A Better Grade Of Grade

by T. Ted Miyake, Sr. Project Engr.; Leighton and Associates, Inc., 2121 Alton Parkway, Irvine, CA 92714,
Garry Lay, Assoc. Engr.; Leighton and Associates, Inc., 2121 Alton Parkway, Irvine, CA,
Michael T. Peak, Exec. Vice Pres.; Sukut Construction, Inc., 4010 West Chandler Ave., Santa Ana, CA 92704,
David L. Thielen, Sr. Engr.; GeoEngineers, Portland, OR,

Serial Information: Civil Engineering—ASCE, 1993, Vol. 63, Issue 10, Pg. 52-55

Document Type: Feature article


A new technique for using geogrid reinforcement to construct natural-looking steep earth slopes called landform contour grading helped meet engineering, economic and aesthetic challenges at a Southern California hillside development where every piece of usable land was precious and geotechnical constraints abounded. A total of 29 reinforced slopes were contoured horizontally and vertically. The maximum slope gradient was 1H:1V. The highest compound slope, which varied from 5H:1V to 1H:1V, was 135 ft high. The highest 1H:1V section was 65 ft high and 1,800 ft long, perhaps the longest reinforced slope ever built. On all slope sections steeper than 2H:1V, we used primary reinforcement layers of HDPE geogrids. Intermediate reinforcement consisted of layers of polypropylene geogrids. All of the walls were eliminated by the reinforced slopes. Also, we used steep reinforced slope sections on many of the project's interior slopes, including those surrounding the golf course, to produce aesthetically pleasing final grades.

Subject Headings: Slope stability | Geogrids | Aesthetics | Soil stabilization | Economic factors | Light rail transit | Land use | Polyethylene | California | United States

Services: Buy this book/Buy this article


Return to search