7/29/2019 jbkbk

1/12

01-10-2008, 10:06 PMMt s cu hi kh c bn trong khi cc bn tin hnh bo v n tt nghip!

Cu hi n tt nghipCu 5: Nu tc dng ca dm dc (Dm ging)?Gi n nh cho khung ngang chu lc. xc nh cc lc x ngang.

Chu ti trng thng ng truyn theo phng dc.Cu 6: Ti sao trong khung b tng ct thp, ct khung li b tr ct thp i xng, cn dm khung li b trct thp khng i xng?Ct thp trong ct b tr i xng v ct l cu kin chu nn ct thp chu m men sinh ra do tc dng calc x ngang nh gi tri, gi phi.Ct thp trong dm b tr khng i xng v dm l cu kin chu un, ct thp chu m men sinh ra do titrng tc dng thng ng.Cu 7: Nu s tnh ton ? So snh s tnh khp do v s n hi ?S khp do cho php nt cn s n hi khng cho php nt.S khp do khng c tnh cho sn mi, sn khu v sinh, sn ban cng. S n hi cho php tnhtt c cc loi cu kin.Cu 8: Ti sao khng tnh ct ai trong sn ?Thng thng lc ct trong bn sn nh, b tng kh nng chu ct, nhng trong bng t hp nu c titrng ln vn phi kim tra theo cng chu ct.Cu 9: Nu cch tnh ton cu thang (Tnh ton bn thang, dm chiu ti, dm chiu ngh ) ?

+Bn thang:-Loi c cn thang: tnh nh bn sn truyn lc theo mt phng ( bn loi dm ), hai phng ( bn k 4cnh ). Cn thang tnh nh dm n gin k ln hai u l dm chiu ti v dm chiu ngh.-Loi khng c cn: bn thang ct dc 1( m ) theo chiu di bn thang sau tnh nh dm n gin k lndm chiu ngh v dm chiu ti.+Tnh dm chiu ngh v dm chiu ti: tnh nh dm n gin ch lc tp trung khi c cn thang v lcphn b khi khng c cn thang.

Cu 10: Cch cht ti khung phng v khung khng gian ?Khung phng cht ti cch tng, cch nhp.Khung khng gian cht ti cch .Cu 11: Trong khung nt no quan trng nht ? V sao ?Trong khung nt trn, trong cng, ngoi cng l nt quan trng nht. V ti mmen ln nht nhng lcdc li b nht.

Cu 12: Trong khung phn t no tnh nh, phn t no siu tnh ?Trong khung conson l tnh nh, cn cc phn t cn li l siu tnh.Cu 13: Hy nu cch neo ct thp ca ct trn ti nt ?Ct thp ca ct trn neo t di ln trn.Cu 14: Ct trn khc ct ch nht im no ?Ct trn khc ct ch nht ch l hnh dng, cch b tr thp dc.Ct trn chu lc nn t trong ra ngoi.Cu 15: Khi b tr ct thp trong ct khung ngi ta quan tm n cp ni lc no?Cu 17: Trnh t thit k cng trnh ?-Chn thit k tit din cc b phn kt cu.-Lp s tnh ton khung lin kt.-Xc nh cc loi ti trng tc dng ln kt cu. Sp xp cc loi tnh ti v hot ti. -Tnh ton ni lc cho tng loi ti trng v t hp ni lc.+T hp c bn.+T hp c bit.-Tnh ton cc loi ct thp chu lc, kim tra hm lng v thng k vt liu.Cu 18: Ti sao cn phi bo dng b tng ? cung cp nc m bo qu trnh thu ho xi mng khi b tng tng cng .Trnh b tng b trng mt, r mt.Cu 19: Ti sao b tng thng phm st cao hn b tng th cng ? B tng thng phm dng bm v c thng cha nn c st cao hn c tnh linh ng d hn. Ngoira b tng thng phm phI vn chuyn t nh my n nn yu cu lu ng kt hn l b tng trn tich.

7/29/2019 jbkbk

2/12

mngCu 20: Ti sao trong i khng b tr cu to ct thp?Do b tng trong i ln chu lc ct.Cu 21: Cch xc nh chiu cao i mng ?T iu kin m thng khng k thp, hi ? 2d (d: ng knh i cc ).Cu 22: Th no l trng thi cn bng gii hn ?Trng thi s khp do xut hin lm cho kt cu tr thnh h tnh nh.

Trng thi gii hn l trng thi ng vi kt cu khng cn kh nng chu lc v khng cn iu kin trn tra cho n nh iu kin cng , n nh, mi.Cu 23: Tc dng ct thp cu to, ct gi ?Gi n nh cho thp dc chu lc khi b tng v s co ngt t nhin trong b tng.B m cao ? 70 ( cm ), b rng ln th ct gi cn gim s phnh n b tng gia tit din dm, ng thigi n nh cho ct ai.Cu 24: ngha on neo ct thp ?m bo lc dnh gia b tng v ct thp cho kt cu lm vic.Cu 25: Khi no tnh ton theo s khp do v s n hi ?-S n hi: l s m vtliu cn lm vic trong min n hi. Khi tnh ton theo s n hi thni lc trong kt cu khng c s phn phi li khi chu lc. -S khp do: l s m vt liu lm vic khi xut hin cc khp do. Khi tnh ton theo s bindng do th c s phn b li ni lc.+Sn nh cng nghip v sn nh dn dng bnh thng tnh theo s bin dng do tit kim vt liu.+Sn nh chu ti trng ng hoc trong mi trng d b n mn nn tnh theo s n hi (sn WC,

panel ).-Nguyn l:+S n hi A ? 0,42+S bin dng do A ? 0,3.

