Seismic Assessment, the process of determining the earthquake resistance level of an existing building or infrastructure facility

Seismic Assessment

It is the process of determining the earthquake resistance level of an existing building or infrastructure facility. This evaluation considers the current condition of the structure, material properties, structural system, soil conditions, and regional seismic hazard. The aim is to predict the performance of the structure in a potential earthquake, identify risks, and provide a basis for strengthening measures if necessary.

Seismic Assessment According to Turkish Legislation

In Turkey, seismic evaluation is of great importance, especially for determining the earthquake safety of the existing building stock. Law No. 6305 on the Transformation of Areas Under Disaster Risk and related regulations (e.g., Principles Regarding the Detection of Risky Buildings) define the seismic evaluation processes and criteria. The 2018 Turkish Building Earthquake Code (TBDY 2018) also provides methods and performance targets for the evaluation of existing buildings. The evaluation typically includes visual inspection, material tests (e.g., core testing), structural linear and nonlinear analyses, and geotechnical investigations.

Seismic Assessment Areas of Application

• Detection of risky buildings and within the scope of urban transformation projects.
• Seismic safety analyses of existing public and private buildings.
• Determination of the earthquake resistance and strengthening projects of historical and cultural heritage.
• Before the repair and strengthening of damaged structures.
• Seismic performance analyses of large-scale infrastructure projects like bridges, viaducts, dams, etc.

Seismic Assessment Importance

• Minimizing loss of life and property.
• Preventing or limiting structural damage.
• Providing data for developing urban transformation strategies.
• Reducing economic losses.
• Establishing a basis for post-disaster response and recovery efforts.
• Extending the safe service life of existing buildings.

Seismic Assessment Sanctions

• The demolition and inclusion in urban transformation of buildings identified as risky is a legal obligation.
• Strengthening or reconstruction works may be mandatory for public buildings found to have inadequate earthquake safety.
• Building inspection companies and relevant professionals may face legal liabilities if they provide incorrect or incomplete information during seismic evaluation processes.
• New buildings must be designed and constructed in accordance with earthquake regulations; otherwise, a building permit cannot be obtained, and legal action will be taken.

Seismic Assessment According to European Union (EU) Legislation

• As earthquake risk varies across the EU, there is no single binding legislation on seismic evaluation. However, Eurocode 8 (EN 1998): Design of structures for earthquake resistance serves as an important reference for harmonizing structural design and safety standards. While Eurocode 8 provides detailed rules for the design of new buildings, it also includes principles and methods for the evaluation and strengthening of existing structures. Member states adapt and implement Eurocode 8 into their national legislation. Seismic evaluation typically involves structural analyses, material testing, and soil investigations.

Seismic Assessment Areas of Application

• Determining the earthquake safety of existing buildings in EU member states.
• Evaluating critical structures such as public buildings, schools, and hospitals, especially in high-risk regions.
• Seismic performance analyses of infrastructure projects like bridges, tunnels, etc.
• Conservation and strengthening projects of historical buildings.
• Urban planning and risk management studies.