u01b0\u1edbt v\u00e0 t\u1ea3i tr\u1ecdng thi c\u00f4ng. Khi \u0111\u00f3 \u0111\u1ed9 v\u00f5ng c\u1ee7a t\u1ea5m t\u00f4n \u0111\u01b0\u1ee3c t\u00ednh theo c\u00f4ng th\u1ee9c :<\/p>\n

                                                    < [] = L\/150                                        (5)<\/p>\n

                    Trong \u0111\u00f3:    L: Chi\u1ec1u d\u00e0i nh\u1ecbp ,  L = 2m ;<\/p>\n

                                        p : T\u1ea3i tr\u1ecdng b\u00eat\u00f4ng \u01b0\u1edbt v\u00e0 t\u1ea3i tr\u1ecdng thi c\u00f4ng 15 KG\/m2<\/sup><\/p>\n

                                     p = (h \u2013 da<\/sub>\/2)**n + 15*1,2 = ( h \u2013 0,023)*2650*1,1 + 18 (KG\/m2<\/sup>)<\/p>\n

                                     p = h*2915  + 85,05  (kG\/m2<\/sup>)<\/p>\n

                                     E = 2,1.106<\/sup>  kg\/cm2<\/sup> = 2,1.1010<\/sup> kg\/m2<\/sup><\/p>\n

                    \n\t          = 90,3 cm4<\/sup> = 90,3.10 .10-8<\/sup> m4<\/sup>   (trong 1m ti\u1ebft di\u1ec7n t\u00f4n).<\/p>\n

                    b.4 – <\/strong>\u0110i\u1ec1u ki\u1ec7n v\u1ec1 \u0111\u1ed9 v\u00f5ng c\u1ee7a b\u1ea3n s\u00e0n khi l\u00e0m vi\u1ec7c:        f < [f] = L\/150<\/p>\n

                            Quy \u0111\u1ed5i di\u1ec7n t\u00edch t\u1ea5m t\u00f4n d\u1ea1ng s\u00f3ng trong 1m ti\u1ebft di\u1ec7n v\u1ec1 t\u1ea5m t\u00f4n d\u1ea1ng ph\u1eb3ng: <\/p>\n

                                Fs\u00f3ng<\/sub> = Fph\u1eb3ng<\/sub> =>  [n1<\/sub>.b1<\/sub>+ n2<\/sub>.b2<\/sub> +(n1<\/sub> + n2<\/sub>).da<\/sub>\/sin]*t = 1m*tt\u0111<\/sub><\/p>\n

                      \n
                    • \n\t\t1,233*0,002 = 1*tt\u0111<\/sub>=>tt\u0111<\/sub> = 0,00247 mm<\/li>\n<\/ul>\n

                                   Di\u1ec7n t\u00edch t\u1ea5m th\u00e9p l\u00e0: Fph\u1eb3ng<\/sub> = 2,466.10-3<\/sup> m2<\/sup><\/p>\n

                       <\/p>\n

                       <\/p>\n

                       <\/p>\n

                       <\/p>\n

                       <\/p>\n

                       <\/p>\n

                       <\/p>\n

                       <\/p>\n

                       <\/p>\n

                       <\/p>\n

                       <\/p>\n

                      Khi \u0111\u00f3 ti\u1ebft di\u1ec7n t\u01b0\u01a1ng \u0111\u01b0\u01a1ng c\u00f3 d\u1ea1ng:<\/p>\n

                       <\/p>\n

                       <\/p>\n

                       <\/p>\n

                       <\/p>\n

                       <\/p>\n

                       <\/p>\n

                       <\/p>\n

                       <\/p>\n

                       <\/p>\n

                       <\/p>\n

                       <\/p>\n

                       <\/p>\n

                       <\/p>\n

                       <\/p>\n

                       <\/p>\n

                       <\/p>\n

                       <\/p>\n

                      M\u1eb7t kh\u00e1c:<\/p>\n

                      X\u00e9t t\u1ec9 s\u1ed1 gi\u1eefa m\u00f4\u0111un \u0111\u00e0n h\u1ed3i c\u1ee7a th\u00e9p ( Et<\/sub> ) v\u00e0 m\u00f4\u0111un \u0111\u00e0n h\u1ed3i c\u1ee7a b\u00eat\u00f4ng ( Eb<\/sub> ):<\/p>\n

