N Bấ TễNG CT THẫP II GVHD : ThS NGUYN QUC TRUNG N Bấ TễNG CT THẫP II Mc Lc: N Bấ TễNG CT THẫP II THIấT Kấ KHUNG NGANG TRUC S Liu Thit K : -Nha tõng -Nhip truc ch : A-B,B-C,C-D / 6.3 , 2.8 , ( m) -Nhip truc sụ : 4.2 (m) -Chiờu cao tõng : + Trờt : 4.8 ( m ) + Lõu : 3.4 (m ) -Gio : IIA -ia hinh : B -Bờ tụng : B20 ( M250 ) -Thep nhom : CI , CII SVTH : TRN QUC CNG - 1511543495 Trang N Bấ TễNG CT THẫP II GVHD : ThS NGUYN QUC TRUNG I LA CHN GII PHP KấT CU : 1.Chn vt liu s dng Bờ tụng : B20 ( M250 ) Rb = 11.5 MPa , Rbt = 0.9 MPa Thep nhom : CI = RS = RSC = 225MPa CII = RS = RSC = 280MPa 2.La chn gii phỏp kt cu cho sn Chn gii phỏp kt cu san bờ tụng toan khụi , khụng bụ trớ dõm phu , ch co cỏc dõm qua ct SVTH : TRN QUC CNG - 1511543495 Trang N Bấ TễNG CT THẫP II GVHD : ThS NGUYN QUC TRUNG 3.Chn kớch thc chiu dy sn Sn S1 : hb = ( * 1 1 ữ ) L1 = ( ữ ).4200 = (105 ữ 84 ) 40 50 40 50 cm h b = 100mm = 10cm Chn : Sn S2 : hb = ( * 1 1 ữ ) L1 = ( ữ ).2800 = (70 ữ 56) 40 50 40 50 cm h b = 100mm = 10cm Chn : Sn S3 : hb = ( * 1 1 ữ ) L1 = ( ữ ).4200 = (105 ữ 84 ) 40 50 40 50 cm h b = 100mm = 10cm Chn : *Hot ti tớnh toỏn : S1 ,S3 ( phũng lam viờc ) Ps = pc * n = 2*1.2 = 2.4 (kN/m2) S2 ( hanh lang ) Ps = pc * n = 3*1.2 = 3.60 (kN/m2) SVTH : TRN QUC CNG - 1511543495 Trang N Bấ TễNG CT THẫP II Giỏ Tri Tiờu Chun (kN/m2) Cỏc lp cu to bng Gch ceramit 10 mm ,0 kN/m3 GVHD : ThS NGUYN QUC TRUNG Hờ Sụ Vt Ti Giỏ Tri Tớnh toỏn (kN/m2) = 20 0.01*20 = 0.2 1.1 0.22 = 20 0.03*20 = 0.6 1.3 0.78 Bn BTCT day 100mm , = 25 kN/m3 0.1*25 = 2.5 1.1 2.75 Va trỏt trõn : 20 mm , = 20 kN/m3 0.02*20 = 0.4 1.3 0.52 Va lot day 30 mm , kN/m3 Tng 4.27 Tng ti trng ụ sn S1 , S3 ( Phũng lm vic ) Qs = Ps + Gs = 2.4 + 4.27 = 6.67 (kN/m2) Tnh ti tớnh toỏn ca ụ sn S2 ( hnh lang ) Gs = g0 + bt*hs*n =1.52+25*0.06*1.1 = 4.27 (kN/m2) SVTH : TRN QUC CNG - 1511543495 Trang N Bấ TễNG CT THẫP II GVHD : ThS NGUYN QUC TRUNG Tng ti trng ụ sn S2 ( hnh lang ) Qs = Ps + Gs = 3.6 + 4.27= 7.84 (kN/m2) Vi sn mỏi : Hot ti : Pm = pc * n = 0.75*1.3 = 0.975 (kN/m2) Cỏc lp cu to bng Va lot chụng thm day 30 mm , = 20 kN/m3 Giỏ Tri Tiờu Chun (kN/m2) 0.03*20 = 0.6 Hờ Sụ Vt Ti 1.3 Giỏ Tri Tớnh toỏn (kN/m2) 0.78 Va trỏt trõn : 20 mm , = 20 kN/m3 0.02*20 = 0.4 1.3 0.52 Bn BTCT day 100mm , = 25 kN/m3 0.06*25 = 1.5 1.1 1.65 Tng 2.95 Tng ti