$1.$ As shown in Fig$\mathrm{.}4,$ the steel beam is connected to the column using friction$-$type high$-$strength bolts. $10$ bolts are set with $5$ at each side in the connection. The high$-$strength bolt type is grade $10\mathrm{.}9,$ M$20,$ with the pre$-$tension P$=155$kN$,$ and the slip coefficient at the contact surface is $\backslash$mu $=0\mathrm{.}45.$ The concentrated load N$=200$kN is applied with an eccentricity of $300$mm to the bolted connection. To check the strength of the bolt.

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