November
Structural Engineering and Construction Construction
Situation 1 –
A student pushes the 600-N ladder horizontally horizontally as shown in the Figure in order to prevent it fro sliding! "! #eteri #eterine ne the the vertical vertical reactio reaction n at A! A! A! $00 N C! 600 N %! &00 N #! ''0 N (! #eteri #eterine ne the the horizont horizontal al reacti reaction on at A! A! A! ""0 N C! "60 N %! "(0 N #! $0 N )! #eteri #eterine ne the pushing pushing forc force e e*erted e*erted +y the the student! student! A! ')(!$ N C! &$,! N %! 6)'!, N #! '6!) N
Situation 2 –
.he crane shown in the Figure carries the )' /N load at %! .he crane
weighs $ /N!
November
Structural Engineering and Construction Construction
&! hat is the tension in ca+le A#1 A! )0!"( /N C! )(!6' /N %! )'!6 /N #! (6!'( /N '! hat is the total reaction at C1 A! '6 /N C! ()!"" /N %! 6$ /N #! 60!'$ /N 6! 2f the tension of ca+le A# is liited to &( /N3 what is the a*iu value of the load 1 A! '(!", /N C! ',!,, /N %! 6'!$' /N #! ''!(& /N Situation 3 –
.he para+olic ca+le supports the truss shown in the Figure! .he truss
is pinned at #! ,! hat is the tension at F where the tangent is zero1 A! &$,!' /N C! )$6!, /N %! '($!, /N #! '0&!) /N $! hat is the vertical reaction at pin #1 A! &$!$, /N C! &"!'6 /N %! '6!(" /N #! ),!&, /N ! hat is the vertical reaction at A1 A! (!&$ /N C! ,&!6 /N %! ,!,) /N #! $&!(& /N
Situation 4 –
.he pole 4AF shown in the Figure is secure +y a +all-and-soc/et 5oint at F and +y four steel wires at A! .he diaeter of steel wires is 6!' ! use E (00 47a for steel! "0!2f 7 ( /N3 what is the tensile stress in wire A#1 A! "&( 87a C! ",$ 87a %! "0, 87a #! "(' 87a ""!2f 7 ( /N3 what is the elongation of wire A#1 A! "'!0, C! "(!0' %! !0& #! "0!(&
November
Structural Engineering and Construction
"(!2f the elongation of wire A# is (( 3 +y how uch will point 43 the tip of the pole3 ove horizontally1 A! '"! C! 6)!$ %! '$!, #! &,!'
Situation 5 –
.he hoogeneous stic/ shown in the Figure weighs $ N! End 9A: leans against a vertical wall and end 9%: is supported +y a +all-and-soc/et 5oint! Neglect all friction!
Structural Engineering and Construction
November ")!#eterine the value of 7! A! )!( N
C! "! N
%! (!' N "&!#eterine the reaction at A! A! (!'6 N %! "!," N "'!#eterine the total reaction at %! A! 6!6) N %! ,!'& N
#! (!$ N C! "!, N #! "!(' N C! '!(& N #! $!6( N
Situation 6 –
.he hoogeneous +oo AC shown in the Figure weighs )' /N and is supported +y a +all-and-soc/et 5oint at C and two ca+les A# and A%! "6!hat is the tension in ca+le A%1 A! ""!)( /N %! "(!'$ /N C! (6!") /N #! )0!'& /N ",!hat is the tension in ca+le A#1 A! )0!'& /N C! "(!'$ /N %! (6!") /N #! ""!)( /N "$!hat is the total reaction at C1 A! 6$!', /N C! 6'!" /N %! ,0!&$ /N #! ,)!'$ /N Situation 7
– .he +ea shown in the Figure is supported +y two "6--diaeter +olts at A and a "'0 * (00 plate at %!
