B$3.$ Fig. B$3$ shows a tied scaffold with a size $9$ m high $10\mathrm{.}5m$ width supports a uniformly distributed load of $10k\frac{N}{m}($including construction load$)$ and all horizontal forces are also listed in the diagram.

a$)$ Verify that the overturning moment acting on the scaffold structure is ${226}_{?}kN-m_{?}$ and determine the leg load of each leg in kN under the combined vertical and horizontal loading condition. Neglect the stabilizing force provided by the tie provided.

$(12$ marks$)$

b$)$ Determine the tension force in the member if any.

$(1$ mark$)$

c$)$ Use Design Table in Page $6$ to check the axial loading capacity of the verticals against buckling under the maximum load calculated in a$).$ Assume the tubes and couplers comply with BS$1139$ and of "Used" condition.

$(2$ marks$)$

d$)$ Determine the minimum number of diagonal braces required to resist the horizontal load. Coupler capacity is $5$ kN each.

$(5$ marks$)$

e$)$ If a tie is provided to stabilize the scaffold structure against lateral stability, determine the minimum tension required in the tie to keep the structure having a minimum factor of safety of $3\mathrm{.}0$ against overturning under the given horizontal loads.

$(5$ marks$)$

UDL $10$ kN$/$m

Fig. B$3$

$($Not to Scale$)$