Cu 26: Chn tit din dm da vo yu t no ? - mnh ct nh:-Ti trng tc dng.-iu kin vng cho php.Cu 27: Ti sao phi khng ch hm lng ?max , ?min ? ?min l hm lng ti thiu ct thp chu nhng ng sut ph do co ngt t nhin ca b tng.?max l tr s khng ch ct thp khng nhiu qu gy ra hin tng co ct thp, ct thp nhiu s cns co ngt ca b tng, gy nt cho b tng, ng thi tn dng ht kh nng lmvic ca hai loi vtliu ny.Cu 28: V cc mt bng ca kt cu lm g ?

xc nh ti trng truyn ln dm khung, xc nh v tr dm khung chu lc ca tng sn.Cu 29: bn panel tnh ton vng nh th no ?f =f1 - f2 + f3f1: vng do ton b ti trng tc dng ngn hn.f2: vng do ti trng di hn tc dng ngn hn.f3: vng do ti trng di hn tc dng di hn.Cu 30: Ti sao hot ti phi t lch tng, lch nhp ?Hot ti xp lch tng, lch nhp cho c tr s mmen dng dm ln nht l bt li nht.Hot ti t lch tng, lch nhp phn nh gn st vi thc t v iu kin s dng.Khng c trng hp hot ti cht ton khung v nh vy khng phn nh iu kin s dng thc t.Cu 31: u nhc im bn thang c cn v khng c cn ? Bn thang c cn nhp tnh ton ngn (gia cn)Bn thang khng c cn nhp tnh ton l hai u lin kt, di hn nn cn ch vng. Do bn khng ccn s c vng nhiu hn v bt li hn. Cu 32: Tc dng ca ct ai trong ct ?

Ct ai trong cu kin chu nn c tc dng gi n nh cho ct dc chu nn. Ct ai cng c tc dng chulc ct. Ngi ta ch tnh ti ct ai khi cu kin chu lc ln cn thng thng th b tr theo cu to.Cu 33: Xc nh gi ni v gi ngoi khc nhau nh th no ?-Gi ni: l gi sinh ra b trong lng cng trnh do s chnh lch p lc nhit v p lc kh ng ? bc mi.-Gi ngoi: l gi t bn ngoi tc ng trc tip ln b mt ngoi kt cu ? sinh ra mmen cho khung lmun ct.Cu 34:Khi no th dng sn panen, khi no th dng sn ton khi ?Sn panen c dng cho mt bng c kch thc chun, c iu kin thi cng c gii, thng dng trongcc nh cng nghip.

7/29/2019 jbkbk

3/12

Sn ton khi c dng cho cc loi nh c mt bng khng theo mt qui tc nht nh, nh, hoc cc nhc yu cu c bit, dng trong nh dn dng.Cu 35: Trong nh lm vic theo mt phng v hai phng, kch thc ct lm vic nh th no cho hp l?Chn kch thc ct ch nht ( vung ) kch thc cnh ln theo phng mmen ln nht hoc an tonta c th chn ct vung kch thc ly theo mmen ln nht.Cu 36: Ti sao khi tnh ton phi tnh gi theo phng vung gc vi trc nh ?

V khi tnh vung gc vi trc nh ti gi s ln nht, nu tnh nghing mt gc a th ti trng gi phi nhnthm cosa ( m cosa thng nh hn 1 ) ? p lc gi s nh.Cu 37: Khi tnh ton nh cao tng trn nn t yu, trnh dao ng bng cch no ?Cc dao ng nu n t bn ngoi th ta tin hnh cch ly nn mng vi khu vc c dao ng ( omng, rnh )Khi tnh theo s phng th ta chn phng no nguy him nht tnh khung, mng thng l phngngn, cu to thp sao cho chu c ti trng nguy him nht theo phng .Cu 38: Hy nu quan nim cu to dm mng ?nhng ni t khng ng nht, trnh ln khng u nn tng cng bng cch lm sn dc (dmmng). V cu to da trn s tnh, phng php tnh, kh nng lm vic, phng lm vic ca kt cu,quan nim tnh ton, tuy nhin phi tun theo cc qui phm.

Cu 49: S n c nh hng nh th no n ni lc ca khung ? Gi quyt conson nh th no khi giikhung bng my ?S n lm cho mmen trong khung tng ln mmen m ngay gi v mmen ct.

Khi gii khung bng my consol trong khung ta qui v mmen t ti nt khung ca conson hoc c thxem consol l mt phn t gii hn gia hai nt.Cu 40: Hy nu l do thay i kch thc ct ? L do thay i kch thc ct l: tit kim vt liu, tit din hp l vi ti trng, theo yu cu kin trc.Cu 41: C th thay i mc b tng m gi nguyn kch thc ct c khng ?Phi tnh li v hm lng ct thp cng s thay i theo.Cu 42: Khi tnh gi nu mt n gi so le th c xem l phng c khng ?Tnh gi nu mt n gi so le th c th xem l phng c, v khi tnh ti trng gi tc dng vung gc lnb mt cng trnh khi cng trnh cao ? 40( m ) th xt n gi ng.Cu 43: Khi thay i tit din dm, nu tnh theo trc ca dm chnh (ln) th dm no khng an ton ? Dm consol, v dm nh.Cu 44: Cch tnh ch giao nhau gia hai khung ?Tnh theo phng ngang, phng dc sau ly ni lc ln nht t ch giao nhau.Ct t trn dm th ct truyn lc ln dm.Cu 45: Lin kt gia mng v kt cu bn trn dng lin kt g ?

