ABSTRACT
This paper presents the study case related to combination of geosyntethics used as riverbank slope normalization located in Cimanggis residential area, West Java, Indonesia. The combination of gabion, geogrid reinforcement combined with wiremesh facing and geocomposite of geotextile non woven-geogrid slope protection were applied along the section of the riverbank slope. The riverbank slope section spans 390 meters along Cikeas river where it will later become access road and near the crest will be constructed housing area. Slope stability analysis was conducted to determine the value of the slope safety factor with the aim of concluding what preventive and security measures could be. From the results of the analysis, it showed that the 13 meters high slope of the Cikeas river's safety factor was below the criteria stated in Indonesian National Standard for Geotechnic Design Requirements with a safety factor 1.20 (the slope safety factor must be above 1.50). The combination of geosythetics were applied in the program and yield the safety factor up to 1.613 which indicated safe slope. This design also considered the earthquake pseudostatic load, where the result of the safety factor was 1.103 and fulfilled the criteria stated in Indonesian National Standard for Geotechnic Design Requirements (the slope safety factor must be above 1.10). The combination of those geosynthetics application worked effectively for normalizing the river bank slope.
