Turkey is located on one of the world's most active earthquake zones. This reality makes earthquake-resistant building construction a vital issue for our country. After the February 6, 2023 earthquakes, public awareness of earthquake-resistant construction has significantly increased. In this article, we examine in detail how earthquake-resistant buildings are constructed and which technologies are used.
Critical Importance of Soil Investigation
The first and most important step in earthquake-resistant building construction is conducting a comprehensive soil investigation. Soil investigation determines the geological and geotechnical properties of the land where construction will take place. Parameters such as soil bearing capacity, groundwater level, liquefaction potential, and proximity to fault lines are revealed through this study.
Soil investigation results provide critical data in determining the foundation type and creating the structural design. Special foundation solutions such as pile foundations or raft foundations are applied in weak soils.
Strong Foundation Design
The foundation is the most critical structural element that transfers all building loads to the ground. Foundation design in earthquake-resistant buildings should be carried out in accordance with the following principles:
- Raft Foundation: A reinforced concrete slab foundation system covering the entire building area
- Pile Foundation: A foundation type that reaches solid ground by going deep in weak soils
- Continuous Foundation: A foundation system that continues continuously under walls
- Base Isolation: Isolating the structure from ground vibrations using seismic isolators
Reinforced Concrete Design Principles
The design of reinforced concrete elements in earthquake-resistant buildings directly affects the seismic performance of the structure. Strong column-weak beam principle, ductile design, and adequate reinforcement detailing are fundamental design principles.
Column Design
Columns form the backbone of the building's structural system. In earthquake zones, column cross-sections must be of adequate size, and stirrup densification must be meticulously applied especially at column-beam connection zones. Column longitudinal reinforcement ratio and stirrup spacing must be calculated in accordance with current earthquake regulations.
Beam Design
Beams transfer floor loads to columns and assume the role of energy dissipation during earthquakes. Ductile behavior is ensured by stirrup densification at beam support zones. Beam height and width should be optimized according to the load it carries and its span.
Seismic Isolator Systems
Seismic isolators are advanced technology systems that significantly reduce the transmission of earthquake energy to the building by separating the structure from its foundation. Thanks to these systems, the building moves independently of ground motion during an earthquake, and structural damage is minimized.
Lead-core rubber isolators and friction pendulum isolators are the most common seismic isolation technologies applied in Turkey. The use of seismic isolators is becoming increasingly widespread, especially in critical structures such as hospitals, schools, and public buildings.
Shear Walls and Steel Frame Systems
Shear walls are reinforced concrete structural elements that carry a significant portion of earthquake loads. They increase the rigidity of the building, limit story drifts, and contribute to maintaining structural stability. Steel frame systems, with their high strength and ductility properties, form an alternative structural system preferred in earthquake-resistant building design.
Concrete and Steel Quality
The quality of concrete and steel used in earthquake-resistant buildings is extremely important. C30 and higher concrete classes should be used as standard in buildings in earthquake zones. B420C and B500C class ribbed reinforcing steel should be preferred for steel reinforcement. Vibrator compaction during concrete pouring, curing application, and quality control tests must be carried out meticulously.
Current Earthquake Regulations
The Turkish Building Earthquake Regulation (TBDY), which came into effect in 2018, determines the rules to be followed in building design. This regulation aims to control the behavior of buildings under different earthquake levels with a performance-based design approach. All new buildings must be designed and constructed in accordance with this regulation.
Strengthening of Existing Buildings
Strengthening existing buildings that carry earthquake risk is also extremely important. The earthquake performance of existing structures can be improved through methods such as column jacketing, carbon fiber wrapping, steel brace addition, and foundation strengthening. A detailed structural performance analysis must be conducted before strengthening.
Conclusion
Earthquake-resistant building construction is a complex process that requires engineering science and technology to work together. Meticulous work at every stage, from soil investigation to structural design, from material quality to application details, is of vital importance. As MIFAYOL CONSTRUCTION, we adopt building safe and durable structures in compliance with the most current earthquake regulations in all our projects as our fundamental principle.