Masonry Design. = calculated compressive stress in masonry f. = masonry design compressive stress f

Transcription

1 ARCH 614 Note Set 7.1 S014bn Monry Deign Nottion: A = ne or re A n = net re, equl to the gro re ubtrcting ny reinorceent A nv = net her re o onry A = re o teel reinorceent in onry deign A t = re o teel reinorceent in onry colun deign ACI = Aericn Concrete Intitute ASCE = Aericn Society o Civil Engineer b = width, oten cro-ectionl C = ne or copreion orce C = copreion orce in the onry or onry deign CMU = horthnd or concrete onry unit d = eective depth ro the top o reinorced onry be to the centroid o the tenile teel e = eccentric ditnce o ppliction o orce (P) ro the centroid o cro ection = xil tre b = bending tre = clculted copreive tre in onry = onry deign copreive tre = tre in the teel reinorceent or onry deign v = her tre F = llowble xil tre F b = llowble bending tre F = llowble tenile tre in reinorceent or onry deign F t = llowble tenile tre F v = llowble her tre F v = llowble her tre o the onry F v = llowble her tre o the her reinorceent h = ne or height = eective height o wll or colun I x = oent o inerti with repect to n x-xi j = ultiplier by eective depth o onry ection or oent r, jd k = ultiplier by eective depth o onry ection or neutrl xi, kd L = ne or length or pn length M = internl bending oent = type o onry ortr M = oent cpcity o reinorced onry be governed by teel tre M = oent cpcity o reinorced onry be governed by onry tre MSJC = Monry Structurl Joint Council n = odulu o elticity trnortion coeicient or teel to onry n.. = horthnd or neutrl xi (N.A.) N = type o onry ortr NCMA = Ntionl Concrete Monry Aocition O = type o onry ortr P = ne or xil orce vector P = llowble xil lod in colun r = rdiu o gyrtion S = ection odulu = type o onry ortr S x = ection odulu with repect to n x-xi t = ne or thickne T = ne or tenion orce T = tenion orce in the teel reinorceent or onry deign TMS = The Monry Society w = ne or ditributed lod 1 = coeicient or deterining tre block height, c, in onry LRFD deign = trin in the onry = trin in the teel = reinorceent rtio in onry deign 1

2 ARCH 614 Note Set 7.1 S014bn Reinorced Monry Deign Structurl deign tndrd or reinorced onry re etblihed by the Monry Stndrd Joint Coittee coniting o ACI, ASCE nd The Monry Society (TMS), nd preent llowble tre deign well liit tte (trength) deign. Mteril = onry pri copreive trength ro teting Reinorcing teel grde re the e thoe ued or reinorced concrete be. Unit cn be brick, concrete or tone. Mortr conit o onry ceent, lie, nd, nd wter. Grde re ned ro the word MASONWORK, with verge trength o 500pi, 1800 pi, 750 pi, 350 pi, nd 75 pi, repectively. Grout i lowble ortr, uully with high ount o wter to ceent teril. It i ued to ill void nd bond reinorceent. Allowble Stre Deign For unreinorced onry, like onry wll, tenion tree re llowed in lexure. Monry wll typiclly ee copreion tree too. For reinorced onry, the teel i preued to reit ll tenile tree nd the tenion in the onry i ignored. Fctor o Sety re pplied to the liit tree or llowble tre vlue: bending (unreinorced) F b = 1/3 bending (reinorced) F b = 0.45 bending (tenion/unreinorced) tble..3. be her (unreinorced or lexure) F v = pi be her (reinorced) M/(Vd) 0.5 F v = 3.0 be her (reinorced) M/(Vd) 1.0 F v =.0 Grde 40 or 50 reinorceent F = 0 ki Grde 60 reinorceent F = 3 ki Wire joint reinorceent F = 30 ki where = peciied copreive trength o onry

3 ARCH 614 Note Set 7.1 S014bn Internl Equilibriu or Bending C = copreion in the onry = tre x re = T = tenion in teel = tre x re = A C = T nd M = T (d-kd/3) = T (jd) M =C (jd) t d BIA Teknote 17 erie b(kd) where = copreive tre in the onry ro lexure = tenile tre in the teel reinorceent kd = the height to the neutrl xi b = width o tre re d = eective depth o ection = depth to n.. o reinorceent jd = oent r ro tenion orce to copreion orce A = re o teel n = E /E ued to trnor teel to equivlent re o onry or eltic tree = reinorceent rtio b grout unit n.. A kd STRAIN A bd /n STRESS F=0: T =A A C = b(kd)/ jd M kd b Criteri or Be Deign For lexure deign: kd M b jd 0. 5 bd jk or M A jd ρbd j The deign i dequte when b Fb in the onry nd F.in the teel. Sher tre i deterined by v = V/A nv where A nv i net her re. Sher trength i deterined ro the her cpcity o the onry nd the tirrup: F v = F v + F v. Stirrup pcing re liited to d/ but not to exceed 48 in. where: 1 M P Fv where M/(Vd) i poitive nd cnnot exceed 1.0 Vd An Av F d (F Fv 0. 5 v = 3.0 when M/(Vd) 0.5 ) Anv (F v =.0 when M(Vd) 1.0.) Vlue cn be linerly interpolted. 3

4 ARCH 614 Note Set 7.1 S014bn Lod nd Reitnce Fctor Deign The deign ethodology i iilr to reinorced concrete ultite trength deign. It i ueul with high her vlue nd or eiic deign. The liiting onry trength i Criteri or Colun Deign 1 c c T C (Monry Joint Code Coittee) Building Code Requireent nd Coentry or Monry Structure deine colun hving b/t < 3 nd h/t > 4. where b = width o the wll t = thickne o the wll h = height o the wll A lender colun h iniu dienion o 8 on one ide nd h/t 5. Colun ut be reinorced, nd hve tie. A iniu eccentricity (cuing bending) o 0.1 tie the ide dienion i required. Allowble Axil Lod or Reinorced Monry h P 0.5 An 0.65AtF 1 or h/t r 70r P 0.5 An 0.65AtF or h/t > 99 h Allowble Axil Stree or Unreinorced Monry h F or h/t r where 70r F 0.5 or h/t > 99 h h = eective length r = rdiu o gyrtion A n = eective (or net) re o onry A t = re o teel reinorceent = peciied onry copreive trength F = llowble copreive tre in colun reinorceent with lterl conineent. Cobined Stree When xiu oent occur oewhere other thn t the end o the colun or wll, virtul eccentricity cn be deterined ro e = M/P. 4

5 ARCH 614 Note Set 7.1 S014bn Monry Colun nd Wll b There re no odiiction ctor, but in ddition to tiying 1. 0, the tenile tre F F cnnot exceed the llowble: reinorced onry: F or the copreive tre exceed llowble or b t b Fb provided F. b 5

6 ARCH 614 Note Set 7.1 S014bn Exple 1 Deterine i the unreinorced CMU wll cn utin it lod with the wind. Speciy ortr type nd unit trength per MSJC. b Fb 3 F F b h F or 140r 70r F 0 5. or h h r 99 h r M b S 99 P A 14-1B: h 1 t( 1in ) 11in o F r 3. 1in in lb 4k( 1000 k ) 133pi 30in 3.1 (1 tkip/t ) (t) (in/t) Mx = Pe b 1/3 154/(1/3) = 46 pi M = Pe/ Mx = wl /8 pi 1; 1056 pi Moent ditribution ro eccentricity Moent ditribution ro ditributed wind lod 5 pi pi 6 = 1056 pi (govern)

7 ARCH 614 Note Set 7.1 S014bn 7