Research on the acceleration of settlement by installing vertical drain and preloading with sand

Abstract

The container yard, which facilitated the Container Terminal of the Jakarta International Container Terminal (Terminal Peti Kemas Koja), at Tanjung Priok Jakarta is located on a land which the subsurface soil is predominated by a compressible clay layer, from 5.00 to 22.00 m depth. The load from containers quite high and will stay for a long period. Without soil improvement, the estimated consolidation settlement is 1.418 m, which will take place in a very long time. Soil improvement has carried out by accelerating consolidation, by installing vertical jute fiber-drain, and loading the soil by a preload of sand to elevation of +8.50 m. To investigate the effectiveness of the installed vertical jute fiber-drain, geotechnical instruments also installed, which are settlement plate, standpipe piezometers, pneumatic piezometers, magnetic extensometers, and inclinometers. Vertical jute fiber-drain is a Prefabricated Vertical Drain (PVD) made of natural jute fiber and coconut coir designed to accelerate consolidation of soft clayey soil. It has high tensile strength to withstand installation stresses and excellent water discharge capacity. The cross section of natural fiber PVD measures 80-120 mm in width and 8–12 mm in thickness and have a tensile strength of above 7 kN. The present drain differs from the others drain is that its manufactured in existing jute mills machinery, the manufacturing process entails low energy consumption, and has capability of varying the width, thickness and weight per linear meter to suit different soft clayey soil conditions. An important feature of the jute burlap is its swelling nature that allows it to function as filter without clogging and it's biodegradable, hence environmentally friendly.