Church Steeple Project
Church Steeple Project
I did some searching and did not find anything addressing this issue posted so far, but if anyone knows of something similar, feel free to let me know!
Project: Renovations, Repairs, and Replacements on a church built circa 1850.
Conditions: We are on the final stages of the planned projects - replacement of the church steeple and spire. The supporting structure below the steeple has seen many renovations over the century-and-half, including steel beams and heavy framing support. We have decided to use the existing structure and support the replacement steeple in the same location as the existing steeple. The site is in a 110mph Zone, Exposure B, with many buildings and tall trees around.
Steeple: The steeple will stand approximately 28'6", with an 18'6" Spire, atop 18'6" of the main building. There is a clock and bell on two platforms, we estimate their combined weight of 2,000lb. There will be a perforation of 3'6"x6'8" on four sides (steeple is 8'0" square) approximately 20'0" up from base of steeple.
Construction: The steeple will use 8"x8"x28'4" cedar posts (we're trying to convince the builder to switch to modern PT columns) at all four corners with 6x6/4x6 lateral girts and for all framing. The exterior will be 1/2" plywood with traditional wood cladding.
Problem: Wind Design.
The structural design is pretty straight forward. I calculated the wind load to be 28.2 psf (using ASCE 7-05). The issue now is figuring out how to actually analyze the steeple to withstand wind loading and the best methods of making connections to the existing building. Thus far I have proposed a structural analysis using MultiFrame and using standard shear wall design, both of which resulted in 6/12 nailing and less than 10kips uplift at the post bases.
Question: Basically my boss isn't comfortable with using these methods for such a tall structure (we typically just deal with standard residential construction). Using MultiFrame and its panel tools doesn't actually give results of shear/tension as each connection, I've just interpreted its results to be similar to what I've found with traditional shear wall designs put through MultiFrame. So now I'm reaching out to see what other engineers think or might know about designing such structures.