Stability Analysis Of Slope Excavation In The Sutet Area With A Combination Of Soil Nailing And Ground Anchor Reinforcement

GHEOTECNIC

Abstract

ABSTRACT

This study examines slope stability on the IKN Toll Road Section 3A project (STA 15+250–15+325) adjacent to the high-voltage transmission line (SUTET) area. Land limitations necessitate a special excavation design with steep slopes, making slope stability analysis crucial. The objective of this study was to analyze the factor of safety (FS) of the slope before and after reinforcement using a combination of soil nailing and ground anchors. The research method included secondary data collection in the form of SPT data from boring logs (BH-11, BH-11A, BH-T4, OP1-BH4) at a depth of 60 m and limited laboratory test data. Soil parameters not available from laboratory tests were determined through empirical correlation. The stability analysis was performed using the Bishop method (manually) and Plaxis 2D software. The results of the study showed that the unreinforced slope had FS <1.5 (unstable according to SNI 8460:2017) both in manual analysis (FS = 1.227 without earthquake; FS = 1.123 with earthquake) and numerical (FS = 1.282 without earthquake; FS = 1.102 with earthquake). The application of soil nailing and ground anchor reinforcement was able to increase FS by 48.8% from before reinforcement, which was FS = 1.908 from the results of numerical analysis, so that the slope was declared stable according to the SNI standard FS ≥ 1.5. This study shows that the combination of soil nailing and ground anchor can increase slope stability in toll road projects in limited areas, and can be a reference for slope reinforcement design in similar cases in the future