Khi lin kt gia mng v kt cu bn trn th ta dng lin kt ngm .Cu 46: Hy cho bit s khc nhau gia khung cng v vch cng ?Khung l mt h dm ct chu ni lc do ti trng cng trnh v ti trng gi gy raVch cng l vch chu ni lc do ti trng gy ra.Phng php tnh khung v vch cng:+Phng php chuyn v: phng php tnh bng my.+Phng php lc.Quan nim tnh:+Tnh theo s n hi ( trng thi 1 )Ti sao chon phng php khanzi ?Chn phng php khanzi v tnh ton n gin,u im ni bt l n c th t ng kh c nhng sailm trong tnh ton ( thc hin php lp ) ? Bn cht n l phng php chuyn v.Cu 47: Ti sao dm dc v dm ngang khng gia cng thp ? Ti sao phi t ai dy ?Dm dc v dm ngang khng gia cng thp v thng ti trng nh, khng chu lc chnh. t ai dy trnh ph hoi theo tit din nghing ( hay cn gi l chng ct )ai gia cng t gi n lc tp trung u tin t trong khong l L/4. Cu 48: Hy nu phng php tnh cu thang ?Khi tnh cu thang tnh theo dm n gin ( hai u l khp ). Quan nim tnh theo s n hi ( hay nicch khc phng php tnh cu thang theo kt cu h tnh nh )Cu 49: Nu tc dng ca khe nhit v khe ln ?Tc dng ca khe nhit l lm cho kt cu khng b bin dng khi nhit thay i. Khe nhit tnh t mtmng ln n ht mi (phn ngm coi nh khng b bin dng do nhit).Tc dng ca khe ln l lm cho kt cu khng b bin dng khi ln. Khe ln tnh t y mng n ht mi)Cu 50: i vi nh cao tng khi c ti trng gi th c k n chuyn v khng ?i vi nh cao tng khi c ti trng gi th phi k n chuyn v.

7/29/2019 jbkbk

4/12

lp ngi trn cao ta phi dng my vn thng, cn cu, gi ngi khng bay ta phi trnh gi ni bc mi.Cu 51: Khi no dng lin kt cng, khi no dng lin kt khp ? Dng lin kt cng khi kt cu l mt h siu tnh.Dng lin kt khp khi kt cu l mt h tnh nh.Cu 52: Dng mng cc gii quyt vn g l ch yu ? Hn ch c bin dng ln c tr s ln, bin dng khng ng u ca nn, m bo n nh khi c ti

trng ngang tc dng, rt ngn thi gian thi cng, tit kim c vt liu trong thi cng.

Cu 53: p cc khi no khng cn p tnh ?Khi cng trnh ngoi vi thnh ph khng nh hng n xung quanh.Cu 54: Xc nh mng trn nn t, khc nhau nh th no ? Khi no phi thit k mng bng theo haiphng ?Xc nh mng trn nn t da vo ti trng tiu chun tnh ton theo trng thi gii hn II bin dng (ln).Xc nh mng trn nn l da vo ti trng tnh ton, kim tra theo trng thi gii hn cng (khngcn tnh ln).Khi ti trng ln, nn t yu th ta thit k mng bng theo hai phng. Cu 55: Nh nhiu tng trn nn t yu trnh dao ng bng cch no ?Khi tnh ton ta chon trng hp bt li nht, h s an ton cao ? khng kinh t.Cch ly cng trnh vi nhng giao ng do tc ng ngoi.Khi tnh theo s phng th ta chn phng no c dao ng ln nht tnh.

Cu 56: Khi tnh mng hp davo vn g ?Khi tnh mng hp da vo biu ni lc ca kt cu m tnh.Cu 57: Khi chon tit din cc da trn c s no ? Ti sao ? Trnh t thit k cc?Chn tit din cc da trn chiu su chn cc (chiu di cc), cng sut thit b vn chuyn v mng cc.Ngoi ra chiu di tit din, cng vt liu v ct thp dc c quan h cht ch vi nhau.*Gii thch ti sao:Trnh t thit k cc sau khi xc nh ti trng truyn xung mng.+Chn vt liu lm cc v kt cu mng+Chn chiu su t i cc da vo iu kin a cht.+Xc nh sc chu ti ca cc+Xc nh s b kch thc i cc+Xc nh s lng cc (lc ny ti trng phi k thm t ph trn i v i cc)

+Cu to v tnh ton i cc+Kim tra lc tc dng ln cc phi nh hn sc chu ti ca cc

+Kim tra lc tc dng ln nn t+Kim tra ln ca mng cc+Xc nh chi thit k ca cc+Kim tra cc khi vn chuyn v cu lpCu 58: Phng php ng cc v cc khoan nhi khc nhau nh th no ?+ng cc: dng my p hoc ng xung nn t+Khoan nhi: khoan ly t ln to l, sau t ct thp v b tng.Cu 59: Dng cch no kim tra su cc ?Trc khi ng cc trn cc ta vch nhng mc thc su, khi ng nhn vo kim tra.Cu 60: Cc ng ttrong ra ngoi hay t ngoi vo trong ?Khi ng cc th ta ng cc theo hnh xon c t trong ra ngoi.Cu 61: Khi no cn tnh chi ?Khi cn kim tra kh nng chu tc dng ca ti trng cng trnh (nu chi thc t nh hn chi thitk thcc c kh nng chu c tc dng ca ti trng).Nu chi thc t ln hn chi thit k th cn b sung hoc thit k li cc trong mng.Cu 62: Lm th no bit cc chu un ?Khi ti trng ngang rt ln.Khi thi cng cc p, ni cc theo phng php hn bn thp ni vi bn thp ch sn v nh v bng cctim ch sn.p lc p chn bng 1,3 ? 2 ln sc chu ti tnh ton ca cc l hp l.Dng ai xon nhm tng cng kh nng chu chn ng khi ng cc, i ny chu lc tt nhng thi cngkh.Cu 63: Cc di vch cng v di mng c khc nhau khng ?Khng khc nhau v cch lm vic ca cc nh nhau.Mng c xem l tuyt i cng: l khi mng hon ton khng chu un ( mng cng l mng chu un rt

7/29/2019 jbkbk

5/12

t hay ni cch khc l rt nh ).Cu 64: Ti sao b tr ct thp u trong cc ? Ti sao u cc phi t ct ai dy ? B tr thp u trong cc l v khi cu lp c mmen m v dng ? chu c c hai.u cc t ct ai dy nhm tng kh nng chu ti khi ng (ti trng cc b) ? trnh v u cc. Cu 65: Mng bng khi tnh ton nguyn h v chia ra thnh cc phn khc nhau th cch no l hp l vkinh t?Mng bng khi tnh nguyn h th hp l hn v kinh t hn.

