Principles of Earthquake resistant design of Structures
This document discusses principles of earthquake-resistant building design and structural vibration control technologies. It explains that earthquake-resistant structures are designed to withstand expected earthquakes while minimizing loss of life and damage. This is achieved through methods ranging from ensuring adequate structural strength and ductility to using base isolation and vibration control systems. Base isolation allows a building to survive seismic impacts by installing flexible isolators between the structure and its foundation. Passive systems require no external power while active systems counterbalance earthquake forces using computer-controlled dampers. Hybrid systems combine aspects of passive and active control for reduced costs.
Principles of Earthquake resistant design of Structures
- 1. Principles of Earthquake resistant design of Structures K . TARUN KUMAR STRUCTURAL ENGINEERING
- 3. • According to building codes, earthquake-resistant structures are intended to withstand the largest earthquake of a certain probability that is likely to occur at their location. • This means the loss of life should be minimized by preventing collapse of the buildings for rare earthquakes while the loss of functionality should be limited for more frequent ones.
- 5. • The range from appropriately sizing the structure to be strong and ductile enough to survive the shaking with an acceptable damage, to equipping it to minimize the forces. • BASE ISOLATION • STRUCTURAL VIBRATION CONTROL TECHNOLOGIES
- 6. Base Isolation: • Base isolation is one of the most powerful tools of earthquake engineering pertaining to the passive structural vibration control technologies. • It is meant to enable a building or non-building structure to survive a potentially devastating from seismic impact.
- 8. ADVANTAGES: • The isolators work in a similar way to car suspension, which allows a car to travel over rough ground without the occupants of the car getting thrown around. • A fixed-base building (built directly on the ground) will move with an earthquake’s motion and can sustain extensive damage as a result. • Base isolation technology can make medium-rise masonry (stone or brick) or reinforced concrete structures capable of withstanding earthquakes, protecting them and their occupants from major damage or injury.
- 9. STRUCTURAL VIBRATION CONTROL TECHNOLOGIES : In earthquake engineering, vibration control is a set of technical means aimed to mitigate seismic impacts in building and non- building structure. 1. Passive seismic control. 2. Active seismic control. 3. Hybrid seismic control.
- 10. Passive seismic control: • Passive seismic control system in which they do not require any additional energy source to operate and are activated by earthquake input motion only.
- 11. Active seismic control: • This system provides seismic protection by imposing forces on a structure that counterbalance the earthquake forces. • This system is active in that it requires an energy source and computer – controlled to operate dampers throughout the building. • Active seismic control is comparatively newest invention in the field of seismic control systems that applies a 3 dimensional network. • This technology is highly sophisticated and expensive one and may not be feasible one for small projects even in far future.
- 13. Hybrid seismic control: • This system combines features of both passive and active seismic control systems. • In general, it has reduced power demands, and reduced cost when compared to fully active systems. • Hence it utilizes the advantages of both passive and active seismic control systems.