                                                             <\/p>\n

                      V\u1eady quy \u0111\u1ed5i di\u1ec7n t\u00edch t\u1ea5m th\u00e9p th\u00e0nh di\u1ec7n t\u00edch b\u00eat\u00f4ng l\u00e0:<\/p>\n

                                 Fquy \u0111\u1ed5i<\/sub> = Fph\u1eb3ng<\/sub> * n =  2,466.10-3<\/sup> * 6,77 =  0,017 m2<\/sup><\/p>\n

                       <\/p>\n

                      Ti\u1ebft di\u1ec7n t\u01b0\u01a1ng \u0111\u01b0\u01a1ng c\u00f3 d\u1ea1ng:<\/p>\n

                       <\/p>\n

                       <\/p>\n

                       <\/p>\n

                       <\/p>\n

                       <\/p>\n

                       <\/p>\n

                       <\/p>\n

                       <\/p>\n

                       <\/p>\n

                       <\/p>\n

                       <\/p>\n

                       <\/p>\n

                       <\/p>\n

                       <\/p>\n

                       <\/p>\n

                       <\/p>\n

                       <\/p>\n

                       <\/p>\n

                                Nh\u01b0 v\u1eady \u0111\u00e2y l\u00e0 m\u1ed9t ph\u00e9p quy \u0111\u1ed5i t\u01b0\u01a1ng \u0111\u01b0\u01a1ng v\u1ec1 t\u1ec9 s\u1ed1 (E*J) c\u1ee7a ti\u1ebft di\u1ec7n.<\/p>\n

                             – X\u00e1c \u0111\u1ecbnh tr\u1ee5c trung ho\u00e0 c\u1ee7a ti\u1ebft di\u1ec7n:<\/p>\n

                              G\u1ecdi  x \u2013 x v\u00e0 y \u2013 y l\u00e0 tr\u1ee5c trung ho\u00e0 c\u1ee7a ti\u1ebft di\u1ec7n. Ta th\u1ea5y h\u00ecnh c\u00f3 t\u00ednh ch\u1ea5t \u0111\u1ed1i x\u1ee9ng qua tr\u1ee5c y \u2013 y.<\/p>\n

                       <\/p>\n

                              B\u00e2y gi\u1edd c\u1ea7n x\u00e1c \u0111\u1ecbnh tr\u1ee5c x \u2013 x:<\/p>\n

                       <\/p>\n

                       <\/p>\n

                       <\/p>\n

                       <\/p>\n

                       <\/p>\n

                       <\/p>\n

                       <\/p>\n

                       <\/p>\n

                       <\/p>\n

                       <\/p>\n

                      Ch\u1ecdn h\u1ec7 tr\u1ee5c ban \u0111\u1ea7u C2<\/sub>X2<\/sub>Y. V\u00ec tr\u1ee5c y l\u00e0 tr\u1ee5c \u0111\u1ed1i x\u1ee9ng n\u00ean xc<\/sub> = 0<\/p>\n

                      yc<\/sub> x\u00e1c \u0111\u1ecbnh theo c\u00f4ng th\u1ee9c:       <\/p>\n

                      Trong \u0111\u00f3:  <\/p>\n

                       <\/p>\n

                        (m2<\/sup>)<\/p>\n

                                     <\/p>\n

                      V\u00e0 m\u00f4men qu\u00e1n t\u00ednh c\u1ee7a 1m ti\u1ebft di\u1ec7n s\u00e0n l\u00e0:<\/p>\n

                        .<\/p>\n

                       <\/p>\n

                       <\/p>\n

                       <\/p>\n

                        \n
                      • \n\t\tT\u00ednh \u0111\u1ed9 v\u00f5ng c\u1ee7a 1m chi\u1ec1u r\u1ed9ng s\u00e0n \u1edf nh\u1ecbp bi\u00ean:<\/strong><\/li>\n<\/ul>\n

                                  Ta bi\u1ebft r\u1eb1ng, bi\u1ec3u \u0111\u1ed3 m\u00f4men c\u1ee7a 1m chi\u1ec1u r\u1ed9ng s\u00e0n \u1edf nh\u1ecbp bi\u00ean c\u00f3 d\u1ea1ng nh\u01b0 sau:<\/p>\n

                        \n\t <\/p>\n

                        V\u00e0 gi\u00e1 tr\u1ecb treo \u0111\u1ed9 v\u00f5ng \u1edf ti\u1ebft di\u1ec7n gi\u1eefa b\u1ea3n (d\u1ea7m) l\u00e0: <\/p>\n

