Tributary Width vs Tributary Area¶
Tributary Width¶
If the members are equally spaced, because tributary width is is half the distance to the next member on one side and half the distance on the other side, the tributary with is equal to the member spacing.
Tributary Area¶
In many cases a uniform spacing of members is used throughout the framing plan. This example is designed to illustrate the concept of tributary area rather than typical framing layouts.
$\text{Trib. A} = \text{trib. width} \times \text{span}$
- Joist J1 - $\text{Trib. A} = 2 ft \times 12 ft = 24 ft^2$
- Joist J2 - $\text{Trib. A} = 2 ft \times 14 ft = 28 ft^2$
- Girder G1 - $\text{Trib. A} = \left(\frac{12 ft}{2} + \frac{14 ft}{2}\right) \times 20 ft= 260 ft^2$
- Girder G2 - $\text{Trib. A} = \left(\frac{12 ft}{2} + \frac{14 ft}{2}\right) \times 24 ft = 312 ft^2$
- Column C1 - $\text{Trib. A} = \left(\frac{12 ft}{2} + \frac{14 ft}{2}\right) \times \left(\frac{20 ft}{2} + \frac{24 ft}{2}\right) = 286 ft^2$
- Exterior column C2 - $\text{Trib. A} = \left(\frac{12 ft}{2}\right) \times \left(\frac{20 ft}{2} + \frac{24 ft}{2}\right) = 132 ft^2$
- Corner column C3 - $\text{Trib. A} = \left(\frac{14 ft}{2}\right) \times \left(\frac{20 ft}{2}\right) = 70 ft^2$
References:¶
Class website (Use this link to if you are taking the course on e-learning.)
Github.io version of course website (Do not use this link if you are taking this course in Summer A or B.)
IPython.org (IPython is the opensource software used in the development of much of this course.)