Problem Statement:

Design a tube and coupler multi$-$span scaffolding system including planks, bearers, and posts, to

meet the following criteria$/$parameters:

a$.$ Uniform loading required for concrete work.

b$.$ Steel bearers and posts, and dimensional lumber planks.

c$.$ Use $6\text{'}{8}^{\text{'}}$ bays $(6\text{'}$ front to back, $8^{\text{'}}$ bearer to bearer$)$

d$.7$ levels, height between levels $=5^{\text{'}}$

e$.$ Bear deflection requirement: L$/240.$

f$.$ Use a $4\mathrm{.}0$ factor of safety $($FOS$)$

g$.$ Steel material: Steel pipe A$36$ standard schedule NO$.40,F_b=\frac{F_y}{F}OS,F_v=0\mathrm{.}4\frac{F_y}{F}OS,F_a=$

$\frac{F_y}{F}OS,E=29{10}^6$ psi.

h$.$ Wood material: $F_b=1,900$ psi, $F_v=180$ psi, both already include FOS;$E=1\mathrm{.}9{10}^6.$

Hints:

$(1)$ Use Table $4\mathrm{.}1($page $62)$ in the textbook $($or Slide $25$ of the Scaffolding System lecture$)$ to find

the design load $($psf$)$ for concrete work.

$(2)$ Do not forget to check for bending, shear, and deflection for the plank and bearer. For the

posts, check for buckling and combined stress.