STUDI PERENCANAAN PONDASI RAKIT PADA GEDUNG RAYZ HOTEL SENGKALING UNIVERSITAS MUHAMMADIYAH MALANG

This is a case study on the raft foundation planning for the Rayz Hotel Sengkaling which was switched from the existing pile to raft foundation. Foundation must be designed to accommodate the bearing capacity and the settlement that might occur to avoid any exceeding of control permit. The bearing capacity and foundation settlement are based on the SPT data (Standard Penetration Test). The analysis was initialized with the upper structure by considering the combination of dead load, life load, and earthquake based on the prevailing SNI. The output of ETABS 2016 program analysis showed the total force on the ground floor was due to the vertical load of 68854.9 kN. The permitted bearing capacity of raft foundation with 1.2 m width and 612 m2 of surface area using Mayerhof analysis was 183.01 N/m2(SF=3). Therefore, the maximum load of raft foundation is 112001.11kN>95384.65 kN which means the foundation met the safety control requirement towards the bearing capacity. The consolidation of settlement on the raft obtained the value of 51.3 cm> 18 cm (permitted settlement) which resulted in the spun pile foundation planning to reduce the settlement. There were twenty-four planted piles which were designed to have a diameter of 300 mm on the depth of 9 meter and were based on the sand layer. From the additional piles, there was a total reduction (S=Si+S) of 10.42 cm< 18 cm that fulfilled the permit settlement control for high-rise building based on Geotechnical RSNI: 178