DaVinci Engineering holds a broad spectrum of licenses and certificates, providing 100% engineering services across North America and Internationally for Landa and its clients. DaVinci engineering staff are accredited and active members of CSA, TIA, ASCE (Dynamics of mobile and permanent latticed structures), CSA Technical Committee on Communication Towers, and Wind Energy. Engineering is recommended for every tower install to ensure safe antenna and mobile tower deployment. DaVinci Engineers utilize their combined years of experience with custom engineering software and Landa’s extensive R&D, enabling a match for every loading configuration requirement. For each tower deployment, the location of the COW, location of guy cables, quantity of guy cables, coaxial cables, specific antenna loading, and antenna elevation are all critical factors in determining the specifics of that tower. Therefore, we analyze each specific COW deployment based on the above criteria to determine its feasibility. The TIA-222-G uses the following factors considered in the wind pressure design of these towers; we will also comply with the new 2016 ANSI/TIA-322 guidelines as they come into operation.
Continue to use DaVinci Engineering as they hold a broad spectrum of licenses and certificates providing engineering services across North America and internationally for Landa and its clients. DaVinci Engineering’s staff are accredited and active members of the industrial design committees. Engineering is recommended for every tower install to ensure safe antenna and mobile tower deployment. DaVinci Engineers utilize their combined years of experience with custom engineering software and Landa’s extensive R&D, enabling a match for each loading configuration requirement. For each tower deployment, the location of the COW, location of guy cables, quantity of guy cables, coaxial cables, specific antenna loading, site location, and topography and antenna elevation are all critical factors in determining the specifics of that tower. Therefore, we analyze each specific COW deployment based on the above criteria to determine its feasibility. The ANIS/TIA-222-H uses the following factors considered in the design of the wind pressure of these towers.
- Structure Class: Used to determine the essential factor for the structure based on the hazard to human life, property damage, and the necessity of essential services.
- Exposure Category: An exposure category that adequately reflects the characteristics of ground surface irregularities at the site shall be determined. Variations in ground surface roughness from natural topography and vegetation, as well as man-made / constructed features, shall be considered.
- Topographic Category: A factor to consider is wind speed-up at isolated hills, ridges, and escarpments, constituting abrupt changes in the general topography.
- Wind Speed: The essential wind speed and ice thickness per the IBC wind maps shall be considered to come from any horizontal direction. We recommend using the ASCE 7-16 wind speed correlating to a 10-year MRI (mean recurring interval) or less for temporary deployments to determine the wind speed accurately. This is critical to minimizing the guy anchoring systems.
- Gust Effect Factors: Factors that account for the effects of wind gusting and the calculated response of a tower-type structure.
- Load Combinations: Used to determine the “timing” or combinations of loads on the structure simultaneously per the 2018 IBC.
Over the past three decades, the LMS has documented site-specific data that shows the tower sections failing before any damage to the trailer frame or outriggers.
For example, tower sections have failed due to hurricane winds, while the trailer and outrigger showed no signs of damage. This means we verify that the trailer will not tip over based on the assumption that there is no structural failure within the trailer frame or outriggers.
Per section 1609.1.1 of the 2018 International Building Code, communication structures are designed following the Electronic Industries Association / Telecommunications Industries Association Standards ANSI/TIA-222-H, “Structural Standards for Steel Antenna Towers and Antenna Supporting Structures.” This nationally recognized standard is modeled after the American National Standards Institute document known as ASCE-7. The ANSI/TIA-222-H standard was developed by professional engineers experienced in the design of communication structures.
A structural failure per LRFD is determined when a structure exceeds its limit state. This does not necessarily mean that the structure “falls.” Limit state design requires the structure to satisfy two principal criteria: the ultimate limit state (ULS) and the serviceability limit state (SLS). A limit state is a set of performance criteria (e.g., vibration levels, deflection, strength, stability, buckling, twisting, collapse) that must be met when the structure is subject to loads. In the unlikely event that this COW would possibly fail due to an extreme wind load that exceeds the design wind criteria, it would first begin to yield within the tower sections. A qualified professional engineer has designed these COW tower sections for a design wind speed that meets the local and regional requirements and the ANSI/TIA-222-H. The tower has been appropriately analyzed with all the applicable load factors, load combinations, and resistance factors as required by the code.