HomeMy WebLinkAboutSUMMIT VIEW CHURCH WTF MOBILITIE - PDP180016 - SUBMITTAL DOCUMENTS - ROUND 2 - WTE / WTF INFORMATION651 W. Galena Park Blvd., STE 101 / Draper, UT 84020 / T (801) 990-1775 / F (801) 990-1776 / www.vectorse.com
Project Number: U1223-989-191
April 4, 2019
Larson Camouflage, LLC
1501 South Euclid Avenue
Tucson, AZ 85713
REFERENCE: Summitview Church (Larson#: P19064)
Fall Zone Letter
To Whom It May Concern:
A 71 ft monopine pole has been proposed for this site. This monopole will consist of a 71 ft tall 18-sided tapered
steel pole.
The above-mentioned pole has been designed in accordance with the International Building Code, 2015 Edition and
the ANSI TIA-222-G “Structural Standard for Antenna Supporting Structures and Antennas”. Additionally, all steel
members have been designed to meet the requirements of the AISC Steel Construction Manual.
The pole has been designed for the following criteria:
1. Wind speed: 134 mph (3-second gust)
2. Ice: none
3. Basic wind speed of 60 mph (3-second gust) for the service condition (deflection limitations only)
4. Structure Class II, Exposure C, Topographic Category 1
It has been requested that the proposed monopole be designed for a fall zone radius equal to a 1:1 ratio of pole
height. To satisfy this requirement the structure has been designed such that the highest stress rating of all structural
elements is 80% of capacity or less.
Please note that “fall zone” is a term not defined in the standards listed above. Our approach to the fall zone design
is described in the preceding paragraph and is our best attempt to meet what we believe to be the intent of the fall
zone request. Current code does not address failure mechanics. It is difficult to impossible to predict the behavior
of a failing structure. Physics of a fall during a wind event, including possible bouncing or rolling, may place all or
part of the ruptured pole section outside of the intended fall zone. Nonstructural components attached to the steel
structure are outside of our scope. Nonstructural components may break free from the structure and fall outside of
the fall zone even at loads below code-specified magnitudes if the components and their attachments are not
properly designed and installed.
We hope this meets your needs. If you have any further questions regarding this matter, please call this office at
your convenience.
Very truly yours,
VECTOR STRUCTURAL ENGINEERING, LLC
Clifton M. Palmer, P.E.
Senior Engineer
CMP/cfa