Two $45$ mm tie bars in a bridge structure are to be joined together using rivets arranged in a Lozenge joint configuration. The tie bars are to withstand a tensile force of $850$ kN$.$ Assume a double shear factor of $2,$ a factor of safety of $5,$ and ultimate stresses as follows: Sut $=480$ MPa, Ssu $=460$ MPa, and Suc $=540$ MPa. Determine the following: $1\mathrm{.}1$ Allowable stresses, $1\mathrm{.}2$ rivet diameter, $1\mathrm{.}3$ suitable width for the tie bars, $1\mathrm{.}4$ number of rivets per side $1\mathrm{.}5$ efficiency of the joint.