I. TI LIU THIT K I.1.Ti liu cng trnh S hiuCt N(kN) Mx

(kNm) My

(kNm) Qx

(kN) Qy

(kN) I2II5a1400x140028607,56892,5493,9437,12111,25

*Ti trng sn tng hm: -Din tch chu ti l 8,4mx8,1m - Chiu dy sn :o= 300mm = 0,3 m - Tnh ti tnh ton l :N1 = 1,1.15.0,3.8,4.8,1=336,798 (kN) - Hot ti tiu chun : p = 500kg/m2 - Hot ti tnh ton l : N2 = 1,3.5.8,4.8,1 = 442,26 (kN). * Ti trng tnh ton: Ntt = N + N1+ N2 = 28607,56 + 336,798 + 442,26 = 29386,62( kN)Mx = 892,5 (kNm) ,My = 493,94 (kNm),Qx = 37,12 (kN), Qy = 111,25 (kN) . * Ti trng tiu chun : Khng c t hp ti tiu chun nn s liu ti trng ti chn ct c th ly c nh sau : Ntc = N/n , Mxtc = Mx/n , Mytc = My/n ,Qxtc = Qx/n , Qytc = Qy/n (n h s vt ti : n = (1,1 1,2). Chnn = 1,15 ) Ntc =25553,58(kN); Mxtc = 776,09(kNm); Mytc = 429,51(kNm) Qxtc = 32,28 (kN); Qytc = 96,74 (kN) I.2.Ti liu v a cht Lp tS hiuChiu dy (m) 1t lp1,6 2418,4 3516 4296 57011,5 6 Cui si rt cht N>100, E0=500kg/cm2,g=8 kg/cm2 V cng * Lp 1 : t lp , dy 1,6(m) * Lp 2 : S hiu 41 , dy 8,4 (m) c cc ch tiu c l sau :

W % Wnh % Wd % T/m3A c kg/cm2 Kt qu TN nn p e ng vi P (KPa) qc (MPa) N 50100150200 36,538,624,81,782,6560400,090,9840,9460,9180,8980,413 T ta c : - H s rng t nhin : ( )012, 65.1.(1 0.365)1 1 1, 0321, 78nWeA ++= = =- Kt qu nn : H s nn ln trong khong p lc 100 200 kPa( )1 240,946 0,9182,8.10 1/ )200 100a kPa= = - Ch s do : A = Wnh Wd =38,6 24,8 = 13,8 - st : 36, 5 24,80,84813,8dW WBA= = = . - Tr s N = 3, = 6040 t st pha nho - M un bin dng : qc = 0,41 MPa = 41 T/m2 E0 = . qc = 4.41 = 164 T/m2 . * Lp 3 : S hiu 5 , dy 16 (m) c cc ch tiu c l sau : Thnh phn ht (%) tng ng vi cc c ht W % A qc MPa N 1 2 0,5 1 0,25 0,5 0,1 0,25 0,050,1 0,010,05 0,0020,01 < 0,002 68,51835,5157,563,518,52,63616 - C ht d> 0,5 mm chim 14,5 % ; d >0,25 mm chim 32,5% ; d > 0,1 mm chim 68%. - Ta thy hm lng c ht ln hn 0,1 mm di 75 % lp 3 l lp ct bt . - Sc khng xuyn qc = 6 MPa = 600 T/m2 lp 3 l lp ct bt trng thi cht va =350, e0 = 0,65. - Dung trng t nhin :( ) ( )( )301 0, 01 2, 63.1. 1 0,1851,89 /1 0, 65 1nWT meA + += = =+ + - M un bin dng : qc = 600 T/m2E0 = . qc = 2.600 = 1200 T/m2(Chn =2).* Lp 4 : S hiu 29 , dy 6 (m) c cc ch tiu c l sau : Thnh phn ht (%) tng ng vi cc c htW % A qc MPa N 5 - 22 -11 0,50,5 - 0,250,25 - 0,1 202723219142,631630 -Ta thy hm lng c ht ln hn 0,5 mm chim 70% > 50 %, vy lp 4 l lp ct ht th. - Sc khng xuyn qc = 16 MPa = 1600 T/m2 ct thuc trng thi cht =400, e0 = 0,55. - Dung trng t nhin :( ) ( )( )301 0, 01 2, 63.1. 1 0,141,93 /1 0,55 1nWT meA + += = =+ + - M un bin dng : : qc = 1600 T/m2 E0 = . qc = 2.1600 = 3200 T/m2(Chn =2). * Lp 5 : S hiu 70 , dy 11,5 (m) c cc ch tiu c l sau :

