Post on 02-Jun-2018
8/11/2019 Krohn_valmont_TIA.pdf
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2010 Valmont Industries, Inc. All rights reserved.
COMMUNICATIONSTRUCTURES SPECIFICATIONS
Steve Krohn, P.E.
8/11/2019 Krohn_valmont_TIA.pdf
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2010 Valmont Industries, Inc. All rights reserved.
Make Sure You Get What You OrderTodayand in the Future
Explain the implications of goodspecifications Short term and long term financial
impacts Are you getting everything you are
asking for? Comparison of Specification
Interpretations Examples of specifications based
on our experience Question and Answer session
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2010 Valmont Industries, Inc. All rights reserved.
Structure Specifications
Are you meeting your future requirements?Is your 4 carrier structure really a 4 carrierstructure?
Are you really saving money?Is todays choice affecting tomorrowsreinforcement budget?
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2010 Valmont Industries, Inc. All rights reserved.
Structure SpecificationsThe Playbook
Basic RequirementsDetails your design expectationsProvides the loading requirements that you havespecified for current and future useProvide the same specifications to allmanufacturers so you receive comparable bids
Ensures all manufacturers are designing basedon the same requirements
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2010 Valmont Industries, Inc. All rights reserved.
Important Specification Information
Structure Height Design Code Mount Options Antenna/Microwave Mount Locations
Design purposes only? Antenna Sizes Dish Specifications Site Location
Longitude and Latitude
Exposure Category Topography Category
Structure Classification Cable/Waveguide Size and Quantity Additional Load Clarification
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2010 Valmont Industries, Inc. All rights reserved.
Design Code Options
TIA/EIA-222-Rev F vs. TIA-222-Rev G Rev F
Allowable Design
Fastest Mile wind speed Rev G
Limit State Design 3-sec gust wind speed
Site Characteristics included when considering windloading Includes Seismic and Ice Loading consideration
90 mph Rev G is approximately 75 mph Rev F
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Platforms 13 Low Profile Platform without handrails 13 Low Profile Platform with handrails
Extensions Arms T-Arms
Significant EPA differences
Mount Options
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8/11/2019 Krohn_valmont_TIA.pdf
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Site Characteristics and Structure Classification
Exposure Category Variations in ground surface roughness that arise from topography and vegetation as
well as from constructed features. (TIA-222-G)
Exposure B : Structures in Urban or Suburban areas.
Exposure C (default) : Structures located in open terrain scattered with obstructionsthat are less than 30 tall.
Exposure D : Structure is in flat, unobstructed shoreline exposed to wind flowing overopen water.
8/11/2019 Krohn_valmont_TIA.pdf
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Topography Category Location of structure to hills, ridges, and escarpments that constitute abrupt changes in
geography will result in wind speed-up effects. (TIA-222-G)
Category 1 (default) - No abrupt changes in general topography.
Category 2 - Structures located at or near the crest of an escarpment. Category 3 - Structures located in the upper half of a hill.
Category 4 - Structures located in the upper half of a ridge or mountain.
Site Characteristics and Structure Classification
Escarpment Flat Hill Mountain
8/11/2019 Krohn_valmont_TIA.pdf
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Site Characteristics and Structure Classification
Structure Classification Importance factor based on classification of human hazard/property damage if
structure was out of service for an extended period of time (TIA-222-G)
Class 1 (I=0.87): Structures that due to height, use or location represent a low hazard
to human life and damage to property in the event of a failure and/or used forservices that are optional. I.E. Ham Radio Tower
Class 2 (I=1.0) (default): Structures that due to height, use or location represent asubstantial hazard to human life and damage to property in the event of a failureand/or used for services that may be provided by other means. I.E. Typical Cell Tower
Class 3 (I=1.15): Structures that due to height, use or location represent a high hazard
to human life and damage to property in the event of a failure and/or used forprimary communication. I.E. Emergency Response Tower
8/11/2019 Krohn_valmont_TIA.pdf
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Dish Specifications
Sway Requirements based on dishfrequency and dish size
The higher the frequency the stricter
the twist and sway requirements
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Steps to competitive and proper designs
Well written specificationsContact Valmont Industries for all yourspecification questions and concerns.
Provide any clarification to all manufacturersReview designs
Ensure that specifications are adhered to
If base reactions are significantly different thereis a difference in specification interpretation
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Steps to competitive and proper designs14
The lowest price doesnt always meet yourneeds.
Did you get what you wanted?
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Questions15
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Site Characteristics and Structure Classification
Exposure Category Variations in ground surface roughness that arise from topography and vegetation as
well as from constructed features. (TIA-222-G)
Exposure B : Urban and suburban areas, wooded areas, or other terrain with numerousclosely spaced obstructions having the size of single-family dwellings or larger. Use ofthis exposure shall be limited to those areas for which terrain representative ofExposure B surrounds the structure in a ll directions for a distance of at least 2,630 ft(800m) or ten times the height of the structure, whichever is greater.
Exposure C : Structures located in open terrain scattered with obstructions that are lessthan 30 tall (9.1m). This category includes flat, open country, grasslands andshorelines in hurricane prone regions.
Exposure D : Structure is in flat, unobstructed shoreline exposed to wind flowing overopen water (excluding hurricane prone regions) for a distance of at least 1 mile (1.61km). Shorelines in Exposure D include inland waterways, lakes and non-hurricanecoastal areas. Exposure D extends inland a distance of 660 ft (200 m) or ten timesthe height of the structure, whichever is greater. Smooth mud flats, salt flats and othersimilar terrain shall be considered as Exposure D.