The investigation team discovered several main factors which contribute to the building collapse after investigate the disaster site.
The causes are:• The land is not suitable for construct multi-storey building. • Quality of the construction materials is poor.• The load supported by the building is exceeding its original design limit.• The enforcement and regulation of building codes is poor.• The demand of garment market is high.Based on Whearty et al (2014), the ground for this location is unfit for construct a multi-story building. The ground of the Rana plaza originally was a swampy land with a small size pond. Dietz (2014) said the composition of the soil for the plaza land was not stable and caused uneven settlement of foundation.
This is the reason why the soil is not strong enough to sustain the building weight. The materials used to fill in the swamp land ware trash and rubbish. To avoid the inspection, the owner bribed the officials in order to get the construction permits. He also bribed a few engineers and local authority to sign and approve the project. Hence, the structure was weakening because of the differential settlement which caused by poor strength of soil.The team discovered that the quality of the cement and iron rods used to construct the plaza was poor. This is because they want to cut down the cost of the project.
The cement was weak brittle for the building because it mixed with too much sand. The depth of the subfloor is casted too thin and causing it unable to support the building loads. The subfloor can’t sustain the load because it did not have the necessary strength and depth to distribute the load equally. The reinforced steel used in the concrete also was cut down to decrease the budget of the project.
Less reinforcement steel bar was fixed in the concrete had decreased the overall concrete strength and made it suspected to more tension loads. Besides, Dietz (2014) said that smooth bars were chosen as the reinforced bar material. The smooth bars can’t form a strong connection with aggregates compare to the textured bars. The connection of textured bars with aggregates is strong and it can support more tensile force within the concrete. Thus, the structure was weak due to the low quality cement and smooth bars (Whearty et al, 2014). The original design of the plaza was planned to build a four story height retail and office building.
Nevertheless, additional four floors were added illegally to the building. It also noticed at the time of collapse ninth floor was under construction. Based on Mothlagh (2014), Sohel successfully obtained the approval for the extra floors from the local authority through extortion and bribery. The illegal extra floods construction caused the building sustained tremendous stress which over its original design limit. In addition, the building was proposed to handle the loads for office and retail.
In the end, only first and second floor occupied by the retail shop and banks whereas third until eighth floors were used as a garment factory. Therefore, the structure was suspected to support larger loads that caused by the heavy sewing machine, workers and large stock of fabrics and garments (Whearty et al, 2014). Figure 3.2 below shows the uniform design loads stated in the Bangladesh National Building Code. By referring to figure 3.2 the uniform load for manufacturing category was twice larger than the office and retail types. Furthermore, on the roof of the Rana plaza four diesel generators were installed in there to back up the electricity for the building.
On 24 April, the electricity of Rana plaza has been cut down so they activated the generators. The structure began to shake when the generators activated and jeopardize it further. The vibration caused the ultimately unsettled building and led the progress of collapse.The corruption and politic in Bangladesh had played an important character throughout the construction industry. The building owner can easily influence or convince the officials or local authority via bribery to get whatever they want. For this cases, the building owner Sohel Rana using his wealth and connection to political allies to bribe the official’s approval to build a structure on swampy land, add extra floors without consider the design limit, obtain the construction permits and force the garment workers goes back to work (Motlagh, 2014). This disaster had led to thousand workers death and all this happen because of the greedy of the Sohel. Although the building code of Bangladesh stated that all the new construction building must apply for and obtain a certificate of occupancy from the government agency.
But the building code is rarely followed by the owner. For instance, since 2008 only six buildings have been issued properly despite more than 4000 building were constructed in Bangladesh every year (Whearty et al, 2014). These despites that the corruption level in Bangladesh is still very high and the owner building tried to take advantages of this system.
The demand of cheap jeans, shirts and dresses is higher. This is because all the consumers around the world are demanding to buy cloth and other merchandise with lowest price. They will not care where the products are from. Due to this demand, corporations tried to put more pressure to the factory manager in order to increase the productivity. The factory manager will force the workers to work for long time and pay low salary to them especially in Bangladesh. This demand led to Sohel Rana had made wrong decision and resulted thousands of people death because of his greediness (Motlagh, 2014).