A geosynthetic wrap-face vegetated wall system: For highway embankment construction

摘要

A GWFV wall system was selected to construct bridge-approach embankments for a culvert-elimination fisheries project in Pend Oreille County in northeastern Washington state. Suitable structural fill soil and topsoil were located at nearby borrow sources, and large construction equipment (such as dozers, trackhoes, large side-dump trucks and vibratory roller compactors) could be used effectively due to ready access from the existing roadway. Compaction control was monitored regularly throughout embankment construction using a nuclear moisture-density gauge per project specifications. After the construction crew had been trained and gained some experience with the wall system, installation rates typically ranged from 25 to 40 square feet (2.3 to 3.7 m~2) of wall face per hour. For project sites with more difficult access or limited to smaller construction equipment, the installation rate likely could be reduced by 50 to 75 percent. Figure 10 shows the completed west embankment with excellent vegetation cover 22 months after wall completion.