                        Hay vi\u1ebft d\u01b0\u1edbi d\u1ea1ng kh\u00e1c:  <\/p>\n

                               <\/p>\n

                         <\/p>\n

                        T\u1eeb c\u00e1ch vi\u1ebft n\u00e0y, ta d\u1ec5 d\u00e0ng t\u00ecm \u0111\u01b0\u1ee3c \u0111\u1ed9 v\u00f5ng c\u1ee7a b\u1ea3n l\u00e0:<\/p>\n

                        \n\t <\/p>\n

                        * V\u1eady \u0111\u1ed9 v\u00f5ng c\u1ee7a b\u1ea3n  \u1edf nh\u1ecbp bi\u00ean c\u1ea7n tho\u1ea3 m\u00e3n \u0111i\u1ec1u ki\u1ec7n l\u00e0:<\/p>\n

                                                                                   (45)<\/p>\n

                         <\/p>\n

                          \n
                        • \n\t\tT\u00ednh \u0111\u1ed9 v\u00f5ng c\u1ee7a 1m chi\u1ec1u r\u1ed9ng s\u00e0n t\u1ea1i nh\u1ecbp gi\u1eefa:<\/strong><\/li>\n<\/ul>\n

                                    Ta bi\u1ebft r\u1eb1ng, bi\u1ec3u \u0111\u1ed3 m\u00f4men c\u1ee7a 1m chi\u1ec1u r\u1ed9ng s\u00e0n \u1edf nh\u1ecbp gi\u1eefa c\u00f3 d\u1ea1ng nh\u01b0 sau:<\/p>\n

                          \n\t <\/p>\n

                           <\/p>\n

                          V\u00e0 gi\u00e1 tr\u1ecb treo \u0111\u1ed9 v\u00f5ng \u1edf ti\u1ebft di\u1ec7n gi\u1eefa b\u1ea3n (d\u1ea7m) l\u00e0: <\/p>\n

                          Hay vi\u1ebft d\u01b0\u1edbi d\u1ea1ng kh\u00e1c:  <\/p>\n

                           <\/p>\n

                           <\/p>\n

                          \n\t <\/p>\n

                           <\/p>\n

                          T\u1eeb c\u00e1ch vi\u1ebft n\u00e0y, ta d\u1ec5 d\u00e0ng t\u00ecm \u0111\u01b0\u1ee3c \u0111\u1ed9 v\u00f5ng c\u1ee7a b\u1ea3n l\u00e0:<\/p>\n

                           <\/p>\n

                          \n\t <\/p>\n

                          \n\t <\/p>\n

                            \n
                          • \n\t\tV\u1eady \u0111\u1ed9 v\u00f5ng c\u1ee7a b\u1ea3n\u1edf nh\u1ecbp bi\u00ean c\u1ea7n tho\u1ea3 m\u00e3n \u0111i\u1ec1u ki\u1ec7n l\u00e0:<\/li>\n<\/ul>\n

                            \n\t <\/p>\n

                                                                                          (46)<\/p>\n

                             <\/p>\n

                            b.5<\/strong>. – \u0110i\u1ec1u ki\u1ec7n v\u1ec1 chi\u1ec1u cao s\u00e0n nh\u1ecf nh\u1ea5t:<\/p>\n

                                       hmin<\/sub> =  da<\/sub> + 2* + a = 4,6 cm + 2*0,6 cm + 3 cm = 8,8 cm.<\/p>\n

                                      <\/p>\n

                             <\/p>\n

                                     T\u1eeb nh\u1eefng \u0111i\u1ec1u ki\u1ec7n r\u00e0ng bu\u1ed9c tr\u00ean, ta t\u00ecm \u0111\u01b0\u1ee3c chi\u1ec1u cao s\u00e0n h = 12 cm.<\/p>\n

                                     M\u1eb7t c\u1eaft 1m b\u1ec1 r\u1ed9ng s\u00e0n nh\u01b0 sau:<\/p>\n

                             <\/p>\n

                             <\/p>\n

                             <\/p>\n

                            V. Thi c\u00f4ng s\u00e0n Composite.<\/strong><\/p>\n

                            1. T\u1ea1o s\u00f3ng g\u1ea5p n\u1ebfp cho t\u1ea5m th\u00e9p b\u1eb1ng m\u00e1y C\u00e1n tr\u1ee5c l\u0103n.    <\/strong><\/p>\n

