Geogrid reinforced soil structures reach new heights PROJECT HIGHLIGHTS WV ROUTE 10 RSS OWNER West Virginia DOT LOCATION Lyburn, W.Va. GENERAL CONTRACTOR Vecellio & Grogan Inc. DESIGN ENGINEER Terracon Consultants Inc. FASCIA SYSTEM Welded wire form with TRM and vegetative facing GEOSYNTHETIC PRODUCTS Maccaferri Uniaxial geogrids Nonwoven geotextile GEOSYNTHETICS MANUFACTURER Maccaferri Inc. FIGURE 7 Relocated WV Route 10 RSS cross section FIGURE 8 Relocated WV Route 10 RSS facing detail 20 Geosynthetics | June July 2019 Relocated West Virginia Route 10: Reinforced soil slope The project consisted of construction of an embankment for the relocated West Virginia Route 10 over Laurel Branch in Logan County, W.Va. The underlying rock at the project location is comprised of the Pennsylvanian-aged Kanawha Formation of the Pottsville Series. The Kanawha Formation is generally described as consisting of sandstone (approximately 50%), shale, siltstone and coal. A subsurface investigation showed presence of natural alluvial soil and existing fill material consisting of silty to clayey sand and gravel at the toe of the proposed slope and within the valley bottom. An embankment consisting of an MSE wall midslope or a 0.75H:1V RSS were considered as alternative options. Out of these two options, RSS was selected by the West Virginia Department of Transportation (WVDOT) as a feasible option due to the availability of on-site reinforced fill material and other considerations. The on-site soils consist of residual fine-grained to coarsegrained soils. Most of the embankment material was obtained from excavating on-site bedrock material and crushed and screened to meet WVDOT standard material specifications. RSS was proposed to extend from the top of the roadway embankment to a height of about 120 feet (36.6 m) at the deepest portion of the valley. A select embankment fill was placed within the proposed undercut up to an elevation of 720 feet (219.5 m) with a front slope configuration of 1.5H:1V, as shown in Figure 7. This configuration created an approximate 20- to 30-foot (6- to 9-m) wide bench at the toe of the highest portion of the RSS. A culvert that carries Laurel Branch through the embankment was constructed within the select embankment foundation material that is placed to an elevation of 720 feet (219.5 m) prior to construction of the RSS. The computer program ReSSA 3.0 was used to design the reinforcement of the slope for a minimum factor of