Construction World December 2022

AFRISAM INNOVATION AWARD FOR SUSTAINABLE CONSTRUCTION

I dent i fying the need to improve the qual i ty of i ts employees’ work- l i fe balance, private bank RMB planned to consol idate various employee wel l -being of ferings into a new integrated l i festyle faci l i ty bui lding wi thin i ts exi st ing Merchant Place Campus in Sandton, Johannesburg. Structural calculat ions revealed that the load carr ying capaci ty of the exi st ing columns and foundat ions in the basement was insuf ficient to support the addi t ional load f rom the new bui lding. Accompl i shing the aesthet ical ly striking archi tectural vi s ion and cl ient ’s concept for the new bui lding requi red except ional ingenui ty and civi l engineering expert i se. Zutari played a crucial role in bringing thi s wel lness centre to f rui t ion by providing structural , civi l , wet ser vices and sustainabi l i ty consul t ing ser vices . The bui lding was awarded a 4 Star Green Star cert i ficat ion under the Publ ic and Educat ion Bui lding scheme of the Green Bui lding Counci l South Af rica (GBCSA) . Occupants’ heal th and wel l -being and opt imal bui lding per formance are central to the des ign of the bui lding. Strengthening detai ls were developed for the exi st ing columns us ing reinforcement concrete col lars . The exi st ing foundat ions were strengthened by underpinning wi th new micro pi les and pi le caps . The sur face bed was removed to a s i ze that al lowed suf ficient access for the pi l ing rig to instal l the new micro pi les . Exi st ing ser vices in the basements (e.g. , water tanks) could not be moved, which posed addi t ional chal lenges , resul t ing in some of the foundat ions RMB 8 MERCHANT PLACE

having the underpinning pi les instal led eccentrical ly to avoid exi st ing ser vices . Tie beams were introduced to resolve the eccentric loads showing the t ie beam reinforcement . Once micro pi les and the pi le caps were cast , the columns were strengthened. Thi s was done by cast ing reinforced concrete col lars around the columns . To transfer the new bui lding loads to new micro pi les , a new reinforced pi le cap was constructed underneath the exi st ing pi le cap. The load f rom the current pi le cap i s transferred to the new pi le cap through a combinat ion of the bearing of the exposed part of the bottom of the exi st ing pi le cap on the top of the new pi le cap and shear f rict ion (enhanced by dowels) between the shaf t of the current pi le and the new pi le cap. The loads are then transferred to the micro pi les f rom the new pi le cap through a strut-t ie mechani sm. The strengthening work had to be carried out wi th minimal inter ference to the funct ioning of the bui lding and vehicle movement along Bute Lane and in the basements . Al though the parking bays next to the columns and foundat ions being strengthened were temporari ly blocked, most of the basement parking area remained access ible. Zutari was respons ible for ensuring that measures were implemented to mi t igate the ri sk . Thi s included assess ing the addi t ional load on the exi st ing structure during construct ion and the l i fe of the new bui lding and developing strengthening solut ions to enable the structure to remain fi t for purpose. The necessar y detai ls and informat ion requi red for the strengthening of the exi st ing bui lding and the des igns for the new bui lding were communicated

94 21 st Best Project Awards 2022