What is component amplification factor?

The component amplification factor (denoted as PCA/PFA) incorporates the effects of component inherent damping and component ductility. The PCA/PFA ratio ranges between 1.4 for high-ductility components and 4.0 for elastic components with an assumed damping ratio of 5%.

What is CS in seismic design?

Cs = seismic response coefficient determined in Section.

What is SS and S1 in seismic design?

Ss: Spectral acceleration parameter at short periods corresponding to the mapped maximum considered earthquake. S1: Spectral acceleration parameter at a period of 1 sec corresponding to the mapped maximum considered earthquake.

What is a seismic component?

Seismic component devices are innovative structural elements designed to protect bridges during extreme hazards, such as earthquakes, by absorbing or dissipating input external energy. Two most commonly used seismic component devices are seismic isolators and dampers.

What is SDS and SD1?

The parameters SDS and SD1 are used to calculate the design response spectrum in Section 11.4. 5 and the design base shear in Section 12.8.

What is Response Reduction Factor?

Response reduction factor (R) is an indication of extent to which the energy is dissipated through inelastic deformation during an event of seismic excitation. Many of the design codes recommends the different values of ‘R’ accounting for their ductility, over strength and Redundancy of the structure.

How is SS and S1 calculated on PGA?

The GSHAP values are multiplied by 2 to approximate 2%-in-50-year PGA values, and then multiplied by 2.5 and 1.0, respectively, to estimate SS and S1.

What is a component importance factor?

13.1. The component importance factor, Ip, shall be taken as 1.5 if any of the following conditions apply: The component is required to function for life-safety purposes after an earthquake, including fire protection sprinkler systems. The component contains hazardous materials.

What is seismic importance factor?

The Importance Factor is a multiplier that increases or decreases the base design loads. Typically, the base design loads are outlined by the code as a 2% annual probability of exceedence (2% in 50 years for seismic loads).

What does seismic design category B mean?

For Seismic Design Category (SDC) B, which designates a low seismic hazard region, structural engineers still need to complete a full seismic design process to meet the building code requirements.

What is strength reduction factor?

Conventionally, strength reduction factor (R factor) is defined as the ratio of elastic strength to yield strength. The importance of estimating R factor originates in the need for directly deriving inelastic spectra.

What is IE in seismic design?

The seismic importance factor (Ie) is used in the Seismic Response Coefficient (CS) equations with the intent to raise the yield level for important structures (e.g., hospitals, fire stations, emergency operation centers, hazardous facilities, etc.).