                                    \u0110\u00e2y l\u00e0 lo\u1ea1i m\u00e1y n\u0103ng su\u1ea5t cao nh\u1ea5t, d\u00f9ng \u1edf c\u00e1c nh\u00e0 m\u00e1y luy\u1ec7n kim, nh\u00e0 m\u00e1y s\u1ea3n xu\u1ea5t h\u00e0ng lo\u1ea1t l\u1edbn. M\u00e1y g\u1ed3m m\u1ed9t d\u00e3y c\u00e1c tr\u1ee5c c\u00e1n, c\u00f3 h\u00ecnh d\u1ea1ng kh\u00e1c nhau (h\u00ecnh 3). D\u1ea3i th\u00e9p \u0111i qua c\u00e1c tr\u1ee5c c\u00e1n, d\u1ea7n d\u1ea7n \u0111\u01b0\u1ee3c thay \u0111\u1ed5i h\u00ecnh d\u1ea1ng . C\u00f3 th\u1ec3 c\u00e1n \u0111\u01b0\u1ee3c d\u1ea3i th\u00e9p d\u00e0y 0,3 \u0111\u1ebfn 18 mm, r\u1ed9ng 20 \u0111\u1ebfn 2000 mm. T\u1ed1c \u0111\u1ed9 c\u00e1n 10 \u0111\u1ebfn 30 m\/ph\u00fat.<\/p>\n

                                    Lo\u1ea1i m\u00e1y c\u00f3 n\u0103ng su\u1ea5t cao, s\u1eed d\u1ee5ng \u00edt nh\u00e2n c\u00f4ng, m\u1ed7i n\u0103m c\u00f3 th\u1ec3  s\u1ea3n xu\u1ea5t h\u00e0ng tri\u1ec7u m\u00e9t c\u1ea5u ki\u1ec7n. Tuy nhi\u00ean m\u1ed7i b\u1ed9 tr\u1ee5c c\u00e1n ch\u1ec9 d\u00f9ng cho m\u1ed9t lo\u1ea1i ti\u1ebft di\u1ec7n , mu\u1ed1n \u0111\u1ed5i ti\u1ebft di\u1ec7n ph\u1ea3i thay \u0111\u1ed5i tr\u1ee5c c\u00e1n, do \u0111\u00f3 gi\u00e1 th\u00e0nh cao. Hi\u1ec7n nay \u1edf Vi\u1ec7t Nam , b\u00ean c\u1ea1nh c\u00e1c m\u00e1y c\u00e1n l\u1edbn c\u1ee7a c\u00e1c c\u00f4ng ty n\u01b0\u1edbc ngo\u00e0i, nhi\u1ec1u c\u00f4ng ty nh\u1ecf trong n\u01b0\u1edbc c\u0169ng \u0111\u00e3 c\u00f3 nhi\u1ec1u m\u00e1y c\u00e1n, s\u1ea3n xu\u1ea5t h\u00e0n lo\u1ea1t ti\u1ebft di\u1ec7n th\u00e0nh m\u1ecfng, \u1ed1ng c\u00f3 m\u1ed1i h\u00e0n \u0111\u1ec3 s\u1eed d\u1ee5ng trong x\u00e2y d\u1ef1ng.<\/p>\n

                             <\/p>\n

                             <\/p>\n

                             <\/p>\n

                             <\/p>\n

                             <\/p>\n

                             <\/p>\n

                             <\/p>\n

                             <\/p>\n

                             <\/p>\n

                             <\/p>\n

                            \n\tH\u00ecnh 3. M\u00e1y c\u00e1n tr\u1ee5c l\u0103n.<\/em><\/p>\n

                            2.  Tr\u00ecnh t\u1ef1 thi c\u00f4ng s\u00e0n composite cho m\u1ed9t t\u1ea7ng \u0111i\u1ec3n h\u00ecnh.<\/p>\n

                                  Khi c\u00e1c d\u1ea7m c\u1ee7a s\u00e0n \u0111\u00e3 \u0111\u01b0\u1ee3c thi c\u00f4ng l\u1eafp d\u1ef1ng xong, ta m\u1edbi ti\u1ebfn h\u00e0nh thi c\u00f4ng s\u00e0n Li\u00ean h\u1ee3p Th\u00e9p – B\u00eat\u00f4ng. C\u00e1c b\u01b0\u1edbc th\u1ec3 hi\u1ec7n nh\u01b0 sau :<\/p>\n

