NEWS JET DEMOLITION IMPLODES THREE HIGH-RISE BUILDINGS IN INDIA

Demolition specialist Jet Demolition has successfully completed a three-building implosion project in the Maradu region of Kochi in Kerala, India. This is not only the demolition specialist’s first project in India, but also marks the first time a high-rise building in that country has been demolished by means of implosion.

PUBLIC SAFETY

The three high-rise apartment buildings were the 20-storey Holy Faith H2O, the 18-storey Jains Coral Cove, and the 16-storey Golden Kayaloram. The former was imploded successfully on 11 January 2020, while the latter two were imploded successfully on 12 January 2020. All three buildings were located within 1.5 km of each other.

A successful business relationship established with Edifice Engineering of Mumbai last year resulted in Jet Demolition being recommended, and tendering successfully, for this flagship project. The major concern of the Indian authorities was the safety of the public in this high-density area and surrounding properties, the closest being a school only six metres away from Golden Kayaloram.

‘Here our trump card was our well-proven methodology and extensive experience in Africa and Indonesia,’ Jet Demolition director Joe Brinkmann comments. The demolition specialist’s answer to protecting the school was to effectively split the 16-storey building into two, thereby collapsing it in two directions in order to avoid the school.

Initial ground investigations revealed the structures had been built on alluvium, or soft soil, in a designated wetland area. This meant the magnitude of the ground vibrations induced by the implosions was sufficiently low not to cause any damage to surrounding buildings.

‘The major factor from an operational point of view was the close proximity. Therefore we had to ensure we had good control in order to mitigate any chance of damage,’ Brinkmann highlights. Another major challenge was the fast-track nature of the project.

RACE AGAINST THE CLOCK

Due to the fact that an urgent demolition order for the three buildings had been issued by the Supreme Court of India for violating building regulations, Jet Demolition had only 2.5 months from inception to successful completion. The fast-track project saw the team work 12 to 16 hours a day, seven days a week. The Jet Demolition team was led by Brinkmann, together with senior site manager Kevin Smit, safety manager Marthinus Botha and site manager Ian Ehlers.

Edifice Engineering provided a local crew of 160 people, while Jet Demolition itself had a 12-person team on-site to carry out the design, engineering management, and oversight of all operations.

The Mumbai contractor has also been tasked to remove all of the rubble following the successful implosions.

With safety being paramount during the implosions, five layers of wire mesh were placed around the columns where the explosives were fixed, followed by a five-layer geotextile cover acting as source protection to contain the rubble. Secondary protection included hanging perimeter curtains on the façades of surrounding buildings in order to contain the dust that was generated.

A total of 600 kg of cartridge explosives was used, in addition to 31 000 m of detonating cord and 5 300 blast holes. Due to the tight timeframe, diamond-drill coring was not feasible. Instead, electric percussion drills were used for drilling charge holes, and was only carried out on certain sections such as the liftshaft walls.

Some 800 national and 300 local police personnel oversaw the evacuation process and traffic control on the day of the implosions themselves. ‘Everything went very much according to plan. A project of this complexity, within this timeframe and to this level of detail would not have been possible without the dedication, co-operation, and support from all stakeholders. Local authorities were elated with the end result, which stands us in good stead of securing additional partnership and collaborative projects of this nature in future,’ Brinkmann concludes. It is estimated India has in excess of 18 000 illegal buildings at present, with the government embarking on a concerted campaign to demolish all structures that do not adhere to the relevant regulations.

The imploding of Jains Coral Cove