iu kin b u tha ca mng bng l:+Ngay ti cc khe ln+Ngay ti ct u tin ( do M = 0)+Thi cng c ct mng bng trn mt khi khng b nt.Cu 66: Mng bng v mng n c g khc nhau ? (u, khuyt im, gi thnh, n nh ).Cn c vo h s a cht ( h khoan, tnh cht c l ca t ).Cn c vocao qui hoch ca khu v cao thit k ca cng trnh.Cu 67: Hy nu s khc nhau gia mng bng v mng kp ?Mng bng l mng c sn, ti trng phn b trn chiu di sn ( phn lc nn )Mng kp l mng khng c sn, bn chu lc, ti trng tc dng tp trung ging nh mng n.Cu 68: Khi tnh bin dng nn phi chp nhn gi thit g ? ln tnh ton Stt ? [S]?S ? [?S]Cu 69: V tr v dm ging phi b tr nh th no i vi khung bn trn v mng bn di cho hp l ?Dm ging b tr ngay ti mi ni gia ct thp dc ca ct v thp ch ca ct chn sn trong mng, ch

ni thp ny c chn ni thun tin cho thi cng c th ngay mt mng hoc c th mt nn nh.Cu 70: Hy nu s khc nhau gia ln v ln lch ?Ln l bin dng ca nn t khi chu ti trng.Ln lch l s chnh lch bin dng ca nn mng khi chu ti trng.

Ln lch nguy him hn n s gy ph hoi kt cu cng trnh.Cu 71: Lc ct khc vi lc xuyn thng nh th no ?Lc ct l ni lc ca kt cu sinh ra do ng sut tip trong qu trnh chu ti.Xuyn thng l lc dc ( ni lc ) sinh ra do ng sut ko chnh.Cu 72: Cn c vo c s no chn lp t p ? Lp t gia ti ?Nu l cc u tin th nh ln ri khoan mi cho qua khi lp sau ng su theo thit k.Nu l cc th th ta p b u cc coi nh n l t v ng tip cho cc hng k.Nu hng no cng vy ( thng 2 ? 3 hng ) phi xem xt tnh ton li.Cu 73: Th no l nn WRINKLER ? u v khuyt im ? Nn WRINKLER l phng php h s nn gi thit l ti mi im mt y mng ca dm trn nn n

hi, cng ca ti trng ( R ) t l bc nht vi ln ( ln ny bng vng ca dm s = y ) nhvy R, C, Y, ( X ) vi C l h s nn. +Nn WRINKLER cn gi l nn n hi bin dng cc b.+M hnh l dy v s l so lm vic c lp vi nhau.-u im:n gin, tin dng trong tnh ton, thit k gn ng vi thc t c dng nhng nn t yu, rt yu.-Nhc im:Khng phn nh c tnhphn phi hay lin h c ca t nn v t c tnh ma st trong nn khi chutrng ti cc b th t c th li ko hay gy ra ln vng ln cn ( ngoi phm vi t ti ) cng lm vicchung.+Khi nn t ng nht th trng ti phn b u lin tc trn dm, theo m hnh ny dm s ln u vbin dng nhng thc ra khi trng ti tc dng phn b u th dm vn b un ( vng ) gia nn nhhng xung quanh nhiu hn nh vy s ln nhiu hn u dm.+Khi mng tuyt i cng, ti trng t i xngth mng s ln u theo m hnh ny nh vy ng suty mong s phn b u nhng theo o c thc t thi ng sut phn b khng u.+H s nn C c tnh cht qui c khng r rng, C khng phi l mt hng s.

forever

01-10-2008, 10:13 PMCu 74: Ti sao khi mng cc i cao ? Di thp ? Cch kim tra xuyn thng ?Tnh mng cc i cao khi cng trnh nm ni t thp, nhiu nc kh thi cng i, cn phi thi cngnhanh, gp rt mng.Tnh mng cc i thp khi cng trnh nm nhng ni t cao, mc nc ngm su, tuy nhin vt liu vti trng nhiu nhng b li th mng cc i thp n nh hn.+Kim tra xuyn thng:

7/29/2019 jbkbk

6/12

Nu cc nm trong phm vi hnh thp p lm th khng cn kim tra Nu kim tra th Pct < 0,752.k1.h.b.Cu 75: Khi ng cc gp phi mt lp t hay mt lp no khc m cc khng th vt qua th phi x lnh th no ?Mng n thit k thi cng n gin, gi thnh r nhng ch s dng c cho nhng cng trnh c ti trngnh, nn t tng i tt.Mng bng tnh ton thi cngphc tp hn, gi thnh cao ? n nh hn s dng cho nhng cng trnh c

ti trng tng i ln, nn t yu.Cu 76: Ti sao khi thit k mng bng thng chn bn mng nm di, dm mng nm trn ? Khi tnh mng bng ta tnh nh dm ch T cho nn i vi trng hp tnh trn m hnh WRINKLER th ngaychn ct y mng chu ko, ngay gia nhp y mng chu nn do ta thit k bn mng nm di ( cnhch T nm trong vng chu nn) s tit kim vt liu hn v tng cng chu nn ca kt cu hn, hp lhn. mng nm trn l do mt trn chu ko m b tng khng tnh cho chu ko nn v mt cng cgi tr tit nh tit din ch nht ( bxh ) nn b tr nh vy l hp l v mt tnh ton v biu s titkim c vt liu.+Ch : Khi thit k mng bng m bn mng nm trn, dm mng nm di l da vo biu ni lcca kt cu, khi ton b kt cu chu ko ? tit din lm vic l( bcxli ) khng phi l ( b x h ).+Ch khi gii FEAP-i vi consol : ngi ta a v dng mt lc tp trung v mt m momen ti ngay nt consol ( mc ch gim bt s nt phn t, n gin tnh ton, nhng nu nguyn cng c ).

