Comparative of flat slab type raft foundation taking into account of difference building code and design methodology

Abstract

This project report was carry out the existing project of one storey of the warehouse at Meru, Klang. This warehouse was built in 1991 and the superstructure of this warehouse with size area 150 m x 25 m is a steel structure with the ground slab. Unfortunately, four of this warehouse is not fully usable due to severe damage to the ground floor. Forensic engineering has been done and found that the ground slab had settled up to 400 mm depth. The foundation failure is the main cause of slab settlement. Soil investigation was done and found that hard layer at ±23 meters depth with SPT 50. The upgrading of the functionality of the warehouse to the hotel laundry will apply new loading based on new equipment. This study will present the comparative analysis of flat slab type raft foundation design using computer software STAAD-Pro and analytical calculation according to Eurocode 2 and BS 8110. The result of the numerical method by using STAAD-Pro show that the differences of BS 8110 are 5.09% slightly higher than Eurocode 2. While the analytical solution the result is 5.16% BS 8110 higher than Eurocode 2. The percentage of comparison for process analysis between STAAD-Pro and analytical solution is 18% due to the result of the bending moment. While for the reaction shown that 10% of differences where the STAAD-Pro result is higher than the analytical solution. Besides that, in term of deflection, the differences of allowable limit is 39.39% where the Eurocode 2 is much higher than BS 8110. The total result between Eurocode 2 and BS 8110 not much different. This report shows that the reinforcement design according to BS 8110 is lower than Eurocode 2 because of the coefficients of BS 8110 used are lower than Eurocode 2 and the technical considerations are more conservative.