A Beginner's Guide to Structural Mechanics/Analysis

Tributary Areas and Load Diagrams

(c) 2007, T. Bartlett Quimby

Section TA.5

Homework Problems

Last Revised: 11/04/2014

Dormitory Building Design Problems

Tributary area concepts can be use to compute loads supported by most of the beams and columns in the dormitory structure.  The following problems can be used to identify the areas tributary to particular areas.

Problem D_TA.1:  On a neatly drawn scaled sketch of the second floor framing plan (or a copy of DORM 1/S1), show the areas tributary to each of the girders.  Report that area (in sqft) for each of the areas identified on the sketch that are located all or in part between grids A & G.

Problem D_TA.2:  On a neatly drawn scaled sketch of the roof framing plan (or a copy of DORM 1/S2), show the areas tributary to each of the girders. Report that area (in sqft) for each of the areas identified on the sketch that are located all or in part between grids A & G.

Problem D_TA.3:  On a neatly drawn scaled sketch of the second floor framing plan (or a copy of DORM 1/S1), show the areas tributary to each of the columns for which graphical tributary area concepts are readily applied.  Indicate why graphical tributary area concepts are difficult to apply to the other columns.  Report that area (in sqft) for each of the areas identified on the sketch that are located all or in part between grids A & G.

Problem D_TA.4:  On a neatly drawn scaled sketch of the roof framing plan (or a copy of DORM 1/S2), show the areas tributary to each of the columns for which graphical tributary area concepts are readily applied.  Indicate why graphical tributary area concepts are difficult to apply to the other columns.  Report that area (in sqft) for each of the areas identified on the sketch that are located all or in part between grids A & G.

Problem D_TA.5:  On a neatly drawn scaled sketch of the east architectural elevation (or a copy of DORM 4/A1), show the areas tributary to each of the horizontal diaphragms (floors and roof).  Report that area (in sqft) for each of the areas identified on the sketch.

Truss Bridge Design Problems

Tributary area concepts can be used to compute the loads on the various deck beams and girders as well as the panel point loads where the girders connect to the trusses.

Problem B_TA.1:  Neatly sketch, to scale, a plan view of the bridge deck.  Clearly indicate on your sketch the areas tributary to each of the deck beams.  Report that area (in sqft) for each of the areas identified on the sketch.

Problem B_TA.2:  Neatly sketch, to scale, a plan view of the bridge deck.  Clearly indicate on your sketch the areas tributary to each of the deck girders.  Report that area (in sqft) for each of the areas identified on the sketch.

Problem B_TA.3:  Neatly sketch, to scale, a plan view of the bridge deck.  Clearly indicate on your sketch the areas tributary to each truss panel point that connects to a deck girder.  Report that area (in sqft) for each of the areas identified on the sketch.