                                  B\u01b0\u1edbc 1 <\/u>: L\u1eafp \u0111\u1eb7t h\u1ec7 s\u00e0n c\u00f4ng t\u00e1c :<\/strong><\/p>\n

                                  D\u00f9ng c\u1ea7n tr\u1ee5c th\u00e1p c\u1ea9u s\u00e0n c\u00f4ng t\u00e1c \u0111\u1eb7t v\u00e0o v\u1ecb tr\u00ed \u0111\u1ec3 ph\u1ee5c v\u1ee5 cho vi\u1ec7c thi c\u00f4ng s\u00e0n.<\/p>\n

                             <\/p>\n

                            \n\t <\/p>\n

                             <\/p>\n

                                     B\u01b0\u1edbc 2 : \u0110\u1eb7t l\u1edbp th\u00e9p \u0111\u00e3 t\u1ea1o s\u00f3ng l\u00ean d\u1ea7m :<\/strong><\/p>\n

                                  –  C\u1ea7n ph\u1ea3i l\u01b0u \u00fd \u0111\u1eb7t sao cho n\u1ebfp s\u00f3ng th\u1ec3 hi\u1ec7n \u0111\u00fang ph\u01b0\u01a1ng ch\u1ecbu l\u1ef1c c\u1ee7a n\u00f3.<\/p>\n

                                   – Sau khi t\u1ea5m \u0111\u01b0\u1ee3c \u0111\u1eb7t v\u00e0o \u0111\u00fang v\u1ecb tr\u00ed th\u00ec h\u00e0n \u0111\u1ec3 li\u00ean k\u1ebft n\u00f3 v\u00e0o c\u00e1nh d\u1ea7m \u0111\u1ec3 tr\u00e1nh gi\u00f3 l\u1eadt.<\/p>\n

                             <\/p>\n

                             <\/p>\n

                            \n\t <\/p>\n

                            \n\tL\u1eafp gh\u00e9p t\u1ea5m t\u00f4n g\u1ea5p n\u1ebfp v\u00e0o d\u1ea7m<\/em><\/p>\n

                            \n\t <\/p>\n

                             <\/p>\n

                            \n\t <\/p>\n

                             <\/p>\n

                             <\/p>\n

                             <\/p>\n

                             <\/p>\n

                             <\/p>\n

                                                                              H\u00e0n m\u1ea5u neo v\u00e0o d\u1ea7m<\/em><\/p>\n

                             <\/p>\n

                                    B\u01b0\u1edbc 3: \u0110\u1eb7t c\u1ed1t th\u00e9p tr\u00f2n l\u00ean s\u00e0n.<\/strong><\/p>\n

                                    Theo thi\u1ebft k\u1ebf, ta \u0111\u1eb7t th\u00e9p tr\u00f2n  l\u00ean s\u00e0n theo hai ph\u01b0\u01a1ng.<\/p>\n

                             <\/p>\n

                             <\/p>\n

                             <\/p>\n

                                    B\u01b0\u1edbc 4: D\u1ef1ng h\u1ec7 c\u00e2y ch\u1ed1ng  v\u00e0 x\u00e0 g\u1ed3 .<\/strong><\/p>\n

                                   Theo t\u00ednh to\u00e1n, ta ch\u1ec9 c\u1ea7n \u0111\u1eb7t m\u1ed9t h\u00e0ng ch\u1ed1ng gi\u1eefa hai d\u1ea7m, v\u00ec khi m\u1edbi \u0111\u1ed5, b\u00eat\u00f4ng ch\u01b0a l\u00e0m vi\u1ec7c li\u00ean h\u1ee3p \u0111\u01b0\u1ee3c v\u1edbi s\u00e0n. Kho\u1ea3ng c\u00e1ch c\u00e1c c\u00e2y ch\u1ed1ng trong m\u1ed9t h\u00e0ng l\u00e0 1,5m.<\/p>\n

                             <\/p>\n

                             <\/p>\n

                                    B\u01b0\u1edbc 5: \u0110\u1ed5 b\u00eat\u00f4ng s\u00e0n .<\/strong><\/p>\n

                             <\/p>\n

                                    Nh\u01b0 v\u1eady l\u00e0 \u0111\u00e3 ho\u00e0n thi\u1ec7n vi\u1ec7c thi c\u00f4ng s\u00e0n li\u00ean h\u1ee3p t\u1ea7ng \u0111i\u1ec3n h\u00ecnh.<\/p>\n

