Road Embankment Test Sections over Soft Peat Layer, Võõbu, Estonia

Abstract

Various road embankment reinforcements on over a 2 to 4 meter thick peat deposit have been constructed in summer to autumn 2015 in the area of Kose-Võõbu in the northern part of Estonia. The test sections consist of five different reinforced road embankments: one layer of georeinforcement, two layers of georeinforcements, geocell mattress, light weight aggregate (LWA) and expanded polystyrene (EPS) light weight embankment structures with georeinforcement. An additional test section is a mass replacement. To accelerate the consolidation of the peat, reinforced test sections are loaded with surcharge. This paper presents information about peat field and laboratory tests, geodetic monitoring, settlement predictions and preliminary evaluation of the structures. The settlements of each test section are precisely measured with settlement plates installed over the peat layer, over e.g. EPS and LWA layers and surface dressing (bituminous layer). In addition, the surface treatment layer has been mapped by high-resolution laser scanning, also after surcharge removal the scanning will be conducted to obtain settlement profile due the surcharge. The intent of this test construction is to validate technical and economic feasibility of different reinforcement methods over designed road alignment (road E263).