The Effectiveness of Vacuum Consolidation to Soft Soil Settlement

Abstract

The main issue of building constructions on soft soils is not a uniform settlement of soft ground, which has a slow process that effected construction failures and rising maintenance expenses. For many decades, to the improvement of ground soil stability, then applied using prefabricated vertical drain (PVD). Along the development of science and technologies, which followed by improvement of the soil stability method, that is called as Vacuum Consolidation Method (VCM). The objectives of this study are to determine how the effectiveness of vacuum consolidation with various patterns to soft soil settlement of constructions, and to find the right spacing of PVD installation due to un-uniform settlement of soft soils. The analysis of this study compared the numbers and rates of settlements in preloading, PVD, and VCM with various patterns, and to get a uniform settlement by two scenarios analysis, which are various spacing with single suction pressure (scenario 1) and single spacing with various suction pressures. Based on the result of analysis which showed the settlement of VCM in both patterns are 2.247 m in 105 days (square pattern) and 2.252 m in 90 days (triangular pattern). It means with a triangular pattern has 70.2 more effective than others in the rate of the settlement period. It also showed the VCM has larger than others in volume settlements. The results of 2 scenarios analysis showed that the implementation of scenario one was difficult due to various spacing, while scenario two can be implemented because numbers of settlements depend on suction pressure of the vacuum.