                             <\/p>\n

                             <\/p>\n

                            3. Tr\u00ecnh t\u1ef1 thi c\u00f4ng s\u00e0n composite theo chi\u1ec1u cao c\u00f4ng tr\u00ecnh.<\/p>\n

                                 M\u1ed9t s\u1ed1 \u0111i\u1ec3m c\u1ea7n l\u01b0u \u00fd :<\/p>\n

                              \n
                            • \n\t\tL\u1edbp b\u00eat\u00f4ng tr\u00ean s\u00e0n li\u00ean h\u1ee3p r\u1ea5t m\u1ecfng n\u00ean \u1ea3nh h\u01b0\u1edfng c\u1ee7a nhi\u1ec7t \u0111\u1ed9, \u0111\u1ed9 \u1ea9m v\u00e0 gi\u00f3 tr\u00ean cao \u0111\u1ebfn s\u1ef1 ph\u00e1t tri\u1ec3n c\u01b0\u1eddng \u0111\u1ed9 c\u1ee7a b\u00eat\u00f4ng l\u00e0 r\u1ea5t quan tr\u1ecdng. \u0110i\u1ec1u n\u00e0y c\u1ea7n \u0111\u1ebfn v\u1ea5n \u0111\u1ec1 b\u1ea3o d\u01b0\u1ee1ng th\u1eadt k\u1ecbp th\u1eddi v\u00e0 khoa h\u1ecdc.<\/li>\n
                            • \n\t\t\u0110\u1ec3 r\u00fat ng\u1eafn th\u1eddi gian thi c\u00f4ng, c\u1ea7n ph\u1ea3i c\u00f3 bi\u1ec7n ph\u00e1p ph\u1ed1i h\u1ee3p tr\u00ecnh t\u1ef1 c\u00f4ng vi\u1ec7c h\u1ee3p l\u00fd.<\/li>\n<\/ul>\n

                                   \u0110\u1ec3 \u0111\u01b0a ra \u0111\u01b0\u1ee3c gi\u1ea3i ph\u00e1p thi c\u00f4ng t\u1ed1t nh\u1ea5t th\u00ec m\u1ea5u ch\u1ed1t \u0111\u1ec1u xu\u1ea5t ph\u00e1t t\u1eeb qu\u00e1 tr\u00ecnh ph\u00e1t tri\u1ec3n c\u01b0\u1eddng \u0111\u1ed9 c\u1ee7a b\u00eat\u00f4ng s\u00e0n. Do \u0111\u00f3 ta c\u1ea7n ph\u1ea3i nghi\u00ean c\u1ee9u s\u1ef1 ph\u00e1t tri\u1ec3n c\u01b0\u1eddng \u0111\u1ed9 c\u1ee7a b\u00eat\u00f4ng trong \u0111i\u1ec1u ki\u1ec7n kh\u00ed h\u1eadu n\u00f3ng \u1ea9m \u1edf mi\u1ec1n b\u1eafc n\u01b0\u1edbc ta.<\/p>\n

                                   K\u1ebft qu\u1ea3 c\u1ee7a nghi\u00ean c\u1ee9u v\u1ec1 s\u1ef1 ph\u00e1t tri\u1ec3n  c\u01b0\u1eddng \u0111\u1ed9 c\u1ee7a b\u00eat\u00f4ng trong \u0111i\u1ec1u ki\u1ec7n kh\u00ed h\u1eadu n\u00f3ng \u1ea9m \u1edf mi\u1ec1n b\u1eafc n\u01b0\u1edbc ta.<\/p>\n

