DESIGN AND ANALYSIS OF HOARD WITH MICROPILE TO SURMOUNT THE RECLAMATION SOIL INSTABILITY AT JAKARTA BAY

• Main Author: Wicaksono Wibowo, Bramantio
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/51737
• Institution: Institut Teknologi Bandung

The escalation in population is directly relative to the escalation in the basic needs of the population. The accessibility of a place to stay and shelter is one of the basic human needs. To fulfill the needs, adequate land is required to construct a shelter. In densely populated coastal areas such as the City of Jakarta, the reclamation area is one method of providing land. The coastal area of Jakarta City has loam and soft soil conditions because it is sited at the estuary of the rivers along the island of Java. Based on Geotechnical research, the soil condition has a low level of stability, bearing capacity, shear resistance, and high compressibility. However, if this type of soil is extended out by embankment on reclaimed land, it will be caused large consolidation and in a long periode of time. Hence that a special study is required for reclamation design work. The aim of this study is to analyze and design a reclamation land at the Jakarta Bay, i.e. the determination of the reclamation elevation, designing embankments, calculate the safety factor stability of landfills and embankments, also, conducting design tests using a concrete micropile at the fondation of the reclamation. The whole phase of analysis along with reclamation planning will be modeled using PLAXIS 2D software and completed with calculations. Based on the calculation results, the design elevation of the top of the embankment is +4.31 meters from the lowest water level with an embankment slope of 18.4 °. As for concrete micropile dimensions, a square cross-section size of 0.2 meters x 0.2 meters with a length of 9 meters is used. The configuration of the distance between the micropile columns used in soil reinforcement at the underside of the embankment is 1 meter, whereas at the bottom of the sandpile embankments is 2 meters with a square pattern. The soil reinforcement is also combine by a layer of geogrid and geotextile woven to adding a safety factor value in order that meets the minimal criteria for embankments and reclamation piles on soft soils in the Jakarta Bay area. The results of the modeling analysis, the embankment design which is equipped with soil reinforcement with a micropile, showed the soil stability has increased within a load of embankments with a safety factor value of 1.3. In the process of land subsidence that occurs due to embankment loads, land subsidence due to soil elastic conditions is 0.3 meters, while land subsidence due to the primary soil consolidation process is 1.11 meters. Based from the calculation, land subsidence due to primary consolidation, takes approximately 61.5 years to reach 90% consolidation.