Marvella Mall located in Surat consists of Two towers, Two basement floors, Ground floor and Four floors. Flat slab having thickness 200mm was provided with drop panels having clear drop of 200mm by using Monostrand Unbonded Post-Tensioning System. There were four single span P-T beams of 22 mtr. connecting the opposite wings of P-T floor. Post-tensioning was done in approximately 60,000 Sq. Ft. area of Upper basement floor slab and Ground floor slab each.
After some years of construction and putting the building into operation, client was willing to propose a 22 storey high rise on a part of land on which Marvella Mall was constructed. So, according to the client’s requirement, an area of 15,000 Sq. Ft. was required to be demolished from all the floors.
P-T cables pass continuously along the span of this flat slab. So when a certain portion of slab is dismantled, the cables running along that portion were to cut. Hence the remaining length of cables in the non-demolished portion too were to get normalized. Therefore, the remaining slab was propped and re-stressing of cables was carried out to restore them with required force.
Demolition of a P-T slab is a critical event because if not done with proper procedure and precautions, it may end up with undesirable consequences during the demolition. PTSI safely and successfully accomplished such other demolitions too after their construction.