-i vi cc lin kt bin: ti ti nt cc lin kt bin, ch t c theo cc phng t do, cn cc phngb kho thkhng t c.V d: Lin kt bin l ngm ti nt khng t ti P v M c.Lin kt bin l gi c nh th ti nt khng t ti P c nhng M th c.Lin kt bin l gi di ng th ti nt khng t ti P theo phng Y c, nhng theo phng X v M thc.Cu 77: Thp mng v thp sn l thp chu un hay chu ct ?Thp mng v thp sn l thp chu un .Khong cch 1, trong thc t c khi n < 1 kt cu li nguy him hn, nh lc ta tnh s n nh ca i ncm bo khng b nghing, th khi tnh trng lng i nc trng thi nh hn bnh thng .

Nh cao my tng tr ln th c xem l nh cao my loi I ?Nh cao t 9 tng tr ln th oc xem l nh cao tng loi I.Cu 81 :S kt cu cng l g ? L nhng nh v cng trnh m kt cu ca n c kh nng c bit chu ni lc gy ra bi bin dng cann .Cu 81:Mng cng l g ?Mng tuyt i cng l g ? Mng cng l mng ch chu lc nn (mng hc, mng gch ) mng cng khng xt n kh nng chu

7/29/2019 jbkbk

7/12

ko do un ca vt liu lm mng, gc m ? ca mng cng nh hn hoc bng ?max, tc l t s H/Lkhng nh hn tr s nu trong qui phm cotg? ? 2 (vi ?=300)-Mng tuyt i cng l mng lm bng b tng hc, gch. Cc loi mng ny cu to sao cho khngxut hin ng xut ko trong chnmng lm cho mng b nt, mun vy th phi ly cotg?=H/L.Cu 82 : Chiu di on ct thp chn vo mng di bao nhiu ? on ct thp chn vo mng vi cc thanh chn su vo sut chiu cao v chiu di bng 30d (k c onb ngang).

on thp khung ni vo thp ch ?30 dCu 83: Ti sao gi l nn n hi ?Tnh dm trn nn n hi ?-Nn n hi : s dng khi cngtrnh t trn t mm, di tc dng ca ti trng cng trnh, nn t cbin dng ln lm cho cng trnh bn trn cng b bin dng theo, do gy ra cc ng lc trong kt cuca cng trnh, cc nn t c bin dng ln ngi ta gi l nn n hi.-Dm trn nn n hi: dm c t trn nn n hi gi l dm trn nn n hi (mng bng c gi lmng dm ).+Ti sao gi l tnh dm trn nn n hi ?-Tnh ton trng thi ng sut, bin dng ca cng trnh xy dng trong iu kin cng lm vic vi nnmm ( ngha l cng bin dng vi nn ) c gi l tnh ton dm ( kt cu) trn nn n hi.+Khi no th tnh dm trn nn n hi ?-Khi kt cu c cng hu hn ngi ta quen gi l kt cu mm ( EJ = 0 ), khi nn bin dng kt cutrn nn pht sinh ni lc ( do bin dng ): mng bng-Kt cu mm tuyt i ( EJ = 0 ) khi nn bin dng th kt cu bin dng theo, v vy m trong kt cukhng sinh ni lc.

-Kt cu cng tuyt i ( EJ = ?) d nn bin dng th no th kt cu khng bin dng g, nhng tht ra cbin dng nh c th b qua c ( nh: tr cu, mng mi, kiu ng khi ).-Khi kim tra iu kin p lc nhm m bo cho vng bin dng do trong nn hi bin dng.Pth < RtcPmax ? 1,2.RtcDo c th coi nn l bin dng tuyn tnhv ch khi nn la bin dng tuyn th mi xc nh c ngsut trong nn theo cac cng thc ca l thuyt n hi va mi tnh c bin dng ca t nn theo ccphng php hin nay.+Cc m hnh nn t:M hinh WRINKLER.M hnh bn khng gian n hi.M hnh nn mng.M hnh nn tm.M hnh n hi vi hai h s nn.M hnh lp n hi hu hn.

+Ti sao tnh dm n hi trn nn WRINKLER ?i vi nhng nn t mm m hnh WRIKLER ph hp, gn ng vi thc t, va n gin, va tin dngtrong tnh ton thit k.Trong iu kin nc ta nhng vng ng bng sng Hng, sng cu Long t mm cha nhiu nc,mc nc ngm cao: Tnh phn phi t yu do ta chn m hnh nn t l m hnh WRINKLER .Cu 84: Khi no th s tnh ton mng bng l dm lin tc ? l khi kt cu bn trn tuyt i cng ( EJ = ?), nhng iu ny thc t khng sy ra v kt cu phntrn khng tuyt i cng.Cu 85: Khi chn chiu su chn mng th chon theo iu kin no ?Khi chn chiu su chn mng thng chn bng 1/15 n 1/12 ln chiu cao ngi nh.

Cu 86: Trong tnh ton nn mngth cc ch tiu no phi ly ch tiu tnh ton ?Cc ch tu nh: ?, ?, ?, ?, ?, e, phi ly ch tiu tnh ton.Cu 87: Ti sao khi thit k nn mng li s dng ti tiu chun ?Khi thit k nn mng ( la chn kch thc ca mng ) l vic kim trabin dng, xc nh theo tnh tonkhng c vt qu tr s gii hn do cc qui phm qui nh m bo iu kin bnh thng ca mng.Hin tng vt ti ( khi tnh ti trng tnh ton ), trong s dng thng gy ra trong thi gian ngn nnkhng cnk n khi tnh ton theo trng thi gii hn v bin dng m ch dng ti trng tiu chun. Cc nn t cng 1/2 t, 1/2 khi chu ti s t ti trng thi th I, trc khi sut hin trng thi II.Cc nn t mm ngc li gy ra bin dng rt ln d ti trng cn rt nh, i vi iu kin vng chuth sng Hng, vng ng bng sng Cu Long t mm ch yu tnh theo trng thi gii hn II l gii hnv bin dng ( phn x l a cht chn ? = 0.85 ).Cu 88: Tnh h s nn c my cch ?Tnh h s nn c hai cch:+Cch 1: tin cy, chnh xc l dng th nghim nn.

