Roadway reconstruction on STH-106 with MIRAFI

Overview:

Wisconsin Highway 106 (STH-106) underwent reconstruction over a marsh area but soon faced problems with uneven settling. The Jefferson County Highway Department sought a quick reconstruction method that would limit the need to remove large volumes of wet, organic soil while ensuring a stable base for the flexible pavement road. The solution needed to be sturdy enough to prevent uneven settling along the road, maintaining a smooth and ridable surface.

Challenge:

The main challenge was dealing with wet, saturated silt and peat deposits, extending over 30 feet (9.14 m) beneath the existing pavement. The solution involved a robust construction approach using a single layer of MIRAFI^® H₂Ri geosynthetic material placed directly on the subgrade. This was followed by a 15-in (38 cm) layer of crushed stone, a layer of MIRAFI BXG110 biaxial geogrid, and another 15-in (38 cm) layer of crushed stone. The MIRAFI H₂Ri reinforcement and moisture management created a "raft"-like platform for the road, improving drainage, particularly during spring thaws and heavy rains.

Solution:

The Jefferson County Highway Department was satisfied with the installation process. The multi-layer geosynthetic reinforcement provided a strong, stable base, allowing for smooth paving operations. This robust system reduced the need for subgrade removal to just 30 in (76 cm), significantly less than the 5-8 ft (1.52-2.44 m or more) that might have been necessary given the soil conditions. The MIRAFI H₂Ri not only saved costs but also allowed for quicker installation.