|Mitigation of Disasters in Health Facilities: Volume 3: Architectural Issues (PAHO)|
|Chapter 5: mitigating nonstructural damage|
|Reduction of vulnerability|
The selection of facings and finishes in a hospital is not only concerned with esthetics and durability but also with the mitigation of risk. This is very important because it is not only a question of the hospital failing structurally, but also of its finishes, walls, doors, windows, and ceilings, etc., remaining in place so that they do not become a danger to life or hinder the movements of patients, medical and paramedical personnel, and all other people in the building or those that enter the building in a time of disaster.
Ceilings are usually hung from the structure or floor slab of the building, and in hospitals this is an almost unavoidable feature, since the space formed between the ceiling and the floor slab houses the water, electric power, and gas networks. For this reason their construction should be as technically perfect as possible in order to avoid their becoming detached during an earthquake and posing a threat to the lives of the users of the building. The specifications of the ceiling should comply with aseptic standards and be made of non-flammable materials, that are light and capable of resisting movement. One of the recommended materials that fulfills these conditions and also serves as an acoustic and thermal insulator is fiberglass.
Nevertheless, areas exist whose functions do not permit the use of this kind of ceiling because of the rigorous necessity for asepsis. Examples of this are surgery and obstetrics areas, laboratories, humidification therapy, and kitchen and laundry areas for which thought must be given to solutions similar to those proposed, but with finishes that ensure asepsis, such as enameled materials and epoxy paints.
There is sometimes a need for sacrificing aesthetic considerations in order to meet the needs of mitigation; this is true in the case of roofs, especially in buildings for horizontal hospitals. A tile roof is quite heavy, which makes the roof more vulnerable to earthquakes; in addition, it contains multiple small elements that in falling would threaten the lives of the building's users.
Facades are commonly made of materials that may become detached during an earthquake. These materials, mostly of ceramic, also represent a threat to the lives of the users of the hospital. In order to mitigate this threat it is recommended that structural materials be used on facades, such as open-faced brick.
Most finishing pieces are also prefabricated and affixed to the facade. These elements are the first to fall in strong earthquakes, with all the attendant dangers previously mentioned. In order to avoid these risks,
· Anchorage should be firm in order to ensure
· Solid materials should be used on building fronts.
Very large glass surfaces are dangerous in the event of earthquake, since they can be converted into weapons that threaten the lives of the users of a building. Designers can specify safety glass and/or reduce the size of panes. Flagpoles, signs, and pergolas are attached to the building, and consequently should be very well anchored to the masonry or the structure to avoid becoming additional risk factors.
There is a trend toward the use of prefabricated elements for railings on balconies, and in most cases sufficient anchorage is not specified for them to be integral elements of the building, increasing their likelihood of becoming detached. This is also true of other railings and banisters, etc. Such elements should be firmly anchored to the masonry or to the structure to prevent the risk of detachment.
Some designers decide to hang flower boxes on building facades, thereby increasing loads still further. These kinds of elements should not be used in hospitals.
Large spaces, such as entrance halls, are often lighted by means of hanging panels, which must be well anchored to the structure and overhead floor slab in order to ensure that they will remain in place when the building is subjected to strong movement.
At the present time large canopies are used in solariums, which in most cases are finished with glass and are extremely dangerous. Although acrylic or plexiglass panels are not fully safe, they can nevertheless be used with a greater degree of reliability in order to avoid the risk of accident when telluric movements occur and the components of the canopy fall.
There are many nonstructural finishes in building interiors that become additional risk factors for the users of the building, such as moldings, cornices, stucco ornaments, etc. In a great majority of cases they are attached to walls or columns, thereby constituting an additional hazard. It is recommended that a minimum number of such elements be used, and if they are used, that they be built as an integral part of the structure.
Hallways in hospitals often have wall protectors, which are usually made of wood and are attached to the walls with bolts every 50 or 80 centimeters. Special care must be taken to anchor these wall protectors to the wall to ensure that they do not become an obstacle and constitute a danger to free circulation.
Most hospitals have sign panels suspended from the floor slabs, particularly in information areas, nurses' stations, and at counters where the public is received. It is recommended that designers and builders propose designs that will provide more guarantees of safety and carefully specify the type of anchorage that should be used.
Materials that provide durability and asepsis are usually specified for hospitals, mostly in the form of enameled ceramic. These materials should also be firmly fastened to the wall in order to prevent detachment by seismic vibration. Although the danger of such materials causing accidents to users is minimal, they can become obstacles for the movement of hospital staff.
The situation is similar with regard to tables, mirrors, and furniture hung from the walls. It is important to take into account how they are anchored to or hung from the walls. In the case of furniture, it is recommended that wherever possible it should be embedded between walls and anchored, if possible, on both the sides and backs.
Hollow brick or cinder block is usually employed in nonsupporting walls between the structural support axes. Their collapse could cause injury or death. Consequently, the walls should be contained or interlocked in such a way that they provide better stability, as mentioned in the preceding chapter.
The same is true of spaces designed as open office cubicles, as they are made up of panels and shelving partitions. In some cases the furniture forms part of these partitions, which in falling can cause not only injury but also block traffic and evacuation. It is recommended that these partitions be secured above and below in order to provide a greater degree of safety and thus be able to avoid the risks referred to above.
The infinite range of factors that should be considered for the purpose of mitigating architectural risks is left to the reader's imagination.