Demolition of Building Structures

Demolition of a building is the process of dismantling or destroying a structure after its life of serviceability by pre-planned and controlled methods. It is the science and engineering in safely and efficiently tearing down buildings and other artificial structures. The tallest planned demolition of a building was the 47-storey Singer Building in New York City, built-in 1908 and torn down in 1967–1968 to be replaced by One Liberty Plaza

Building Demolition methods:

There are two types of demolition methods used for buildings and structures, Non-explosive demolition and Explosive demolition. In the non-explosive method, demolition of a structure is done with some equipment, without the use of any explosive. In contrast, in the explosive method, demolition is done with the help of bombs and explosives.

Building Demolition Process:

Different steps are involved in the process of demolition of building structures. They are:

1. Surveying

2. Removal of hazardous materials

3. Preparation of plan

4. Safety measures

Surveying:

Building surveying and Structural surveying are the two types of surveying that are mainly conducted. In a survey of buildings for demolition, we analyse the type of construction material used and the usage of building prior and present during demolition. The presence of wastewater, hazardous materials, matters arising from toxic chemicals, flammable or explosive and radioactive materials, and others are checked. While in the structural survey, we check the construction method, the structural system and structural conditions of basements, underground tanks and vaults, the original structural system employed in the design, and the condition of the building, among others.

Removal of Hazardous Materials:

If hazardous materials like asbestos minerals, petroleum contamination, and radioactive metals are found in the investigation of the site for demolition. Specialised personals are called for the removal of hazardous materials from the site prior to the demolition of the structure.

Preparation of Demolition Plan for Structures:

A comprehensive demolition plan is made, which exemplifies the different process involved, such as the location of the building to be demolished, the distances from the building to be demolished to its adjacent buildings & streets, the structural support systems of the building. And also, a plan showing the procedure for the demolition of the building, a detailed sequence of demolishing structural members, and the method of demolition to be adopted is prepared.

Safety Measures during Demolition of Building Structures:

All the workers, site supervisors and engineers, including plant and equipment operators, are briefed with the potential hazards and demolition processes. All goods that are flammable, like timber, fuels etc., are removed from the site and stored in proper storage facilities unless required in the work involved. Fire fighting appliances are stationed in the demolition site till the process is completed.

WRITTEN BY:-Shailesh and Ayusha