A Comparison Analysis of Buildings as per Norwegian and Ethiopia ES-EN1998-1 Seismic Code (2024)

FAQs

What is seismic analysis of building structures? ›

Seismic analysis is a branch of structural analysis that involves calculating a building's (or nonbuilding's) earthquake reaction. In earthquake-prone areas, it is an element of the structural design, earthquake engineering, or structural evaluation and retrofit (also structural engineering).

The evaluation of the seismic resistance of existing structures and their deficiencies is essential before an appropriate repair or upgrade system can be designed. The performance of the structure may be evaluated in terms of its lateral load resistance, global or interstory drift and potential damage.

The methods for analysing irregular structures under the seismic loads are static methods such as equivalent lateral force method and pushover analysis, and dynamic methods such as Response Spectrum Analysis and Time History Method.

The criteria of evaluation of building will depend on materials, strength and ductility of structural components and detailing of reinforcement. Visual inspection is an integral part of evaluation, and in fact, is the most widely used form of non-destructive evaluation (NDE).

SPC ratings range from 1 to 5 with SPC 1 assigned to buildings that may be at risk of collapse during a strong earthquake and SPC 5 assigned to buildings reasonably capable of providing services to the public following a strong earthquake.

To apply seismic loads in finite element analysis, the large mass method (LMM) was adopted. This method is used generally when the ground is affected by acceleration to analyze the dynamic behavior of the structure that is fixed to the ground. In the LMM, an appropriate ground mass must be determined.

The classic approach for computing seismic reliability of a structural system requires a seismic hazard curve and a fragility function and leads to the estimation of the failure probability of the investigated damage state.

Base isolation involves constructing a building on top of flexible steel, rubber and lead pads. When the base moves during an earthquake, the isolators vibrate while the structure remains steady. This effectively helps to absorb seismic waves and prevent them from traveling through the building.

There are currently two comple- mentary experimental techniques to simulate the effect of an earthquake on a structure: one based on the shak- ing table and the other on the reaction wall and strong floor system (see image on page 56).

Seismic analysis in FEA is predominantly used in civil engineering to evaluate a building's response to an earthquake and the oscillations from it.

What is the objective of seismic analysis of building? ›

Seismic analysis involves evaluating how a structure responds to earthquake-induced forces. This process helps engineers understand potential stress points and the overall behavior of a building during seismic events.

It mainly includes four aspects: the seismic fortification level, building the performance level, the structural seismic performance target, and the design method to achieve the structural seismic performance target.

The goal of probabilistic seismic hazard analysis (PSHA) is to quantify the rate (or probability) of exceeding various ground-motion levels at a site (or a map of sites) given all possible earthquakes.

Seismic design is a vital process of structural analysis while designing a building, which is subjected to Earthquake ground motions, such that the facility continues to function and serve its purpose even after an Earthquake.

The seismic structure interpretation is realized using quantitative and qualitative descriptions based on the seismic processing results.

Seismic loading is one of the basic concepts of earthquake engineering which means application of a seismic oscillation to a structure. It happens at contact surfaces of a structure either with the ground or with adjacent structures.