"!2f 7 /N3 what is the stress in the +olts at point A1 A! ),!)0 87a C! ''!' 87a %! $!,' 87a #! &(!6$ 87a (0!2f 7 /N3 what is the +earing stress in concrete at %1 A! "!(6 87a C! 0!,0 87a %! ""!0' 87a #! 0!$, 87a ("!2f the allowa+le tensile stress of the +olts at A is &0 87a3 what is the a*iu value of 71 ((!Structural Engineering November ()!and Construction A! 6!&)& /N %! ,!(&( /N
C! $!''( /N #! 6!$,& /N
Situation 8 –
.he +olt shown in Figure S'6-))" is su+5ected to a total tensile force of 0 /N! (&!#eterine the tensile stress in the +ody of the +olt in 87a! A! ,0!'& %! $$!", C! ,!)6 #! 6"!,( ('!#eterine the tensile stress at the root of the +olt in 87a! A! $,!" %! """! C! !' #! "(&!) (6!#eterine the copressive stress at the head as the +olt +ears on the surface to resist the tensile load! A! &0!)) 87a C! &'!), 87a %! '0!&" 87a #! )'!( 87a Situation 9
– .he +ea shown in the Figure is supported +y the seat angle! .he angle is fastened to the colun +y two "6--diaeter +olts! .he +ea reaction is &( /N! (,!hat is the +earing stress on contact surface +etween the +olts and the angle1 A! 6!) 87a %! $,!' 87a C! $"!& 87a #! "0"!, 87a ($!hat is the shearing stress in the +olts1 A! "(6!) 87a C! ""'!6 87a %! (!' 87a #! "0&!& 87a (!hat is the +earing stress on contact surface +etween the +ea and the angle1 A! (!&" 87a C! (!( 87a %! &!'$ 87a #! )!(& 87a
November Situation 10 –
Structural Engineering and Construction
.he strut shown in the Figure carries an a*ial load of 7 $' /N!
)0!#eterine the +earing stress +etween the pin and strut; A! (6'!6 87a %! (&(!$ 87a C! (,$!& 87a #! (6!( 87a )"!#eterine the shearing stress in the pin! A! ()6! 87a %! "'!$ 87a C! ((&!, 87a #! (""!& 87a )(!#eterine the shearing stress in the +olts! A! $'!, 87a %! 6!) 87a C! "!' 87a #! "0)!' 87a
Situation 11 –
A gravity da is acted upon +y the forces
60?! ))!Calculate the a*iu foundation pressure! A! "6!' /7a %! "$'!) /7a C! "'&!( /7a #! ",&!' /7a )&!Calculate the iniu foundation pressure! A! $(!& /7a C! $,!, /7a %! ,6!$ /7a #! 6!' /7a )'!2f the coe@cient of friction +etween the +ase and the soil is 0!)'3 what is the factor of safety against sliding1 A! "!)" C! (!"' %! "!$" #! "!6) )6!A hallow circular shaft ( long is *ed at one end and free at the other end! .he outer diaeter of the shaft is )00 and its thic/ness is 6 ! 2f the shaft is su+5ected to a torsional oent of 6 /N- deterine the angle of twist of the shaft! Bse 4 ,$ 47a! A! 0!0,)6? C! 0!0("&? %! 0!0'(6? #! 0!0"($?
Situation 12 –
A solid circular shaft (!' long and ,' in diaeter is su+5ected to torsional oent! Bse 4 ,$ 47a!
