Vacuum consolidation technology: Principles and field experience

Abstract

Vacuum consolidation is an effective means for improvement of saturated soft soils. The soil site is covered with an airtight membrane and a vacuum is created underneath it by using a dual venturi and vacuum pump. Experience gained from several site experiments and full scale field implementation indicate that this technology can provide an equivalent preloading of about 4.5 m high conventional surcharge fill. The effectiveness can be increased when applied with combination of a surcharge fill. Field experience indicate a substantial cost and time savings by this technology compared to conventional surcharging. This paper presents the principle behind vacuum consolidation, the technological know-how and several case histories from France where this technology has been successfully implemented. The performance of the vacuum consolidation system is evaluated based on settlement as well as pore pressure measurements at these sites.