Performance Category 3 and 4 Structures, Systems, and Components

DOE-STD-1020-2002

Evaluate capacities of SSCs, CC, from code ultimate values when strength

design is used (e.g., IBC for reinforced concrete or LRFD for steel) or from

allowable stress levels (with one-third increase) when allowable stress design

is used. Minimum specified or 95% non-exceedance in-situ population

values statistically adjusted for sample size, for material strengths should be

used for capacity estimation.

Compare demand, DTI, with capacity, CC, for all SSCs. If DTI is less than

or equal to CC, the facility satisfies the seismic force requirements. If DTI is

greater than CC, the facility has inadequate seismic resistance.

Evaluate story drifts (i.e., the displacement of one level of the structure

relative to the level above or below due to the design seismic forces),

including both translation and torsion. Calculated story drifts should not

exceed the limitations in IBC 2000.

Elements of the facility shall be checked to assure that all detailing

requirements IBC 2000 provisions are met keeping into consideration the

seismic design category of the building.

A quality assurance program consistent with model building code

requirements shall be implemented for SSCs in Performance Categories 1

and 2. In addition, peer review shall be conducted for Performance Category

2 SSCs.

2.3.2 Performance Category 3 and 4 Structures, Systems, and

Components

The steps in the procedure for PC-3 and PC-4 SSCs are as follows:

Evaluate element forces, DNS, for the non-seismic loads expected to be

acting concurrently with an earthquake.

Calculate the elastic seismic response to the DBE, Ds, using a dynamic

analysis approach and appropriate damping values from Table 2-2.

Response Level 3 is to be used only for justifying the adequacy of existing

SSCs with adequate ductile detailing. Note that for evaluation of systems

and components supported by the structure, in-structure response spectra are

used. For PC-3 and PC-4 SSCs, the dynamic analysis must consider 3

orthogonal components of earthquake ground motion (two horizontal and

one vertical). Responses from the various direction components shall be

combined in accordance with ASCE 4. Include, as appropriate, the

contribution from seismic anchor motion. To determine response of SSCs

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