W % Wnh % Wd % T/m3A c kg/cm2 Kt qu TN nn p e ng vi P (KPa) qc MPa N 100200300400 30,850,322,51,882,73110550,180,8760,8450,8180,7941,938 T ta c : - H s rng t nhin : ( )012, 73.1.(1 0.308)1 1 0,8991,88nWeA ++= = =- Kt qu nn : H s nn ln trng khong p lc 200 400 kPa( )1 240,846 0, 7942,55.10 1/ )400 200a kPa= = - Ch s do : A = Wnh Wd =50,3 22,5 = 27,8 . - st : 30,8 22,80, 28827,8dW WBA= = = - Tr s N = 8, = 11055 t st pha ,do mm - M un bin dng : qc = 1,93 MPa = 193 T/m2 E0 = . qc = 4.193 = 772 T/m2 . * Lp 6 : Cui si rt cht N >100,E0=500kg/cm2,g=8 kg/cm2 ,chiu dy v cng. Ta c kt qu tr a cht nh sau : I.3.Tiu chun xy dng ln cho php i vi nh khung Sgh = 8 (cm) & chnh ln tng i cho php / 0, 2% S L A = ( Tra ph lc 28, bi ging nn mng TS Nguyn nh Tin ) II. XUT PHNG N - Cng trnh ch ti trng rt ln. - t nn gm 4 lp : + Lp 1 : t lp + Lp 2 : st nho, dy 8,4 (m). + Lp 3 : Ct bt cht va,dy 16 (m). + Lp 4 : Ct ht th cht va,dy 6 (m). + Lp 5 : st pha, do mm, dy 11,5 (m). + Lp 6 : Cui si rt cht, dy v cng . - Chn gii php mng : Chn mng cc i thp + Phng n 1: Dng cc BTCT 35x35 cm ,i t vo lp 2, mi cc h su xung lp 4 khong 3 4 m.Thi cng bng phng php ng p + Phng n 2 : Dng cc BTCT 45x45 i t vo lp 2.Cc h bng phng php ng vo lp 4 khong 3 4m. + Phng n 3 : Dng cc khoan nhi ng knh 1m, i t vo lp 2.Cc c ngm vo lp t 6 khong 3 - 4m. Phng n ny n nh cao. Chn phng n 3III.PHNG PHP THI CNG V VT LIU MNG i cc : + B tng : 300 # c Rn = 1300T/m2; Rk = 10T/m2 + Ct thp : thp chu lc trong i l thp loi AII c Ra = 28000T/m2 + Lp lt i : b tng ngho 100 # dy 10 cm. + i lin kt ngom vi ct v cc.Thp ca cc neo trong i> 20d ( y chn 50cm ) v u cc trong i 30cm Cc khoan nhi : + B tng : 300# Rn = 1300T/m2 + Ct thp : thp chu lc AII , ai - AI. + Cc chi tit cu to xem bn v. IV.CHIU SU T MNG Hm Tnh hmin chiu su chn mng yu cu nh nht :

0 0min6, 67 2.(3, 712 11, 25)45 1, 58( )2 0, 78.620, 7. 45 . 0, 72 .dnmQh tg tgb+ | | | | = ||\ . \ .> =Trong : Q = Qx + Qy = 14,962 T ,b: b rng i ch s b b = 6 m

