Slope Remediation

1
Slope Remediation

• ESS 315 Tiffany Litz

2
Importance

• Will lead to loss of s.
• Can lead to loss of lives.
• Avoidable messes

3
Importance

• Slopes are often located on coastal properties
  and offer beautiful views
• Despite risks, houses in these areas will always
  be desired.

4
Importance
The Seattle area has many unstable slopes that
are prone to movement and slides.
5
Importance

• https//myapa.planning.org/Landslides/Images/Lands
  lides_Animation.gif
• Landslide in an area that has a retaining wall
• Careful planning is necessary to find the best
  solution for each slope.

6
Unstable Slopes

• Creep - Slow and steady downward movement of a
  slope.
• Indicated by curved tree trunks, bent fences or
  retaining walls, tilted poles or fences, and
  small soil ripples or ridges

7
Unstable Slopes

• Rockslide - Rock mass that suddenly detaches and
  falls from the top of a steep slope
• Causes gravity or freeze/thaw action

8
Unstable SlopeS

• Mudslide Sudden flow of mud down a slope
• Occurs when soil becomes suddenly saturated (in
  storms, snow thaw, floods, etc)

9
Unstable Slopes

• Earthflow The upper section of a sloping
  water-soaked terrain that collapses, forming a
  tongue of land the length of the slope.

10
Slope Mitigation

• The effort to reduce the impact of land movement
  for people and their property.
• can be used to strengthen roads, bridges, and
  other critical facilities.
• guide local decision makers in their involvement
  with land use and development issues.

11
Slope Mitigation

• Four types
• Altering - Modifying the hazard involves
  eliminating or reducing the frequency of its
  occurrence. Stabilizing stream banks from
  continued erosion is an example.
• Averting - Redirecting the impact away from a
  vulnerable location by using structural devices
  or land treatment can shield people and
  development from harm. Retaining walls and
  diverting runoff represent physical efforts
  implemented to keep the risk away from the
  people.
• Adapting Modifying structures and altering
  design standards of construction. Pre-identified
  landslide hazards require special building
  standards and construction practices in order to
  reduce vulnerability to damage.
• Avoiding-- Keep people away from the hazard area
  or limit development in a risk area. Enforcement
  actions such as zoning regulations, building
  codes and ordinances are intended to restrict,
  limit or deny access to specially identified risk
  areas.

12
Slope Mitigation techniques

• Terracing

13
Slope Mitigation techniques

• Retaining Wall

14
Slope Mitigation techniques

• Mulching and Adding Groundcover
• Mulch protects against rain and wind, and reduces
  loss of soil moisture during extended dry periods.

15
Slope Mitigation techniques
Soil Redistribution
16
Slope Mitigation techniques
Deflecting Wall
17
Slope Mitigation techniques
Shotcrete reinforces the strength of the
rockface
Drape Mesh reinforces the strength of the
rockface
18
Sources

• http//www.terraerosion.com/projects/slope-stabili
  zation.htm
• http//www.ecy.wa.gov/programs/sea/pubs/93-30/vege
  01.html
• http//landslides.usgs.gov/recent/archives/1997sea
  ttle.php
• http//extension.missouri.edu/publications/Display
  Pub.aspx?PG1509
• http//pubs.usgs.gov/of/2004/1396/1396.gif
• http//www.seattle.gov/DPD/Landslide/Study/part1.a
  sp
• http//faculty.washington.edu/tswanson/ESS/315/Stu
  dent20PP20Presentations/sloperemediation.ppt