                              \n\t <\/p>\n

                                      Ta th\u1ea5y r\u1eb1ng trong \u0111i\u1ec1u ki\u1ec7n c\u00f3 b\u1ee9c x\u1ea1 tr\u1ef1c ti\u1ebfp c\u1ee7a m\u1eb7t tr\u1eddi, v\u1eadn t\u1ed1c gi\u00f3 l\u1edbn th\u00ec b\u00eat\u00f4ng b\u1ecb m\u1ea5t n\u01b0\u1edbc r\u1ea5t nhanh trong nh\u1eefng gi\u1edd \u0111\u1ea7u, \u0111i\u1ec1u n\u00e0y c\u00f3 h\u1ea1i cho s\u1ef1 ph\u00e1t tri\u1ec3n c\u01b0\u1eddng \u0111\u1ed9 c\u1ee7a b\u00eat\u00f4ng. H\u01a1n n\u1eefa, trong nh\u1eefng gi\u1edd \u0111\u1ea7u th\u00ec c\u01b0\u1eddng \u0111\u1ed9 c\u1ee7a b\u00eat\u00f4ng c\u00f2n r\u1ea5t nh\u1ecf n\u00ean ta kh\u00f4ng th\u1ec3 t\u01b0\u1edbi n\u01b0\u1edbc l\u00ean ngay \u0111\u01b0\u1ee3c. V\u00ec v\u1eady c\u00e1ch t\u1ed1t nh\u1ea5t l\u00e0 l\u00e0m gi\u1ea3m qu\u00e1 tr\u00ecnh m\u1ea5t n\u01b0\u1edbc c\u1ee7a b\u00eat\u00f4ng, \u0111i\u1ec1u n\u00e0y c\u00f3 ngh\u0129a r\u1eb1ng h\u00e3y \u0111\u1ec3 b\u00eat\u00f4ng \u0111\u01b0\u1ee3c ph\u00e1t tri\u1ec3n c\u01b0\u1eddng \u0111\u1ed9 trong b\u00f3ng m\u00e1t.<\/p>\n

                                      T\u1eeb k\u1ebft lu\u1eadn \u0111\u00f3 em \u0111\u01b0a ra gi\u1ea3i ph\u00e1p kh\u1eafc ph\u1ee5c nh\u01b0 sau:<\/p>\n

                              Thi c\u00f4ng l\u1eafp d\u1ef1ng s\u00e0n th\u00e9p tr\u01b0\u1edbc m\u1ed9t s\u1ed1 t\u1ea7ng, sau \u0111\u00f3 m\u1edbi \u0111\u1ed5 b\u00eat\u00f4ng cho s\u00e0n t\u1ea7ng d\u01b0\u1edbi.       <\/p>\n

                              S\u01a1 \u0111\u1ed3 thi c\u00f4ng \u0111\u01b0\u1ee3c th\u1ec3 hi\u1ec7n \u1edf h\u00ecnh v\u1ebd sau:<\/p>\n

                              \n\t <\/p>\n

                               <\/p>\n

                                VI. K\u1ebft lu\u1eadn:<\/strong><\/p>\n

                                      \u0110\u00e2y l\u00e0 m\u1ed9t d\u1ea1ng k\u1ebft c\u1ea5u m\u1edbi tr\u00ean th\u1ebf gi\u1edbi, c\u00f3 hi\u1ec7u qu\u1ea3 s\u1eed d\u1ee5ng cao. N\u00f3 th\u00fac \u0111\u1ea9y qu\u00e1 tr\u00ecnh thi c\u00f4ng m\u1ed9t c\u00e1ch nhanh ch\u00f3ng, ti\u1ebfn xa so v\u1edbi vi\u1ec7c thi c\u00f4ng s\u00e0n b\u00eat\u00f4ng th\u00f4ng th\u01b0\u1eddng, h\u01a1n n\u1eefa s\u00e0n c\u00f3 kh\u1ed1i l\u01b0\u1ee3ng r\u1ea5t nh\u1eb9 n\u00ean c\u00f3 \u1ea3nh h\u01b0\u1edfng t\u00edch c\u1ef1c \u0111\u1ebfn s\u1ef1 l\u00e0m vi\u1ec7c c\u1ee7a khung s\u01b0\u1eddn v\u00e0 n\u1ec1n m\u00f3ng, do \u0111\u00f3 \u00edt c\u00f3 gi\u1edbi h\u1ea1n v\u1ec1 chi\u1ec1u cao c\u1ee7a c\u00f4ng tr\u00ecnh.<\/p>\n

                                      Do \u0111\u00f3 sau khi nghi\u00ean c\u1ee9u v\u1ec1 lo\u1ea1i s\u00e0n n\u00e0y, em th\u1ea5y r\u1eb1ng n\u00f3 ho\u00e0n to\u00e0n \u00e1p d\u1ee5ng \u0111\u01b0\u1ee3c trong \u0111i\u1ec1u ki\u1ec7n kh\u00ed h\u1eadu, \u0111i\u1ec1u ki\u1ec7n kinh t\u1ebf v\u00e0 k\u1ef9 thu\u1eadt x\u00e2y d\u1ef1ng \u1edf n\u01b0\u1edbc ta.<\/p>\n

