Slope protection using geosynthetic materials - a case study on the graveyard complex of mataram royal king

This paper presents the study case of landslide occurred at the Imogiri Cemetery, Mataram Royal Kings Graveyard Complex. On March 17, 2019, a landslide occurred, it was expected to have been triggered by heavy rainfall of 148 mm/day intensity. The study was carried out by slope stability modelling using PLAXIS software. Based on the results of field observations and numerical analysis, the type of slope failure that has occurred is a translational landslide. The failure line is between hard soil layer that tends to be horizontal and weak surface soil. In anticipating the occurrence of subsequent landslides, a reinforcement solution is needed with a combination of Geosynthetic and bored pile at the bottom of the slope which functions as a counterweight. The output of this analysis safety factor value is around 1.55 for the static load. This design also considered the earthquake pseudo-static load, where the result of the safety factor was 1.15 and fulfilled the criteria stated in Indonesian National Standard for Geotechnic Design Requirement (the slope safety factor must be above 1.10). The combination of Geosynthetic and Bored Pile application work effectively as a retaining wall because it is a more economical solution, faster and more environmentally friendly.