0.16
Zone 3. This zone is classified as a Moderate Damage Risk Zone which is liable to MSK VII. The IS code assigns a zone factor of 0.16 for Zone 3. Several megacities like Chennai, Mumbai, Kolkata and Bhubaneshwar lie in this zone.

Seismic Zone Factor (Z): It is represent the peak ground acceleration in studied site as a percentage of gravity. acceleration g (9.81 m/sec2).

The Hazard Factor, Z, is equivalent to the effective peak ground acceleration with a return period of 500 years. The Z value in Australia ranges from 0.03 to 0.22 (refer Figure 3) with a Z=0.08 value for Sydney and Melbourne.

Seismic Zone Factor – Z This is the factor that represents the magnitude of the ground accelerations. There are size zones as per the UBC 97. Each zone has a different peak ground acceleration.

The four Site Coefficients S1 to S4 of the UBC 1994, which are independent of the level of ground shaking, were expanded to six soil profile types, which are dependent on the seismic zone factors, in the 1997 UBC (SA to SF) based on previous earthquake records.

A seismic zone is used to describe an area where earthquakes tend to focus; for example, the New Madrid Seismic Zone in the Central United States. A seismic hazard zone describes an area with a particular level of hazard due to earthquakes.

The CBC states that an existing building will have to “conform to the seismic requirements for a new structure” when a change of use is contemplated that intensifies the use (e.g., increase the number of occupants and/or the amount of combustible materials stored in the building).

The Richter scale and how it measures earthquake magnitude. The Richter scale calculates an earthquake’s magnitude (size) from the amplitude of the earthquake’s largest seismic wave recorded by a seismograph. Each increase of one unit on the scale represents a 10-fold increase in the magnitude of an earthquake.

Based on the past seismic history, Bureau of Indian Standards grouped the country into four seismic zones namely Zone-II, Zone-III, Zone-IV and Zone-V. Of all these four zones, Zone-V is the most seismic active region whereas Zone-II is the least.

Uniform Building Code
The Uniform Building Code (UBC) was a building code used primarily in the western United States.

A collection of rules and regulations adopted by authorities having appropriate jurisdiction to control the design and construction of buildings, alteration, repair, quality of materials, use and occupancy, and related factors of buildings within their jurisdiction; contains minimum architectural, structural, and …

Seismic Zone Factor – Z This is the factor that represents the magnitude of the ground accelerations. There are size zones as per the UBC 97. Each zone has a different peak ground acceleration.

The seismic coefficients, Cv and Ca are measures of the expected ground acceleration at the site. They may be found in Tables 16-Q and Tables 16-R of UBC code (see image below) respectively. The coefficient, and hence the expected ground accelerations are dependent on the seismic zone and soil profile type.

The near-source factors Na and Nv are found on the table 16-S and table 16-T respectively as shown below. In seismic zone 4, they are used in conjunction with the soil profile type to determine the seismic coefficients Cv and Ca. 11.

According to UBC 97, the following procedure shall be adopted. Δ S = Design level response displacement. This is obtained from the static analysis and it is the relative displacement at the level we consider. This can be calculated from the following equation. Limiting values of the story drift are classified based on the period of the structure.