ANALISIS KESTABILAN LERENG STUDI KASUS DI LAPANGAN GOLF GOMBEL LAMA SEMARANG, JAWA TENGAH

Abstract

Semarang city is a city which has the variety of slope. Besides face some problems like the fload and rob, Semarang also faces the mass movement problem. One of the region that has the mass movement in Semarang is Gombel Lama Semarang Golf Course. The original soil condition in Gombel Lama Semarang Golf Course dominated by clay and supported by the hilly topography condition which attract the mass movement. Otherwise, the change of slope geometry from the original condition which is used to make golf course influence the mass movement happened. This research has purpose to know and learn about the slope stability condition in Gombel Lama Semarang Golf Course and recommend the slope strength method which is right to use. The research method used is the descriptive and experiment methods. The analysis method that is used for analysis slope stability is the limit equilibrium method with Bishop Method. Analysis with Bishop Method is helped by model from Xstabl program.Based on the result of slope stability analysis, the first model condition of slope in research region is to have value of safety factors about 1.321. This value are limit equilibrium value where the condition of slope in research region isn’t safe anymore. In that case, it can be seen from the condition of slope is still have the mass movement. The expedient which have to do for saving the slope in there are with the simulation of parameter change of cohesion and groundwater surface. The simulation of parameter change of cohesion has purpose to strength the slope with grouting method. Otherwise, the simulation of parameter change of groundwater surface has purpose to strength the slope with drainase method. Based on the simulation of parameter change of cohesion and groundwater surface which are used to saving the slope, increasing the relative cohesion value is easier to do well, even though increased groundwater surface parameter more difficult to do and can’t fulfill the criteria of safety factors which definite. In that case, it indicated that from the strength slope method which affective to safety slope in this research is grouting method. Based on the result of grouting calculation, therefore to create the safety slope in Gombel Lama Semarang Golf Course is needed Grouting until depth 22 meter with 3 spation stripes which each has radius about 3 meter.