Category: Protection of Buildings

1. Objective Bureau of Indian Standards IS: 13920 : 1993 recommends for special design to ensure adequate toughness and ductility (with ability to undergo large inelastic reversible deformation) for individual members such as beams, columns and walls and their connections and to prevent other non-ductile types of failure. As a general rule, to maintain overall…

Bureau of Indian Standard have specified the minimum design requirements for earthquake–resistance design in IS codes: 1893 (Part I): 2002, IS: 4326: 1993 and IS: 13920: 1993. These requirements have been stipulated after considering the characteristics and probability of occurrence of earthquakes, the characteristics of the structure and the foundation and the amount of damage…

During an earthquake, ground motions occur in a random fashion, both horizontally and vertically, in all directions, radiating from the epicentre. The ground accelerations cause structures to vibrate and induce inertial forces on them. Hence, structures to be constructed in earthquake-prone areas need to be suitably designed and detailed to ensure stability, strength and serviceability.…

Varying geological conditions at different locations of the country may have at any time damaging earthquakes to occur. Thus there is a need for seismic zone map of the country so as to design structures taking into effect the magnitude of earthquake likely to occur at a particular location. Figure 29.6 Location of epicentre from travel-time…

Earthquakes may be caused by natural reasons or due to man-made activities. Natural causes are tectonic forces or volcanic eruption and man-made activities such as reservoir-associated forces. 1. Tectonic Earthquakes Earthquakes are mainly caused due to sudden movement along faults which in turn due to tectonic origin. Such earthquakes generally result from sudden yielding to…

Lightning protection should be provided in the following areas: The lightning-protection system consists of an unbroken chain of conductors from the roof of a building to the ground. This provides an easy path for the heavy electrical power released by the lightning to discharge to the earth in the shortest time possible. The conductor should…

Apart from the steps taken in construction of buildings the following general measures of fire safety have to be adopted. 1. Alarm Systems Alarm systems are installed with a view to give an alarm and to call for assistance from neighbours in case of fire. As per the saying ‘prevention is better than cure’, the…

All building should satisfy certain safety requirements against fire, smoke and fumes. 1. Maximum Height The height of a building is restricted depending on the number of storeys, the number of occupancy and the type of construction. Furthermore, all the above factors in turn depend on the width of the road in front of the…

Bureau of Indian Standards (BIS 1641–1968) has graded the structural elements into five grades with respect to ‘time in hours for resisting standard fire’, as shown in Table 29.2. Table 29.2 Fire resistant grades National Building Code graded type of construction into four categories as Type 1 to 4 as given in Table 29.3. Based on…

The amount of heat liberated in combustion of any content or part of the building of a floor area is referred to as fire-load. It is represented in kilojoules per square metre (kJ/m2). The fire-load is the ratio of the weight of all combustible materials (by their respective calorific values) to the floor area under…