COMPARATIVE STUDY ON SOFT SOIL IMPROVEMENT DESIGN BY USING PREFABRICATED VERTICAL DRAIN WITH GEOTECHNICAL INSTRUMENTATION CASE STUDY RESIDUAL FLUID CATALYTIC CRACKING PROJECT PT. PERTAMINA REFINERY UNIT IV CILACAP

• Main Author: ADJANI (NIM : 15009026), ALYSSA
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/20994
• Institution: Institut Teknologi Bandung

Every single infrastructure development activity is implemented on the ground. However, it is frequently encountered soil with poor conditions on some construction sites. This kind of soil has a low bearing capacity and a huge tendency to subside when being subjected to a certain load. This phenomenon becomes a serious problem since the soil must be able to withstand the ultimate given load, so that the desirable structure can stand firmly without experiencing any significant post-construction settlement. There are many ways that can be carried out on-site to improve the existing soil quality. One of the most popular soft soil improvement methods available nowadays would be the combination between preloading and the usage of synthetic vertical drainage. <br /> <br /> <br /> <br /> This Final Project emphasizes more on the comparison and analysis on soft soil consolidation settlement that occurs through some different calculation methods. Those settlement calculation methods are performed using one-dimensional Terzaghi method, Finite Element method by using PLAXIS 8.2, and verification by Asaoka method using field geotechnical instrumentation. Field observation data that were obtained in this Final Project include the field settlements from Settlement Plate, pore water pressure generation from Piezometer and lateral ground movement data from Inclinometer. The main source of these data is derived from field investigation and geotechnical instrumentation of the Residual Fluid Catalytic Cracking project in Cilacap, Central Java. <br /> <br /> <br /> <br /> The comparison shows that, with a same load and PVD spacing, the predicted settlement calculations by using Terzaghi method, PLAXIS 8.2, and Asaoka method produce different soil settlement values for a certain Area. The generated differences are solely caused by different principles applied in calculations for each method used. Terzaghi method only takes into account the vertical deformation that is based on the principle of one-dimensional consolidation. In addition to manual calculation, it is assumed that the designed load is considered as a distributed load. PLAXIS 8.2 calculates horizontal and vertical deformations by using 3-dimensional Biot consolidation theory, while the Asaoka method considers the three-dimensional consolidation based on the actual data obtained from the field.