# floor framing

## Solution to Problem 543 | Floor Framing

**Problem 543**

A portion of the floor plan of a building is shown in Fig. P-543. The total loading (including live and dead loads) in each bay is as shown. Select the lightest suitable W-shape if the allowable flexural stress is 120 MPa.

## For Girders (G - 2) | Solution to Problem 542

## For Girders (G - 2)

$S_{required} = \dfrac{M}{f_b} = \dfrac{120(1000^2)}{120}$

$S_{required} = 1000 \times 10^3 \, \text{mm}^3$

## For Beams (B - 3) | Solution to Problem 542

## For Beams (B - 3)

$M_{max} = \frac{1}{8}(20)(62)$

$M_{max} = 90 \, \text{kN}\cdot\text{m}$

$S_{required} = \dfrac{M_{max}}{f_b} = \dfrac{90(1000^2)}{120}$

$S_{required} = 750 \times 10^3 \, \text{mm}^3$

## For Beams (B - 2) | Solution to Problem 542

## For Beams (B - 2)

$\Sigma M_{R2} = 0$

$6R_1 = 20(4) + 10(2)(5) + 15(4)(2)$

$R_1 = 50 \, \text{kN}$

$\Sigma M_{R1} = 0$

$6R_2 = 20(2) + 10(2)(1) + 15(4)(4)$

$R_2 = 50 \, \text{kN}$

## For Girder (G - 1) | Solution to Problem 542

**For Girder (G - 1)**

$S_{live-load} = \dfrac{M}{f_b} = \dfrac{40(1000^2)}{120}$

$S_{live-load} = 333.33 \times 10^3 \, \text{mm}^3$

## Solution to Problem 542 | Floor Framing

## Solution to Problem 541 | Floor Framing

**Problem 541**

The 18-ft long floor beams in a building are simply supported at their ends and carry a floor load of 0.6 lb/in^{2}. If the beams have W10 × 30 sections, determine the center-line spacing using an allowable flexural stress of 18 ksi.

## Solution to Problem 540 | Floor Framing

**Problem 540**

Timbers 8 inches wide by 12 inches deep and 15 feet long, supported at top and bottom, back up a dam restraining water 9 feet deep. Water weighs 62.5 lb/ft^{3}. (a) Compute the center-line spacing of the timbers to cause f_{b} = 1000 psi. (b) Will this spacing be safe if the maximum f_{b}, (f_{b})_{max} = 1600 psi, and the water reaches its maximum depth of 15 ft?

## Solution to Problem 539 | Floor Framing

**Problem 539**

Timbers 12 inches by 12 inches, spaced 3 feet apart on centers, are driven into the ground and act as cantilever beams to back-up the sheet piling of a coffer dam. What is the maximum safe height of water behind the dam if water weighs = 62.5 lb/ft^{3} and ( f_{b} )_{max} = 1200 psi?

## Solution to Problem 538 | Floor Framing

**Problem 538**

Floor joists 50 mm wide by 200 mm high, simply supported on a 4-m span, carry a floor loaded at 5 kN/m^{2}. Compute the center-line spacing between joists to develop a bending stress of 8 MPa. What safe floor load could be carried on a center-line spacing of 0.40 m?