Perbaikan Tanah Lunak Kombinasi Preloading dengan Prefabricated Vertical Drain Studi Kasus Rencana Tanggul Lapindo Porong

Abstract

Sidoarjo mud is a volcanic mudflow disaster which until now still emits massive mud, therefore the PPLS plans to increase the construction of the embankment on the east side of the main embankment area to increase the strength of the embankment so that it can anticipate if one day there is an overflow so it does not penetrate the area. other. In the previous soil investigation stage, it was shown that the embankment area had subgrade with a relatively small N-SPT value with a thick soft soil layer up to a depth of 30 meters. The construction of this embankment is planned to be built on subgrade conditions which are classified as soft soil so that in the process before the construction of the embankment is very necessary with the improvement of the subgrade.The method of improving soft soil with thickness is proposed using a combination of preloading with PVD to accelerate settlement.To obtain a design height of 5.50 m, the required initial embankment height is 6.77 m with a compression of 1.307 m. The preloading system without the combination of PVD the time a consolidation degree of 90% (U = 90%) for 82.34 years. While the combination preloading system with PVD size 10 x 0.5 cm with a rectangular installation pattern and installation distance (S) 0.80 m, the time consolidation degree 90% (U = 90%) for 3 weeks. Implementation of gradual hoarding at a rate of 0.5 / week for 14 weeks