),!Calculate the torsional rigidity of the shaft! A! ((&!$ /N-( C! (6)!, /N-( %! (&(!) /N-( #! ('&!, /N-( )$!Calculate the torsional stiness of the shaft! A! 0!'& /N-Drad C! "0&!', /N-Drad %! 6!( /N-Drad #! $'!6) /N-Drad )!Calculate the a*iu shearing stress on the shaft due to a ) /N- torue at its free end! A! )0!'$ 87a C! &(!'& 87a %! )&!'$ 87a #! )6!(( 87a Situation 13
– .he state of stress of the aterial is illustrated +y the 8ohr Circle shown in the Figure! &0!hat is the a*iu noral stress3 *1 A! "(0 87a %! &0 87a C! ""0 87a #! $0 87a &"!hat is the iniu noral stress3 y1 A! &0 87a %! )0 87a C! $0 87a #! '0 87a &(!Calculate the a*iu shearing stress! A! '0 87a %! (0 87a C! )0 87a #! &0 87a
Situation 14 –
An eleent is su+5ected to a pure shearing stress as shown in the
Figure! &)!hat is the noral a*ial stress on the eleent1 A! &0 87a C! "(0 87a %! $0 87a #! 0 &&!hat is the shearing stress on the eleent1 A! $0 87a C! "(0 87a %! 0 #! &0 87a &'!hat is the angle of the plane of a*iu shear fro the principal plane1 A! &'? C! 0? %! )0? #! 60?
Situation 15
– .he hallow pole shown in the Figure has an outside diaeter of )00 thic/ness of 6 ! .he pole weighs "'0 N per linear eter! &6!hat is the a*iu copressive stress at the +ase1 A! '!(& 87a %! &!,' 87a C! )!6' 87a #! 6!$, 87a &,!hat is the a*iu tensile stress at the +ase1 A! &!)6 87a %! (!$, 87a C! (!&' 87a #! )!'" 87a &$!hat is the a*iu shearing stress in the pole1 A! 0!"6( 87a C! 0!''& 87a %! 0!)(& 87a #! 0!($, 87a
Situation 16 –
.he concrete pad shown in Figure C0'-'6) is su+5ected to unifor
loads! &!#eterine the +ase pressure! A! 6 /ND C! "( /ND %! "0& /ND #! "($ /ND '0!#eterine the a*iu oent in the sla+! A! &)6 /N- C! ))6 /N- %! )$& /N- #! "( /N- '"!#eterine the location of zero +ending oent easured fro the left end of the sla+! A! ' C! & %! , #! 6
Situation 17 –
.he +arge shown in the Figure supports the loads w " and w( for this pro+le3 w" "&' /ND3 w (0 /ND3 G " ) 3 G( ) ! '(!hat is the length of the +arge 9G: so that the upward pressure is unifor1 A! "' C! (0 %! "( #! "$ ')!hat is the shear at ) fro the left end1 A! -"6( /N C! -"& /N %! -"'" /N #! -",& /N '&!At what distance fro the left end will the shear in the +arge +e zero1 A! & C! ' %! '!' #! &!'
Situation 18 –
.he sei-circular arch is loaded as shown in the Figure! For this pro+le3 7" "!$ /N3 7 ( 0!0 /N3 and 7 ) 0!&' /N! ''!hat is the resultant of the three forces1 A! (!0& /N %! )!"( /N C! (!$' /N #! (!&6 /N
'6!#eterine the reaction at %!
A! "!,' /N %! "!6) /N ',!#eterine the reaction at A! A! "!06 /N %! "!,' /N
C! "!06 /N #! "!(& /N C! "!6) /N #! "!(& /N
'$!A 6 long ti+er +ea ((0 wide +y &00 deep is siply supported at its ends and carries a uniforly distri+uted load throughout its length! 2f the allowa+le deHection is GD)603 nd w! Bse E !' 47a! A! "& /ND C! "( /ND %! ") /ND #! "" /ND '!A "0-eter long +ea is siply supported at the right end and at ( eters fro the left end! 2t is reuired to deterine the a*iu shear at the iddle of the supported length due to a uniforly distri+uted oving load! hat is the total length of the +ea that ust +e su+5ected +y the unifor load1 A! & C! ) %! 6 #! ' Situation 19 –
Classify the structures shown in Figure )&6-() as sta+le3 unsta+le3 deterinate or indeterinate! 2f indeterinate3 state the degree of indeterinacy! 60!Figure )&6-()a is; A! 2ndeterinate to the second degree %! Bnsta+le C! #eterinate #! 2ndeterinate to the rst degree 6"!Figure )&6-()+ is; A! 2ndeterinate to the second degree %! 2ndeterinate to the third degree C! Bnsta+le #! 2ndeterinate to the rst degree 6(!Figure )&6-()c is; A! 2ndeterinate to the third degree %! Bnsta+le C! 2ndeterinate to the rst degree #! 2ndeterinate to the second degree
Situation 20 –
.he Hoor fraing plan of a coercial +uilding is shown in the Figure! hen the coluns at E and I are deleted3 +ea %EIJ +ecoes a singlespan girder which can +e assued *ed at % and J! .he concentrated load on girder %EIJ at E and I are each (,( /N and the unifor load on the entire span is ' /ND!
