§ 6-558. Major structures.

(a)

Structural requirements:

(1)

Design and construction. Major structures, except for mobile homes, shall be designed and constructed in accordance with Section 1205 of the 1986 revisions to the 1985 Standard Building Code using a fastest-mile wind velocity of 110 miles per hour. Major structures, except mobile homes, shall also comply with the applicable standards for construction found elsewhere in the Standard Building Code.

(2)

Mobile homes. Mobile homes shall conform to the Federal Mobile Home Construction and Safety Standards or the Uniform Standards Code ANSI A119.1, pursuant to Section 320.823, Florida Statutes, as well as the requirements of subsection (a)(3) below.

(3)

Elevation, floodproofing and siting. All major structures shall be designed constructed and located in compliance with the National Flood Insurance Regulations as found in 44 CFR, Part 50 and 60, or Ordinance No. 77-26 as amended (section 8-71 et seq., of this Code).

(b)

Design conditions:

(1)

Velocity pressure. Major structures, except mobile homes, shall be designed in accordance with the requirements of Section 1205 of the 1986 revisions to the 1985 Standard Building Code using a minimum fastest-mile wind velocity of one hundred ten (110) mile per hour. These minimum design pressures are as follows:

Table 1205.2A

Velocity Pressure (psf)

Building Height 60 feet or less

Mean Roof Height (ft.)	Fastest-Mile Wind Velocity, V (mph) 110
0—15	25
20	28
40	34
60	38

 

Table 1205.3A

Gust Velocity Pressure (psf)

Building Height Greater Than 60 Feet

Height (ft.)	Fastest-Mile Wind Velocity, V (mph) Coastal Exposure 110
0—30	35
31—50	40
51—100	47
100—200	54
200—300	61
300—400	66
400—500	70

 

(2)

Foundations. The elevation of the soil surface to be used in the design of foundations, calculation of pile reactions and bearing capacities shall not be greater than that which would result from the erosion reasonably anticipated as a result of design storm conditions. Foundation design and construction of a major structure shall consider all anticipated loads acting simultaneously with live and dead loads. Erosion computations for foundation design shall account for all vertical and lateral erosion and scour producing forces, including localized scour due to the presence of structural components. Foundation design and construction shall provide for adequate bearing capacity taking into consideration the type of soil present and the anticipated loss of soil above the design grade as a result of localized scour. Erosion computations are not required landward of coastal construction control lines established or updated since June 30, 1980. Upon request, the department of natural resources may provide information as to those areas within coastal building zones where erosion and scour of a 100-year storm event is applicable.

(3)

Wave forces. Calculations for wave forces resulting from design storm conditions on building foundations and superstructures may be based upon the minimum criteria and methods prescribed in the Naval Facilities Engineering Command Design Manual, NAVFAC DM-26, U.S. Department of Navy; Shore Protection Manual, U.S. Department of the Army Corps of Engineers; U.S. Department of the Army Coastal Engineering Research Center Technical Papers and Reports; the Technical and Design Memoranda of the Division of Beaches and Shores, Florida Department of Natural Resources; or other professional recognized methodologies which produce equivalent design criteria.

Breaking, broken and nonbreaking waves shall be considered as applicable. Design wave loading analysis shall consider vertical uplift pressures and all lateral pressures to include impact as well as dynamic loading and the harmonic intensification resulting from repetitive waves.

(4)

Hydrostatic loads. Calculations for hydrostatic loads shall consider the maximum water pressure resulting from a fully peaked, breaking wave superimposed upon the design storm surge with dynamic wave setup. Both free and hydrostatic loads shall be considered. Hydrostatic loads which are confined shall be determined by using the maximum elevation to which the confined water would freely rise if unconfined. Vertical hydrostatic loads shall be considered both upward and downward on horizontal or inclined surfaces of major structures (i.e., floors, slabs, roofs, walls). Lateral hydrostatic loads shall be considered as forces acting horizontally above and below grade on vertical or inclined surfaces. Hydrostatic loads on irregular or curved geometric surfaces shall be determined by considering the separate vertical and horizontal components acting simultaneously under the distribution of the hydrostatic pressures.

(5)

Hydrodynamic loads. Hydrodynamic loads shall consider the maximum water pressures resulting from the motion of the water mass associated with the design storm. Full intensity loading shall be applied on all structural surfaces above the design grade which would affect the flow velocities.

(c)

Structural requirements for nonhabitable major structures. Nonhabitable major structures need not meet the specific structural requirements of subsection (a)(1) above, except that they shall be designed to produce the minimum adverse impact on the beach and dune system and shall comply with the applicable standards of construction found in the Standard Building Code. All sewage treatment and public water supply systems shall be floodproofed to prevent infiltration of surface water anticipated under design storm conditions. Underground utilities, excluding pad transformers and vaults, shall be floodproofed to prevent infiltration of surface water expected under design storm conditions or shall otherwise be designed to function when submerged under such storm conditions.

(Ord. No. 86-52, §§ 5.02-5.04, 12-3-86)