trng san mỏi Qm = Pm + Gm = 0.975 + 2.95 = 3.925 (kN/m2) La chn kớch thc tit din cỏc b phn a.Kớch thc tit din dm: (nhp Ldc = 6300mm) * 1 1 h dc = ữ L dc = ữ .6300 = ( 525 ữ 787 ) mm 12 12 h dc = 600mm = 60cm Chn: * 1 1 b dc = ữ ữh dc = ữ ữ 60 = ( 15,7 ữ 30 ) cm 4 SVTH : TRN QUC CNG - 1511543495 Trang N Bấ TễNG CT THẫP II GVHD : ThS NGUYN QUC TRUNG b dc = 25cm Chn: Chn dõm 250x600 , dõm trờn mỏi chiu ti trng nh hn nờn ta chn dõm 250x500 (nhp Ldc = 6000mm) * 1 1 h dc = ữ L dc = ữ .6000 = ( 500 ữ 750 ) mm 12 12 h dc = 600mm = 60cm Chn: * 1 1 b dc = ữ h dc = ữ 60 = (15 ữ 30 ) cm 4 b dc = 25cm Chn: Chn dõm 250x600 , dõm trờn mỏi chiu ti trng nh hn nờn ta chn dõm 250x500 (nhp Ldc = 2800mm) * 1 1 h dc = ữ L dc = ữ .2800 = ( 233 ữ 350 ) mm 12 12 h dc = 300mm = 30cm Chn: * 1 1 b dc = ữ h dc = ữ 30 = ( 7,5 ữ 15) cm 4 b dc = 20cm Chn: Chn dõm 200x300 , dõm trờn mỏi ta chn dõm 200x300 SVTH : TRN QUC CNG - 1511543495 Trang N Bấ TễNG CT THẫP II GVHD : ThS NGUYN QUC TRUNG (nhp Ldc = 4200mm) * 1 1 h dc = ữ L dc = ữ .4200 = ( 350 ữ 525) mm 12 12 h dc = 500mm = 50cm Chn: * 1 1 b dc = ữ h dc = ữ 50 = (12.5 ữ 25) cm 4 b dc = 25cm Chn: Chn dõm 250x500 , dõm trờn mỏi ta chn dõm 250x400 b.Kớch thc tit din ct Ac = Tit diờn ct c xỏc inh da theo cụng thc: kìN Rb Trong o: k: hờ sụ xet n nh hng ca ti trng gio, ly k = (1.1 1.5) N = N i ( vi Ni = qi Si la ti trng thng ng tỏc dung lờn san tõng th i) qi : 1m2 La ti trng thng ng tỏc dung trờn san ca tõng th i ( gm trng lng bn thõn cỏc lp cu to san, dõm, tng, ct, va hot ti s dung san).Co th ly gõn ỳng Si qi = ( ữ14 ) kN / m Vi cụng trinh chn q=10kN/m2 : La diờn tớch ca san tõng th i truyờn ti trng ng vao ct xet tớnh a.Ct tõng 1,2 truc A va D ( Vi ct truc A va D, ụi xng va chiu ti giụng ) - Diờn truyờn ti ca ct truc A va D SVTH : TRN QUC CNG - 1511543495 Trang N Bấ TễNG CT THẫP II GVHD : ThS NGUYN QUC TRUNG SA = 6.3/2*4.2 = 13.23 (m2) Lc dc ti phõn bụ ờu trờn bn san N1 =qs*SB = 6.67*13.23 = 88.2441 (kN) Lc dc ti ngn ca tng 220 mm N2 = gt*lt*ht = 5.14*( 6.3/2+4.2)*4.8 = 181.33 (kN) ( õy s b chiờu cao tng bng chiờu cao tng tõng trờt ht = 4.8 m ) Lc dc ti phõn bụ ờu trờn san mỏi N3 =qsm*SB = 3.65*13.23 = 48.29 (kN) *Vi nha tõng co san tõng in hinh va tõng san mỏi ni*Ni = 2*(88.2441 +181.33) + 1*48.29 = 587.46 K n nh hng ca momen ta chn k = 