KAJIAN PENURUNAN FONDASI RAKIT DI ATAS TANAH LEMPUNG BERPASIR DI GEDUNG DITRESKRIMSUS POLDA BALI

Abstract

The foundation is the part of the building that transmits the load that is supported into the ground. High-rise buildings are usually built using deep foundations such as piles, but there are also tall buildings built using shallow foundations such as raft foundations. The raft foundation serves to spread the load from the structure to the ground below which consists of a single extending slab. The raft foundation designed in several previous studies was for soft soil with an SPT value of < 10. In the Ditreskrimsus Polda Bali Building which has a basement area and will function as a parking lot, related to this, the selection of the use of raft foundations is carried out even though the SPT value is > 10 and the depth is below 3.5 m is dense sandy loam soil. The planned raft foundation in this building is a raft foundation with thickening at the bottom of the column. The analysis used is a stress analysis that occurs from the sum of all axial forces that occur in each column divided by the total area of ​​the raft foundation plan, with this solution it is expected that the building will become more stable against immediate settlement. Based on the analysis, the dimensions of the raft foundation are 23.65 m x 48.65 m, the plate thickness is 350 mm and the thickness at the critical bottom of the column is 900 mm. The planned raft foundation is safe from the shearing of the puncher. The maximum foundation stress of 82 kN/m² is still smaller than the soil bearing capacity of 335.09 kN/m². The immediate settlement of 13.63 mm is still smaller than the maximum settlement of 65 mm.