White Point Landslide White Point...
Transcript of White Point Landslide White Point...
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