1.2 Ac = k ì N 1.2 ì 587.46 = = 613(cm ) Rb 1.15 Vy ta chn kớch thc ct b*h = 25x30 cm co A= 750 cm2 so vi Ac= 613 cm2 b.Ct tõng 1,2 truc B va C ( Vi ct truc B va C , ụi xng va chiu ti giụng ) Diờn truyờn ti ca ct truc B va C SA = (6.3/2+2.8/2)*4.2 = 19.11(m2) Lc dc ti phõn bụ ờu trờn bn san N1 =qs*SB = 7.87*19.11 = 150.4 (kN) Lc dc ti ngn ca tng 220 mm N2 = gt*lt*ht = 5.14*( 6.3/2+4.2)*4.8 = 181.34 (kN) ( õy s b chiờu cao tng bng chiờu cao tng tõng trờt ht = 4.8 m ) Lc dc ti phõn bụ ờu trờn san mỏi N3 =qsm*SB = 3.925*13.23 = 51.928 (kN) SVTH : TRN QUC CNG - 1511543495 Trang N Bấ TễNG CT THẫP II GVHD : ThS NGUYN QUC TRUNG *Vi nha tõng co san tõng in hinh va tõng san mỏi ni*Ni = 2*(150.4 +181.34) + 1*51.928 = 715.41 K n nh hng ca momen ta chn k = 1.2 Ac = k ì N 1.2 ì 669.53 = = 699(cm ) Rb 1.15 Vy ta chn kớch thc ct b*h = 250x350 mm co A= 875 cm2 so vi Ac = 699 cm2 Cang lờn cao lc dc cang gim , nờn ta chn tit diờn ct nh sau *Ct truc A , D : 250x300 t tõng lờn tõng mỏi *Ct truc B , C : 250x350 t tõng lờn tõng , tõng mỏi chn ct 250x300 SVTH : TRN QUC CNG - 1511543495 Trang N Bấ TễNG CT THẫP II GVHD : ThS NGUYN QUC TRUNG Mt bng b trớ kt cu SVTH : TRN QUC CNG - 1511543495 Trang 10 N Bấ TễNG CT THẫP II GVHD : ThS NGUYN QUC TRUNG Khong cỏch thit k cụt S= (stt,sct,smax ) = 15 cm =150 mm +Ta bụ trớ 6a150 cho dõm Kim tra li iờu kiờn cng trờn tit diờn nghiờng theo ng sut nen chớnh ta ó co bụ trớ cụt : Q 0.3b Vi +5 1.3 Dõm bụ trớ 6a150 co = = 0.0015 Es 2.1*105 = Eb 2.3*104 = 9.13 = 1+5 = 1+5*0.0015 = 1.0075 < 1.3 = = 1- = 1-0.01*11.5 = 0.885 Ta thy = 0.885*1.0075 = 0.89 Ta co Q = < 0.3b = 0.3*1.0075*0.885*115*25*55.5 = 42681.57 daN Dõm kh nng chiu ng sut nen chớnh b Chn ct cho cỏc phn t dm ( 2,3,7,8,9 ) bxh =250x600 Ta thy cỏc dõm co kớch thc bxh =250x600 thi Dõm co lc ct ln nht Q = 139 (kN) , dõm c t cụt theo cu to 6a150 -> chn cụt 6a150 cho cỏc dõm co kớch thc bxh =250x600 c Tớnh ct cho cỏc phn t dm ( tng ) nhp BC , bxh = 200x300 T bng t hp ni lc , ta chn lc ct nguy him nht cho dõm Q = 22.49 (kN) Bờ tụng cp bờn B20 co Rb = 11.5 ( Mpa ) 115 (daN/cm2 ) , Rbt = 0.9 MPa = (daN/cm2) Thep nhom AI co Rsw = 175 Mpa = 1750 daN/cm2 , Es = -2.1*105 Mpa +Dõm chiu ti trng tớnh toỏn phõn bụ ờu vi g =g1+g01 = 505+0.2*0.3*2500*1.1 = 670 daN/m = 6.7 (daN/cm ) SVTH : TRN QUC CNG - 1511543495 Trang 42 N Bấ TễNG CT THẫP II GVHD : ThS NGUYN QUC TRUNG (vi g01 la trng lng bn thõn dõm ) P = 820.5 (daN/m ) = 8.205 (daN/cm ) Giỏ tri q1: q1 = g + 0.5p = 6.7 +0.5*8.205 = 10.8 (daN/cm ) Chn a = 4.5 (cm) -> h0 = h a = 30-4.5 = 25.5 (cm) + Kim tra cng tit diờn nghiờng theo ng sut nen chớnh Q 0.3*w1*b1*Rb*b*h0 Do cha bụ trớ cụt nờn ta gi thuyt w1*b1 =1 Ta co : 0.3*Rb*b*h0 = 0.3*115*20*25.5 = 17595 (daN) > Q =2249 (daN) Dõm kh nng chiu ng sut nen chớnh + Kim tra s cõn thit phi t cụt B qua nh hng ca lc dc truc nờn n =0 Qbmin = b3*(1+ n ) *Rb*b*h0 = 0.6*(1+0)*9*20*25.5 = 2754 (daN) Q = 2249 (daN) < Qbmin -> Cõn phi t cụt chiu ct + Xỏc inh giỏ tri Mb = b2*(1+f +n)*Rbt*b*h02 = 2*(1+0+0)*9*20*25.52 = 234090 (daN.cm ) Do dõm co phõn cỏnh nm vựng chiu keo f = Xỏc inh giỏ tri Qb1= = = 3180 daN = + co* 2M b 2* 234090 = 503cm Q Qb1 2249 3180 Mb q1 + Ta co = 234090 10.8 = 110 cm M b 2* 234090 = Q 2249 co = c = + giỏ tri qsw tớnh toỏn qsw = Q Gớa tri = 208 cm Mb 234090 q1c 2249 10.8*208 c 208 = = 5.4daN / cm c0 208 Qbmin 7492.5 = 2h0 2*25.5 = 147(daN/m ) SVTH : TRN QUC CNG - 1511543495 Trang 43 N Bấ TễNG CT THẫP II ( Yờu cõu qsw Q Qb1 Qbmin : ) 2h0 2h0 GVHD : ThS NGUYN QUC TRUNG nờn ta ly giỏ tri qsw = 147 (daN/m ) tớnh cụt +S dung , sụ nhỏnh n=2 Khong cỏch s tớnh toỏn : Rsw nasw 1750 * 2*0.283 = qsw 147 Stt = = 6.7 cm Dõm co h = 60 cm >45 cm -> sct= min( h/3 , 50cm ) = 20 cm b ( 1+ ) *R *b*h 1.5 ( + ) *9* 20 * 25.52 smax = n bt 02 Q = 2249 = 78cm Giỏ tri smax : Khong cỏch thit k cụt S= (stt,sct,smax ) = 15 cm =150 mm +Ta bụ trớ 6a150 cho dõm Kim tra li iờu kiờn cng trờn tit diờn nghiờng theo ng sut nen chớnh ta ó co bụ trớ cụt : Q 0.3b Vi +5 1.3 Dõm bụ trớ 6a150 co àw = = n sw *0.283 = = 0.0018 bs 20*15 Es 2.1*105 = = 9.13 Eb 2.3*104 = 1+5 = 1+5*0.0018 = 1.009 < 1.3 = 1- = 1-0.01*11.5 = 0.885 Ta thy = 0.885*1.009 = 0.89 Ta co Q = 2249 < 0.3b = 0.3*1.009 *0.885*115*20*25.5 = 15711.72 daN Dõm kh nng chiu ng sut nen chớnhChn cụt cho cỏc phõn t dõm ( 2,3,7,8,9 ) bxh =200x300 Ta thy cỏc dõm co kớch thc bxh =200x300 thi Dõm co lc ct ln nht Q = 22.49 (kN), dõm c t cụt theo cu to 6a150 -> chn cụt 6a150 cho cỏc dõm co kớch thc bxh =200x300 SVTH : TRN QUC CNG - 1511543495 Trang 44 N Bấ TễNG CT THẫP II GVHD : ThS NGUYN QUC TRUNG d Chn ct cho cỏc phn t dm ( 5,6 ) bxh =200x300 Ta thy cỏc dõm co kớch thc bxh =200x300 thi Dõm co lc ct ln nht Q = 23.49 (kN), dõm c t cụt theo cu to 6a150 -> chn cụt 6a150 cho cỏc dõm co kớch thc bxh =200x300 e.B trớ ct thộp cho dm Vi dõm co kớch thc 250x600 : - phõn õu dõm on L/4 ta bụ trớ cụt t day 6a150 , vi L la nhip thụng thy ca dõm Phõn cũn li t tha hn theo cu to Sct = (3h/4 , 50 cm ) = 30 cm Vi dõm co kớch thc 200x300 : nhip dõm ngn ta bụ trớ cụt 6a150 t suụt dõm IX.TINH TON CT THẫP CT Vt liu s dng Bờ tụng : B20 ( M250 ) Rb = 11.5 MPa , Rbt = 0.9 MPa Thep nhom : CII = RS = RSC = 280MPa b2 = =0.429 = 0.623 2.Tớnh toỏn ct thộp cho phn t ct : bxh = 250x300 *.s liu tớnh toỏn Chiờu dai tớnh toỏn l0 = 0.7H = 0.7*4.8 = 3.36 (m) = 336 (cm) *Gi thit a =a =4 cm -> h0= h-a = 30 =26 cm Za = ho a = 26 = 22 cm mnh : = l0/h = 336/30 = 11.2 > ( Xet n s nh hng ca uụn dc ) T hp ni lc ta c SVTH : TRN QUC CNG - 1511543495 Trang 45 N Bấ TễNG CT THẫP II Ky hiờu cp ni lc c im ca cp ni lc Mmax (emax) Nmax GVHD : ThS NGUYN QUC TRUNG M (kN.m ) 40.3 38.7 N (kN) 483.9 521 e1 = M/N (cm) 8.3 7.43 ea (cm) 1.5 1.5 eo = max(e1, ea) (cm) 8.3 7.43 Tớnh ct thộp i xng cho cp 1: M = 40.3 (kN.m) = 403000 (daN.cm) N = 483.9 (kN.m) = 48390 (daN) + Lc dc ti hn c xỏc inh theo cụng thc : N cr = 6.4.Eb l02 SI + Is ữ l l0 = 336 (cm) Eb = 23*103= (Mpa) = 230*103(daN/cm2) + Mụmen quỏn tớnh tit diờn I= bh3 25*303 = = 56250 12 12 (cm4) + Ga thuyt = 0.02% = 0.0002 Is = = 0.0002*25*26*(0.5*30-4)2 = 15.73 (cm4) = Es 21*104 = = 9.13 Eb 23*103 = 0.5-0.01 336 30 0.01*11.5 = 0.273 e0 8.3 = = 0.28 h 30 e = max (min) = 0.28 SVTH : TRN QUC CNG - 1511543495 Trang 46 N Bấ TễNG CT THẫP II GVHD : ThS NGUYN QUC TRUNG Hờ sụ k n nh hng ca lờch tõm 0.11 0.1 + e p 0.11 0.28 0.1 + S= + 0.1 = +0.1 = 0.39 Vi BTCT thng =1 + Hờ sụ xet n nh hng ca ti trng dai hn : M dh + Ndh y M + Ny 38.7 + 483.9*0.15 40.3 + 521*0.15 = 1+ = 1+1 Vi y = 0.5h = 0.5*0.3 = 0.15 (m) = 1.04 < 1+ = = vi bờ tụng nng + Lc dc ti hn c xỏc inh theo cụng thc : Ncr = 6.4* 230.103 0.39*56250 ( +9.13*15.73) = 276904 3362 1.04 (daN) +Hờ sụ uụn dc = 1 = = 1.21 N 48390 1 N cr 276904 e = = 1.21*8.3 +30/2-4 = 21.043 (cm ) +S dung bờ tụng B20 , thep AII -> R = 0.623 x= N 48390 = Rb b 115* 25 = 16.83 cm > Rho = 0.623*26 = 16.2 cm + Nen lờch tõm be Tớnh thep theo phng phỏp ỳng dõn : N ( e + 