Oregon State University
Ecampus
CE 381
Dr. Miller
Kearney Hall Applications #2
PROBLEM #1: Floor Framing Supporting the 3rd Floor of Kearney Hall
Attach a HW evaluation sheet as the first page. Draw your load paths (arrows) with values on the
Cropped Floor Plan found in Resources item c. in the HW description in Assignments in Canvas.
Show all necessary calculations on engineering paper.
GIVEN
Cropped 3rd Floor Framing Plan
FIND: Draw complete load paths (with values shown in kips) on the Cropped 3rd Floor
Framing Plan found in item c. in the Resources section of the Assignment. Draw the paths
directly on that floor plan. The load path should include 6 deck sections, 6 beams and 2
girders. Note that 4 of the beams and deck spans extend beyond the boundaries of the dashed
red lines and the entire lengths should be considered. Those entire lengths can be found in the
entire floor plan in item b. of Resources.
Oregon State University
Ecampus
CE 381
Dr. Miller
SOLUTION
A. In this problem, use the classroom floor live load + partition load given in the General Notes
= 40 psf + 20 psf = 60 psf over the entire portion of the floor considered here. Do not use
live load reductions. For simplicity, do not include the dead load in this assignment, but it
would definitely need to be considered in an actual design.
B. In your load paths, I want you to use the convention below to indicate the magnitude of the
loads. In the top figure, I show how the loads flow in a one-way system (like a corrugated
metal deck) from the deck to the beams. Note that the 10 k shown means 10 kips flowing in
each direction.
C. Think carefully about the load path, and make sure that the tributary column loads from
the third floor at grid lines C and D agree with the loads flowing into those columns from
the members framing into them. You can determine/check the column loads using their
tributary areas.
Oregon State University
Ecampus
CE 381
Dr. Miller
An example of the necessary calculation is shown in the plan and 3D views below. The load
going into the column C = B1 + B2 + G, where B1 and B2 are the loads flowing in from the
two beams, and G is the load coming in from the girder. B1, B2 and C are easily calculated
from the tributary areas of the beams and column, respectively. Then, G = C - B1 - B2 is the
load coming from the girder.
D. Another much more complicated way to determine the load coming from the girder is to
look at each beam spanning into it and proportioning the loads to each end of the girder. A
very simple example with just one beam is shown below. For the Kearney Hall girder, you
would need to properly proportion each of the forces coming from the beams, taking into
account their locations along the girder. I would personally recommend the simpler
approach shown in C. above.
Oregon State University
Ecampus
CE 381
Dr. Miller
Hints to Help Get you Started:
1) Floor system is one-way - why?
2) Tributary area for Column at grid line D in the Cropped Floor Plan = 464 sf. Show how this
is determined in your calculations.
Note that you can very carefully scale off the needed dimensions from the floor plan by hand using
an engineer’s or architect’s scale or a ruler, using proportions from a known dimension. Or, you
can use Bluebeam software to do exactly the same thing using the Measure/Calibrate and
Measure/Length tools. Try it. It’s really pretty easy and a very useful tool, and especially useful
when needing to scale a number of dimensions like in this case. For instructions on how to use
Bluebeam, please look at them in the Kearney Hall APPLICATIONS #1 assignment that you
completed last week.
Resources
See the complete list of resources on the Kearney Hall Applications #2 page. Looking at the
photographs and complete set of structural and architectural drawings would be time well-spent
to help you better understand the entire building and how the portion examined here fits in.