7/29/2019 jbkbk

8/12

+Cch 2: da vo bng tra.Cu 89: Hy nu trnh t tnh ton mng bng v mng n ?Chn kch thc s b tnh Rtc.Chn kch thc chu ti.Kim tra ?tb, ?max, ?min, < Rtc ( 1.2Rtc ).Tnh v b tr thp.Cu 90: C my s tnh khung ?

C hai s xc inh ni lc khi tnh khung:+S n hi.+S bin dng do.Cu 91: C my loi lin kt nt khung ? khuyt im ca n ?Lin kt cng (ngm): cng ca khung cao, bin dng t, mmen un phn b ra u n hn gi ntv cc thanh, do cc thanh lm vic hp l hn, lm c nhp ln hn (nu ct lin kt cng vi mngthng l n gin, ph bin nht mmen ti chn ct ln ? tit din mng ln). Khung ton khil ccu to vi nt cng.Lin kt khp: cng ca khung ln, ti trng gy ra mmen ln cho b phn trc tip chu tc dng can, mmen tp trung vo gia v chn ct, cc tit din chu ni lc ln, thanh lm vic t hp l ( nuct lin kt khp vi mng ) th ti y M = 0 mc ch l gim kch thc mng khi gp nn su, tuynhin lin kt khp chn ct s lm tng mmen un u ct v nhp x, lm cho cc cu kin b trn nng hn khp chn ct cn c tc dng gim bc siu tnh ca khung, do cng gim c ni lcpht sinh do khng nn u ca gi ta, do co ngt v t bin ca b tng.Ngoi ra cn hiu rng cc lin kt cng vi mng ch l tng i v di tc dng ca ti trng t nn s

bin dng v lm cho mng b xoay i d ch l rt t, khi mng b xoay th mmen chn ct gim xung cnmmen u ct v u x s tng sy ra s phn b ni lc. Cu 92: Trong n ln ca cc mng ly bng my ?i vi mng n: 0.05 ? 0.06 ( cm )i vi mng bng: 0.08?0.1 ( cm )i vi mng cc: 0.028?0.033 ( cm )Cu 93: Th no gi l cc chng ?Khi kh nng chu lc ca cc ti hn m kh nng chu lc ca t cha ti hn th gi l cc chng, d t mi cc khng phi l t cng.Cu 94: ?max, ?min trong dm v ct l g ?+?min : l hm lng ct thp qu t b ph hoi t ngt ( ph hoi gin ) khi b tng b nt th ton b lcko do ct thp chu, trnh iu cn phi m bo ? > ?min.+?max: l lng ct thp qu nhiu, trng hp ny cn phi trnh v khng vn dng kh nng lm vicca ct thp, v rt nguy him v dm b ph hoi khi bin dng cn nh, kh phng. kt cu lm vic hp l m bo khng xy ra ph hoi do th ?min < ? < ?max tn dng ht kh nng

lm vic ca b tng v ct thp.

Cu 95: ?max ca dm khc vi ?max ca ct nh th no ??max dm < ?max ct.?max dm = 1.5( % )?max ct =3( % ), c th l =6?8 ( % )Cu 96: Ct thp trong ct ti sao thng i xng ?Mmen trong ct c cng tr s nhng khc nhau.Thun tin thi cng trnh t nhm thp.Hnh dng ct i xngPn v Rn chnh lch nhau khng ln khi tnh ct khng i xng.Cu 97: Hy nu nguyn tc lm vic ca ct xin ?Cu 98: Hy nu nguyn l lm vic ca ct ai ?Cu 99: Hy nu cch t ct thp tit din ch T?Cu 100: Khi no th lin kt gia sn vi dm l ngm ? L khp ?L ngm khi: hs < 1/3 hdL khp khi: hs > 1/3 hdCu 101: Khi no th lin kt gia dm vi ct l ngm ? L khp ?Khi cng n v ca ct ln hn 6 ln cng n v ca dm th xem dm ngm vo ct.Khi cng n v ca dm ln hn 4 ln cng n v ca ct th xem dm k ln ct.Cu 102: Khi no lin kt gia ct v mng l ngm ? L khp ? +Lin kt l ngm khi ln ca mng nh.+Lin kt l khp khi mng c ln ln.Cu103: Nt cng l g ?Nt cng l mt khi nim yu cu cc thanh ng qui ti nt.

7/29/2019 jbkbk

9/12

Cu 104: Ngm n hi l g ?Ngm n hi l lin kt c cng va phi, khi ni lc ln khng cn l ngm.Cu 105: Khi a lc tp trung v lc phn b th ta s dng iu kin g ? C mt lc tp trung a v lc phn b bng cch nhn lc tp trung vi khong cch chu lc ca ktcu .Lc phn b tam gic bng 5/8 tam gic u.Cu 106: Trong cng trnh xy dng mmen do ti trng gi v mmen do titrng thng ng th mmen

no gy ra ln hn ?Tu thuc vo mt bng v chiu cao c th, thng thng nh nh hn 10 tng th mmen do ti trng ginh.Cc cng trnh cao tng th phi tnh ton c th.Cu 107: Khi cng trnh c tng lng th tng lng c chu ti trng khng ?Khi cng trnh c tng lng th tng lng vn chu ti trng gi bnh thng.Cu 108: Lm th no c c cp ni lc nguy him nht trong t hp ni l ?Phi xt t hp ti trng:-T hp c bn 1: tnh ti + hot tithng xuyn + mt hot ti-T hp c bn 2: tnh ti + hot ti thng xuyn + tt c cc hot ti-T hp c bit: tnh ti + hot ti thng xuyn + hot ti c bit.Cu 109: Khi tnh ct th c my cp ni lc kim tra ?Khi tnh ct th c 3 cp ni lc kim tra :+Mmax, Nt+Mmin, Nt

+Nmax, MtNgoi ra cn xt:+Qmax+Mmax, Qt i vi dm.Cu 110: Khi bit M, N kch thc axb hp l khi no ?Nu M nh th nn cu to mng vung ( a = b).Nu M ln nn cu to mng c tit din ch nht.Mng c thit k hp l khi: ng sut di y mng tng i u, vi mng lch tm th:+Pmin > 0.+Pmax < 1.2Rtc+Pth < RtcCu 111: Khi no th tnh mng cng ?Mng cng c tnh khi t nn tt, n nh, ti trng tc dng ng tm.Mng cng c cu to bng gch, , b tng.

