ANALYSIS AND DESIGN OF STONE COLUMN FOR LIQUEFACTION MITIGATION AT LOMBOK, NUSA TENGGARA BARAT

• Main Author: Mardiansyah, Arief
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/33608
• Institution: Institut Teknologi Bandung

An earthquake is a natural phenomenon that can cause damage to nature and the location of human civilization. As a country surrounded by active tectonic plates, Indonesia is very vulnerable to damage caused by earthquakes. Liquidation is a phenomenon that arises as a result of an earthquake. The purpose of this study was to design and analyze soil improvement with a stone column as a liquefaction mitigation effort. This research was conducted in Lombok, West Nusa Tenggara, Indonesia. The approach in this study is qualitative and quantitative. Qualitative analysis is carried out with historical criteria and geological criteria. Quantitative analysis is done using the simplified seed method. Based on the qualitative analysis of liquefaction potential, it was concluded that Lombok had the potential for liquefaction. From the results of qualitative analysis, analysis of the potential of liquefaction is carried out qualitatively. Where the quantitative liquidation potential analysis criteria used is if the FS value <1 then the location has the potential for liquefaction, and if the FS value > 1 location is not potentially liquefied. Based on the results of the quantitative analysis of the potential of liquefaction, the study location has a high potential level of liquefaction. The analysis was continued to determine the depth of the soil that must be repaired at the study site. the results of the analysis show that the soil depth that must be repaired is 15-16 m for conditions soil improvement using LPI method, and 10-12 m for conditions soil improvement using Ishihara method. Both of these depth criteria are then used for the stone column design parameters at the study site. The results of the analysis and design process carried out obtained configuration for soil depth criteria for soil improvement using LPI method is: stone column diameter = 1 m, space between columns = 1.7 m, with triangular equilateral pattern. While for the depth criteria for soil improvement using Ishihara method, the configuration of the stone column with a diameter of 1 m is obtained, the distance between 1.8 m spacing between columns, and the triangular equilateral pattern.