What it checks
The module calculates atmospheric ice accretion loads on structural members, cables, and guys in accordance with ASCE 7-22 Chapter 10. It determines the design ice thickness by applying importance and topographic factors to a nominal thickness, then computes the resulting weight of ice on a cylindrical reference member. The engine also evaluates the concurrent wind load acting on the ice-covered surface. It combines the ice weight and the wind pressure to produce a total combined load per linear foot. The design method follows the prescriptive formulas for freezing-rain ice accretion, utilizing specific density values and exposure coefficients defined in the standard.Inputs
- Ice Parameters - Nominal ice thickness from ASCE 7 Figure 10.4-2 (in), importance factor Ii per Table 10.4-1, and topographic factor Kzt per Ch 26.
- Geometry - Reference cylinder diameter for cable or pipe (in) and structure or member height above ground (ft).
- Environmental - Concurrent wind speed (mph) derived from ASCE 7 Figure 10.6 maps.
- Classification - Utility type specified as "transmission" or "other" to affect design thickness selection per ASCE 7 §10.4.
What it reports
- Design Ice Thickness - The calculated thickness td in inches, derived from the product of the importance factor, topographic factor, and nominal thickness.
- Ice Density - The ice density γ_ice in pcf, echoed for transparency based on the standard value of 56 pcf.
- Ice Weight - The weight of ice per linear foot (lb/ft) on the reference cylinder.
- Wind Pressure - The wind pressure on the ice-covered surface in psf.
- Concurrent Wind Load - The wind load per linear foot (lb/ft) acting on the ice-covered member.
- Total Combined Load - The sum of ice and wind loads per linear foot (lb/ft).
- Summary - A short summary line for the user interface banner.
Code references
The engine cites ASCE 7-22 Chapter 10 for atmospheric ice loads. Specific clauses include §10.4 for design ice thickness, §10.4.1 for ice density, §10.5 for the weight of ice on a cylindrical reference member, and §10.6 for concurrent wind on the ice-covered member. It also references Table 10.4-1 for importance factors, Figure 10.4-2 for nominal ice thickness, Figure 10.6 for wind speed maps, and Ch 26 for the topographic factor.