0.5 x1 h0 ) As = Rsc Z a 48390 ( 21.043 + 0.5*16.2 26 ) = 2800* 22 SVTH : TRN QUC CNG - 1511543495 = 2.5 cm2 Trang 47 N Bấ TễNG CT THẫP II GVHD : ThS NGUYN QUC TRUNG N + Rs As 1ữ R h 2R A Rbbh0 + s s ' R x= Ne Rb bx ( h 0.5x ) A = *26 = 16.62 cm 48390*21 115*25*16.62* ( 26 0.5*16.62 ) Rsc Z a s = 48390 + 2*2800*2.5 1ữ 0.623 2* 2800* 2.5 115* 25* 26 + 0.623 2800* 22 = = 2.7 (cm2) Ham lng cụt thep gi thuyt hp lớ + Chn 2ỉ16 co As = 4.02 cm2 > 2.7 cm2 Tớnh ct thộp i xng cho cp 2: chn thep M = 38.7 (kN.m) = 387000 (daN.cm) N = 521 (kN.m) = 52100 (daN) + Lc dc ti hn c xỏc inh theo cụng thc : N cr = 6.4.Eb l02 SI + Is ữ l l0 = 336 (cm) Eb = 23*103= (Mpa) = 230*103(daN/cm2) + Mụmen quỏn tớnh tit diờn I= bh3 25*303 = = 56250 12 12 (cm4) + Gi thuyt = 0.02% = 0.0002 Is = = 0.0002*25*26*(0.5*30-4)2 = 15.73 (cm4) = Es 21*10 = = 9.13 Eb 23*103 = 0.5 0.01 l0 0.01Rb h = 0.5-0.01 SVTH : TRN QUC CNG - 1511543495 336 30 0.01*11.5 = 0.273 Trang 48 N Bấ TễNG CT THẫP II GVHD : ThS NGUYN QUC TRUNG = = 0.25 e = max (min) = 0.273 Hờ sụ k n nh hng ca lờch tõm 0.11 0.1 + e p 0.11 0.273 0.1 + S= + 0.1 = + 0.1 = 0.394 Vi BTCT thng =1 + Hờ sụ xet n nh hng ca ti trng dai hn : M dh + N dh y 38.7 + 483.9*0.15 = 1+1 M + Ny 40.3 + 521*0.15 = 1+ Vi y = 0.5h = 0.5*0.3 = 0.15 (m) = 1.04 < 1+ = = vi bờ tụng nng + Lc dc ti hn c xỏc inh theo cụng thc : Ncr = 6.4* 230.103 3362 ( 0.394*56250 1.04 + 9.13*15.73) = 279725 (daN) +Hờ sụ uụn dc = 1 = = 1.23 N 52100 1 N cr 279725 e = = 1.23*7.43+30/2-4 = 20.14 (cm ) +S dung bờ tụng B20 , thep AII -> R = 0.623 x= N 52100 = R b b 115* 25 = 18 cm > Rho = 0.623*26 = 16.2 cm +Nen lờch tõm be Tớnh thep theo phng phỏp ỳng dõn : N ( e + 0.5 x1 h0 ) As = Rsc Z a 52100 ( 20.14 + 0.5*16.2 26 ) = 2800* 22 SVTH : TRN QUC CNG - 1511543495 = 1.9 cm2 Trang 49 N Bấ TễNG CT THẫP II x= GVHD : ThS NGUYN QUC TRUNG N + Rs As 1ữ R h 2R A Rbbh0 + s s ' R Ne Rb bx ( h 0.5x ) Rsc Z a s A = = 52100 + 2*2800*1.9 1ữ 0.623 2*2800*1.9 115* 25* 26 + 0.623 *26 = 17.6 cm 52100*20.14 115*25*17.6* ( 26 0.5*17.6 ) = 2800* 22 = 2.8 (cm2) + Cp ni lc ũi hi lng thep bụ trớ la ln nht Vy ta bụ trớ cụt thep ct phõn t ct theo = 2.8 (cm2) Chn 2ỉ16 theo iờu kiờn cu to co = 4.02(cm2) > 2.8 (cm2) 3.Tớnh toỏn ct thộp cho phn t ct : bxh = 250x350 *.s liu tớnh toỏn Chiờu dai tớnh toỏn l0 = 0.7H = 0.7*4.8 = 3.36 (m) = 336 (cm) Gi thit a =a =4 cm -> h0= h-a = 35 =31 cm Za = ho a = 31 = 27 cm mnh : = l0/h = 336/35 = 9.6 > ( Xet n s nh hng ca uụn dc ) T hp ni lc ta c SVTH : TRN QUC CNG - 1511543495 Trang 50 N Bấ TễNG CT THẫP II Ky hiờu cp ni lc c im ca cp ni lc Mmax (emax) Nmax GVHD : ThS NGUYN QUC TRUNG M (kN.m ) 34.21 25.07 N (kN) 93.9 105.5 e1 = M/N (cm) 36.4 23.8 ea (cm) 1.5 1.5 eo = max(e1, ea) (cm) 36.4 23.8 Tớnh ct thộp i xng cho cp 1: M = 34.21 (kN.m) = 342100 (daN.cm) N = 93.9 (kN.m) = 9390 (daN) + Lc dc ti hn c xỏc inh theo cụng thc : N cr = 6.4.Eb l02 SI + Is ữ l l0 = 336 (cm) Eb = 23*103= (Mpa) = 230*103(daN/cm2) + Mụmen quỏn tớnh tit diờn I= bh3 25*353 = = 89322 12 12 (cm4) + Ga thuyt = 0.02% = 0.0002 Is = = 0.0002*25*31*(0.5*35-4)2 = 28.25 (cm4) = Es 21*104 = = 9.13 Eb 23*103 = 0.5-0.01 336 35 0.01*11.5 = 0.29 e0 36.4 = = 1.04 h 35 SVTH : TRN QUC CNG - 1511543495 Trang 51 N Bấ TễNG CT THẫP II GVHD : ThS NGUYN QUC TRUNG e = max (min) = 1.04 Hờ sụ k n nh hng ca lờch tõm 0.11 0.1 + e p 0.11 1.04 0.1 + S= + 0.1 = +0.1 = 0.2 Vi BTCT thng =1 + Hờ sụ xet n nh hng ca ti trng dai hn : M dh + Ndh y M + Ny 25.07 + 93.9*0.175 34.21 + 105.53*0.175 = 1+ = 1+1 Vi y = 0.5h = 0.5*0.35 = 0.175 (m) = 1.78 < 1+ = = vi bờ tụng nng + Lc dc ti hn c xỏc inh theo cụng thc : Ncr = 6.4 * 230.103 0.2*89322 ( +9.13* 28.25) = 134220 3362 1.78 (daN) +Hờ sụ uụn dc = 1 = = 1.08 N 9390 1 N cr 134220 e = = 1.08*36.4 +35/2-4 = 52.8 (cm ) +S dung bờ tụng B20 , thep AII -> R = 0.623 x= N 9390 = Rb b 115* 25 = 3.3 cm < Rho = 0.623*31 = 19.31 cm + Xy trng hp x < 2a = (cm) + Lng cụt thep yờu cõu As = As' = N (e Za ) 9390*(52.8 27) = = 3.15 Rs Z a 2800* 27 + Chn 2ỉ16 co As = 4.02 cm2 > 3.15 cm2 Tớnh ct thộp i xng cho cp 2: SVTH : TRN QUC CNG - 1511543495 Trang 52 N Bấ TễNG CT THẫP II GVHD : ThS NGUYN QUC TRUNG M = 25.07 (kN.m) = 250700 (daN.cm) N = 105.53 (kN.m) = 10553 (daN) + Lc dc ti hn c xỏc inh theo cụng thc : N cr = 6.4.Eb l02 SI + Is ữ l l0 = 336 (cm) Eb = 23*103= (Mpa) = 230*103(daN/cm2) + Mụmen quỏn tớnh tit diờn I= bh3 25*353 = = 89322 12 12 (cm4) + Ga thuyt = 0.02% = 0.0002 Is = = 0.0002*25*31*(0.5*35-4)2 = 28.25 (cm4) = Es 21*104 = = 9.13 Eb 23*103 = 0.5-0.01 336 35 0.01*11.5 = 0.29 e0 36.4 = = 1.04 h 35 e = max (min) = 1.04 Hờ sụ k n nh hng ca lờch tõm 0.11 0.1 + e p 