Sponsored by ASCE Continuing Education and ASCE's Geo-Institute (G-I)

INSTRUCTORS:
Gordon R. Keller, P.E., G.E., M.ASCE
Robert (Rob) Douglas, Ph.D., PEng 

"ASCE webinars are great for us. We are in a remote location and it is difficult to get quality training for our staff without much expense."  -  Anonymous Attendee

Purpose and Background

This webinar goes over the available techniques in detail to equip road maintenance personnel with the tools they need to address surficial slope movement problems. Simple slope stabilization techniques include the use of traditional small gravity walls and gabions, the use of simple geotextile-reinforced earth retaining structures (“burrito walls”), reinforced fills, and “deep-patch” shoulder repairs with several layers of geosynthetic reinforcement. Shallow earth anchors can be used to stabilize local failure areas. Also reshaping, compaction, and improved drainage, combined with revegetation, are common treatments for shallow failures on relatively flat ground.

The use of vegetation and other erosion control techniques are other common treatments to prevent slope movement. Deep-rooted vegetation, with a combination of grasses, shrubs, and trees, is key to providing slope stabilization and surficial erosion control. Many products such as erosion control mats, turf reinforcing mats, nettings, and bonded fiber matrices are used to stabilize the soil and prevent erosion while protecting seeds and promoting revegetation. The control of surface drainage and prevention of the concentration of surface flows, or the construction of armored channels are fundamental to the prevention of erosion and the formation of gullies. Frequent culvert cross-drains, rolling dips, lead-off ditches, drop inlets, downdrains, and other measures help avoid excessive water accumulation and associated damage.
 
Soil bioengineering and biotechnical slope stabilization measures, where structures are combined with vegetation can be employed. These biotechnical treatments are a combination of physical structures in conjunction with live vegetation to offer both mechanical and vegetative stabilization, plus root support. Other bioengineering treatments also create structures with dense mats of roots. Useful bio-slope stabilization treatments include live stakes, brush layering, brush packing, live crib walls, and a variety of retaining structures using the inclusion of live vegetation.

Primary Discussion Topics

• Use of traditional small gravity walls and gabions
• Use of simple geotextile-reinforced earth retaining structures
• Soil stabilization products
• Current methods of avoiding excessive water accumulation
• Biotechnical and soil bioengineering methods for slope stabilization and erosion control

Learning Outcomes

• Alert participants to the importance of shallow slope stabilization
• Show that common erosion control practices can be adapted and used in conjunction with simple slope stabilization treatments and drainage
• Learn about the variety of shallow slope treatments that exist, and be provided with a number of useful references that address these solutions in detail

Webinar Benefits

• Understanding the importance of keeping slopes from failing
• Understanding the importance of water control and ground cover to prevent shallow slope instability
• Awareness of the range of shallow slope repair and deep erosion control options that exist
• Learning about the use of simple retaining structures, vegetation, and biotechnical treatments to prevent shallow slope failures
• Acquiring a useful set of references that address these simple and low cost treatments

Intended Audience

The webinar is designed for civil engineers, road managers, maintenance personnel, field technicians, and resource specialists (soil scientists, hydrologists, geologists, etc.) involved in the planning, design, maintenance, repair, and management of low-volume roads.

Webinar Outline

• Introduction to shallow slope instability problems on low-volume roads
• Approaches to dealing with slope instability and erosion control
• Simple slope stabilization treatments
• Erosion control and drainage needs
• Soil bioengineering and biotechnical soil stabilization treatments
• Combining structures, aesthetics, and sustainability in slope stabilization solutions