Demolition by implosion technology of serene towers at Kochi, India

Abstract

In 2006, Maradu Panchayat granted building permits to Serene builders for two towers without Coastal Zone Management Authority approval, disregarding coastal guidelines. Construction began in 2007, featuring two 16-floor towers with 60 apartments, totalling 200,000 sq ft area. Due to soft topsoil, deep bored cast in-situ piles into dense sand at 45m depth were used as foundations. In 2008, a vigilance probe revealed rule violations. Builders obtained a court-ordered stay, and completed the project in 2010. After a prolonged legal battle, the Supreme Court deemed permissions illegal in 2019, instructing the government to demolish the towers. Controlled implosion with delayed detonation was chosen, despite challenges including proximity to backwaters, nearby houses, and a hotel complex. This paper discusses various preventive measures adopted to control blast impact and field vibration monitoring. Tower demolition occurred on January 11, 2020. Ground vibrations were measured using accelerometers placed on concrete blocks. For Tower 1, peak acceleration ranged from 4.92 to 14.18 m/s², while for Tower 2, it spanned 1.38 to 12.75 m/s². An attenuation relationship for peak particle velocity (PPV) was developed to assess damage potential in the surroundings. Vibrations impacts were found to be insignificant due to short duration and varying frequency content.