6)! the shear at %! A! )00!,' /N C! (0!,' /N %! )('!&' /N #! ($0!'0 /N 6&!#eterine the a*iu shear at E! A! (,$!(' /N- C! (&'!,' /N- %! (6!)& /N- #! (60!,$ /N- 6'!hat is the a*iu positive oent in the +ea1 A! (0&!, /N- C! (6$!, /N- %! "$!' /N- #! ()$!& /N-
#eterine
Situation 21 –
.he steel truss shown in the Figure is loaded with three concentrated loads applied at %3 #3 and F! Bse F y (&$ 87a and E (00 47a! 66!#eterine the reaction at 4! A! "& /N C! (6 /N %! (, /N #! (" /N 6,!hat is the a*ial stress in the e+er #21 A! &!') 87a C! '!($ 87a %! 6!(& 87a #! ,!)( 87a 6$!hat is the allowa+le load of e+er #21 4iven the following properties of #2; Area "$'$ (3 r* (6!, 3 r y )& ! A! $!' /N C! ""(!' /N %! "0&! /N #! "(6!& /N
Situation 22 –
.he entrance of a +uilding has a roof that supports the load 9wK as shown in the Figure! .he supports at A and % can +e considered hinge! .he colun AC is *ed at C! 7roperties of AC; G &&' * "0 6 ( d &66!"0 ( A ""3)'' E (00 47a r* "0!"" Fy (&$ 87a ry &)!0( 6!Copute the allowa+le a*ial load on e+er AC! Bse (00" NSC7! A! ""'6 /N C! "0) /N %! '( /N #! "()& /N ,0!2f the allowa+le load on AC is 00 /N3 copute the value of w! A! "&& /ND C! "(0 /ND %! ")6 /ND #! ""( /ND ,"!2f the load w ""( /ND3 copute for the load on AC! A! $00 /N C! ,00 /N %! $'0 /N #! ,'0 /N
Situation 23 –
.he dec/ of a +ridge consist of ri++ed etal dec/ with "00 concrete sla+ on top
2pact factor 7roperties of $'0 * "$'; A ()3,'0 d $'0 +f (0 tf (0
L + 37
≤
)0M3 where G length in !
