White Point LandslideWhite Point LandslideGary Lee Moore, City Engineer

City of Los AngelesWhite Point LandslideWhite Point LandslideOctober 2, 2012

City of Los AngelesBureau of Engineering

Eng.lacity.org

Vicinity Landslide Map

August 2011

November 2011

November 2011

December 2011

Core SamplesCore Samples

B 10B-10

B-11

Groundwater Well and Instrumentation Map

Model Landslide and Stability Analysis

Stability Analyses Performed on Geologic Cross Sections Constructed from Collected Field Datafrom Collected Field Data

Potential Landslide Contributing Factorsote t a a ds de Co t but g acto s

• Irrigationg• Coastal Bluff Erosion• Precipitation• Residential Development• Road Construction• Underground Utilities

Note: Based on observations it has been concluded thatNote: Based on observations, it has been concluded that the presence of the Nike Missile Base did not contribute to activation of the 2011 landslide.

Recommended Immediate Measures ($7 64 Million)Measures ($7.64 Million)

FUNDING APPROVED BY CITY COUNCIL ON SEPTEMBER 18, 2012

• Install additional monitoring points – Done• Install additional monitoring points – Done• Grade surface topography around

landslide edgelandslide edge• Install series of passive drains• Slope anchor system• Traffic improvementsp

Subject to Environmental Review

Subject to Environmental Review

Subject to Environmental Review

ScheduleFor Immediate RepairsFor Immediate Repairs

• CONCRETE REMOVAL/PHASE I GRADING– Bid & Award: October 3, 2012 – October 31, 2012– Construction: November 1, 2012 – December 31, 2012

• DEWATERING IMPROVEMENTS– Bid & Award: November 1, 2012 – November 30, 2012Bid & Award: November 1, 2012 November 30, 2012– Construction: December 1, 2012 – January 31, 2013

• SLOPE ANCHORS/PHASE II GRADING/TRAFFIC IMPROVEMENTS– Bid & Award: February 1 2013 – February 28 2013Bid & Award: February 1, 2013 February 28, 2013– Construction: March 1, 2013 – June 30, 2013

No further work other than Immediate Repairs

OPTION 1 – Restore Roadway to Previous Location Without Retaining Wall - $42M - $50M

OPTION 2 – Restore Roadway to Previous Location With Retaining Wall - $22M - $27M

OPTION 3 – Restore Roadway to Previous Location With Bridge - $57M - $62M

OPTION 4 – Regrade Roadway - $4M - $8M

OPTION 5 – Reroute Roadway - $4M - $8M

Conceptual Long-Term Repair Optionsp g p pSubject to Environmental Review

$• Abandon roadway (< $1M)• Graded roadway ($4-8M)• Restore roadway with slope reconstruction ($42-

50M)$• Restore roadway with retaining wall ($22-27M)

• Restore roadway with bridge ($57-62M)• Reroute roadwa

• Residents and visitors are warned to keepResidents and visitors are warned to keep out of the closed-off area

• Final Geotechnical Report can be viewed• Final Geotechnical Report can be viewed at the following website:

http://eng lacity org/whitepoint/whitepointlandslide htmhttp://eng.lacity.org/whitepoint/whitepointlandslide.htm

Examples of Slope Anchors