Seismic Safety of Non-Structural Elements and Contents in Hospital Buildings14 Feb 2007
Experience in damaging intensity of earthquakes has shown that buildings are destroyed or damaged to various extents. Also their contents are badly shaken and they fall down by toppling over, or by rolling if resting on rollers or wheels, or by sliding on their supports and crashing down on the floor. Many times such objects injure or even kill the inmates by cutting, piercing or hammering effects.
Experience in damaging intensity of earthquakes has shown that buildings are destroyed or damaged to various extents. Also their contents are badly shaken and they fall down by toppling over, or by rolling if resting on rollers or wheels, or by sliding on their supports and crashing down on the floor. Many times such objects injure or even kill the inmates by cutting, piercing or hammering effects. In most cases the functioning of the building as a hospital or library or a shopping centre or an industry gets adversely impacted.
A building may remain standing after an earthquake, but it might be functionless due to nonstructural damage to the equipment, lifeline conduits and other non-structural elements like partition walls, veneers, ceilings, window panes etc. Assessment of non-structural vulnerability is to be made in order to estimate the expected damage that these elements may suffer when subjected to earthquake shaking at different levels of intensity and the consequence to the functionality of the hospital. The cost of the non-structural elements in a building may even be much higher than that of the structure. Particularly in hospitals, it may reach upto 80 - 90% of the total facility value. Moreover, the susceptibility to nonstructural damage could be high even in a moderate level earthquake (MMI VI-VII). This can affect or destroy vital aspects of a hospital including those directly related to its function, without significantly affecting the structural components. Thus, in an earthquake, the external appearance of a hospital might be unaffected, but it may not be able to care for patients if the internal facilities have been damaged.
The desired level of performance of hospital facilities is much higher than that of other utility services because it is imperative that hospitals remain fully functional after an earthquake. In the case of large number of injuries expected, demand for medical services will be very high within the first 24 hours. In summary, a non-structural vulnerability assessment and consequent implementation of mitigation measures in hospitals will be justified on the following grounds:
1. Hospital facilities must remain as intact as possible after an earthquake due to their role in providing routine medical services as well as attending to the possible increase in demand for medical treatment following an earthquake.
2. In contrast to other types of buildings, hospitals accommodate a large number of patients who, due to their disabilities, are unable to evacuate a building in the event of an earthquake.
3. Hospitals have a complex network of electrical, mechanical and sanitary facilities as well as a significant amount of costly equipment all of which are essential both for the routine operation of the hospital and for emergency care. Failure of these installations due to a seismic event cannot be tolerated in hospitals as this could result in its functional collapse.
4. The ratio of the cost of nonstructural elements to the total cost of the building is much higher in hospitals than in other buildings. In fact, while nonstructural elements represent approximately 60% of the value in housing and office buildings, in hospitals these values range from 80% to 90%, mainly due to the cost of medical equipment and specialized facilities.