                              \n\tT\u00e0i li\u1ec7u tham kh\u1ea3o<\/strong><\/p>\n

                              \n\t <\/p>\n[1]. Edwin H. Gaylord Jr<\/strong>: Structural engineering handbook<\/em>.<\/p>\n[2]. Structural systems for tall buildings<\/em>.<\/p>\n[3]. The structural design of tall and special buildings<\/em>. 2003<\/p>\n[4]. \u0110\u1ec1 t\u00e0i NCKH c\u1ea5p ng\u00e0nh: N\u00e2ng cao n\u0103ng l\u1ef1c thi\u1ebft k\u1ebf c\u00e1c c\u00f4ng tr\u00ecnh \u0111\u1eb7c bi\u1ec7t <\/em><\/p>\n

                                     trong x\u00e2y d\u1ef1ng d\u00e2n d\u1ee5ng (cao t\u1ea7ng v\u00e0 kh\u00f4ng gian l\u1edbn) (quy\u1ec3n 3).<\/em>   <\/p>\n

                                     Tr\u01b0\u1eddng \u0110\u1ea1i h\u1ecdc Ki\u1ebfn tr\u00fac H\u00e0 N\u1ed9i. H\u00e0 N\u1ed9i 9\/2004.<\/p>\n[5]. GS. TSKH V\u00f5  Nh\u01b0  C\u1ea7u<\/strong>: T\u00ednh k\u1ebft c\u1ea5u theo ph\u01b0\u01a1ng ph\u00e1p t\u1ed1i \u01b0u<\/em>.<\/p>\n

                                     NXB X\u00e2y d\u1ef1ng \u2013 2003.<\/p>\n[6]. Ketcau.com.<\/p>\n[7]. Internet information v\u00e0 m\u1ed9t s\u1ed1 t\u00e0i li\u1ec7u chuy\u00ean ng\u00e0nh kh\u00e1c do GS L\u00ea Ki\u1ec1u cung c\u1ea5p.<\/p>\n

                               <\/p>\n","protected":false},"excerpt":{"rendered":"

                                S\u00e0n li\u00ean h\u1ee3p ( s\u00e0n composite) l\u00e0 m\u1ed9t d\u1ea1ng k\u1ebft c\u1ea5u h\u1ed7n h\u1ee3p gi\u1eefa b\u00eat\u00f4ng v\u00e0 s\u00e0n th\u00e9p, trong \u0111\u00f3 s\u00e0n th\u00e9p c\u00f3 c\u1ea5u t\u1ea1o d\u1ea1ng t\u1ea5m g\u1ea5p n\u1ebfp, n\u00ean \u0111\u00e3 gi\u1ea3m b\u1edbt chi\u1ec1u d\u00e0y v\u00e0 tr\u1ecdng l\u01b0\u1ee3ng s\u00e0n \u0111\u1ebfn m\u1ee9c t\u1ed1i \u0111a. \u01afu \u0111i\u1ec3m c\u1ee7a lo\u1ea1i s\u00e0n n\u00e0y l\u00e0 kh\u00f4ng c\u1ea7n s\u1eed d\u1ee5ng…<\/p>\n","protected":false},"author":1,"featured_media":1024,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[6,27],"tags":[],"class_list":["post-459","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-sach-pham-mem-xay-dung","category-thu-vien-mau"],"_links":{"self":[{"href":"https:\/\/tailieuxaydung.net\/index.php?rest_route=\/wp\/v2\/posts\/459","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/tailieuxaydung.net\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/tailieuxaydung.net\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/tailieuxaydung.net\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/tailieuxaydung.net\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=459"}],"version-history":[{"count":2,"href":"https:\/\/tailieuxaydung.net\/index.php?rest_route=\/wp\/v2\/posts\/459\/revisions"}],"predecessor-version":[{"id":1023,"href":"https:\/\/tailieuxaydung.net\/index.php?rest_route=\/wp\/v2\/posts\/459\/revisions\/1023"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/tailieuxaydung.net\/index.php?rest_route=\/wp\/v2\/media\/1024"}],"wp:attachment":[{"href":"https:\/\/tailieuxaydung.net\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=459"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/tailieuxaydung.net\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=459"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/tailieuxaydung.net\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=459"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}