The Effect of variations in PVD installation distance and thickness of soft soil layer for the degree of consolidation and time of consolidation at Gunung Anyar, Surabaya

Abstract

Gunung Anyar is one of the areas in East Surabaya which has quite a high indication of the spread of soil clay with The combined Cv is 0.0008 - 0.000125 cm2/s, which indicates long a consolidation time. The appropriate soil improvement method to speed up the consolidation time is to use a combination of preloading and prefabricated vertical drain. Simple statistical analysis was performed to obtain prefabricated vertical drain’s thickness and length in general is 3.33 mm and 100 mm. The analysis consists of the effect PVD installation distance which is 1 m, 1.5 m and 2 m of triangular and rectangular patterns and variations thickness of soft soil clay are 10 m, 15 m, and 20 m. At the same installation distance with different thickness of soft soil layer, the changes of degreethe of consolidation was only <1%. Triangular pattern with an installation distance of 1 m PVD soft soil thickness 20 m, with 90% degree of consolidation the time requirement is 11 – 25 weeks. if soft soil thickness same and the difference in installation distance of 1 m, degreethe of consolidation decreased by 18.32% - 51.05% triangular pattern and 23.75%-45.69% rectangular pattern.