CISUMDAWU HIGHWAY SECTION 4 OPEN CUT SLOPE STABILITY ANALYSIS DUE TO BLASTING VIBRATION WITH NEWMARK DISPLACEMENT ANALYSIS

• Main Author: Adib Ardhana, Zharfan
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/63061
• Institution: Institut Teknologi Bandung

Section 4 Cisumdawu Toll Road was built by carrying out blasting activities. Blasting could affect slope stability, so it is necessary to find the value of the Factor of Safety (FoS) dynamically. The analysis was conducted using 2D numerical modeling with Slide2 software for Limit Equilibrium Method (LEM) and RS2 software for Finite-Element Method (FEM). Dynamic FoS was analysed using Newmark Displacement Analysis. Newmark Displacement Analysis was able to input the parameters of acceleration towards time graph from blasting vibration. With acceleration waves towards time, we can create FoS waves towards time. When the FoS slope is below 1, it will cause displacement. The value of the acceleration that makes FoS equal to 1 is called the critical acceleration. When the seismic acceleration surpasses the critical acceleration, an instability area will be formed. With double integral to the formed area, the displacement value may be obtained. In addition to the Newmark Displacement Analysis, the analysis was carried out utilizing the Strength Reduction Factor (SRF) method. SRF reduces the resisting force on the slope by reducing the cohesion value and friction angle. The larger the SRF, the greater the displacement that occurs. The SRF value is the FoS value when the slope is unstable. The unstable slope parameter is determined by the critical displacement value. The critical displacement used is 5 mm for conservative findings and 50 mm for optimistic findings. The results of the Dynamic FoS obtained are 17.6 for a critical displacement of 5 mm and 19.6 for a critical displacement of 50 mm.