Cu 112: Khi chn tit din ngang ca mng bng cn c vo u ?Chn chiu rng mng bng:-Cn c vo a cht cng trnh ( cng ca t nn )-Ti trng tc dng.-iu kin bin dng ca t nn ( ln ca mng ).Chn chiu cao mng bng:-Ti trng tc dng.-p lc ca t nn.-Kch thc ct.Cu 113: Hy nu cc bc tnh mng bng ?Xc nh ti trng tc dng xung mng.nh gi iu kin a cht thu vn.Chn chiu su chn mng.Xc nh kch thc s b ca mng.Xc nh cng ca t nn.Kim tra ln cho mng.Xc nh chiu cao mng v kch thc dm mng.Tnh ni lc.Tnh ton ct thp.Tnh ct ai, v ct xin.Kim tra cht lng ct thp.Cu 114: Mng bng l dm trn nn no ?Mng bng l dm trn nn n hi.M hnh tnh ton l m hnh WRINKLER ( m hnh v bin dng cc b ).Mng bng thit k theo phng ngang tt hn theo phng dc v cng theo phng ngang ln hn

7/29/2019 jbkbk

10/12

cng theo phng dc.Phn nn mngCu 01: Nu cng dng ca lp b tng lt mng ?B tng lt trc khi b tng mng c cng dng lm sch y b tng mng, ngn cn s mt nc ximng ca b tng mng vo t nn.

Cu 02: Nu nguyn nhn gy ln khng u ?Do tnh nn ln ca nn t phn b khng ng u trong mt bng v do a hnh phc tp.Do t b ph v kt cu.Do nc chuyn ng di t.Do ti trng t lch tm v tng phn cng trnh c ti trng khc nhau.Cu 03: Nu tc hi ca s ln khng u ?c bit khi c tr s ln rt nguy him cho kt cu siu tnh, gy cn tr cho vic s dng cng trnh v lmmt m quan ca cng trnh.Cc kt cu nh tng, khung, sn mi,...s xut hin cc ni lc b sung c th lm nt hng kt cu.Cu 04: Cng trnh c cn lm ging mng khng ?Cng trnh phi lm ging mng v ging mng ni cc mng trong cng trnh li vi nhau to thnh hkhng gian cng. Chu ni lc sinh ra khi c s ln lch ca mng. Ngoi ra cn to lin kt khng gianchng trt, cc mng phn b u ng sut xung mng tng n nh ct.Cu 05: Th no l nn ?Nn l chiu dy cc lp t trc tip chu ti trng ca cng trnh do mng truyn xung.

Cu 06: c im cu to mng hp khi (cch tnh ton ) ?Khi tnh ton cc mng n di ct cc trc gn nhau to thnh mng hp khi. Mng hp khi l mng cchung bn mng v c t 2 ct tr ln. Tnh ton nh bn dm c ti trng tc dng l p lc t tc dngln mng.Cu 07: Khi chn loi nn mng cn c vo nhng yu t no ?c im ca cng trnh.Tr s ca ti trng.Nn v mng cng trnh ln cn.iu kin a cht cng trnh, iu kin a cht thu vn.Cc yu t khc nh chn ng,..

Cu 08: Th no l mng cng, mng mm ?Mng cng l mng khng b un khi chu tc dng ca ti trng. Khi xc nh ng xut tip xc di y

mng ta khng k n un ca mng. Gm cc loi mng gch , b tng, mng n b tng di ct,mng bng b tng ct thp di tng.Mng mm ( mng c cng hu hn ) l mng b un ng k khi chu tc dng ca ti trng. S unny phn b li ng sut tip xc, phi k n nh hng ca un gm: mng bng, mng bng giao thoab tng ct thp di cc dy ct.Cu 09: Bng thng k ct thp lm g ? lp d ton v lp tin thi cng, d ton trc gi thnh cng trnh, cng nhn ct, un thp theothit k.Cu 10: Nu cc ch tiu xc nh t nn ?Trng lng ring ca t t nhin.Trng lng ring ca ht t. m.Gii hn chy.Gii hn do.H s thm.Gc ma st trong.Lc dnh n v.H s nn.M un bin dng tng qut.nh gi t theo st.nh gi ct theo rng.Cu 11: Khi tnh ton mng ( cng nh cc cu kin khc ) khi no s dng ti trng tnh ton, khi no sdng ti trng tiu chun ?Khi tnh ton cu kin theo trng thi gii hn 1 ( Kh nng chu lc, sc chu ti, n nh ) th ta tnh vi titrng tnh ton.

7/29/2019 jbkbk

11/12

Khi tnh cu kin theo trng thi gii hn 2 ( bin dng, ln, vng, khe nt ) ta tnh vi ti trng tiuchun.

Cu 26: Ti sao tnh vng li dng ti trng tiu chun ?Ti trng tiu chun l ti trng da theo qui phm thit k, theo kch thc hnh hc v ti trng ca chngloi vt liu l ti trng tng i chnh xc v gy t bin mi lu di nn gy vng (???)Cn ti trng tnh ton ck thm h s tin cy, k n yu t bt li lm tng gi tr ti trng do ti

lch vi thit k, sai lch khi thi cng, s tng ti trng t ngt. M nhng trng hp khng gy bindng, t bin m hot ng c khng k n.

