Contemporary building regulations are effective in ensuring the safety of occupants throughout the life cycle of the structure. Government agencies have the responsibility of inspection to ensure safety and enforcing compliance to regulations and codes during constructions. Building design and construction methods evolve in response to emerging trends and demands in the industry. Advancements within the design and construction industries transform the demands and orientation of structures as per the consumer demand.
Building designs and construction methods have associated types of collapse. Designs and construction methods determine the gravity resistance system of buildings. Different building designs and construction methods have related hazards from the collapse of structures.
Fire resistive buildings
Fire resistive building designs integrate the application non-combustible materials in construction. This prevents the construction materials from adding to the fire load and smoke within and spread from the building. Construction materials used in this design of buildings should conform to the provisions of the international building code, 2006. They should meet the fire-resistance ratings for both exterior and interior walls. Structural stability is vital to avoid possibilities of structural collapse. Fire resistant materials such steel components enclosed in concrete that are resistant to collapse because of their strength are applicable for constructing this building design. Firewalls made of non-combustible materials are important for the safety of the occupants.
Although concrete is strong and resistant to collapse, its construction should last for an approximate time of one month to cure. Most constructors and sub-contractors, however, rarely allow this time for concrete to fully cure for best resistance against collapse. Construction always takes a fast pace and does not allow space for strong concrete that is resistant to collapse. This is a reason for the failure of most frameworks. Pre-cured concrete used in other floors may fail to support subsequent floors and causes a failure in formwork. Floors that are not strong enough to support the upper floor causes a collapse. Other sources of hazards related to concrete buildings involve failure of joints to support the weight of the slabs. Connection points that are weak can cause serious cracks and exposure supporting steel. This can lead to collapse of the entire structure of a particular floor affected by the weakness in the joint. Joints are among the most inspected point in a structure since they can be sources of collapse from weak constraints.
Non-combustible building structures
Non-combustible building designs are effective in avoiding possible collapse of buildings from fire accidents. Non-combustible building construction methods have a structural steel used in their construction. The international building code, 2006 requires this design of buildings to have an enhanced fire protection coating using resistant sheet rock. There are lightweight steel bar joints embraced in the building to enhance the corrugated steel. Non-combustible building designs are notably resistant to collapse.
Roof failure is among the causes of collapse of most no combustible structures. International building code, 2006 allows the use of treated wood framing that are resistant to fire in the interior of the building. Non-combustible building design is suitable for large commercial occupancies. Large commercial occupancies require ample space to construct structures as malls. Large mall buildings also require large window frames on the sides. Windows of large structures have steel support used to sustain the walls. Steel lintel used to make the windows are important in enhancing the resistivity of the structure against possible collapse. If the steel lintel does not support the structure, it is highly susceptible to collapse because of a weak parapet wall.
Ordinary construction structures
Ordinary construction structures have walls of masonry construction of heavy loads and can also may consist of parapet wall. Ordinary buildings have wooden floors and roofs. The walls should be strong to support the roof weight. When walls are not properly braced weak fractures may occur and cause part of the building to collapse. Spreader sheets placed on masonry walls should be able to provide utmost stability. Ordinary buildings are prone to collapse when spreader sheets get displaced.
Heavy timber structure
Heavy timber structures have thick masonry walls that render them resistant to collapse. When these structures stay for long without renovations, joints may become weak. Weighty timber truss may also cause collapse once the joints become weak. Should roofs fail, the from rear wheels may break to cause a collapse of part of or the entire building structure. The collapse may be violent and dangerous.
Wood frame structures
Building designs may include structure made of wood frame. Wood frame structures entirely consist of wooden parts. Varying wood size is applicable in the construction of the walls, floors and roofs. There are different designs used to make wood frame structures. Braced frame structure is a building design that consists of vertical posts connected to horizontal beams. Balloon frame designs have wall studs with uniform continuity from the foundation upwards.
Wood frame structures are not very vulnerable to collapse but improper and quick building may pose a threat to residents. In most cases, constructors give little consideration to setting up a strong floor that can support the entire wood frame structure. The load from upper floors may be too heavy and cause a collapse of the building. Built-in-compensations are important to provide extra support for the building. Built-in-compensation are important to avoid collapse of wood frame structure by supporting the wall's weight. Collapse may occur when the wood weight exceeds the resistivity of the floor.
High-rise building designs have high-risk of spread of fire (Mohammad, 2009). However, well-built high rise buildings are only susceptible to the risk of fire induced collapse in extreme conditions. Extreme fire conditions were the cause of the world trade center collapse, for instance. High occupancy density decreases chances of escape from high-rise buildings during an emergency because of crowdedness. Occupants in the upper floors have a challenge during escape because of the height and possible obstruction to the egress system. Design configuration of high-rise structure may increase the occupants' vulnerability during fire emergencies. Smokes move through open shafts into rooms and cause suffocation (Mohammad, 2009).
Ultra high rise buildings should have vertical transportation facilities as elevators that function efficiently. Structural modifications should integrate shock absorption designs. Their designs should also embrace anti-seismic facilities to guard against earthquakes. Resistivity to possible collapse from wind is vital for the safety of occupants. Fire control facilities and refuge floors should be present in all ultra high-rise buildings. Fire alarm systems installation in high rise buildings is essential.
Building regulations and codes
The failure of most structures and building and the rampant collapse emanate from the building feature that render structures unsafe during construction and to the final occupants. Sustainable buildings are safe throughout their life cycle, from construction to occupation. Building codes prevent progressive collapse through performance-based set standards for contractors and sub-contractors. The U.S. leadership in energy and environmental design (LEED) rating system encourages stakeholders to put up sustainable building structures that encourage occupational safety of residents. The LEED certification program came into effect in 1998 and operates through a prevention through design (PTD) program. Implementation of the program helps in the mitigation of risks in the early stages of the development. OSHA law and regulations are also important in preventing the rampant collapse of buildings and instill safety during construction and occupancy.
The OSH Act renders employers responsible for setting up safe working conditions during constructions and compliance to building standards. The OSHA general duty clause requires employers to keep their employees safe from hazards related to the constructions. Standards set for all contractors and sub-contractors include provisions to provide training and outreach programs. Provision of education and assistance is also essential under the act. According to Randall, 2005, the impact of OSHA in the building industry was notably the most influential. It reduced the number of fatalities from accidents in during building and construction. OSHA addressed concerns of roofing elements that caused a high number of fall accidents through the introduction of fall protection measures (Randall, 2005).
Changes in building codes
After investigations into the tragic 9/11, the institute of standards and technology recommended a change in building and fire codes (Bukowski, Jensen & Laurel, 2012). Changes aimed at creating buildings that residents can easily evacuate in cases of emergencies. The new codes approved by the international code council (ICC), aimed at ensuring public safety. According to Ling and Soh, 2005, reforms on the codes addressed concerns of safety against fire and collapse. Reforms in the building codes aimed at improving structural resistance. New codes aim at ensuring high resistivity of building against fire accidents. Tall buildings should have third stair cases for exit during emergencies. The new regulations also aimed at improving the material technology used in tall buildings (Ling & Soh, 2005). The materials used should have the resistivity to withstand extreme temperatures.
New codes provide for an expansion of staircases in high-rise buildings. Improved bonding criteria constitutes an important aspect of the reforms…