Abstract
The East Java Provincial Government seeks to build a new road network in the form of the Surabaya West Outer Ring Road (JLLB) which has a length of ± 19.8 km with a width of 55 meters. It is expected to break down congestion in the center of Surabaya in order to facilitate access of the population and increase economic growth.The soil condition at this location is soft clay soil which reaches a depth of 21 meters, Soft soil itself has properties that are not technically profitable to support a construction work. In general soft soil has a low carrying capacit, Low permeability and high compressibility cause this land to experience a very large decline and require a long time. One alternative soil improvement to overcome this problem is a combination of preloading methods with prevabricated vertical drain. This method is carried out by overloading the ground with an initial load greater than or equal to the planned building load. This study aims to accelerate the process of land consolidation in order to increase the carrying capacity of the soil so that road construction using heaps can be carried out and analyze the efficiency of the budget plan. Based on the analysis results to reach the final heap height of 4,949 m, Hinitial is needed for 6.78 m with a total land subsidence of 1.81 m, prior to a very long 100-year consolidation period. So that it is planned to use PVD with a triangular pattern, the distance between PVD of 1 meter with a length of 12 meters which is able to accelerate the time of consolidation of land at U 90% with the final time of compression process 7.5 weeks. Because Hplan > Hcr requires hoarding in stages (Stepped Preloading) with an increase in carrying capacity of 9,896 t / m2 gives a safety figure of 1.65 > 1.4 that is permitted. The total construction cost needed is Rp. 1,124,286,000.00.
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