Cu 12: Khi thi cng mng cn ch nhng g ?Cn ch tim chun, ct chun.Cu 13: iu kin thi cng xong mt cc ? Chon b tng n su thit k.Th ti m bo sc chu ti khng c khuyt tt.Cu 1: Tc dng ca thp cu to, ct gi ?Gi n nh ct dc chu lc khi b tng, khi chu lc, chu ng sut ct.B rng ca dm rng th n cn gim s phnh, gi n nh cho ct ai.Cu 2 : Tc dng ca thp phn b sn ?Gi n nh cho ct dc, chu lc theo phng kia.Cu 3: ngha ca lp bo v ct thp ?Chng xm thc n mn ct thp, to lc dnh gia b tng v ct thp.

Yu cu: Dm h > 250 an = 2 cm.Bn hb < 10 cm an = 1 cm; hb < 1cm an = 1,5 cm.Mng an = 5 ? 7 cmCu 4: ngha ca on neo ct thp ? m bo lc dnh gi b tng v ct thp.Ct thp khng b ko tut dn n b tng v ct thp cng kt hp lm vic.Cu 5: Khi no tnh ton theo s khp do, s n hi ?Tnh ton theo s khp do: BT mc < 300; A < 0,3; tnh cho nhng cng trnh bnh thng, thngkhng c xm thc ct thp.Tnh ton theo s n hi, khng nt i vi nhng cng trnh quan trng.Cu 6: S cc th nn tnh l bao nhiu ?S cc th nn tnh l 1% v = 1 cc.Cu 7: on p b tng u cc l 10d on hn v lentenite l 1m.Cu 8 : Cch xc inh chiu di ct khung mt tng 1?K t nh mng tr ln mc sn.

Cu 9: K thut b tng i cc ?Bng bm.Cu 10: b tng bng phng php bm khc phng php th cng ch no ? st th cng 3 ? 4cm; bng bm 10 ? 15 cm.Cu 11: Ti sao b tng bng phng php bm yu cu st cao hn ? b tng c tnh linh ng hn khi i qua ng ca my bm.Cu 12: Ti sao phi kim tra st b tng trc khi b tng mng ct, mng khung ? st phn nh do v tnh linh ng ca va b tng, nn b tng c st hp l mi chui quakhong cch ct thp to nn lp bo v v t b r mt (Nhng phi khng ch v lin quan n thi gianninh kt v cng ca b tng).Cu 13: Chn tit din dm da vo nhng yu t no ? - mnh ca ct nh :-Kinh nghim.-Ti trng tc dng.Cu 14: Chn tit din dm da vo nhng yu t no ? Xut pht t iu kin vng cho php.Cu 15: Cch kim tra kt qu chy my ?Tch mt phn t khung v kim tra vi ti trng tc dng.Kim tra3 phng trnh cn bng:

Cu 16 : Gii thch cch lp tin thi cng, phng php lp, mc ch v da vo u lp c ?Cu 17: Cch iu chnh h s k1, k2 ; da vo u lp c hm s no. iu chnh tin bng cch lptin thi gian hnhthnh cc qu trnh xy dng.-Nu biu nhn lc, vt liu khng iu ho th ch yu m bo s lng cng nhn khng iu ho,nu thiu th phi iu ho ( ch thay i 10 ? 15%)

7/29/2019 jbkbk

12/12

S cng d / Tng s cng.-Nu iu chnh th nn iu chnh h s k1v Amax gim i ng thi s cng cng gim i, thay i c li,nhng gim Amax th ko di thi gian thi cng.

-Nu tng Ath th c th rt ngn thi gian, cng v k1 > 1 ko theo k2 = 0.Cch b tr cc trong i l 3,6.d.-Khong cch cc < 3d. Cc cc lm vic gn v gim s ma st gia cc cc v khong cch mng qui c

nh.-Khong cch gia cc cc > 6d cc cc lm vic nh cc n c lp.Cu 18: Khung nh cao tng khc khung nh thp tng cch b tr ct thp.-Yu cu nt khung do ( ct ai nh th no ).-Nt khung do chng nhng chn ng do ng t v dao ng cng trnh.Cu 19: Nguyn tc b tr ct thp trong cc khoan nhi, cng dng ca thp dc v thp ai ?-Thp dc chu un v nn.-Thp ai gi n nh ct dc, cng ct dc to li m khi b tng cho b tng trong ct ai chu nntt hn.-Ti sao ko thp sut cc.V khi tnh ton sc chu ti ca cc ly tr s Pv.Cu 20: Vai tr dy neo ging vn khun ct.(Ch ct bin pha bn kia khng chng mi cn)Cu 22: V cc mt bng kt cu lm g ? xc nh ti trng truyn ln dm khung, xc nh v tr dm khung chu lc ca mng.

Cu 23: Ct v ni thp trong ct, ct u, khi no c ct ?Ni thp chn ct th thun li cho thi cngn < 4 thanh ni 1 v trn = 5?8 thanh ni 2 v trn>8 thanh ni 3 v tra. Khi ct thp chu nn ng tm v lch tm b (e0 < 0,2h0) th c ct ni mt v tr d mt thanhhay bao nhiu thanh.b. Khi ct chu nn lch tm ln (e0 > 0,2h0)th tun theo qui nh trnCu 24: Qui nh din tch s thanh thp c ct , 1/3, 1/2 chiu di dm.1/3ld : Ct = 2 thanh v = 1/3 ln1/4ld : Ct s thanh cn li.Vi mmen dng v tr ct = 1/5ldCu 27: Cng dng ca ct ai trong ct, ti sao on ni thp, ct ai phi dy, cu to ct ai.Cng dng: chu lc ct, gi n nh ct ai, chu lc khi thi cng v chu lc khi phn ni ct thp, ct ai

t dy.Cu 28: Nu tnh ton khung theo tnh cht i xng th s nh th no?Cc thanh thp dc phn ni c tnh cht gim nn khong cch ct ai dy cn hn ch s n hng cab tng ct lm tng cng b tng ln.