Seismic Code Highlights Determining what level of Seismic Restraints are Required Arkansas Fire Prevention Code 2002 Based on the IBC 2000

Arkansas Seismic Code (Determining what level of Seismic Restraint is Required) Need to determine the following: Seismic Use Group (Section ) A classification assigned to a building based on its use as defined in Section Site Class (Table ) A classification assigned to a site based on the types of soils present and their engineering properties as defined in Section Spectral Response Acceleration (Figure 1615) Seismic Design Category (Section ) A classification assigned to a structure based on its Seismic Use Group and the severity of the design earthquake ground motion at the site.

Seismic Use Groups Seismic Use Group III – structures having essential facilities which are required for post earthquake recovery and those substantial quantities of hazardous substances (Table ) Seismic Use Group II – structures the failure of which would result in a substantial public hazard due to occupancy or use as indicated by Table , or as designated by the building official Seismic Use Group I – structures not assigned to either Seismic Use Group II or III

Table

Site Class

Spectral Response Acceleration Can be determined from Maps in Figure 1615 for Site Class B. For Site Class other than B the spectral response acceleration will have to be adjusted in accordance with Table

Spectral Response Acceleration

Seismic Design Category Based on Seismic Use Group and design spectral response acceleration Determined from Table (1) or Table (2)

Seismic Design Category

Arkansas Seismic Code (Determining what level of Seismic Restraint is Required) Best way to get the seismic information of a Building. Look on the Structural Plans or ask the Structural Engineer

Seismic Restraint of HVAC Components HVAC Components have the same Seismic Design Category unless otherwise noted in the Code. All HVAC components must be Seismically Restrained …Except:

Seismic Restraint of HVAC Components Exceptions (Section ): 1. Components in Seismic Design Category A 2. Mechanical components in Seismic Design Category B 3. Mechanical components in Seismic Design Category C when the component importance factor (Ip) is equal to Mechanical components in all Seismic Design Categories, where Ip = 1.0 and flexible connections between components and associated ductwork, piping, and conduit are provided, that are mounted at 4 feet or less above the floor level and weigh 400 lbs or less, and are not critical to the continued operation of the structure. 5. Mechanical components in Seismic Categories D, E, or F that weigh 20 lbs or less, where the Ip=1.0 and flexible connections between the components and associated ductwork, piping, and conduits are provided.

Arkansas Seismic Code (Determining what level of Seismic Restraint is Required) Component Importance Factors (Section ) Ip=1.5 Life Safety Component is required to function after an earthquake Component contains hazardous or flammable material in quantities that exceed the maximum allowable quantities for an open system listed in chapter 4. Storage racks in occupancies open to the general public Structures in seismic use group III – components needed for continued operation of the facility or whose failure could impair the continued operation of the facility Ip=1.0 All other components

Arkansas Seismic Code (Determining what level of Seismic Restraint is Required) Typical Rules of Thumb Buildings in Seismic Design Category A or B and in either Seismic Use Group I or II do not need seismic restraints If the Building is in User Group III – almost everything will need to have seismic restraints

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