Part I. Sub$-$questions $(1-16)$

A tension member is composed of two C$250*37$ A$36$ steel channels, $200$mm back$-$to$-$back, held together by tie plate as shown in the figures and connected at the ends by double gusset plates, each gusset plate is bolted to the web of each channel. The web$-$to$-$gusset connection shall use three lines of $22$ mm bolts $\backslash (\backslash$mathrm$\{$A$\}325-\backslash$mathrm$\{$N$\}\backslash ).$ the tie plate is connected to each flange using by $\backslash (22\backslash$mathrm$\{$~mm$\}-\backslash$mathrm$\{$A$\}325-\backslash$mathrm$\{$N$\}\backslash )$ bolts staggered with respect to the web bolts by $37\mathrm{.}5$ mm as shown in Figure $(1).$ There are three tie plates one at each end and one at the mid length of the member. The length of the member is $11$ m $.$ mm $37\mathrm{.}5.7-(1$p$)$ For bearing to happen in the gusset plate and in the channel at the same time, knowing that the length of shearing in both gusset and channel are equal, and both are made of the same material, the thickness of one gusset plate shall be:

$$

A$-$ Equal to tw of the channels.

B$-$ Equal to tf of the channels.

C$-$ Greater than $13\mathrm{.}4$ mm $.$

D$-$ A and C$.$

$$ A $13\mathrm{.}4$ C

$8-(1$p$)$ For rupture failure and bearing failure for the case of "deformation is a design consideration", to happen in the $220$ mm wide gusset plate at the same time, the thickness of gusset plate shall be taken:

A$-20$ mm

B$-$ Between $20$ and $25$ mm

C$-$ More than $25$ mm

D$-$ It is not possible for them to happen at the same time. $20$

$2025$

$25$

$9-(1$p$)$ The LRFD strength of the built$-$up member due to shear in connecting bolts is

A$-2545$ KN $.$

B$-5090$ KN $.$

C$-$ More than $5090$ KN $.$

D$-$ None of the above.

$10-(1$p$)$ For shear strength of bolts in the four flans of the built$-$up member in the tie plate connections to be equal to the shear strength of bolts in the gusset plate connections, based on shear in bolts only, the diameter of the tie plate bolts shall be:

B$-$ Twice as gusset plate bolts. $()$

C$-$ This cannot happen. $()$

D$-$ None of the above. $()$

$11-(1$p$)$ The maximum permissible length of the shown member is:

$$

A$-26\mathrm{.}82$ m $.$

B$-10\mathrm{.}3$ m $.$

C$-53\mathrm{.}6$ m $.$

D$-$ None of the above.

$12-(1$p$)$ If the thickness of the gusset plate $\backslash (=10\backslash$mathrm$\{$~mm$\}\backslash ),$ the gross area for shear $\backslash (\backslash$left$(\backslash$mathrm$\{$A$\}\_\{\backslash$mathrm$\{$gv$\}\}\backslash$right$)\backslash )$ for block shear to occur in the built up member is:

A$-7500$ mm $2$

B$-11000$ mm $2$

C$-18500$ mm $2$

D$-$ None of the above

$13-(1$p$)$ If the thickness of gusset plate $\backslash (=15\backslash$mathrm$\{$~mm$\}\backslash ),$ the net tension area $\backslash (\backslash$left$(\backslash$mathrm$\{$A$\}\_\{\backslash$mathrm$\{$nt$\}\}\backslash$right$)\backslash )$ in order to calculate the block shear for

A$-3000$ mm $2$

B$-2940$ mm $2$

C$-2680$ mm $2$

D$-$ None of the above

$14-(1$p$)$ For the above built$-$up member, $\backslash ($ U$\_\{$b s$\}\backslash )$ equal to:

A$-1$

B$-0\mathrm{.}5$

C$-4$

D$-$ None of the above.

$15-(1$p$)$ For block shear to happen in the above built$-$up member with three lines of bolts, the bolts in the middle

A$-$ Increase the section resistance.

B$-$ Decrease the section resistance.

C$-$ Will not affect the block shear strength of the member

D$-$ None of the above.

$16-(1$p$)$ As shown in Figure $1$ above, the edge distance of bolts in the gusset plate equal to the edge distance of the member, the block shear will happen in the gusset plate before the member if:

D$-$ None of the above. $()$