tw "' l* (66( * "0 6 & ly $"!'( * "0 6 &
,(!Calculate the a*iu +ending stress in the +ea due to dead load! A! 0!(' 87a C! $!66 87a %! $$!&' 87a #! '!$6 87a ,)!Calculate the a*iu +ending stress in the +ea due to live load plus ipact! A! 60!( 87a C! ,(!' 87a %! $6!) 87a #! 6'!& 87a ,&!Calculate the a*iu average we+ shear stress in the +ea due to live load plus ipact! A! ,!'& 87a C! $!)& 87a
%! "0!(" 87a
#! !)( 87a
Situation 24 –
Channel sections are used as a purlin! .he top chords of the truss are sloped at &I to "! .he trusses are spaced 6 on centers and the purlins are spaced "!( on centers! Goads; #ead load ''0 7a Give load ,(0 7a ind load "&&0 7a ind coe@cients; indward 0!( Geeward 0!6 7roperties of C(00 * ,6 S* 6!" * "0 & ) Sy "!)$ * "0 & ) eight3 w , /ND Allowa+le +ending stresses3 F +* F+y (0, 87a ,'!#eterine the coputed +ending stress3 f +*3 due to co+ination of dead and live loads only! A! "6 87a C! "") 87a %! ",6 87a #! "'" 87a ,6!#eterine the coputed +ending stress3 f +y3 due to co+ination of dead and live loads only! A! "6 87a C! "&) 87a %! "(, 87a #! "0) 87a ,,!#eterine the value of the interaction euation using the load co+ination of 0!,' <# O G O = at the windward side! A! 0!6 C! "!(' %! "!' #! "!$,
Situation 25 –
.he section of a solid concrete +ea is shown in the Figure! Bnit weight of concrete is ()!' /ND)! Fc (,!' 87a3 f ct (!,' 87a! .he +ea is siply supported over a span of ' ! ,$!hat is the crac/ing oent of the +ea1 A! &6!)( /N- %! ,(!"' /N- C! 6"!(' /N- #! ''!'' /N- ,!2f the crac/ing oent of the +ea is &0 /N-3 what is the a*iu superiposed unifor load can the +ea carry1 A! $!$6 /ND %! !6' /ND C! ,!'& /ND #! "&!)6 /ND $0!2f the +ea is reinforced with )-('--diaeter +ars placed &)' fro the top3 what is the new crac/ing oent1 Assue n $! A! ,"!&' /ND C! 6$!', /ND %! 6'!(( /ND #! 60!$, /ND Situation 26 –
A reinforced concrete +ea has a width of )00 and an overall depth of &00 ! .he +ea is reinforced with four ($--diaeter tension +ars and two ($- diaeter copression +ars! Bse f c (0!, 87a and f y &"' 87a! #istance fro centroid of +ars to e*tree concrete +er is ,0 ! $"!Calculate the depth of copression +loc/! A! "(( C! ""& %! ")& #! "&$ $(!hat is the ultiate oent capacity of the section1 A! ("&!, /N- C! (&&!& /N- %! (,"!6 /N- #! ()$!, /N- $)!2f the +ea is siply supported over a length of 6 3 what additional concentrated live load can +e applied at the idspan if its ultiate oent capacity is &00 /N-1 Bnit weight of concrete is ()!' /ND )! A! (00 /N C! "'0 /N %! "(' /N #! ",' /N Situation 27 –
.he Hoor fraing plan of a reinforced concrete is shown in Figure C"00-("! %ea #EF is poured onolithically with the sla+ a/ing it to +e considered as .-+ea! .he coluns are each )'0 * )'0 ! .he NSC7 coe@cients for continuous +ea is also given in Figure CP#E-'()! For this pro+le3 t "00 3 + w )'0 3 f y &"' 87a3 f c ($ 87a3 f yh (,' 87a!
$&!
Calculate the factored unifor load wu that the +ea can carry +ased on the design strength of the +ea at support! A! 6!" /ND C! ,(!' /ND %! '&!, /ND #! 6)!) /ND $'!Calculate the factored unifor load w u that the +ea can carry +ased on the design strength of the +ea at idspan! A! 6'!( /ND C! ,(!& /ND %! 6"!( /ND #! '$!, /ND $6!2f the factored unifor loaf wu 60 /ND3 deterine the reuired noinal shear strength at critical section near the support at E! A! "' /N C! "6& /N %! " /N #! "$, /N Situation 28 – For the colun shown in the Figure3 f c ($ 87a3 f y &"' 87a3 ( He*ural rigidity E2 "03000 N- Situation 29 – .he section of a concrete colun is shown in the Figure! .he colun is reiforced with "0 ('--diaeter +ars with f y &"' 87a! Bse f c (" 87a!
