Effect of Vertical Drainage Material Variations In Clay Soil Against Settlement Due To Distributed Load

In the building construction, soil has a very important role, which it can acts as the support for building foundation or construction on it. In Indonesia itself, especially in the Klaten Pedan Troketon area has clay soil with a value of PI (Plasticity Index) of 50.20%, and low bearing capacity. To make clay soil have good bearing capacity, this research uses vertical drainage reinforcement with some variation of its material which are sand column, lime, mixture of sand and lime, sand above lime, and lime above sand. Objectives of this study to determine the value of the soil settlement with and without vertical drainage reinforcement. This test uses a box size of 100x40x40 cm which is given reinforcement of vertical drainage and without reinforcement then given a distributed load above the test box and installed with 3 dial to find out the settlement occurred From the test results obtained the largest settlement value occurs in variations that use sand column reinforcement with a settlement value of 5.15 mm, while the least settlement value occurs in variations that use columns containing lime with a value of 2.46 mm. While the variation of sand and lime combination the value obtained is not better than the soil without reinforcement. From these results it can be seen that reinforcement using lime material as a vertical drainage filler has the best reinforcement, because on variations using lime column strength can reduce the soil settlement