0.11 1.04 0.1 + S= + 0.1 = +0.1 = 0.2 Vi BTCT thng =1 + Hờ sụ xet n nh hng ca ti trng dai hn : SVTH : TRN QUC CNG - 1511543495 Trang 53 N Bấ TễNG CT THẫP II M dh + Ndh y M + Ny 25.07 + 93.9*0.175 34.21 + 105.53*0.175 = 1+ = 1+1 Vi y = 0.5h = 0.5*0.35 = 0.175 (m) GVHD : ThS NGUYN QUC TRUNG = 1.78 < 1+ = = vi bờ tụng nng + Lc dc ti hn c xỏc inh theo cụng thc : Ncr = 6.4 * 230.103 0.2*89322 ( +9.13* 28.25) = 134220 3362 1.78 (daN) +Hờ sụ uụn dc = 1 = = 1.08 N 9390 1 N cr 134220 e = = 1.08*36.4 +35/2-4 = 52.8 (cm ) +S dung bờ tụng B20 , thep AII -> R = 0.623 x= N 10553 = R b b 115* 25 = 3.7 cm < Rho = 0.623*31 = 19.31 cm + Xy trng hp x < 2a = (cm) + Lng cụt thep yờu cõu As = As' = N (e Za ) 10553*(52.8 27) = = 3.6 Rs Z a 2800* 27 + Chn 2ỉ16 co As = 4.02 cm2 > 3.6 cm2 + Cp ni lc ũi hi lng thep bụ trớ la ln nht Vy ta bụ trớ cụt thep ct phõn t ct theo = 3.6 (cm2) Chn 2ỉ16 theo iờu kiờn cu to co = 4.02(cm2) > 3.6 (cm2) SVTH : TRN QUC CNG - 1511543495 Trang 54 N Bấ TễNG CT THẫP II GVHD : ThS NGUYN QUC TRUNG 2x2ỉ16 4.Bng tng hp thộp ct b (cm) h (cm) a=a' (cm) gt (%) T/h LT As=A' s (cm2) (%) Taỷi P(t) l (m) STORY3C1 COMB1 -10.553 2.9 25 30 0.8 LT L 2.6 0.8 STORY2C1 COMB7 -31.201 2.8 25 30 0.8 LT L 2.6 0.8 STORY1C1 COMB6 -52.091 4.2 25 30 0.8 LT B 2.8 0.8 STORY3C2 COMB1 -10.274 2.9 25 30 0.8 LT L 2.6 0.8 STORY2C2 COMB8 -30.436 2.8 25 30 0.8 LT L 2.6 0.8 STORY1C2 COMB5 -50.897 4.2 25 30 0.8 LT B 2.6 0.8 STORY3C3 COMB1 -13.087 2.9 25 30 0.8 LT L 2.6 0.8 STORY2C3 COMB2 -36.764 2.8 25 35 0.8 LT L 3.1 0.8 STORY1C3 COMB1 -61.153 4.2 25 35 0.8 LT B 3.6 0.8 STORY3C4 COMB1 -12.58 2.9 25 30 0.8 LT L 2.6 0.8 P.t SVTH : TRN QUC CNG - 1511543495 As ch Chn thộp x 216 4.02 4.02 x 216 4.02 x 216 4.02 x 216 4.02 x 216 4.02 x 216 4.02 x 216 4.02 x 216 4.02 x 216 4.02 x 216 Trang 55 N Bấ TễNG CT THẫP II GVHD : ThS NGUYN QUC TRUNG STORY2C4 COMB2 -35.5 2.8 25 35 0.8 LT L 3.1 0.8 STORY1C4 COMB6 -59.177 4.2 25 35 0.8 LT B 3.1 0.8 4.02 x 216 4.02 x 216 5.Tớnh toỏn thộp cho ct + ng kớnh cụt ỉsw = ( = = mm Ta chn cụt ỉ6 nhom AI + Khong cỏch cụt s : Trong on nụi chng cụt thep dc : S (10ỉmin ; 500mm) = (10*16 ; 500mm) = 160 mm Chn s = 150 mm Cỏc on cũn li S (15ỉmin ; 500mm) = (15*16 ; 500mm) = 240 mm , Chn s = 200 mm SVTH : TRN QUC CNG - 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