( )21, 78 1 0, 78 /dnT m = =, :gc ma st trong = 6040 Chn hm = 2,5m > hmin = 1,58(m) V. CHN CC C TRNG CA MNG CC V.I.Kch thc cc. - Tit din cc D = 1,2 m. - Tng chiu di cc(cha k mi cc):Lc=(1,6+8,4+16+6+11,5+2,2)32,5+0,8=41 m. - Chiu di cc tnh ton ( cha k mi cc ) : lc = 40,2(m). V.II.Tnh ton ct thp cho cc. - Vi cc khoan nhi :0, 4% 0, 65% = .Ta chn = 0,6 % - Ta c: Din tch ct thp l( )2 20, 006.3,14.60 67,824s bA A cm = = = Chn As =15| 25 = 73,63 (cm2) > 67,8 (cm2). VI.TNH SC CHU TI CA CC. VI.1.Sc chu ti theo vt liu. 1.BTCT : ( ). . Q R A R An a sVL b = + Trong : =1 - h s iu kin lm vic As , Ab Din tch ct thp v b tng : As = 73,63 cm2 Ab = 3,14.0,62 73,63.10-4 = 1,123m2. ( )41. 1300.1,123 28000.73, 63.10 1666( )VLQ T= + = . 2.Theo kinh nghim: . Q R A R Au u an sb= + Trong :( )( )2230066, 66 /4,5 4,560 /uRcdaN cmRdaN cm= =s Chn Ru = 60 daN/m2 ( Ru cng tnh ton ca b tng cc nhi, cc b tng trong dung dch Bentonite)

( )( )2226001733 /1,5 1,52200 /anRcdaN cmRdaN cm= =s Chn Ran = 1733 daN/cm2 ( Ran cng tnh ton ca ct thp ) 4600.1,123 17330.73, 63.10 801, 4( )VLQ T= + = . VI.2.Tnh sc chu ti ca cc theo ch tiu c l (PLA) -Ta c: ( )R p c f si iq f Q m m F u m ltc = + - Trong : m h s lm vic ca cc trong t m =1 mR h s lm vic ca t mi cc mR = 1 mf h s lm vic ca t bn thn ccmf = 1 qp sc chng ca t ti mi cc qp = 15000kN/m2 vi h = 45,7 m. Fc din tch tit din ngang thn ccFc = 1,131 m2 u chu vi tit din ngang thn ccu = 3,77 m fsi ma st bn thn ccli chiu di cc trong lp t th i Lp tLoi t su trung bnh hi (m)li (m)fsi (kN/m2)2St pha, nho, B=0,8487,758,47,52 3Ct bt 181673,4 4Ct ht th29691,6 5St pha,do mm,B = 0,22837,7511,591,6 6Cui si44,62,2100

| | ( )1. 1.15000.1,131 3, 77. 8, 4.7, 52 73, 4.16 91, 6.6 91, 6.11, 5 100.2, 228616( ) kNQtc+ + + + +== - Khi : ( ) ()2861617885 1788, 51, 6tcatcQQ kN TK= = = =VI.3 Sc chu ti ca cc theo SPT CT Meyerhof - Ta c: 1 2Q K NA K N Au p stb= +- Trong : N ch s SPT trung bnh trong khong 1d di mi cc v 4d trn mi cc:N = 8 Ap din tch tit din mi cc : Ap = 1,131m2 Ntb ch c SPT trung bnh dc thn cc trong phm vi t ri: Ntb = (30 + 16)/2 = 23 As din tch mt bn cc trong phm vi lp t ri : As = 3,77.1.22 = 82,94 m2 K1,K2 h s , K1 = 120 ,K2 = 1 : cho cc khoan nhi 120.8.1,131 1.23.82,94 2993,38( ) Q Tu = + = 2993, 381197, 35( )2, 5utcdQQ TK= = = ()1197, 357981, 5tcaQQ Tk= = =