SOFT SOIL IMPROVEMENT USING PREFABRICATED VERTICAL DRAIN (PVD) (Study Location of Grand Island Pakuwon City Surabaya, East Java)

Study Location: Housing Development at Grand Island Pakuwon City Surabaya, East Java

Abstract

Planning on the construction of a two-story Grand Island Pakuwon City Surabaya housing area of ​​+/- 3.4 Ha with the existing land elevation being at +0.00 from the local BM and the embankment elevation plan at +3.00 m, apparently must be built on silt clay with a very consistent consistency soft. The purpose of this study is to find out the optimal installation pattern, size, distance of PVD, preloading load system combined with PVD to produce the fastest soil repair time and determine the effect of using a combination of preloading and PVD systems in clay soil improvement on the time of decline , the degree of consolidation and the amount of decline caused.

The topsoil that will be compressed is the very soft clay silt layer, that is, clay soil which has a value of qu <4.8 t / m2 or N value <4. At the study site, the soft soil layer is located at a depth of 16 m. The data needed is soil data (drill log), load received, elevation of building plans, pile soil data. The method used is the preloading method combined with PVD to speed up the consolidation process. You do this by giving a load in the form of pile on soft soil that has previously been installed PVD.

From the results of the calculation of soil improvement using the preloading method combined with PVD it can be concluded that the time of land subsidence can be accelerated and can increase the carrying capacity of the soil. PVD with a triangular pattern of a distance of 1 m to a depth of 16 m obtained a decrease time for 78 weeks compared without soil improvement where the decline time was obtained for 22 years.